reservoir characterization and enhanced oil recovery

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Master's Theses Graduate College

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Reservoir Characterization and Enhanced Oil Recovery Potential in Reservoir Characterization and Enhanced Oil Recovery Potential in

Middle Devonian Dundee Limestone Reservoirs, Michigan Basin, Middle Devonian Dundee Limestone Reservoirs, Michigan Basin,

USA USA

Abrahim Abduslam

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RESERVOIR CHARACTERIZATION AND ENHANCED OIL RECOVERY

POTENTIAL IN MIDDLE DEVONIAN DUNDEE LIMESTONE

RESERVOIRS, MICHIGAN BASIN, USA

by

Abrahim Abduslam

A Thesis

Submitted to the

Faculty of the Graduate Collegein partial fulfillment of the

requirements for theDegree of Master of ScienceDepartment of Geosciences

Advisor: David A. Barnes, Ph.D.

Western Michigan UniversityKalamazoo, Michigan

August 2012

THE GRADUATE COLLEGE

WESTERN MICHIGAN UNIVERSITY

KALAMAZOO, MICHIGAN

Date 07/09/2012

WE HEREBY APPROVE THE THESIS SUBMITTED BY

Abrahim Abduslam

ENTITLED

Reservoir Characterization and Enhanced Oil Recovery Potential in Middle DevonianDundee Limestone Reservoirs, Michigan Basin, USA

AS PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE

DEGREE OFMaster of Science

Geosciences

(Department)

Geology

(Program)

APPROVED

Dean of The Graduate CollegeCollegeDate

Dave Barnes

Thesis Committee Chair

William B.flarrison

Thesis Committee Member

Michael Grammer

Thesis Committee Member

.U(A)ti1oa~

RESERVOIR CHARACTERIZATION AND ENHANCED OIL RECOVERY

POTENTIAL IN MIDDLE DEVONIAN DUNDEE LIMESTONE

RESERVOIRS, MICHIGAN BASIN, USA

Abrahim Abduslam, M.S.

Western Michigan University, 2012

Middle Devonian Rogers City and subjacent Dundee Limestone formations

have combined oil production in excess of 375 MMBO. In general, hydrocarbon

production occurs in two distinct reservoir types: 1) bottom water drive, fractured

dolomite reservoirs in the Rogers City and 2) gas expansion drive, depositional facies

controlled limestone reservoirs of the Dundee.

The main objective of this study is to evaluate the enhanced oil recovery

(EOR) potential in Dundee Limestone reservoirs on the basis of detailed geological

reservoir characterization in several fields in the Michigan Basin. Seven main

depositional facies were identified from core studies in six fields. Three of these

depositional facies are productive reservoirs including: 1) shoal, 2) patch reef, and 3)

peritidal. The average porosity and permeability of these reservoir facies is:

7%/14md; 7%/123md; and 9%/195md, respectively.

Reservoir drive mechanisms, estimated primary recovery efficiency, and

reservoir petrophysics suggest that Dundee reservoirs may be prospective EOR

targets. It is proposed in this study that sedimentary lithofacies dominate the

geological controls on reservoir properties in Dundee limestone reservoirs and that the

interpretation of primary depositional facies contributes substantially to the prediction

of EOR potential in these six large Dundee fields. Laterally persistent facies deposited

in carbonate shoal (i.e., West Branch Field) and peritidal (i.e., Mt Pleasant, Wise, and

North Buckeye fields) environments are most prospective while laterally

discontinuous patch reef deposit (i.e., South Buckeye Field) are more problematic.

Copyright byAbrahim Abduslam

2012

ACKNOWLEDGMENTS

This thesis project would not have been possible without the help, support,

and patience of my principal advisor, and thesis committee members over the past

two years. First, and for most, I wish to express my sincere gratitude towards my

outstanding advisor, Dr. David A. Barnes. His invaluable leadership, support,

attention to detail, and dedication to helping me successfully formulate and carry out

this project. Deepest gratitude is also due to the members of my committee, Dr.

William B. Harrison, III and Dr. G. Michael Grammer whose knowledge and

assistance helping make this study successful.

I would like to acknowledge ExxonMobil, and the Institute of International

Education (HE) and its staff, especially for the scholarship that provided the necessary

financial support for accomplishing this Master of Science Degree. Special thanks

also goes to the Department of Geosciences at Western Michigan University for their

support and assistance since the start ofmy study in Fall, 2010.

I would like to thank my graduate colleagues that I have worked with at

Michigan Geological Repository for Research and Education (MGRRE): Steve Zdan,

Kate Pollard, Shannon Towne, Beth Berg, and John Sosulski. They were invaluable

over the years, and I look forward to continuing collaboration with them in the future.

Last but not least, I would like to thank my wife Eman for her personal

support and great patience at all times. My parents Mohamed and Fatima and my

brothers and sisters who have given me their unequivocal support throughout, as

always, for which my mere expression of thanks likewise does not suffice.

Abrahim Abduslam

n

TABLE OF CONTENTS

ACKNOWLEDGMENTS ii

LIST OF TABLES vi

LIST OF FIGURES vii

CHAPTER

I. INTRODUCTION 1

Summary of the Problems 1

Preliminary Hypotheses 2

Research Objective 3

II. REGIONAL SETTING 5

Michigan Basin 5

Devonian Stratigraphic Framework 9

Dundee Formation Stratigraphic Nomenclature 14

Previous Work 18

III. METHODOLOGY 23

Core Descriptions 23

Petrographic Analyses 24

Conventional Core Analyses 27

Wire-line Log 27

Carbonate Classification Schemes 28

Summary of the Methods 30

iii

Table of Contents—continued

CHAPTER

IV. SEDIMENTOLOGY 32

Depositional Facies 32

Facies 1: Crinoidal skeletal wackestone (open marine) 33

Facies 2: Bioturbated peloidal grainstone/packstone (shallowprotected marine) 35

Facies 3: Crinoidal grainstone (shoal) 38

Facies 4: Coral-stromatoporoid rudstone (reef flank) 41

Facies 5: Stromatoporoid boundstone (patch reef) 43

Facies 6: Skeletal wackestone (lagoon) 45

Facies 7: Fenestral peloidal grainstone/packstone (peritidal) 48

Diagenesis 52

Introduction 52

Diagenetic Alterations in the Dundee Limestone 53

Microbial Micritization 53

Burrowing 54

Dissolution-cementation 55

Fractures and Stylolitization 60

Depositional Environment Model 62

Carbonate Ramp 62

Sequence Stratigraphic Considerations 64

V. GEOLOGIC RESERVOIR CHARACTERIZATION 71

Reservoir Quality 72

iv

Table of Contents—continued

CHAPTER

Porosity and Permeability 72

Diagenetic Controls on the Reservoir Quality 75

Reservoir Compartmentalization and Reservoir Distribution 77

Stratigraphic Correlations and Cross-sections 78

VI. DUNDEE HISTORIC PRODUCTION AND ENHANCED OIL

RECOVERY (EOR) POTENTIAL 87

Historic Production 89

West Branch Field 90

South Buckeye Field 92

Mount Pleasant Field 93

Enhanced Oil Recovery (EOR) 95

VII. CONCLUSIONS 100

BIBLIOGRAPHY 102

APPENDICES

A. Core Descriptions 108

B. Core Charts (Adobe® Illustrator) 148

C. Core Photographs 175

D. Conventional Core Analysis 183

E. Cross-sections 222

v

LIST OF TABLES

1. Stratigraphic section of the Rogers City Limestone, Dundee Limestoneand overlying Bell Shale from outcrop in northeast Michigan 15

2. Cores used in this study 26

3. Dunham classification of carbonate rocks 2

vi

LIST OF FIGURES

1. Location of the study area illustrating the targeted Middle DevonianDundee Oil Fields 4

2. The major structural features of the Michigan Basin 6

3. Basement province map of the southern Peninsula of Michigan 8

4. Structure map of North and South Buckeye oil fields in GladwinCounty, Michigan 9

5. Proposed paleogeography distribution map, showing that the MichiganBasin was located at 30° south latitude during the Middle Devonian 10

6. Stratigraphic column of the Michigan Basin with the Rogers City andDundee formations highlighted in red circle 13

7. Slabbed core and thin-section showing the Rogers City and Dundeecontact from Schember-Shears #3, South Buckeye Field 15

8. Cross-section showing the contact between Rogers City and Dundee:the contact is readily picked in the presence of anhydrite capping theDundee unit in the western part of the Basin (blue box) 17

9. Map of the Michigan Basin showing the spatial distribution of Dundeedepositional environments and cross-sectional (K-L) view of thetransitioning lithologies 19

10. Classification of carbonate pore types 29

11. Crinoidal skeletal wackestone facies (open marine) 34

12. Cross plot of porosity and permeability measurements from whole coreanalyses of crinoidal skeletal wackestone facies 35

13. Bioturbated peloidal grainstone/packstone (protected shallow marine) 37

14. (A) Slabbed core illustrating the crinoidal grainstone tempestitesinterbedded with burrowed skeletal peloidal grainstone facies 37

vn

List of Figures—Continued

15. Cross plot of porosity and permeability measurements from whole coreanalyses of burrowed skeletal, peloidal grainstone/packstone facies 38

16. Crinoidal grainstone facies (shoal) 40

17. Cross plot of porosity and permeability measurements from whole coreanalyses of crinoidal grainstone facies 40

18. Coral-stromatoporoid rudstone facies (reef flank) 42

19. Cross plot of porosity and permeability measurements from whole coreanalyses of reef flank facies 42

20. Stromatoporoid boundstone facies (patch reef) 44

21. Cross plot of porosity and permeability measurements from whole coreanalyses of stromatoporoid boundstone facies 45

22. Slabbed core showing a sharp stylolitic contact between the fenestralpeloidal grainstone/packstone facies and skeletal wackestone facies 47

23. Skeletal wackestone facies (lagoon) 47

24. Cross plot of porosity and permeability measurements from whole coreanalyses of skeletal wackestone facies 48

25. Fenestral peloidal grainstone/packstone facies (peritidal) 50

26. Cross plot of porosity and permeability measurements from whole coreanalysis of fenestral, peloidal grainstone/packstone facies 51

27. The thin-section photomicrograph showing an example of fenestralvugs filled by fine grained micritic internal sediment (red arrow) andthe remnant pore spaces within the fenestrae filled with sparry calcite(yellow arrow) 51

28. The micrite envelopes of the outer part of the shell are a result ofmicrobial microboring and infilling of the holes by micrite 54

Vlll


29. (A) An example of predominantly intraparticle porosity in crinoid stemand stromatoporoid (yellow arrow) (B) Crinoid fragments and otherskeletal fragments, including mollusks, are dissolved leaving abundantmoldic porosity (yellow arrow) in relatively fine grain matrix 56

30. The open galleries of the stromatoporoids are extensively occluded bycalcite cement (yellow arrows) in facies 3 of the North Buckeye Field 56

31. Fenestral fabric in tidal flat facies showing fenestral porosity (Fs) inlight blue that is larger than the associated peloidal texture 57

32. Example of meteorically leached mollusk shells resulting in moldicporosity in the crinoidal grainstone facies 58

33. The syntaxial overgrowth on crinoid ossicles (Cri) has reduced most ofpre-existing interparticle porosity (yellow arrows) 59

34. The presence of fractures (when unhealed with calcite cement) in manycases, can greatly increase the permeability of the rock 61

35. Thin-section photomicrograph of large amplitude stylolites typical ofmany stylolite solutions seems in carbonate mud matrix 61

36. Depositional setting for the seven depositional facies of the Rogers Cityand Dundee Limestone 63

37. Idealized vertical stacking patterns of seven facies seen within the coresexamined in this study 68

38. Stacking pattern in different facies areas/fields observed in the RogersCity and Dundee interval from the six fields 69

39. Changes in sea level recorded in the Middle Devonian deposits inGivetian stage, red star shows the proposed Rogers City and Dundeecontact at approximately 390 Ma 70

40. All core measured porosity-permeability data with the three reservoirfacies highlighted 75

41. Stratigraphic cross-section showing inferred lateral continuity of thefenestral reservoir facies 81

IX


42. Modern analog from the Persian Gulf is used to demonstrateinterpretations of lateral continuity in peritidal facies 82

43. Stratigraphic cross section (A- A') across South Buckeye Field showinglateral variations in the stromatoporoid boundstone facies (marked inyellow) 85

44. Example ofmodern patch reef complex in the Belize coast 86

45. Average per well water production from representative fields with twodistinct trends of relatively high water production per well frominferred bottom water drive in Rogers City (RGRC) dolomite Fields(Fork, Vernon, Crystal, and Deep River Fields) vs. relatively low waterproduction from probable gas expansion drive in Dundee (DUND)Limestone Fields (West Branch and South Buckeye Fields 88

46. Performance history of the West Branch Dundee reservoir showing theoil production per year (green line) associated with primary andsecondary annual decline (pink line). In the West Branch Field, thewaterflood began in 1966 91

47. Performance history of the South Buckeye Dundee reservoir showingthe annual oil production (green curve) and annual water production(blue curve) associated with annual decline (pink line) 93

48. Performance history of the Mount Pleasant Dundee reservoir showingthe annual oil production (green curve) and annual water production(blue curve) associated with 4.5% annual decline (pink line) 94

49. Example of three wells of the fenestral facies showing the heterogeneity(porosity and permeability) within a single well 99

x

CHAPTER I

INTRODUCTION

Summary of the Problems

In carbonate reservoirs, the heterogeneity of reservoir rock properties is a

fundamental complexity that complicates the effective production of hydrocarbon.

Therefore, this research is focused on understanding the geological origin of

heterogeneity on the basis of detailed sedimentologic, petrophysical, and petrographic

study of Middle Devonian Dundee carbonate reservoirs.

Middle Devonian Dundee Limestone reservoir facies in the Michigan Basin

are very heterogeneous and have confounded reservoir quality prediction in most

important hydrocarbon targets. Generally, prediction of vertical and lateral geological

heterogeneity of Dundee Limestone reservoirs and the consequent variation in

petrophysical properties, including porosity and permeability remains a major

problem for exploration and especially, effective production practices. Furthermore, a

better understanding of the regional and in-field distribution of reservoir facies and

reservoir quality in the Dundee can be useful during the enhanced recovery stage of

production, when the detailed understanding of internal heterogeneity of reservoir

facies can be used to increase hydrocarbon recovery from remaining oil in the most

important producers in the Michigan Basin.

Preliminary Hypotheses

Addison (1940) and Curran and Hurley (1992) describe production in the

Dundee Limestone Formation from several pay zones with considerable variation in

thickness, lateral continuity and petrophysical properties. Syndepositional local

structures may have resulted in limited lateral continuity of some, but not all,

reservoir facies. For instance, the presence of patch reef facies may indicate isolated

and non-continuous facies that pinch out on a spatial scale of less than 100 meter

associated with local paleobathymetry highs. Elsewhere, in the absence of patch reef

reservoir facies, grainstone reservoir facies may have greater lateral continuity. The

geometry of facies distribution and reservoir properties are attributable to variable

depositional environments and diagenetic alteration in different Dundee Limestone

fields. In particular, it is uncertain if the key control on reservoir quality is

depositional facies, or syndepositional and postdepositional processes (physical-

chemical) of burial diagenesis.

This study undertakes a sub-regional study of the Dundee Limestone (i.e.

detailed geological and petrophysical characterization) in order to discriminate

between these hypotheses. This will provide a better understanding of reservoir

quality in order to better evaluate the most prospective EOR targets in Dundee

Limestone oil fields in the Michigan Basin.

Thefundamental questions addressed in this study are:

1. What are the important reservoir facies and petrophysical properties of

reservoir facies in the Dundee Limestone?

2. What is the spatial distribution and geometry of Dundee heterogeneity in

reservoirs?

3. What petrophysical and reservoir geometry properties are most prospective

for EOR in the Dundee?

Research Objective

The main objective of this study is to evaluate EOR potential with a focus on

reservoir petrophysics and geometry in several representative Dundee oil fields.

Previous studies have addressed individual reservoir facies, determining the

calcite/dolomite ratio, and production characteristics in Dundee oil fields. However, this

research is an attempt to determine sedimentary lithofacies in high resolution scale

through the development of reservoir characterization method for EOR, and to create a

robust depositional model. This integrated approach uses representative core

observations, petrophysical data, core to wire-line log correlations, and the comparison

of production history data to geological reservoir characterization data to understand

diverse Dundee Limestone reservoirs facies.

A better understanding of vertical and areal porosity and permeability

distribution is significant in planning and implementing waterflood, or CO2 Enhanced

Oil Recovery projects in different Dundee oil reservoirs. The petrophysical properties

are the key to prediction of reservoir quality and heterogeneity, and to the assessment of

potential reservoir, production, and ultimate recovery. Furthermore, EOR projects can

be better designed to take advantages of the discontinuous reservoir facies geometry

(i.e., patch reef).

This study has determined sedimentary lithofacies and the reservoir properties

in six large Dundee oil fields in which primary depositional facies dominate the

geological control on reservoir properties. These fields include Mt Pleasant, Wise,

South Buckeye, North Buckeye, Butman, and West Branch fields, which are located

3

in the central Michigan Basin within Isabella, Midland, Gladwin, and Ogemaw

Counties (Figure 1).

The intensive study of the petrophysical properties and spatial geometry of the

reservoir facies in several Dundee limestone reservoirs provide a better insight for the

assessment of EOR potential within different Dundee Limestone reservoirs in the

Michigan Basin.

CORE 15

O• Butman

GLADWINBuckeye North

iBuckeye South

MIDLAND

ARENAC

BAY

Figure 1. Location of the study area illustrating the targeted Middle Devonian DundeeOil Fields. The cores used in this study are marked by purple circle.

CHAPTER II

REGIONAL SETTING

Michigan Basin

The Michigan Basin is a large, nearly circular, intracratonic Basin in the North

America craton. The Basin is encircled by the Canadian Shield to the north, the

Kankakee arch to the south, Findlay-Algonquin arches to the east and southeast

(Figure 2), and to the west and northwest by the Wisconsin arch and Wisconsin

Highland (Cohee and Landes. 1958). The total area of the Basin is 80,000 mi2

(207,000 km2) which contains up to 16, 000 ft (4800 m) of the Paleozoic sedimentary

rocks. The Basin is predominantly Cambrian marine siliciclastics overlain by Early

Ordovician to Middle Devonian carbonates and evaporites (Cohee and Landes, 1958;

Catacosinos et al., 1990). It has been noted that carbonate rocks are the predominant

lithology in the Michigan Basin (Rullkotter et al., 1986). A Pre-Cambrian complex of

igneous and low grade meta-sedimentary rocks occurs within a major north-northwest

to south-southeast trend associated with a basement gravity anomaly located in the

central portion of the Michigan Basin. This anomaly is interpreted as a failed

Proterozoic rift system and a portion of the Mid-Continent Rift (Fowler and Kuenzi,

1978). Faults and fractures in the Basin mostly trend northwest to southeast and are

associated with the Paleozoic anticlines. These structures characterize the intrabasinal

structural grain of the Michigan Basin (Catacosinos et al., 1990).

Figure 2. The major structural features of the Michigan Basin. Black ring shows theapproximate extent of the Michigan Basin (Modified from Catacosinosetal., 1990).

Much work has been done on characterizing the structural geology of the

Michigan Basin (Pirtle, 1932; Cohee and Landes. 1958; Hinze and Merritt, 1969;

Hinze and Kellogg, 1975; Prouty, 1983; Catacosinos et al., 1990). The Michigan

Basin is characterized by a dominantly northwest to southeast structural trend. Hinze

6

and Kellogg (1975) concluded that the structural phenomenon is a reflection of the

northwest to southeast structural grain in the Precambrian basement and the influence

of subsequent Paleozoic horizontal stress.

Based on the lithologic data collected from drill holes and geophysical data,

Hinze and Kellogg (1975) divided the Precambrian basements province into four

major basement structures: 1- Grenville province in the southeast, 2- Keweenawan rift

zone which transects the Basin in a northwest-southeast trend, 3- Central province in

the southwest and 4- Penokean province in the north (Figure 3).

The general structure interpretations present in the study area are based on

mapping the top Rogers City, a distinctive boundary below the superjacent Bell Shale

in the gamma ray log. These formation tops were picked from wire-line log data. The

basement structural highs trend northwest-southeast and created a possible substrate

for patch reef buildups in the Devonian (Catacosinos et al., 1991). Montgomery

(1986) noted that the South Buckeye field is present on a positive structure

corresponding to the major northwest-southeast trend in the central Michigan Basin

(Figure4), whereas in the nearby North Buckeye field the axis of the anticlinal

structure is transverse to the regional trend. In the West Branch field, about 30 mi (48

km) northeast of North and South Buckeye fields (Figure 1), Curran (1990) described

an asymmetrical anticline with a northwest- southeast trend. The best example of the

larger structural northwest-southeast trend is the Mt Pleasant field, which is

conceivably related to the basement movements (Little, 1986).

MAFIC EXTRUSIVE

AND INTRUSIVE ROCKS

MAFIC VOLCANIC ROCKS

Penokean (1.6-1.8 BY}

Keweenawan{l.QS-1.1B.Y)

Grenville<0.8-1.1 B.Y)

entral(U-1.5B.Y

^^Predominant Structuraltrend

Figure 3. Basement province map of the southern Peninsula of Michigan (Modifiedfrom Hinze et al., 1975).

KEY

— — TowraNp boundariesContour interval: 20 feet

Contoured on the base of the Belt Shale

;Ki!OfTw?te r1.6

filW ft 11

R1W R1E

Figure 4. Structure map of North and South buckeye oil fields in Gladwin County,Michigan (McCloskey, 2012).

Devonian Stratigraphic Framework

Devonian strata represent the second most prolific oil producing units of the

Michigan Basin. Middle Devonian oil producing formations have several significant

reservoir and seal systems, and some of these formations are also EOR and CO2

sequestration targets.

The intracratonic Michigan Basin during the Devonian (385 million years)

was located 20-30 degrees south of the equator (Figure 5). The proposed

paleogeographic distribution map for the Middle Devonian suggest that the Michigan

Basin was located in shallow tropical marine environments, which promotes

carbonate sedimentation (Scotese, 1984 and Blakey, 2005).

Figure 5. Proposed paleogeography distribution map, showing that the MichiganBasin was located at 30° south latitude during the Middle Devonian.Brown and green is the land mass, dark blue is deeper water and lightblue is shallower water. Red square represents the location of theMichigan Basin (After Blakey, 2011).

10

Several regional stratigraphic studies have been conducted in the Michigan

Basin (Fisher, 1969; Gardner, 1974; Lilienthal, 1978; Catacosinos et al., 1990). The

Upper and Middle Devonian strata in the Michigan Basin are overlain by

Mississippian strata, while the lower Devonian is generally absent (Figure 6). The

only remaining portion of Lower Devonian beds are those of the deeply eroded

Garden Island Formation (Lilienthal, 1978). Devonian strata in the Michigan Basin

are underlain by the sequence-bounding base Kaskaskia unconformity, which

separates Silurian Bass Islands Group strata from superjacent Devonian rocks (Ehlers,

1945). The Middle Devonian Dundee Formation is a complex carbonate succession

that is stratigraphically underlain by the Detroit River Group and overlain by the

Traverse Group.

The Detroit River Group consists of mixed carbonate and evaporite strata with

an average thickness of 1100 feet (335m) in the central Basin (Addison, 1940). The

Detroit River Group contains three stratigraphic units: the Sylvania Sandstone at the

base, consisting predominately of well sorted, fine to medium-grained sandstone

interbeded with cherty carbonate sediments (Catacosinos et al., 1991). The

Amherstburg Formation in the middle primarily composed of limestone and varying

amounts of dolomite (Catacosinos et al., 1991), and the upper-most Lucas Formation

comprising mainly evaporite and dolomite sediments, which are interpreted as being

deposited in a mosaic of shallow water restricted environment (Catacosinos et al.,

1991). The Dundee Limestone is readily distinguished from anhydrite or other

restricted and evaporitic lithologies of the underlying Lucas Formation (Gardner,

1974).

The Middle Devonian Dundee Limestone formation is overlain by the Bell

Shale Formation. The Dundee carbonates (more than 400 ft thick in the eastern part of

11

the Basin) have been subdivided into two units in the eastern part of the Basin, the

Dundee Formation is subdivided into the Rogers City and Dundee Limestone units

(Ehlers and Radabaugh, 1938; Gardner, 1974), which will be discussed in more detail

in the following section.

Traverse Group in the subsurface of the Michigan Basin was subdivided into

three units: the Traverse Formation at the top, the Traverse Limestone in the middle,

and the Bell Shale Formation at the base. The Bell Shale, which is underlain by the

Rogers City Limestone, is fossilliferous grayish shale with variable thickness ranging

from 10ft- 80ft and pinches out toward the southwest (Lilienthal, 1978; Catacosinos

et.al, 1991). The Bell Shale is interpreted as being deposited on a shallow shelf with

muddy influx sources to the east (Gardner, 1974). The Bell Shale and the Rogers City

contact is one of the most distinctive log picks in the Michigan Basin (Figure 8).

12

GEOLOGIC TIME

PERIOD

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EPOCH

Late

Early

Late

Middle

Early1 HWMMDWWW WMMMMV

Late

STAGES

Meramecian

Osagian

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Senecan

Erian

Ulsterian

DOMINANT LITHOLOGY

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SUBSURFACE NOMENCLATURE

FORMATION

Bayport Ls

Michigan Fm

Marshall Ss

Coidwater Sh

Sunbury Sh

EHsworthSh

(western!

Berea Ss £

Bedford Sh »

>per Mbr

achine Mbr

Paxton Mbr

— ""Jorvoocl Mb

—:

i Traverse Ls

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Rogers City

Dundee Ls

Lucas Fm

Amherstburg Fm

Sylvania Ss

Bois Blanc Fm

Garden Island Fm

undifferentiated

GROUP

Traverse Gr

Detroit River Gr

Bass Islands Gr

Figure 6. Stratigraphic column of the Michigan Basin with the Rogers City andDundee formations highlighted in red circle (modified from Catacosinosetal., 1990).

13

Dundee Formation Stratigraphic Nomenclature

The stratigraphic nomenclature that is applied to the Dundee interval is based

upon the outcrop and subsurface investigations. The Dundee Limestone and the Rogers

City formations are the units of interest and are considered as two distinct formations,

the Rogers City and the Dundee Limestone formations throughout this study.

The term Dundee Limestone was first proposed by Lane (1893) to describe

outcrops in the southeastern Michigan near the town of Dundee. From the outcrop

studies in northeast Michigan, Ehlers and Radabaugh (1938) described that the upper

part of the Dundee Limestone is characterized by two distinct types of gastropods:

Omphalocirrus manitobensis and Buchelia tyrell (fauna not present in the upper

portion of the Dundee Limestone) which is different from the fauna in the lower part of

the Dundee. Based on these observations, the Dundee was subdivided into the upper

Rogers City and the lower Dundee units. The authors described the Rogers City as a

crystalline fine to medium-grained, gray limestone, with discontinuous alternating

bands of thinly bedded magnesium-rich limestone (Ehlers and Radabaugh, 1938, Table

1).

In the subsurface, Curran and Hurley, (1992) conducted a detailed study of

eleven cores at West Branch field in Ogemaw County. They differentiate between the

Rogers City (above) and the Dundee (below) units in the subsurface through the

recognition of a mineralized, bioeroded hardground surface (Figure 7), which places

open marine (Rogers City) on top of the shallow platform Dundee Limestone. This

bioeroded hardground surface is interpreted as a depositional hiatus or a platform

drowning event. The Dundee Limestone was partially lithified, before the deposition of

the overlying Rogers City Limestone. The Rogers City/Dundee contact was well

documented in the several studied cores in this project.

14

Table I. Stratigraphic section of the Rogers City Limestone, Dundee Limestone andoverlying Bell Shale from outcrop in northeast Michigan (After Ehlersand Radabaugh, 1938).

Unit Bed | Thickness (cm) j LithologyBellShale i

V

ZCDO

oa>

•ac3

Total

-i—

30.4

1493.5

121.9

259.0

243.8

195.5

60.9

1798.3

2194.5

6398.2

Shale, calcareous, bluish gray and abundantly fossiliferous

Limestone, buffgray to bull, medium grained, fairlythickbedded and porous, containing some fossilsLimestone,gray, finely crystalline,dense and thick bedded,containing some fossilsLimestone. Lower 2-3 feet mottled buff and bufl-gray,magnesian and thin-bedded, upper6 feet less mottled and lessmagnesian and thicker bedded than underlying beds,containing some fossilsDolomite, with discontinuous, alternating bulTand buff-graybands, fine-grained and thin-bedded, containing some fossilsLimestone, gray, weathering to a buffgray, composed ofnumerous shells ofbrachiopods and a smaller number of otherinvertebrates

Limestone, gray, weathering buff gray, with few chertnodules, containing some fossils

Limestone, buff gray to buff, weathering to brown, andthickbedded, containing some fossilsLimestone, buff gray to gray, mottled, dense and somewhatmagnesian in lowerpari,containing somefossils

Figure 7. Slabbed core and thin-section showing the Rogers City and Dundee contactfrom Schember-Shears #3, South Buckeye field. This hardground mayalso be present along a mineralized stylolite seam, Sty= Stylolite, Pel=Peloids (picture courtesy of McCloskey, 2012)

15

Kirschner and Barnes (2009) established three hierarchical procedures using

wire-line logs to distinguish between the Rogers City and Dundee units (Figure 8) in

the subsurface: in the presence of anhydrite capping the Dundee unit in the western

part of the Basin, the contact between these two units is readily picked. However, in

the absence of anhydrite in the central and eastern part of the Basin a distinct break

from essentially zero porosity in the Rogers City in the calibrated neutron porosity log

to a more porous section in the Dundee. And finally a distinct gamma ray spike when

porosity logs are unavailable or the Rogers City and Dundee are both dolomitized is

useful to separates the Rogers City and Dundee contact.

The Rogers City interval in the central and eastern part of the Basin is mainly

considered a nonproductive, low porosity limestone. The Dundee unit in the central

Basin is chiefly dolomitized, whereas to the east, the amount of dolomite is sharply

diminished or highly localized (Montgomery et al., 1998).

16

35311

BAKER

37672

DURKEE, B M

36839

1873Mb MCDONALD <4810MI:

34500

KRYSZAK

RGRC

DUND

LUCS

Figure 8. Cross-section showing the contact between Rogers City and Dundee: thecontact is readily picked in the presence of anhydrite capping the Dundeeunit in the western part of the Basin (blue box). GR (track 1 with shadedyellow to brown for increasing GR response), which makes a distinctseparation between Rogers City and Dundee unit (red box), and makes adistinct separation between Bell Shale and underlain Rogers City (redcircle). NPHI (track2) provides a distinct break from zero porosity in theupper Rogers City to more pores section in lower Dundee unit (blackbox). RHOB (track 2 green line) record the much higher density valuesfor the anhydrites in the Lucas Formation which separate Lucasformation from overlain Dundee Limestone (blue circle). NPHI-RHOBseparation in limestone (shaded blue) calibrated logs indicates dolomite(shaded pink) when associated with low GR readings and RHOB<2.9.

17

Previous Work

Gardner (1974) studied the stratigraphic relationships and the depositional

environments of the Middle Devonian stratigraphy in the Michigan Basin. His

interpretations of the depositional environments were based on lithofacies,

sedimentary structures determined from cores, and constructed isopach maps using

wire-line logs. Gardner determined that the depositional history of the Middle

Devonian strata can be related to stages one and two of the Kaskaskia Sequence.

Gardner described the Dundee as a biostromal shelf carbonate, with predominately

dark, fine grained offshore facies to the east and sabkha and lagoonal facies to the

west. In his model (Figure 9) Gardner interpreted the overall depositional setting of

the Dundee as an east to west transgressive system across the Michigan Basin with a

brief regressive stage, which results in the deposition of the Reed City anhydrite in the

western part of the Basin.

Montgomery (1986) studied the Dundee depositional facies and porosity

relationships in the South Buckeye Field. He noted that the distribution of the oil

producing zones in the Dundee Limestone was controlled by the primary depositional

facies and the structural influence. Montgomery also interpreted that the pay zones of

the South Buckeye Field were developed by organic buildups on top of preexisting

structure. These interpretations were based on his observations in 12 conventional

cores. The four major facies Montgomery identified in Buckeye Field were: 1)

stromatoporoid boundstone; 2) skeletal grainstone/packstone; 3) nodular micritic

wackestone/mudstone; and 4) fenestral pelletal packstone.

Lagoon ^P = 1.13-1.20

Laminated CaS04 precipitate,Dolomitization by seepage reflux-ion through porous, transgressive,

biostromal deposits

Biocalcarenites and calcisiltites

Decreasing grain size and increasingdark color seaward

Figure 9. Map of the Michigan Basin showing the spatial distribution of Dundeedepositional environments and cross-sectional (K-L) view of thetransitioning lithologies. Dundee facies were deposited in transgressivesequence that extended across the Michigan Basin with a brief regressivestage that allowed for the deposition of the Reed City anhydrite in thewestern part of the Basin (modified after Gardner, 1974).

19

Curran and Hurley (1992) studied the sedimentology, facies distribution, and

porosity development in the Dundee reservoir in West Branch Field. Based on data

collected from eleven cores and log correlations, six facies were recognized: 1)

crinoidal grainstones; 2) skeletal-peloidal grainstones and packstones; 3) skeletal

wackestones; 4) restricted-fauna mudstones and wackestones; and 5) stromatoporoid

coral rudstone, and 6) fenestral-cryptalgal laminites. This last facies was

volumetrically insignificant as it was located below the oil water contact. Curran and

Hurley suggested that the Dundee reservoir in the West Branch Field was deposited in

normal marine conditions and added that the most productive zone in the reservoir

originated from primary porosity in lenticular beds of skeletal grainstones and reef

related boundstones. They described the contact area between the Dundee Limestone

and the overlying Rogers City unit of the Dundee Formation as a disconformity

consisting of a pyritized bioeroded hardground. They also found that the top 10-15ft

(3-4.5 m) of the Dundee Formation below the Rogers City unit contains pervasive

amounts of dolomite, resulting in high porosity and low permeability facies. Curran

and Hurley concluded that the dolomitization in the Dundee occurred as an early

facies-related feature formed before the deposition of the Rogers City Limestone.

Wood et al. (1996) and Montgomery et al. (1998) stated that most of the wells

in the Dundee were drilled in 1930s and 1940s with initial production rates varying

from 2000-9000 bbl/day due to solution enhanced porosity in some areas (i.e. Rogers

City Dolomite). They observed that excellent primary interparticle porosity occurs in

other places, and high permeability fractures are also present. They also reported that,

wells in many of the Dundee Fields (producing from both Rogers City and Dundee

reservoirs) throughout the Basin were abandoned, due to the aggressive, early

development practices, coupled with the strong water drive which resulted in water

20

coning. This water coning caused a significant volume of oil (about 60-80% of

potentially producible oil) to be bypassed and considered unrecoverable between

wells in some fields (Montgomery et al., 1998). Based on information from the

Cronus Development Tow# 1-3 HD-1 well in Crystal Field (the first horizontal well

in this field), and supplemented with the preexisting field information, Montgomery

et al. (1998) concluded that horizontal drilling was a feasible technique to

significantly enhance production from Dundee reservoirs(i.e. Rogers City Dolomite)

in the Michigan Basin. They estimated that more than 200,000 bbl of recoverable

reserves can be extracted from the Tow #1-3 in Crystal Field. In addition, two

horizontal wells were drilled in another portion of Crystal Field, but those wells

produced mostly water with minute amounts of oil. Montgomery et al., (1998)

believed that these wells were drilled near the oil water contact or crossed fractures

that extended into the water saturated zone. Montgomery et al., (1998) reported that

by early 1998 the initial production from 15 horizontal wells drilled in various

Dundee reservoirs ranged from 5-127 bbl/day. Based on these results, they concluded

that successful horizontal drilling in the Rogers City dolomite and Dundee Limestone

reservoirs requires further study of the reservoir complexity, structure distribution,

and oil water contacts.

Luczaj et al., (2006) studied hydrothermal fractured dolomite distribution and

its characteristics in the Dundee reservoir rocks of the central Michigan Basin using

core description and fluid-inclusion microthermometric methods. Luczaj et al., (2006)

grouped the Rogers City and Dundee units together as the Dundee Formation,

whereas in this thesis the Rogers City and Dundee used as separate units. Luczaj et al.

stated that the Dundee Formation contained fracture-controlled and facies-controlled

reservoirs, and added that in the central Michigan the fractured dolomite reservoirs

21

had tremendous oil production in the Michigan Basin. These authors documented that

the saddle dolomite in the Dundee occurs as a result of hydrothermal fluid circulation

along the fractures and faults with temperature ranging from 120-150 degrees

centigrade. In addition, they concluded that the occurrence of the fractures and the

saddle dolomite precipitation in the Dundee Formation accounts for reservoir

development because both occurred prior to oil migration and reservoirs filling.

Consequently, they concluded that dolomitization in the Dundee Fields (Rogers City

dolomite) of the central Basin were related to deep-seated fault and fracture systems.

Kirschner and Barnes (2009) characterized the geology and the petrophysical

properties of the Dundee Limestone by using wire-line logs and conventional core

analysis including porosity and permeability data. They observed that the separation

of the Rogers City and the Dundee Limestone can b made by the wire-line log

signatures and added that the Dundee Limestone is characteristically porous while the

Rogers City typically has little to no porosity when found as limestone lithology.

Further, Kirschner and Barnes documented an estimated CO2 storage capacity of

0.13Gt in the Rogers City and 1.88Gt in the Dundee limestone. They concluded that

the Dundee Limestone is an important geological sequestration reservoir target

compared to the Rogers City.

22

CHAPTER III

METHODOLOGY

This study utilized several phases of sampling, analysis, and interpretation of

core for reservoir characterization. The core data was gathered from Michigan

Geological Repository for Research and Education (MGRRE) at the Western

Michigan University. There are fifteen cored wells within the selected study area

available at MGRRE core lab and these cores were studied in detail in this research

(Appendix A, B). Generally the core footages cover most of the producing interval of

the Dundee Limestone and part of the overlying Rogers City Limestone. However,

some of the slabbed cores contain a number of missing sections that were removed for

description and other testing. The conventional cores analysis (porosity and

permeability) and petrophysical wire-line logs were available at MGRRE.

Core Descriptions

In this research, fifteen cores were selected based upon the presence of

interval coverage, whole core analyses and an available suite of wire-line logs. A

detailed geologic description was performed on approximately 1100 feet (335 m) in

fifteen cores from six Dundee fields (Table2). Insights from core examination were

supplemented with inspection of 26 cores in South Buckeye field from McCloskey

(2012), and an additional 11 cores in West Branch field from Curran (1990). These

cores were selectively studied to sample each of the seven depositional facies and to

evaluate reservoir characteristics from field to pore scale in order to assess enhanced

oil recovery (EOR) potential in the Dundee Limestone in the Michigan Basin. Cores

that covered the Dundee limestone interval and part of the Roger City were present in

Isabella, Midland, Gladwin, and Ogemaw Counties. All cores are located in the east-

23

central part of the Michigan Basin (Figure 1) and were examined and described

thoroughly using a binocular microscope and hand lens. Core photographs were taken

after the core was polished to improve clarity and maximize the observation and

documentation of depositional features and rock fabric. The core photographs are

located in Appendix C.

Detailed observation of lithology, fossil content, cement type, pore types and

distribution, and primary sedimentary structure were conducted to document the

vertical lithologic succession, define distinct Dundee depositional facies, and develop

depositional environment interpretation and geological control on reservoirquality for

Dundee Limestone. The lithofacies distribution and pore geometry were described

using Dunham (1962) and Embry and Klovan (1971) classification for the

depositional facies and Choquette and Pray (1970) for porosity classifications (Table

3, Figure 10). Some wells have good subsurface data quality (core, core analysis,

wire-line logs) but lack modern wire-line logs or were missing key cored intervals.

The most notable wells that had all of the required data are located in Mount Pleasant,

North Buckeye, and South Buckeye and West Branch fields. Additionally, because of

lost core interval, an interpretation of some but not all cored depth normalized to the

depths used in the wire-line logs. When the shifted depths (i.e., between the core data

and the wire-line logs) are used, the position of a described or analyzed length of core

can be referenced directly to match the wire-line logs (Appendix B).

Petrographic Analyses

During a preliminary study of each core, samples were cut for petrographic

thin-sections analysis. Prior to detailed description of a core, it is desirable to have at

least a preliminary description of each sample in thin-section in order to identify grain

24

types and diagenetic fabrics accurately. Sixty thin-sections were made from selected

facies and supplemented with preexisting thin-section in the collection at the MGRRE

core lab. The thin-sections were impregnated with blue epoxy to highlight porosity,

and some thin-sections were partially stained with alizarin red and potassium

ferricyanide stain. Alizarin red stain allows for the discriminating between calcite and

dolomite. It has been noted by Tucker (2001) that Alizarin red stain changes non-

ferroan calcite to pink while non-ferroan dolomite remains unstained. The potassium

ferricyanide stain has a high sensitivity for ferrous iron, which allows for the rapid

identification of ferroan calcite and ferroan dolomite in carbonate rocks. Hatzman

(1999) stated that the ferroan calcite stains pale to deep blue and ferroan dolomite

stains a turquoise color with potassium ferricyanide. Thin-sections were examined

and photographed for detailed analysis using a Leica DC Camera petrographic

microscope. Petrographic analysis of thin-sections yielded qualitative petrophysical

characterization to identify primary depositional and diagenetic processes in order to

determine the geological controls on reservoir quality and pore geometry. Thin-

section data was compiled with wire-line log derived porosity and the conventional

core analysis data in order to make a comprehensive data set of reservoir quality

attributes.

25

Table 2. Cores used in this study.

Permit

#

Well Name Field

Name

County Production Total Field Production

19693 McNerney, BE3

Wise Isabella Dry Hole 4.2 MMbbl. Through2010

39770 Mt Pleasant

Unit Tract 55

Mt

Pleasant

Isabella Oil 30.4 MMbbl. Through2010

39771 Mt Pleasant

Unit Tract 46

Mt

Pleasant


36367 McClintic-3 Mt

Pleasant


36387 Miller, Viola1

Mt

Pleasant


35461 Sierra Land

CO., INC 1,Mt

Pleasant

Midland Oil 30.4 MMbbl. Through2010

35764 Ames, C W 1 Mt

Pleasant


36227 Sokolowski,CT1

Mt

Pleasant


36259 Pfund-1 Mt

Pleasant


32780 State

Buckeye B-6North

BuckeyeGladwin Oil 21.5 MMbbl. Through

2011

52002 Salla, John 9-11 HD

North


2011

43383 Nusbaum

Kern 3-W,South


2010

36730 Fitzwater #6-

26

South


2010

35720 Huston 1-2 Butman Gladwin Oil 39 Mbbl. Through 2001mostly from Lucas Fm

28399 Grow 4 West

Branch

Ogemaw Oil 14.2 MMbbl Through2011

26

Conventional Core Analyses

Conventional whole core analyses (porosity and permeability data) were

originally obtained from core measurements by the operators prior to the initiation of

this study. The data from conventional whole core analyses were obtained from

MGRRE core lab at Western Michigan University, which includes footage analyzed,

horizontal and vertical permeability values, porosity value, fluid saturations (i.e., oil

and water), bulk density, grain density, and oil and gas production probability.

Twenty-one wells were identified that have full diameter whole core analysis from the

six Dundee oil fields utilized in this study (Appendix D). In addition, an evaluation of

the conventional core analyses was conducted to establish porosity and permeability

relationships within facies throughout the six Dundee fields. Porosity and

permeability data from whole core analysis was converted to digital log curves and

then imported to PETRA to calibrate it with wire-line log derived porosity. These data

were used to produce cross-sections in order to fully characterize Dundee Limestone

reservoir types in the Michigan Basin.

Wire-line Logs

Generally, wire-line logs respond to petrophysical properties and not to

textural and fabric depositional properties. Wire-line logs, for instance, may not be

used to differentiate between grainstone and wackestone or between grain types.

However, wire-line logs can distinguish different rock types based on the bulk

densities/porosity (Lucia, 1999).

More than 1500 wells were identified in the study area, from which 381 (old

and modern wire line logs) were used and digitized during this study using PETRA

software. Fifty wells have useful lithology log data, including gamma ray (GR),

27

neutron porosity (NPHI), bulk density (RHOB) and photoelectric factor (PEF) log

tracks. A few dual lateralog and dual induction resistivity logs (DLL) were also

available. The digitized interval typically extends from the base of the Bell Shale to

the base of the Lucas Formation.

Vertical successions of lithofacies and geologic fabrics obtained from core

descriptions were calibrated with wire-line log response to expand the spatial

coverage of the data. The modern digital logs were used to infer the reservoir

properties and to produce cross-sections and core to log correlations in the subsurface.

These cross-sections provide enhanced understanding of the lateral continuity and

facies distribution of the Dundee reservoir rock types.

Carbonate Classification Schemes

The carbonate classification scheme used in this research is the commonly

used Dunham (1962) and Embry and Klovan's (1971) classification scheme. These

schemes focus on the depositional fabric of carbonate rocks. These schemes divide

limestones on the basis of their texture and mud vs. grain support (Table 3). Generic

names (i.e. mudstone, wackestone, and grainstone) are modified with grain type such

as skeletal wackestone or peloidal grainstone (Embry and Klovan, 1971)

Porosity types in carbonate rocks take a wide variety of forms. The most

widely used porosity classification scheme was proposed by Choquette and Pray

(1970). They divided the porosity types in limestone into three groups. The fabric

selective types contain pores defined by fabric elements of the rocks such as grains or

crystals. The non-fabric selective types cross cut the primary fabric of the rock such as

fracture and channel porosities. The third group may or may not show a fabric control

(Tucker and Wright, 1990). Porosity in this classification is based on both depositional

28

and diagenetic processes (Figure 10). The depositional environments of the studied

rocks in this project are compared with the ideal standard carbonate facies of Wilson

(1975) and microfacies of Flugel (1982, 2004).

Table 3. Dunham classification of carbonate rocks (Modified from Dunham, 1962).

DEPOSITIONAL TEXTURE RECOGNIZABLE DEPOSITIONAL

Original Components Not BoundOriginal

ComponentsBound

1EX1URL

Not

Together During Deposition RECOGNIZABLE

Contains Mud Lacks

mud

and is

grain-Supported

TogetherDuring

Deposition Crystallinecarbonate

Mud-supportedGrain-

supported< 10%

grains

> 10%

grains

(subdivisionsMud- Wacke Packstone Grain Boundstone based on texture

stone stone stone or diagenesis)

FABRIC SELECTIVE

^^. > t. j

i—._

•.^sJM^O

[g*<»itfgft

Interparticle

Intraparticle

Intercrystal

Moldic

Fenestral

Shelter

Growth

framework

NOT FABRIC SELECTIVE

m Fracture

Channel

3

El

Vug

Cavern

FABRIC SELECTIVE OR NOT

Breccia Burrow

[\fa2 Boring J f~ Shrinkage

Figure 10. Classification of carbonate pore types, (Choquette and Pray, 1970).

29

Summary of the Methods

During this research on Dundee carbonate reservoir characterization, technical

methods have been used that integrate, core, whole core analysis, and wire-line log

data, obtained from MGRRE at Western Michigan University. Core data provide

information on various depositional and diagenetic controls on reservoir quality. The

description of facies and geologic fabrics from core material and whole core analyses

(porosity and permeability) was used to address enhanced hydrocarbon recovery and

methods for locating volumes of unswept oil in Dundee reservoirs during waterflood

and CO2 Enhanced Oil Recovery.

Petrographic analysis of thin-sections using mineral staining, allows for the

rapid identification of various carbonate mineral species including calcite vs. dolomite

and ferroan calcite vs. ferroan dolomite. Petrographic analyses of thin-sections was

critical to initial identification of primary depositional and diagenetic textures,

structures and mineral components in order to infer geological controls on reservoir

quality and pore geometry.

Modern wire-line logs were tied to lithofacies obtained from core description

and thin-section data in order to expand data coverage and make a comprehensive data

set. Conceivably, this correlation provides diagnostic log facies which generally

correspond to the lithofacies identified from core. The spatial distribution and

geometry of reservoir facies along with lithofacies characteristics are used to predict

reservoir quality and reservoir continuity issues, which in turn supports

implementation of more effective waterflood or CO2 EOR in diverse Dundee oil fields

in the Michigan Basin.

The availability of core in the Dundee Limestone in Michigan is limited in

stratigraphic coverage and the spatial distribution. Some of the cored wells lack

30

modern wire-line logs, whole core analysis, and contain missing footages. These

factors limit the spatial resolution and increase the uncertainty of the interpretation of

the reservoir quality and geometry. Core only provides one dimensional data,

therefore inter-well correlation using well logs may aid in determining the lateral

continuity of the reservoir facies across the Dundee oil fields. However, due to these

data limitations, the lithofacies that were characterized from cores were tied to the

wire-line logs and some limited whole core analyses in order to identify reservoir-

prone facies and predict their distribution in wells lacking core.

31

CHAPTER IV

SEDIMENTOLOGY

Depositional Facies

Primary depositional facies were defined based on examination of fifteen

cores from the Dundee Limestone in six central Michigan Basin oil fields. These

fields include Mt Pleasant, Wise, Butman, West Branch, North Buckeye, and South

Buckeye fields. The study of facies is most valuable in the context of establishing the

facies associations, interpreting depositional environments, and evaluating the

geological controls on reservoir quality for better evaluating the most prospective

EOR targets in Dundee Limestone reservoirs. Although this study focuses primarily

on the Dundee Limestone, the Rogers City limestone was described throughout the

six fields.

Primary depositional facies identified in this study are chiefly distinguished by

their distinct lithological characteristic, primary sedimentary structures, and fossils

contents using Dunham (1962) and Embry and Klovan (1971) classification schemes

for depositional fabric of carbonate rocks. Pore types and pore distribution are

described using Choquette and Pray classification (1970) for carbonate pore types.

Porosity of carbonate rocks is crucial in understanding diagenetic processes and

critical in identifying reservoir facies.

This analysis resulted in the definition of seven unique facies from

approximately 1100 feet (335 m) in fifteen cores throughout the six fields in the

central Michigan Basin. Three of these depositional facies represent reservoir facies

(facies #3, 5, and 7) because of their higher porosity and permeability values, and oil

saturation (observed on core) relative to non-reservoir facies (Facies #1, 2, 4, and 6).

Typically, all facies recognized in this study were deposited on a shallow carbonate32

ramp setting deepening eastwards in the Michigan Basin (Gardner 1974; Curran and

Hurly 1992). The Rogers City and Dundee facies are interpreted to represent one or

more marine depositional facies including open marine, protected shallow marine,

shoal, reef flank, patch reef, lagoon, and peritidal deposits.

Facies 1: Crinoidal skeletal wackestone (open marine)

Crinoidal skeletal wackestone is the only facies recognized from the Rogers

City. Facies 1 constitutes approximately 16 % of the gross thickness of the fifteen

studied cores examined throughout the study area (Appendix B). This facies is a

uniformly facies in the Rogers City Limestone. Common skeletal components include

crinoids, gastropods, brachiopods, ostracods, trilobites, and forams. This facies is

occasionally interbedded with thin crinoidal packstone beds that range in thickness

from a centimeter to several centimeters, and also contains mud- rich nodular texture

generally of centimeter scale with rounded to elliptical outlines (i.e. Mt Pleasant Unit

Tract 55 and McNerney, B E3 wells, Figure 11). Low amplitude stylolites occur

within sediment packages and at package boundaries. The nodular fabric is often

enhanced by pressure solution, with stylolite sutures surrounding the nodular grains

(Figure 11).

The crinoidal skeletal wackestone facies is characterized as a very dense, low

porosity and permeability rock type that is an effective impermeable seal for the most

Dundee Limestone reservoirs. Limited whole core analysis for this facies indicates an

average porosity of 1 % and average permeability of 0.2md (Figure 12).

Interpretation: Crinoidal skeletal wackestone facies in the Rogers City was

deposited during a marine transgression period, which places deeper marine Rogers

City on top of the shallow marine Dundee Limestone (Curran and Hurly, 1992). The

33

most common textures observed in this facies are wackestone and mud-rich

packstone, which indicates low depositional energy conditions. This type of facies

indicates a low energy, open marine with normal salinity environment of deposition

(Scoffin, 1987). The composition of crinoid stems, bivalve, and gastropods fauna

(Flugel, 2004) suggests that the depositional environment was a low energy, well

oxygenated open marine. In core, the transition from shallow marine Dundee

limestone facies to open marine Rogers City facies is abrupt in most examples. This

facies has a sharp stylolitic contact (Figure 11) of the open marine Rogers City above

shallow carbonate facies of the Dundee Limestone.

MT Pleasant Unit tract 55, 3573' llMT Pleasant I

Sty ' . : .

I m '

0.1 mm

Figure 11. Crinoidal skeletal wackestone facies. (A) Core photograph, mud nodulartexture (Nod) ranging from 1-2 cm in diameter. (B) Slabbed corephotograph showing the contact between the upper Rogers City (RGRC)and the lower Dundee Limestone (DUND), separated by mineralizedstylolite (Sty). (C) Thin-section photomicrograph, showing stylolites inlow amplitude and crinoids-rich (Cri).

34

♦Crinoidal Skeletal Wackestone

2 4

Porosity {%)

Figure 12. Cross plot of porosity and permeability measurements from whole coreanalyses of crinoidal skeletal wackestone facies. Large triangle showsaverage.

Facies 2: Bioturbated peloidal grainstone/packstone (shallow protected marine)

The bioturbated peloidal grainstone/packstone facies was cored in Nusbaum

Kern 3-W, Fitzwater 6-26, State Buckeye B-6, and Grow 4 wells. Facies 2 constitutes

approximately 6 % of the gross thickness of the fifteen studied cores examined

throughout the study area. This facies is interpreted as a non-reservoir facies due to

its low porosity and permeability. Facies 2 is observed at the top of the Dundee just

below the Rogers City contact and it is also observed on or just below the

stromatoporoid boundstone facies, separating it from the crinoidal grainstone facies

(Appendix B).

Peloids are observed as major components of this facies, which comprise of

up to 90% of the rock material (Figure 13). It is commonly very fine to fine-grained

and moderately sorted. The common subordinate constituents within this facies

35

include brachiopods, crinoids, bivalves, ostracods, trilobites, bryozoans, corals, and

phylloid algae. Burrows are the only sedimentary structure present in the peloidal

grainstone/packstone facies, and they are typically filled with peloid grains. This

facies is occasionally found in association with crinoidal grainstone facies (Figure

14).

The major porosity types include interparticle, intraparticle, limited vuggy,

moldic, and intercrystalline porosity. Porosity value in range from 0.4% to 10%, with

average porosity of 4%, and permeability ranging from 0.1md to 29md, with an

average of 1.8md from whole core analyses (Figure 15).

Interpretation: This facies is interpreted as a protected marine environment.

Peloids are very common in shallow marine to more protected or tidal flat settings,

where most peloids are preserved (Wilson, 1975; Scholle and Ulmer-Scholle, 2003).

In this facies micrite envelopes were observed on most of the bivalve fragments as

result of endolithic algae. Micritic coatings formed by microbes are common in

shallow ramp environments (Flugel, 2004). This facies shows no signs of physical

compaction because borrows and peloids are well preserved and more likely a

function of early cementation of peloids making them hardened. That is a result of

substantial synsedimentary lithification of peloid grains followed by early calcite

cementation of the rock, which prevented compaction of peloid grains.

36

Figure 13. Bioturbated peloidal grainstone/packstone. (A) Core photograph, showingthe burrow (Bur). (B) Thin-section photomicrograph, note the uniformlysmall particle size and consistent shape of peloid grains (Pel) with sparrycalcite cement throughout.

|Fitzwater# 6-26, 3592' | JNusbaum Kern 3-W, 3578'

[_M

i

("SHflflH^HE

Figure 14. (A) Slabbed core illustrating the crinoidal grainstone tempestites (outlinedin blue) interbedded with burrowed skeletal peloidal grainstone facies.(B) Core photograph, note the burrow structure (Bur) is surrounded bycrinoids-rich debris (Cri D).

37

100

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Figure 15. Cross plot of porosity and permeability measurements from whole coreanalyses of burrowed peloidal grainstone/packstone facies. Largetriangle represents average.

Facies 3: Crinoidal grainstone (shoal)

The crinoidal grainstone facies was cored in South Buckeye and West Branch

Fields. Facies 4 constitutes approximately 8 % of the gross thickness of the fifteen

cores examined throughout the study area. In the South Buckeye Field this facies

occurs as thin (1-2 ft) interbeds with the stromatoproid boundstone facies but is found

as thicker (5-9 ft) beds in the Nusbaum Kern 3-W and Fitzwater #6-26 well.

However, the crinoidal grainstone facies does occur as significant thick separate units

in Grow # 4 well, West Branch Field with a thickness of 25 feet (7.6m) (Appendix B).

This facies is characterized by moderate to well sorted, fine to medium

grained carbonate sand. Facies 3 is primarily made up of fine grained crinoid ossicles

(Figure 16) with average of 0.1-0.2 mm in diameter and can comprise up to 80% of

38

the rock material. Other skeletal constituents within this facies include brachiopods,

bryozoans, rugose coral and some scattered peloids. Pressure solution associated with

this facies results in low amplitude swarm stylolites both within sediment packages

and at package boundaries.

Major porosity types of this facies include interparticle, intraparticle, and

limited vuggy and moldic porosity. Porosity ranges in this reservoir facies from 2% to

12%o, with average porosity of 7%, and permeability ranging from 0.1 md to 189md,

with an average of 14md from whole core analyses (Figure 17). This facies is the

primary reservoir facies in West Branch Field and a secondary reservoir facies in the

South Buckeye Field.

Interpretation: The crinoidal grainstone facies is interpreted to be deposited in

an inner to middle ramp setting (Figure 36), very high energy shoal, above fair

weather base. Well to moderately sorted grains are common in middle carbonate

ramp and lagoonal patch reef settings (Flugel, 2004), controlled by high energy

conditions, resulting from wave action and/or other shallow water currents. The wave

action winnowed out mud leaving well sorted grains, which suggests a shoal

environment. Sediment deposition and reworking probably occurred in shallow water

depths ranging from near sea level to 20 feet (6 m) below sea level. The major

accumulations of the grainstone occur surrounding the reef facies (i.e. South Buckeye

Field) or are not associated with reefs (i.e. West Branch Field). Pressure solution is

common in the form of stylolites throughout this facies due to chemical compaction.

Burial cement observed in this facies is intergranular calcite crystal as syntaxial rim

cement on crinoid ossicles (Figure 16 and 33).

39

0.3 mm

Figure 16. Crinoidal grainstone facies. (A) Slabbed core photograph of the crinoidalgrainstone facies. (B) Thin-section photomicrograph of crinoids-richsediment (Cri) with sparry calcite cement, porosity is in blue, porositytype is interparticle porosity (BP). Note cleavage extends throughcrinoidal grains and syntaxial cement overgrowth indicating syntaxialovergrowth formation (Sc).

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Figure 17. Cross plot of porosity and permeability measurements from whole coreanalyses of crinoidal grainstone facies. Large triangle represents average.

40

Facies 4: Coral-stromatoporoid rudstone (reef flank)

The coral-stromatoporoid rudstone to rudstone facies is commonly found in

association with stromatoporoid boundstone facies, and probably forms a secondary

reservoir (e.g., South Buckeye Field). This facies was observed in core from three

wells, the Grow #4, Nusbaum Kern 3-W, and State Buckeye B-6. This facies

generally occurs below the reservoir facies (Appendix B). Facies 4 constitutes

approximately 4 % of the gross thickness of the fifteen studied cores examined

throughout the study area.

The reef flank facies is characterized by poorly sorted, re-deposited

accumulations of debris and chunks of crinoids, bryozoans, brachiopods, rugose and

tabulate corals, and stromatoporoid fragments that were deposited in grain-rich matrix

(Figure 18).

Porosity within this facies is predominantly intraparticle and interparticle with

a minor distribution of intercrystalline and moldic porosity. Variable porosity ranges

in this facies from 1% to 8%, with average porosity of 4%, and low to moderate

permeability ranging from 0.1 md to 5.4md, with an average of 0.6md from whole

core analyses (Figure19).

Interpretation: This facies is interpreted as a reef flank environment. The

flank deposits, evident in cores Grow #4, Nusbaum Kern 3-W, and State Buckeye B-

6, contain abundant fragments, mostly of corals and stromatoporoid that were

ultimately derived from the stromatoporoid boundstone facies (facies # 5). This facies

was deposited in high to moderate energy. The reef flank facies typically developed

around the reefs in a circular pattern (Flugel, 2004). The reef flank with characteristic

partial to complete winnowing of mud, poorly sorted sediment, and angular to sub-

41

angular skeletal orientation indicate a high energy environment of deposition,

associated with waves and the erosion of reef builders.

i i Nusbaum Kern 3-W, 3563' ' l|Fitzwater#6-26, 3609' E ' .<

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Figure 18. Reef flank facies. (A) Core photograph, showing the ripped up and re-deposited stromatoporoids (Strom), crinoids (Cri), and bryozoans (Bry)on a reef flank. (B) Thin section photomicrograph of reef flank deposit,porosity in blue, interparticle porosity (BP). Note dominant skeletalgrains are crinoids (Cri), ostracods (Ost), and brachiopods (Brc) withsparry calcite cement throughout.

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Figure 19. Cross plot of porosity and permeability measurements from whole coreanalyses of reef flank facies. Large triangle represents average.

42

Facies 5: Stromatoporoid boundstone (patch reef)

The stromatoporoid boundstone facies represents the most important

hydrocarbon producing facies in the South Buckeye Field (Gladwin County). Facies 5

constitutes approximately 7% of the gross thickness of the fifteen studied cores

examined throughout the study area. This facies is present in most studied core,

Fitzwater #6-26, Nusbaum Kern 3-W, Huston 1-2, and State Buckeye B-6. The core

data from this facies shows that the stromatoporoid patch reef is up to 23 feet (7 m)

thick (Appendix B). This facies is commonly found in association with shoal and reef

flank facies.

The patch reef facies consists primarily of massive stromatoporoids, and

tabular and fragmental corals, brachiopods, crinoids, bryozoans, and trilobites. The

boundaries of the stromatoporoid facies have common sharp and stylolitic or less

common gradational contact with other facies. The stromatoporoids contain pillar and

lamina structures (Figure 20). The folds or undulations are common in these knobby

to bulbous, encrusting forms. Such stromatoporoids are common encrusters of other

organisms and are thus major contributors to the binding of reef constituents as well

as the generation of framework structure during deposition of this facies (Scholle and

Ulmer-Scholle, 2003).

Porosity in facies 5 includes growth framework, vuggy, and interparticle and

also intraparticle porosity. Variable porosity ranges in this reservoir facies from 1% to

16%), with average porosity of 7%>, and permeability ranging from 0.1md to 944md,

with an average of 123md from whole core analyses (Figure 21). The stromatoporoid

facies forms a primary reservoir in the South Buckeye and Butman fields.

Interpretation: the stromatoporoid boundstone facies 5 (Figure 36) is

interpreted to have been deposited in a patch reef environment. Stromatoproid reefs

43 •

are dominate faunal components in Paleozoic reefs and formed exclusively on

platform margins or platform interior in shallow, warm, well-oxygenated

environments (Flugel, 2004). Growth of patch reef generally indicates shallow-water

deposits of 60 feet or less (James, 1983), where wave energy and water circulation

provide clear-water conditions favored for reef development. Stromatoporoids also

occupied a wide range of reef associated environments, varying from high to

moderate energy environments (Flugel, 2004). The patch reefs in the study area were

stabilized by the massive stromatoproid and tabulate coral growth, and these reefs

probably grew to wave base. The pillars and laminae structure of stromatoporoids are

well preserved, which implies an originally calcite mineralogy (Scholle and Ulmer-

Scholle, 2003). The open galleries of the stromatoporoids and the spaces between

latilaminae are partially occluded with calcite cements although many of the chambers

are open pore space (Figure 20). Chemical compaction is very common in the form of

stylolites throughout this facies.

Fitzwater # 6-26, 3565' ->' %?, +*•*. >. •> ._ . , -y ,j- ' ftp ' f • ,. Z..

"WT

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Figure 20. Patch reef facies. (A) Core photograph of stromatoporoid boundstoneshowing pillar and lamina structure (yellow arrows). (B) Thin-sectionphotomicrograph, porosity is in blue, intraparticle porosity is dominant.

44

Note some of the intraparticle pores are partially filled with calcitecements, but most of the galleries are open pore spaces.

10000

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Figure 21. Cross plot of porosity and permeability measurements from whole coreanalyses of stromatoporoid boundstone facies. Large triangle is average.

Facies 6: Skeletal wackestone (lagoon)

The skeletal wackestone facies forms approximately 17% of the gross

thickness of the fifteen studied cores examined throughout the study area (Appendix

B). This facies is found within repeated shallowing upward sequences with cycles

consisting of subtidal lagoonal wackestones grading upward to packstones and

grainstones facies. The skeletal wackestone facies is in sharp stylolitic contact with

the fenestral, peloidal grainstone/packstone facies (facies 7) when present in studied

cores (Figure 22).

The common allochems in this facies include gastropods, ostracods, bivalves,

trilobites, brachiopods, bryozoans, coral, and with minor stromatoporoid debris

present in a few places. These skeletal grains are scattered in carbonate mud (Figure

45

23). Minor intercalations of peloidal skeletal grainstone and wackestone are

occasionally associated with this facies in beds less than a foot thick when present.

Pressure solution of carbonate results in abundant wispy stylolitization.

The porosity types within this facies are vuggy and moldic with limited

fracture porosity. Porosity value ranges from 0.5%> to 10%, with average porosity of

4%, and permeability ranging from 0.0 lmd to 135md, with an average of 2md from

whole core analyses (Figure 24). This facies is interpreted as a non-reservoir facies

due to its generally low porosity and permeability value.

Interpretation: The skeletal wackestone facies was formed in a lagoonal

depositional environment of an inner ramp setting (Figure 36), low-energy with open

water circulation at or just below the fair weather wave base (Flugel, 2004). Limited

distribution of skeletal grains, lack of bioturbation and a muddy matrix suggest a low

energy environment of deposition.

There is little cement observed in this facies due to limited distribution of

primary porosity available for cementation. Other factors that affected this facies are

the dissolution of some calcite crystals and skeletal fragments to form vuggy and

moldic porosity. The minor primary porosity associated with coral and

stromatoporoid fragments, is commonly filled with calcite cement. However, the

secondary dissolution enhancement of porosity is pronounced in few places by the

presence of small amount of moldic porosity that occurs after mollusks shells (Figure

29). Fractures and stylolitization (large and swarm sutured styolites) are common in

this facies. Styolites result in increased permeability by connecting the isolated vugy

porosity in this facies (Figure 34). A sharp stylolitic contact of the skeletal

wackestone facies with the peritidal facies (facies #7) coincides with rapid fluctuation

in sea level.

46

Figure 22. Slabbed core showing a sharp stylolitic contact between the fenestralpeloidal grainstone/packstone facies and skeletal wackestone facies. Thewhite arrow indicating the "up" direction in the core.

Figure 23. Skeletal wackestone facies. (A) Core photograph of skeletal wackestonefacies associated with stylolites (Sty) and fractures (Fr). (B) Thin-sectionphotomicrograph, porosity is in blue, dominant moldic porosity (Mo),skeletal grains include gastropods (Gsp) and ostracod fragments. Notethe low-amplitude suture stylolites (Sty) and oil stain (Oil S).

47

100o Skeletal Wackestone

Figure 24. Cross plot of porosity and permeability measurements from whole coreanalyses of skeletal wackestone facies. Large triangle represents average.

Facies 7: Fenestral peloidal grainstone/packstone (peritidal)

The fenestral peloidal grainstone/packstone facies has produced the most oil

and gas from Dundee limestone reservoirs. It is observed in North Buckeye, Mt

Pleasant, and Wise Fields, which forms approximately 42%> of the gross thickness of

the fifteen studied cores examined throughout the study area (Appendix B). This

facies is commonly the upper most Dundee Limestone unit and is capped by more

open marine Rogers City facies when present. The geometry of this facies is typically

laterally extensive on a field scale. The fenestral reservoir unit is composed of several

shallowing upward, high-frequency cycles consisting of a lower skeletal wackestone

and an upper fenestral grain-dominated grainstone and packstone facies.

Facies 7 is buff to tan limestone with solution enhanced fenestral pores

(commonly ranging from 0.1-6mm long and 0.01-2mm wide). This facies is largely

48

made up of peloids, which can comprise up to 90% of the rock material. The peloids

are fine grained carbonate sand (generally less than 0.2 mm in size), moderately

sorted and spherical to subspherical-shaped and with uniform size. Skeletal grains

within this facies include brachiopods, bivalves, ostracods, gastropods, crinoids,

corals, and stromatoporoids debris. The sedimentary structures found in this facies

include small cyanobacterial mats, tidal laminations, and fenestral structure (Figure

25).

Porosity within this facies is dominantly fenestral, interparticle and

intraparticle with minor fracture porosity. Variable porosity ranges in this reservoir

facies from 1% to 14%, with average porosity of 9%, and permeability ranging from

0.1md to 5200md, with an average of 195md from whole core analyses (Figure 26).

Interpretation: Facies 7 was formed in a peritidal depositional environment in

an inner ramp setting (Figure 36). Shallow platform interior areas are typically

composed of protected shallow marine environments with moderate circulation.

Peloids commonly occurred in shallow marine subtidal and tidal flat settings as thick

graded laminae with fenestral fabric (Wilson, 1975). These tidal flat facies typically

occur as stacked cycles, each ideally containing internal shallowing upward

succession (Flugel, 2004). The formation of fenestral pores is a result of gas

production associated with the decay of organic material and the lateral migration of

water and/or gas, all occurring within peritidal environments (Shinn, 1983a). The

cyanobacteria laminations, buff color and the blocky calcite cement are notable and

observed in the Dundee Limestone peritidal facies. The presence of these features in

facies 7 indicates that the deposits were likely formed in a peritidal environment that

was intermittently exposed above sea level. The fenestral voids in facies 7 were filled

by fine grained micritic internal sediment and the remnant pore spaces within the

49

fenestrae were filled with sparry calcite cement (Figure 27) a further indication of

peritidal deposition. Such internal sediments present in the fenestral voids suggest

that this deposit was formed in peritidal environment and was subaerially exposed

(Scholle and Ulmer-Scholle, 2003). The allochemical components of this facies are

cemented by calcite crystals and some pores were completely occluded by blocky

calcite cement. When the fenestral voids are unfilled, fenestrae may enhance porosity

and permeability when partly connected. Shinn (1968) suggests that the peritidal

sediments resist compaction due to syndepositional cementation. The allochems in

this facies show few signs of physical compaction, whereas pressure solution is very

common in the form of stylolites.

hi

Mt Pleasant Unit Tract 55, 3594'

SybTFL •__

I

Figure 25. Fenestral peloidal grainstone/packstone facies . (A) The core photographdisplays an irregular tidal flat lamination (TFL), cyanobacterial mats(Syb), and fenestral structure (Fs). (B) Thin-section photomicrograph,porosity is in blue color, note fenestral fabric with irregular fenestrae(Fs) in relatively fine peloids grains (Pel). These fenestrae are partlyfilled with calcite cements (CC) and some of them are completelyoccluded in this peloidal peritidal deposit.

50

10000

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JQ

S 10Ec0)

Q. i --

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♦ Fenestral Peloidal Grainstone/Packstone

6 8 10

Porosity (%)16

Figure 26. Cross plot of porosity and permeability measurements from whole coreanalysis of fenestral, peloidal grainstone/packstone facies. Large trianglerepresents average.

MtPleasant Unit Tract 55, 3575' |

•'fa i

P§ {

B8?5

Figure 27. The thin-section photomicrograph showing an example of fenestral vugsfilled by fine grained micritic internal sediment (red arrow) and theremnant pore spaces within the fenestrae filled with sparry calcite(yellow arrow).

51

Diagenesis

Introduction

The diagenesis of carbonates encompasses any physical and chemical

alterations that affect sediments after deposition until the realms of incipient

metamorphism (Tucker and Wright, 1990). Diagenesis often starts at the sea floor

(syngenetic or eogenetic alteration), continues through deep burial (mesogenetic

alteration), and extends to subsequent uplift (telogenetic alteration) (Scholle and

Ulmer-Scholle, 2003). Most carbonates are deposited and start their diagenetic history

in the marine phreatic zone (Longman, 1980).

Diagenesis includes not only distinct processes such as cementation that form

limestones and dissolution which produces caves, but also includes subtle processes

such as the formation of micro-porosity and changes in trace elements content

(Tucker and Wright, 1990). Furthermore, diagenetic processes can enhance, create

and/or destroy porosity in carbonate rocks. As depth increases, there is a general

decrease in porosity; however, there are late processes of dissolution and fractures

that can enhance porosity. Diagenetic processes affecting carbonate sediments and

rocks are micritization, dissolution and cementation, compaction, neomorphism,

dolomitization, and replacement of carbonates by non-carbonates (Flugel, 2004).

Marine carbonates consist of a mixture of aragonite, high-magnesium (Mg)

calcite and low-Mg calcite. Aragonite and high-Mg calcite are common in recent

carbonates and are metastable because they transform to calcite with time. Low-Mg

calcite is the most stable form of CaC03 and deposited from meteoric water (Tucker

and Wright, 1990).

52

Diagenetic alterations in the Dundee Limestone

A study of the diagenetic evolution of Dundee Limestone reservoirs in the

Michigan Basin was undertaken to better understand the controls on reservoir quality.

Core and petrographic analyses of the Dundee Limestone indicate that the original

fabric of most carbonate rocks has been altered by diagenetic processes. The major

syndepositional and diagenetic processes affecting the Dundee carbonate reservoirs

are microbial micritization, dissolution-cementation, burrowing, and physical and

chemical compaction. The most common diagenetic feature present in the Dundee

Limestone is pressure solution and stylolitization.

Microbial Micritization

This is a process whereby the bioclastics and other particles are altered by

endolithic algae, fungi and bacteria while on or just below the sea floor (Tucker and

Wright, 1990). Microbial micritization and micrite envelops formed around many of

the skeletal grains in grainstones and packstones (Bathurst, 1975). These envelopes

were created through the alteration of grains rather than precipitation of a new rind

around the grain. Algae, fungi, or bacteria bore into the grain, die, and the subsequent

alteration of the organic material provides a chemical environment conducive to

calcium carbonate precipitation during the filling of the voids (Bathurst, 1975; Tucker

and Wright, 1990).

Evidence of micritization in the form of micrite envelopes and completely

micritized grains are common in the bioturbated peloidal grainstone/packstone,

crinoidal grainstones, and reef flank facies (facies 2, 3, and 4). The micrite envelope

developed on echinoderm, trilobite, and brachiopod fragments, which were bored by

53

the action of endolithic algae. The pores are filled by surrounding micrite matrix

(Figure 28).

Figure 28. The micrite envelopes of the outer part of the shell are a result of microbialmicroboring and infilling of the holes by micrite. (A) Note the micriteenvelope surrounding the trilobite fragment (Yellow arrow). (B) Note athin coating of micrite envelopes is evident around brachiopodfragments (yellow arrow).

Burrowing

Biological processes, such as burrowing activities, are most widespread in

marine environments. Burrows are formed in relatively unconsolidated sediments by

the activity of animals during feeding, resting or migration, and also make an

important contribution to the structure of carbonate sediments. Burrowing and

bioturbation are more common in inner and mid-ramp environments (Flugel, 2004)

where biologic alteration of primary depositional fabric and grain reworking may

determine the distribution of porosity and permeability pathways.

In this study, evidence of pervasive bioturbation is very common in the

peloidal grainstone/packstone facies (facies 2). Burrows are more recognizable (i.e.,

South Buckeye Field) due to the difference in color between burrow and surrounding

54

sediment (Figure 13). Many burrows are filled by medium to fine sand sized bioclast

fragments and peloids, which affected the porosity and permeability and adds

additional complexity to reservoir quality.

Dissolution-cementation

Dissolution-precipitation processes suggest diagenesis in the meteoric

environment (Wallace et al., 1991). Undersaturated meteoric water in pores will

dissolve carbonate grains, sediments, and cements. Dissolution is more effective in

shallow near surface meteoric environments, in deep burial, cold water, and in the

deep sea (Flugel, 2004), where seawater becomes undersaturated with respect to

aragonite and high Mg-calcite. Mixing zones of marine and non-marine waters is also

considered an important site of major dissolution caused by mixing corrosion (Tucker

and Wright, 1990).

Dissolution and leaching of gastropod and some brachiopod fragments

resulted in the development of many types of secondary porosity including moldic,

intraparticle, and vuggy (Figure 29). The crinoidal grainstone and skeletal wackestone

facies (facies 3 and 6) show areas where dissolutions has occurred and removed

aragonitic skeletal grains. Meteoric dissolution also affects the crinoidal skeletal

wackestone and reef flank facies (facies 1 and 4) where moldic and vuggy porosity is

present.

The moldic, secondary porosity has been partially reduced through later

cementation with blocky calcite crystal cement. In patch reef facies some of the

intraparticle pores and the spaces between latilaminae are partially occluded with

calcite cements but some of the chambers are open pore space (Figure 20). However,

in North Buckeye Field, where the patch reef facies is not a primary reservoir due to

55 •

its low porosity and permeability, the open framework of stromatoporoids is

extensively occluded by calcite cements (Figure 30). One explanation for this contrast

may be related to the timing and intensity of cementation. The most significant

amount of cementation occurs in patch reef environment with higher rates of agitation

and/or lower sedimentation rates (Flugel, 2004).

Figure 29. (A) An example of predominantly intraparticle porosity in crinoid stem andstromatoporoid (yellow arrow) (B) Crinoid fragments and other skeletalfragments, including mollusks, are dissolved leaving abundant moldicporosity (yellow arrow) in relatively fine grain matrix.

State Bucke

Figure 30. The open galleries of the stromatoporoids are extensively occluded bycalcite cements (yellow arrows) in facies 3 of the North Buckeye Field.

56

The fenestral peloidal grainstone/packstone facies (facies 7) shows areas

where most of fenestral porosity is well preserved suggesting that the fenestrae

formed in an active diagenetic environment where early lithification is common

(Shinn, 1983b). Some of the voids are partially filled with blocky calcite spar cement

or internal sediment (Figure 31), however, the effect of this process on the reservoir is

relatively minor because of the large amount of preserved primary porosity.

Figure 31. Fenestral fabric in tidal flat facies showing fenestral porosity (Fs) in lightblue that is larger than the associated peloidal texture. Note some oflarge pores either partially or fully filled with blocky calcite (BC), andsome small pores are either partially or fully filled with sparry calcitecrystals (yellow arrow). This is the main reservoir facies.

The most common types of calcite cement encountered in most studied facies

are calcite crystals and blocky calcite cement. These cement types may indicate

diagenesis in meteoric regime (Longman, 1980). Calcite crystals replace mollusk

57

fragments (Figure 32) and line pore spaces (Figure 32). Calcite crystals range in size

from 0.1 to 0.3mm. All porous facies described here, contain some blocky and calcite

crystal cement. Further, most of the interparticle pore space is lost to cementation by

varying amounts of calcite crystal and blocky calcite cement rather than compaction

suggesting relatively early diagenetic cementation, consistent with early meteoric

processes.

Other observed cements are represented by syntaxial calcite overgrowth

cement. This type of cement is encountered most communally around the echinoderm

debris (Bathurst, 1975), which will be discussed in greater detail in the following.

Figure 32. Example of meteorically leached mollusk shells resulting in moldicporosity in the crinoidal grainstone facies. This moldic secondaryporosity has been partially or fully occluded by calcite crystal and blockycalcite cement (yellow arrows).

Syntaxial overgrowth cement is widespread in wackestones, packstones, and

grainstones. The origin of this cement on echinoderms is explained as a filling of

58

secondary pores produced by differential dissolution of carbonate mud in the vicinity

of echinoderms (Flugel, 2004). The presence of syntaxial overgrowth on echinoderms

is common in the meteoric phreatic zone (Scholle and Ulmer-Scholle, 2003).

However, syntaxial overgrowths are rare in the meteoric vadose zone and deep burial

environment (Longman, 1980). Syntaxial overgrowths were observed in crinoidal

skeletal wackestone and crinoidal grainstone facies (facies land 3) where crinoid

fragments are surrounded by syntaxial cement (Figure 33). In most cases, syntaxial

overgrowth initiates on echinoderm framework grains partially occludes interparticle

porosity (Figure 34).

Fwater # 6-26, 3624' —»• '•*"•; ^—~

Figure 33. The syntaxial overgrowth on crinoid ossicles (Cri) has reduced most ofpre-existing interparticle porosity (yellow arrows).

59

Fractures and Stylolitization

Much burial diagenesis of non-cemented carbonate sediments under an

overburden results in physical compaction, the reduction in porosity and grain

fracture. Physical compaction is commonly followed by chemical compaction, which

results in stylolites and solution seams formed under burial conditions (Flugel, 2004).

Physical compaction includes dewatering, grain reorientation and brittle or plastic

grain deformation reducing porosity in many carbonate deposits (Scholle and Ulmer-

Scholle, 2003).

The physical compaction features observed in this study are fractures and

shattering of relatively robust brachiopod shells. The fractures observed from core and

thin-section examination include small-scale fractures ranging from 0.1-6cm (Figure

22 and 23a), and fractures associated with sutured stylolites (Figure 23a and 34 a),

which generally occur in the open marine and lagoonal facies (facies land 6). Natural

opening-mode fractures are observed and locally abundant in core. In some cases

fractures have a wide range of sizes and most are filled with calcite cement. Some

fractures remain open in the crinoidal grainstone facies (Figure 34b).

Chemical compaction in carbonate rocks results in dissolution and

accumulation of insoluble residue along stylolite surfaces. Stylolitization, which is the

predominate phenomenon of chemical compaction, occurres in all facies in the form

of stylolites and solution seams. Stylolites in all facies are irregular, suture-like, and

have high and low amplitude (Figure 35). Concentrations of insoluble residues occur

along many suture grains contact (Figure 35). Microstylolites are common between

skeletal grains and carbonate mud matrix, implying that pressure solution came after

the matrix was lithified.

60

Figure 34. The presence of fractures (when unhealed with calcite cement) in manycases, can greatly increase the permeability of the rock. (A) A limestonewith multiple fractures associated with stylolites are partially lined upwith calcite cements (white arrows), and small fractures are completelyfilled with calcite cement (yellow arrows). (B) Note opening-mode fractures in crinoidal grainstone facies (yellow arrows).

[State Buckeye B-6, 3624' 1Ki K—#k.

- •**•*, ' V'

-•it

-:;'JLjII^ **#'••

1j

SsSPiiis• *3 '<kM

v*V-"---P^! 0.3mm

Figure 35. Thin-section photomicrograph of large amplitude stylolites typical of manypressure solutions in carbonate mud matrix. Note enrichment of darkinsoluble materials along irregular stylolite, in which case stylolites canbe recognized by change in texture of the rock (yellow arrows).

61

Depositional Environment Model

Carbonate Ramp

A carbonate ramp is very low gradient depositional slope from the shallow

water shoreline or lagoon to the Basin floor, with usually less than one degree slope

and has no slope break (Read, 1995). The carbonate ramp system contains tidal flat,

lagoonal, and shoal facies (Tucker and Wright, 1990). Primarily the carbonate ramp

facies are controlled by energy level (fair-weather wave base and storm wave base)

and also are controlled by sea level fluctuation, which simply shift facies belts up and

down the ramp (Flugel, 2004).

A conceptual model of the Middle Devonian Dundee Limestone is

summarized in Figure 36. This model was constructed based on the interpretation and

definition of depositional facies and their vertical stacking patterns derived from core

analysis. The depositional environment interpretations of the study area indicate that

the Dundee Limestone was deposited in an inner carbonate ramp setting while the

Rogers City was deposited in a mid carbonate ramp setting in the Michigan Basin.

The Rogers City and Dundee Limestone formations along this ramp consist of open

marine, protected shallow marine, grainstone shoal, reef flank, patch reef, lagoonal,

and peritidal environment of deposition. Development of a core-based depositional

model of the Dundee is consistent with the carbonate ramp depositional models

described by Tucker and Wright (1990) and Flugel (2004).

62

Inner Ramp

Middle Ramp

Outer Ramp

Protected shallow marine I BOpen marine

Figure 36. Depositional setting for the seven depositional facies of the Rogers City and Dundee Limestone.

Sequence Stratigraphic Considerations

Although hydrocarbon exploration wells have been drilled in the Dundee

Formation of Michigan Basin since 1930s, there have been no published studies that

focus on the sequence stratigraphy for the subsurface Dundee Formation. Additionally

the correlation of stratigraphic sequences and exact duration and number of higher-

frequency cycles in the Dundee Formation is not well documented due to lack of

chronostratigraphic data, insufficient well penetration, and there is no definitive

evidence of exposure surfaces in the Dundee interval. However in this study, a

lithology-based depositional model and a logical approach to a sequence-stratigraphic

framework interpretation will be introduced, which can be applied to a variety of

depositional settings and hydrocarbon exploration and production practices.

Sequence stratigraphy uses geological response to relative sea level fluctuation

in order to establish chronostratigraphic correlation. Shallow-water marine carbonate

sedimentary systems are primarily affected by water depth. The depositional stratal

patterns and facies distribution are strongly influenced by relative sea level changes

and typically form in tectonically stable settings in intracratonic Basins and cratonic

interior setting during global eustatic highstand (Sarg, 1988). Relative changes of sea

level are controlled by the interplay of eustasy, local tectonics (uplift and subsidence),

and sediment accumulation rates (Plint et al., 1992). Eustatic sea level fluctuations are

largely controlled by changes in the volume of water in the ocean, or changes in

global Basin dimensions influencing the volume of water contained or displaced

(Plint et al., 1992). Carbonate sediment production rates are water-depth dependant

and are highest in shallow water, factors which make carbonate systems sensitive

even to small amounts of subsidence and uplift (Sarg, 1988). The combination of

64

eustasy and tectonic subsidence results in change in relative sea level. The change of

relative sea level provides the accommodation space for sedimentation.

Accommodation is reflected in the sedimentary record as hydrodynamic and biologic

environmental indicators, each of which also serves as the basis for identifying

depositional facies (Sarg, 1988 and Plint et al., 1992).

Sea level fluctuations have been subdivided on the basis of time duration (Haq

and Schutter, 2008). First-order cycles, range from 200 to 400 Ma, and are most likely

caused by the break-up and formation of super-continents. Second-order cycles, vary

between 10 and 100 Ma, and are produced by plate tectonics. The thickness of 2nd

order cycles is commonly hundreds of meters (Read, 1995). The origin of third-order

cycle (1-10 Ma), remains debatable, and in many cases it is not clear whether controls

are tectonic activity or eustatic sea level changes or both (Strasser et al., 2000). The

thickness of third-order cycles can be hundreds of meters (Read, 1995). Fourth-order

cyclicity, ranges from 100 to 400 Ka, and may be caused by climatic changes. These

cycles can attain thickness of tens of meters. Fifth-order cycles (20 to 40 Ka) can be

produced by obliquity throughout ice house periods and precession during green

house periods or autocyclic variations during deposition (Read, 1995).

Dundee Limestone sequence and cycle boundaries can be identified by abrupt

facies shifts from shallow to relatively deeper water facies. Therefore, the idealized

depositional facies stacking pattern presented in this study were determined on the

basis of the observed vertical facies relationships in different facies areas/fields in

order to understand the scales and geometries of the facies variability (Figure 37).

Based on the core examination the Rogers City and Dundee formation stacking

patterns tend to be composed of one low frequency cycle (3rd order) and two to four

65

th th

high frequency cycle (4 and 5 order, Figure 38). Sequence and cycle boundaries

were specifically determined by identification of stacking pattern of different facies

types from core data. These boundaries are picked at abrupt landward shift in facies

(i.e., when any deeper facies overlies a shallower one).

The overall facies patterns observed in the Dundee intervals is a succession of

approximately 10 to 50 feet (3-15m) thick shoaling upward sequences (Figure 38).

This whole succession was then drowned by a return of deeper water deposition at the

Dundee and Rogers City boundary. These overall shallowing upward packages in

different facies successions and dislocation of facies across stratal contacts may

indicate rapid rates of relative sea level change including cyclicity of autocyclic

origin. The change from deposition of patch reef to peritidal facies (facies 5 and 7) in

North Buckeye represents local shallowing of the environment. Cores from Wise and

Mt Pleasant fields, where the dislocation of lagoonal and peritidal facies (facies 6 and

7) are best observed across the stratal stacking pattern contacts, suggest that the

shallower water environment are more sensitive to fluctuation in relative sea level.

The low frequency cycle (upper Dundee to Rogers City) exhibit a thickness of 65 to

130 feet (20 to 40 m). Higher frequency cycle (shoaling upward) exhibits a thickness

of 10 to 50 feet (3 to 15 m), and the entire Dundee interval is approximately 230 feet

(70 m, Appendix B).

Recognition of transgressive and regressive cycles in the Middle Devonian

Dundee of the Michigan Basin has been suggested by Gardner (1974). The contact

between the Rogers City and the Dundee formations observed on all studied cores, is

the most significant dislocation of facies since this contact is interpreted as a major

flooding surface that drowns the whole Dundee platform. This contact may coincide

66

with a portion of relative sea level curve proposed by Haq et al., 2008, which shows a

large sea level regression and subsequent transgression at 390Ma. In this study this

relative sea level event is interpreted as the Rogers City and Dundee contact (Figure

39).

The higher order cyclicity of the Middle Devonian Dundee Formation formed

during overall regression, acted on a range of paleobathymetries, shallow in some

places and progressively deeper elsewhere (e.g., shoal and lagoonal facies), locally

complicated by active structural highs. In numerous examples, structurally controlled

paleobathymetry localized peritidal, patch reef, and shoal facies accumulations in

Dundee carbonate rocks. For example, Mt Pleasant Field represents an inner ramp

setting, but is located in a relatively Basin ward location of the eastward dipping,

Dundee carbonate ramp in the Michigan Basin. This shows local structural control on

facies development. Other fields in the adjoining area of Gladwin County, also exhibit

the development of shoal or reef reservoirs on structurally induced paleobathymetric

highs (e.g., Butman, North and South Buckeye). Evidence is accumulating in the

Dundee Formation that tectonically controlled paleobathymetry is a major predictor of

localized reservoir facies. Available data indicates a coincidence of current

structurally high position with relatively positive paleobathymetry during Dundee

deposition.

67

Idealized Vertical Succession of Seven Facies

Fenestral Peloidal Grainstone/Packstone (Peritidal)

Skeletal Wackestone (Lagoonal)

• F5 Stromatoporoid Boundstone (Patch reef)

i F4 Coral-stromatoporoid floatstone to rudstone (Reef Flank)

F3 Crinoidal Grainstone (Shoal)

Bioturbated Peloidal Grainstone/Packstone (Protected shallow marine)

A ~fT Crinoidal/Skeletal Wackestone (Open marine)

Figure 37. Idealized vertical stacking patterns of seven facies seen within the coresexamined in this study. The blue triangle represents the transgressivesystems tract and the red triangle represents the highstand systems tract.

68

Permit # 36730Permit # 32780

Figure 38. Stacking pattern in different facies areas/fields observed in the Rogers Cityand Dundee interval from six fields. The Dundee interval within the

cores examined in this study has one low frequency cycle and two tothree high frequency cycles. The blue triangle in the low frequencycycles column represents the transgressive systems tract and the red

69

<5

<LU

>-

380

390

triangle represents the highstand systems tract. These symbols representshoaling and flooding events in high frequency column. NPHI = neutronporosity, RHOB = bulk density, perm = permeability.

STANDARD

STAGES &

COMMON

USAGE

FRASNIAN

GIVETIAN

EIFELIAN

ONLAP CURVE

landward Basinward

* Kikwi Cei*rt#*ifc*d S+^tKvn

o ^5c <o _© "O .£3 c «»

</> CO <376 (?>

377 6(2)

mm

380

382

8(1)

0)

384(2)

IB!5(1)4(1)

(2)

3(1)

387

SH

MO391

395 (2)4(t)

___

SEA LEVEL

CHANGES

(meter abovepresent day)

Figure 39. Changes in sea level recorded in the Middle Devonian deposits in Givetianstage, red star shows the proposed Rogers City and Dundee contact atapproximately 390 Ma (Modified after Haq and Schutter, 2008).

70

CHAPTER V

GEOLOGIC RESERVOIR CHARACTERIZATION

Reservoir characterization of the in six Dundee oil fields includes the

description of fifteen conventional cores (Table 2) and petrographic analysis.

Conventional core analyses for 21(Appendix D) wells and wire-line logs for 48 wells

were also studied and compared to core material. Reservoir properties were delineated

for different depositional facies observed in core compared to core analysis data. The

core data were calibrated to the well-log patterns to predict vertical and lateral

reservoir geometry. Correlations are presented in cross-sections that show

interpretations of structure, stratigraphy, and thickness of important reservoir units.

Subsurface correlation is based primarily on stratigraphic continuity, or the premise

that similar facies maintain similar stratigraphic thickness between closely spaced

wells.

The correlation of depositional facies observed in cores, through calibration of

log responses can be used to predict the likely facies in nearby wells in studied fields

on the basis of the similarity in log responses. Understanding the spatial distribution

and properties of reservoir facies is important for predicting reservoir quality and

reservoir continuity, which in turn supports implementation of more effective

waterflood or CO2 EOR in diverse Dundee oil fields in the Michigan Basin. This

chapter addresses the important task of populating the geologic framework with

petrophysical properties and well logs data from the three main reservoir facies,

including crinoidal grainstone, stromatoporoid boundstone, and fenestral peloidal

grainstone/packstone (facies 3, 5, and 7). The goal of this chapter is to examine in

71

depth the need of reservoir properties to implement waterflood or CO2 EOR in the

Dundee Limestone reservoirs.

Reservoir Quality

The quality of a reservoir is a function of petrophysical properties.

\Eetrophysical properties such as porosity and permeability are often highly variable in

carbonate strata and rarely show a regular relationship as in siliciclastics. Carbonate

reservoirs are characterized by the extreme heterogeneity of porosity and

permeability, as a result of depositional and diagenetic processes (Flugel, 2004).

Carbonate rocks have complex porosity distributions as a result of both their

biological genesis and subsequent diagenetic overprinting (Choquette and Pray,

1970). Characterization of carbonate reservoirs is therefore complicated due to the

inherent heterogeneity and complexity of carbonate geological systems. This study

defines three different reservoir types within the Dundee Limestone, which include: 1)

Crinoidal grainstone (facies 3); 2) Stromatoporoid boundstone (facies 5); and 3)

Fenestral peloidal grainstone/packstone (facies 7). Therefore, efficient secondary

recovery of these Dundee reservoirs requires an understanding of fluid flow, which in

turn requires a detailed understanding of porosity and permeability within these

facies.

Porosity and Permeability

Porosity and permeability are two of the important fundamental properties that

control the storage and movement of fluids in reservoirs. Porosity is the ratio of the

pore volume to the bulk volume of material (Lucia, 1999). The porosity in the

sedimentary rocks split into two major categories; primary porosity forms during the

72

depositional phase (i.e., interparticle or framework growth porosity), and secondary

porosity (i.e., moldic or vuggy porosity), forms during diagenesis during all post-

depositional stages (Flugel, 2004). Schmoker et al. (1985) reported that the carbonate

reservoirs within the United States have porosities ranging from 1-35%, with average

values of 12% in limestone reservoirs and 10% in dolomite reservoirs.

Permeability is the ability of a fluid to pass through a sediment or rock.

Permeability is calculated according to Darcy's law (Eq 1) and commonly expressed

in millidarcy (Flugel, 2004). Permeability is important because it is a rock property

that relates to the rate at which hydrocarbons can be recovered. Additionally, the

viability of a carbonate reservoir is more dependent on its permeability rather than

porosity for hydrocarbon recovery (Tucker and Wright, 1990). Typically in carbonate

reservoirs, permeability values vary between 0.01 millidarcy (md) to well over 1

Darcy. A permeability of 0.1 md is generally considered minimum for oil production

(Lucia, 1999).

Equation 1 Darcy's Law:

Where Q is rate of flow, k is permeability, \i is fluid viscosity, (AP)/L is the potential

drop across a horizontal sample, and A is the cross-sectional area of the sample.

Dominant pore types in reservoir facies 3,5, and 7 are commonly interparticle,

intraparticle, and limited fracture and moldic porosity, with the exception of facies 7,

which contains predominately fenestral porosity. Comparisons of all Dundee porosity

vs. permeability show no distinct relationship in these reservoirs (Figure 40). The

73

results of conventional core analysis from studied cores show high contrast and

variation in core properties (porosity and permeability). Large differences in the

relationship between porosity and permeability support the complexity of Dundee

reservoirs. However, when porosity and permeability data for each depositional facies

are plotted individually, better correlation relationships became apparent (i.e., facies 3

and 5, Figure 15 and 19, respectively).

Porosity and permeability cross plots typically demonstrates that the crinoidal

grainstone facies has moderate porosity ranges in this reservoir facies from 2% to

12%, with average porosity of 7%, and permeability ranging from 0.1md to 189md,

with an average of 14md. Stromatoporoid boundstone facies has moderate to high

porosity and permeability with average of 7% and 123 md, respectively. Fenestral

peloidal grainstone/packstone facies has the highest porosity and permeability values

with average of 9% and 195md. The excellent reservoir quality in the fenestral facies

is clearly a result of a well-connected network of fenestral pores developed in the tidal

flat facies, which results in higher permeability values. Porosity and permeability

relationships in these three reservoir facies (facies 3, 5, and 7) are evidence of

generally good reservoir quality indicating that these reservoirs types should be good

candidates for effective waterflood or potential C02 EOR injection activity.

Porosity and permeability variations from well to well within the same field

and within the same facies are significant. Therefore, the facies are not the only

controls on the Dundee reservoir rock properties. There is clearly another factor that

controls on reservoir properties (diagenesis), which will be discussed in greater detail

in the following section.

74

10000

10 12Porosity (%)

Figure 40. All core measured porosity-permeability data with the three primaryreservoir facies highlighted. As shown, there are strong variationsbetween different types as well as within single types.

Diagenetic Controls on the Reservoir Quality

The substantial reduction of porosity with progressive burial has been well

documented in carbonates (Schmoker and Halley 1982; Halley and Schmoker 1983;

Scholle and Halley 1985; Amthor et al. 1994; Brown 1997; Goldhammer 1997),

however, it is not true for permeability with depth relations. In carbonate strata

primary pore types are highly variable in shape and size. Diagenetic alteration of

carbonate pore types adds additional complexity to pore geometry, distribution and

reservoir quality (Choquette and Pray, 1970).

Strata within the Dundee Limestone are buried to a range of at least 2600 to

3550 feet (780 to 1100 m). Core and petrographic analyses of the Dundee Limestone

75

indicates that the original fabric of most depositional facies was subjected to

diagenetic processes that substantially modified reservoir qualities. Diagenesis

typically reduces porosity, redistributes the pore space, and alters permeability

characteristics. Dundee porosity is commonly partially occluded by diagenetic

cements. The dominant pore-occluding cements are blocky/sparry calcite pore fill and

syntaxial overgrowth cement.

In most examples of the patch reef facies (facies 5) primary porosity is only

partially reduced by calcite cement. However, in the North Buckeye Field for

example, the pores in stromatoporoids are extensively occluded by calcite cement

(Figure 30) resulting in very low porosity and permeability, and poor reservoir quality

for this facies. In the grainstone facies (facies 3), interparticle porosity of primary

origin is dominant. Grainstone reservoir facies however, commonly contain

interparticle porosity-occluding sparry calcite or syntaxial overgrowths cement

(Figure 33), which reduces the size of the interparticle pores and decreases the

permeability (<14md average) relative to other reservoir facies. Crinoidal grains are

especially subject to development of syntaxial overgrowths that totally occlude

effective porosity. The fenestral peloidal grainstone/packstone facies (facies 7) has

some fenestral porosity partially filled with blocky calcite spar cement or internal

sediment (Figure 31). In the fenestral reservoir facies the effect of this process is

relatively minor resulting in the large amount of preserved primary porosity. As a

result of the combined influence of primary and secondary processes on the

formation, preservation and destruction of porosity, reservoir quality is higher in

facies 5 and 7 and lower in facies 3. The high degree of variation in reservoir

76

properties in these important reservoir facies is caused by diagenetic changes to

primary pore networks.

Reservoir Compartmentalization and Reservoir Distribution

Reservoir compartmentalization can have a significant impact on effective

field development and secondary and enhanced recovery activity.

Compartmentalization caused by vertical facies variations and fluid flow barriers or

lateral depositional discontinuities can have an adverse effect on oil or gas recovery

factors by reducing drainage and sweep efficiency. Understanding the nature and

geological origin of compartmentalization in Dundee reservoirs is a key to predicting

connected reserves, and effectively optimizing field development in order to increase

production rates and ultimate recovery. Reservoirs in Dundee oil fields are

compartmentalized at both an inter-well and reservoir-scale. In the studied fields the

reservoir facies are vertically compartmentalized by impermeable facies, which baffle

and inhibit vertical fluid flow (i.e., facies 2 and 6).

The patch reef and peritidal facies (facies 5 and 7) form important

hydrocarbon producing facies in most Dundee oil Fields. The patch reef facies forms

a potential reservoir when the open galleries of the stromatoporoids and the

interparticle and intraparticle pores are well connected and not cemented, resulting in

good reservoir quality. A detailed study of core in the stromatoporoid boundstone

facies (23 feet) of Havens-Denham #1; Permit #43382 well at the South Buckeye

Field revealed that the patch reef are likely highly compartmentalized growth

structure resulting in baffles and barriers to fluid flow in the reservoir unit

(McCloskey, 2012). This was documented by a high degree of variation of porosity

77

and permeability values (Appendix D). The fenestral reservoir unit (facies 7) is a

succession of interstratified peritidal and lagoonal facies. This interstratification

further compartmentalizes the reservoir (Figure 41). The lagoonal facies (facies 6)

varies in thickness from a foot to several feet, and appears to be laterally correlative

and relatively continuous (e.g., Mt Pleasant Field, Appendix B). Lagoonal facies have

high potential to act as baffles or flow barriers affecting the reservoir production

performance. Few of these impermeable beds (lagoonal facies) may vertically

compartmentalize the reservoir interval (Appendix B). The heterogeneous

characteristics of the reservoir are well demonstrated in the frequent vertical

variations of core derived porosity and permeability (Appendix D). The crinoidal

grainstone facies (facies 3) however, also contributes to reservoir volume. This facies

occurs as thin beds (1-2 ft) usually below the stromatoproid boundstone facies as

discrete bedded packages (5-9 ft) internally separated by impermeable facies (e.g.,

facies 2 and 6). In contrast, the crinoidal grainstone facies occurs as a significant,

thickly bedded and separate unit in the West Branch Field with a composite thickness

of 40 feet (12 m). This facies might have more enhanced recovery potential because

of its lower primary recovery, porosity and permeability values and greater lateral

extent compared to the stromatoporoid boundstone facies (see below).

Stratigraphic Correlations and Cross-sections

Wire-line logs respond to petrophysical properties and not to geologic

properties (i.e. rock lithology). Wire-line logs, for instance, may not be used to

differentiate between grainstone and wackestone or between grain types. However,

wire-line logs can distinguish different rock types based on the bulk densities/porosity

78

relationships (Lucia, 1999). Wire-line logs can be extremely valuable in inferring

several reservoir properties (e.g., porosity). In this study, on the basis of core to log

calibration, log response corresponds to core and core analysis data with reasonable

consistency.

The primary stratigraphic factors that influence recovery efficiency are

reservoir continuity and associated permeability heterogeneity. The depositional

model construction and vertical successions of facies and rock fabrics obtained from

core descriptions was extended to electric-log-facies correlation field-wide to expand

the coverage of one dimensional data. The stratigraphic correlation is based upon a

grid of regional wire-line log cross-sections, tied to cored wells. Wire-line logs that

have been used for this correlation method include gamma-ray (Gr), neutron porosity

(NPHI), and bulk density (RHOB). Prior to establishing the correlation between the

continuous well log data set and core measurements was performed, three steps were

considered: 1) Shifting the depth of core to match the depth of the wire-line log (±1-

10 feet). 2) Cross-sections were hung on the contact between the Rogers City and The

Dundee. 3) Picking distinct well log signature that could be directly related to distinct

facies types in the recovered core. Some depositional facies (i.e., facies 1, 6 and 7)

have similar log characteristics when discriminated by bulk density and neutron

porosity logs (Figure 41). This correlation work contributed to a better understanding

of the reservoir geometries and may help explain possible waterflood or C02

performance.

In North Buckeye, Wise, and Mt Pleasant fields production comes from one

uniform reservoir type, the fenestral reservoir facies. The cross-section of this

reservoir facies was constructed in the Mt Pleasant Field only because of better

79

available data control. It is inferred that this degree of lateral continuity can be applied

to both the Wise and North Buckeye fields. However, in these fields, due to lack of

modern wire-line logs, core data and conventional core analysis only few cross-

sections can be confidently established (Appendix E).

A field-wide cross-section (Figure 41) was constructed from well logs in the

Mt Pleasant Field in Isabella and Midland Counties. This cross-section was

constructed where conventional cores from wells located from the northwest to

southeast provide good indication of overall reservoir lateral continuity and

reasonable petrophysical homogeneity. In the Mt Pleasant Field the predominant

facies are fenestral peloidal grainstone/packstone and skeletal wackestone facies. It is

composed of several shallowing upward sedimentary cycles. These cycles consist of

shallow lagoonal wackestone that grade upward into fenestral grainstone/packstone

suggesting shallower water, intertidal to supratidal conditions. The stratigraphic cross-

section (Figure 41) demonstrates that these facies are correlative throughout the entire

field representing multiple regressive cycles. These regressive cycles are bounded at

the base by an interpreted flooding surface observed on Pfund #1; Permit #36259 well

(Figure 41). The flooding surface is observed as a crinoidal skeletal wackestone

representing an open marine depositional environment similar to the Rogers City

facies (Appendix B). This flooding surface is laterally traceable throughout the field

based on the distinctive gamma ray log response. The geometry and development of

the fenestral reservoir facies is quite extensive both vertically and laterally across

distances of up to 10 miles and creates a generally uniform producing zone

throughout the Mt Pleasant Field. The packages of the fenestral reservoir facies are

separated by a few inches to several feet of non-productive skeletal wackestone facies

80

(facies 6). The most continuous and highest porosity and permeability reservoir zones

are concentrated in the upper Dundee with an average thickness of 16 feet. Highest

confidence was placed on core data, where lateral relationships and significance of

reservoir unit could be determined through depositional facies correlation. The

interpretation of substantial lateral continuity of the peritidal fenestral reservoir facies

is also supported by modern analogs of Persian Gulf (Figure 42). This modern analog,

in terms of the facies distribution closely matches the fenestral reservoir facies of

portions of the Middle Devonian Dundee of the Michigan Basin.

MILLER. VIOLA

ISABELLA

Mount Pleasant

MT PLEASANT UNIT TRACT 55 SIERRA LAND CO , INC

MIDLAND

Mount Pleasant

MIDLAND

Mount Pleasant

Skeletal Crinoidal Wackestone B Fenestralpeloidal Grainstone/Packstone Skeletal Wackestone

Figure 41. Dip oriented stratigraphic cross-section showing inferred lateral continuity ofthe fenestral reservoir facies in the Mount Pleasant field. The stratigraphic datum for thecross-section is the major flooding surface at the top of the Dundee Limestone (RogersCity/ Dundee contact). A

1

laterally continuous, overall regressive cycle consisting of interbeddedfenestral peloidal grainstone/packstone and skeletal wackestone cycles islocated above an interpreted flooding surface marked with a red dashedline. The flooding surface is traceable throughout the field as shown inthis cross-section. The fenestral facies (light blue line and) skeletalwackestone (green line) are correlative throughout. RGRC = RogersCity, DUND = Dundee, GR = gamma-ray log, NPHI = neutron porositylog, RHOB - bulk density log.

LagoonsOffshore

Coral ReefShoal Tidal flat Sabkha

Tertiary Lsoutcrop

10 km

Figure 42. Modern analog from the Persian Gulf is used to demonstrateinterpretations of lateral continuity in peritidal facies (Modified fromNoel and Robert, 2010).

In the South Buckeye Field where the main reservoir type is the patch reef,

there is a limited lateral extent of the patch reef facies within the Dundee Limestone.

82

Insights from two cores (Nusbaum Kern 3-W and Fitzwater 6) examined in this field

were supplemented with inspection of several cores in South Buckeye Field by

McCloskey (2012). These cores were selectively correlated in strike well log cross

section, which shows the vertical and lateral variation of the patch reef facies. Due to

this spatial variability closely spaced wells (>1 mile) in this cross section, features

such as pinch-outs and gradual facies transitions are clearly documented (Figure 43).

An interesting observation from this cross-section is that in the Oard well, the

reservoir facies (facies 5) is completely absent. This relationship and the overall

variation in stratigraphic position and thickness of the boundstone reservoir facies

confidently supports the limited lateral continuity of the patch reef facies across the

South Buckeye Field within distances a little as 0.4 miles. The stromatoporoid

boundstone reservoir facies therefore has distinct petrophysical and reservoir

geometry properties compared to other reservoir facies in the Dundee Limestone.

The characterization of patch reef reservoirs is often aided by modern analogs

to infer the spatial distribution of facies. The distribution of modern patch reefs across

the Belize coast for example, shows significant variability of patch reefs within 0.25

mile (Figure 44) and helps explain the patch reef geometry in the South Buckeye

Field (McCloskey, 2012). In particular, modern environments are an important tool

for visualizing the spatial distribution of facies in a reservoir during a single slice

through time (Grammer et al., 2004).

The West Branch Field was extensively studied by Curran (1990) and Curran

and Hurley (1992). In this study only one cored well (Grow #4) was studied in detail

and this analysis was supplemented with inspection of 11 cores from Curran (1990).

Based on the observation from 11 cores, Curran concluded that most production

83

comes from primary porosity in the grainstone facies (facies 3). From three field-wide

cross-sections in the West Branch field, Curran has suggested that the reservoir facies

(facies 3) was correlative up to 2-3 mile.

As confirmed from core, conventional core analysis, wire-line log, and

production history in this study, the hydrocarbon production at West Branch Field has

occurred primarily from the shoal grainstone facies (facies 3)whereas with secondary

contributions from the shoal grainstone reservoir facies in the South Buckeye Field.

Total reservoir thickness in the producing wells ranges from 20 to 30 feet in West

Branch Field. The shoal reservoir facies has a grain-supported architecture with

minimal carbonate mud, and therefore, has the highest reservoir capacity. The pore

systems of the shoal reservoir facies consist of interparticle and limited moldic and

vuggy pore types. The correlation between porosity and permeability for crinoidal

grainstones is known to be very good in this reservoir (Figure 19). The geometry of

the grainstone reservoir facies is quite extensive both vertically (40 feet thick) and

laterally across distances of up to 3 miles and creates a uniform producing zone

throughout the West Branch Field. The shoal grainstone facies is associated with

impermeable bioturbated peloidal grainstone/packstone and skeletal wackestone

facies (Appendix B). In contrast, the shoal grainstone facies in the South Buckeye

Field is not well developed either vertically or laterally and results in limited lateral

continuity of the reservoir facies (Figure 43, red color).

WOODRING ESTATE

41014

GLADWINBuckeye South

(Skeletal Crinoidal

Wackestone

FITZWATER

36730


• Bioturbated Peloidal

Grainstone/Packstone

O. OARD

35697


•CrinoidalI Grainstone

NUSBAUM KERN STATE BUCKEYE D

43383 41122


I Coral-stromatoporoidFloatstone

RGRC


StromatoporoidBoundstone

Figure 43. Stratigraphic cross section (A A') across South Buckeye Field showinglateral variations in the stromatoporoid boundstone facies (marked inyellow). Note the absence of reservoir facies at O. Oard well indicatesthat the stromatoporoid boundstone facies is laterally discontinuous(blue line). This cross-section was constructed from well logs in theSouth Buckeye Field, and the datum for the cross-section is the majorflooding surface at the top of the Dundee Limestone (Rogers City andDundee contact). RGRC = Rogers City, DUND = Dundee, GR =gamma-ray log, NPHI= neutron porosity log, RHOB = bulk density log.

85

Figure 44. Example of modern patch reef complex in the Belize coast. Note the X-X'cross-section highlights and illustrates the discontinuous and irregulargeometries and sizes of patch reefs growing on this carbonate platform.

This chapter explored the detailed process of reservoir characterization. In

terms of the application of this study is to maximize the recovery of bypassed or

trapped hydrocarbons in these reservoir facies (Facies 3, 5, and 7), it is critically

important that the operator have access to scientifically predict the geometrical

distribution of the reservoir facies in the Dundee Limestone reservoirs. One of the

interesting results from this study is that in contrast to the layer-cake geology

characteristic of peritidal settings, the lateral relationships of peritidal facies, shown

in figure 41, demonstrate extensive continuity of this facies.

86

CHAPTER VI

DUNDEE HISTORIC PRODUCTION AND

ENHANCED OIL RECOVERY (EOR) POTENTIAL

The Middle Devonian Rogers City and the Dundee Limestone formations are

prolific hydrocarbon reservoirs that have produced in excess of 375 million bbl of oil

(MMBBL) from more thanl37 fields mostly in the central part of the Michigan Basin.

The majority of the Dundee oil Fields were discovered in 1930s and 1940s. However,

wells in many of the fields are now abandoned due to aggressive development during

the early stages of production resulting in overdrilling, pressure loss, or water coning

(Montgomery et al., 1998).

The Rogers City and Dundee reservoir types are characterized as fracture

controlled and/or facies controlled, respectively. The fracture controlled dolomite

reservoirs occur predominantly in the central Basin (Ten Have, 1979). The fractured

controlled reservoirs were generally more productive than facies controlled reservoirs,

although the facies controlled are complex, and often less understood in light of

deposition and diagenesis (Luczaj et.al. 2006). Wood et al., (1998) reported that the

most productive intervals in the Rogers City and Dundee come from the sucrosic

dolomite facies of the Rogers City in the central part of the Basin. However, in the

eastern part of the Basin, where the Dundee reservoir produces primarily from

sedimentary facies controlled limestone reservoirs, the most productive zones in the

Dundee reservoirs are related to primary porosity in lenticular beds of skeletal

grainstones and stromatoporoid and coral patch reef facies (Curran and Hurley, 1992;

Wood et.al, 1998). This study adds another important reservoir facies, the peritidal

facies, which forms a main producing unit in several Dundee Limestone fields (Mt

Pleasant, Wise and North Buckeye fields). This facies has high reservoir quality and

87

laterally (dip and strike oriented) extensive reservoir geometry. It extends up to 10

miles across the Mount Pleasant Field based on core to log correlation. On the basis

of cumulative oil production, the peritidal facies in the Dundee Limestone outweighs

all other producing facies in importance.

Field production characteristics in the Dundee Formation (Rogers City and

Dundee, Figure 45) fields indicate at least two distinct field drive mechanisms: 1)

bottom water and 2) gas expansion. These mechanisms have been interpreted based

on water production and pressure decline curves (personal communication, Harrison,

2012). Pressure decline is more pronounced in the gas expansion fields whereas the

initial pressures are generally preserved in the inferred bottom water drive, Rogers

City dolomite fields.

This chapter briefly compares Dundee Limestone production history along

with geologic framework and petrophysical properties to describe reservoir

performance and help predict the potential recoverable hydrocarbons in the patch reef,

shoal, and peritidal reservoirs.

Vernon Field

__^, Crystal Field

DUND

Figure 45. Average per well water production from representative fields with twodistinct trends of relatively high water production per well from inferred

88

bottom water drive in Rogers City (RGRC) dolomite Fields (Fork,Vernon, Crystal, and Deep River Fields) vs. relatively low waterproduction from probable gas expansion drive in Dundee (DUND)Limestone Fields (West Branch and South Buckeye Fields, fromHarrison, 2001).

Historic Production

There are a number of known limitations in the historic production data, for

Devonian carbonates including the Dundee Limestone formation. There is only

modest production since 1982 and the production is often grouped into multi well

leases. Usually there is no digital data before 1997. From 1934 to 1986 the State of

Michigan produced an annual statistical summary of oil and gas fields in paper

records. It is only annual and cumulative field production and does not contain

individual well or lease information. For many of the older fields, there is a gap in

annual field production data from 1986 to 1997. Additionally, some of these fields

have problems with combining data from different Devonian formations and it is

often not possible to determine whether production came from Lucas, Dundee or

Traverse formations. The three fields studied here however, do have reasonably

reliable production data availability. These fields include West Branch, South

Buckeye, and Mount Pleasant fields.

Many old producing fields in the Dundee are interpreted to have had less than

50% of the oil reserves recovered from the estimated original oil in place (OOIP).

Production rates from these reservoirs decreased because reservoir pressure from the

gas expansion drive is nearly depleted possibly due to extensive flaring of natural gas

early in the field history. Recovery from pressure-depleted zones can be increased by

repressurizing the reservoir. Therefore, the Dundee Limestone fields were selected as

89

the focus of this study because of the fundamentally greater enhanced oil recovery

(EOR) potential compared to bottom water drive, Rogers City reservoirs.

West Branch Field

West Branch oil field is an anticlinal trap with northwest-southeast trend that

is primarily located in T22N-R2E, (West Branch Township) in Ogemaw County,

Michigan. The field is approximately nine miles long and one mile wide (Ten Have,

1979). West Branch Field has produced hydrocarbon from several Middle Devonian

formations including the Dundee. However, the Dundee reservoir is by far the

dominant producing unit in the West Branch Field. The first Dundee production was

discovered on March 8, 1934 with the completion of Pure Oil Company's # 1 Fisk

well in Section 27 of West Branch Township, Ogemaw County. In this well the

Dundee oil reservoir occurs at a depth of 2625 ft (800m) with initial production (IP)

of 21 BOPD (barrels of oil per day). Average gravity of produced oil is 36.8° API

units (Mortl, 1991).

In January, 1966 development of the West Branch Field proceeded on ten-acre

spacing, with the wells located in the centers of governmental-surveyed quarter-

quarter-quarter sections. Drilling by several independent producers extended the field

to the southeast into Section 6, T.21N., R.3E., Mills Township, and to the northwest

into Sections 23 and 24, T.22N., R.1E., Ogemaw Township (Vugrinovich and

Matzkanin, 1981). In 1974, the Marathon Oil Company commenced a field-wide

secondary recovery program that water-flooded the Dundee reservoir using a five-spot

well pattern. Oil production reached its second-highest peak in 1981 (Figure 46),

when about 300,000 barrels was produced. A steep decline ensued after 1986 and is

sustained to date, averaging 5.5% per year (Figure 46).

90

The West Branch Field produces oil from grainstone reservoir facies with an

average porosity and permeability of 7% and 14md, respectively. Thickness of the pay

zone is 20-30 feet (Curran and Hurley, 1992). The reservoir unit in the field is thought

to extend over approximately 1870 acres. Since discovery, more than 325 wells have

been drilled producing an excess of 14 MMbbl. The estimated original oil in place

(OOIP) is 26.4 MMbbl, however, 9.5 MMbbl was produced through primary recovery

and 4.7 MMbbl from secondary recovery to date. The total percentage of estimated oil

recovery (primary and secondary) relative to OOIP is 53%. As of 2010, the field

produces approximately 51,400 barrels per year (Figure 46).

1,000

5

©

e

100

10

West Branch Oil Field Production History

•OilProd

6°oPi iniaiy Annual Decline5.5° o Secondaiv Annual Decline

^rÔro«3cnrvitr>00'-t'*rÔnni£)CrirNLnoOr-<'g-r--Oroi£>0mro^t^^-îniAiflvovovor-rxr^rôooooocriiCiooooo

«H»-HiH»-ti--l«-1r-lr-tr-»T-lr-l.—l<-lT-lr-li-HtHr-lt-t*-lr-lf-lrs|r>jrvirsl

Production Year

Figure 46. Performance history of the West Branch Dundee reservoir showing the oilproduction per year (green line) associated with primary and secondaryannual decline (pink line). In the West Branch Field, the waterfloodbegan in 1966 (from Harrison, 2012).

91

South Buckeye Field

South Buckeye oil field is located on a major anticline fold in T18N-R1W, of

Buckeye Township, in Gladwin County, Michigan, with a few wells located east of

the range line in Hay Township T18N-R1E (Addison, 1940; Harrison, 1991). The

South Buckeye oil field has produced oil and gas from several Middle and Late

Devonian formations including the Dundee. The Dundee reservoir, however, is the

primary unit in the South Buckeye Field and was discovered on July 20, 1936 with the

completion of the Oard No. 1. The Dundee oil reservoir occurs at depth of 3570 ft

(1,088 m) in this well, and the well flowed at rates (IP) greater than 135 BOPD

(Addison, 1940; Mortl, 1991). After production for more than fifty years, the Wiser

Oil Company started a secondary recovery program by water flooding portions of the

field using a five-spot well pattern (Harrison, 1991).

The South Buckeye Field produces oil from patch reef reservoir facies with an

average porosity and permeability of 7% and 123md, respectively. Average thickness

of the pay zone is about 11 feet. Since discovery, more than 240 wells have been

drilled producing an excess of 7.7Mbb through 2011. However, only 45 wells are

active to date, 21 currently water injection wells, and 177 wells were plugged and

abandoned. Average gravity of produced oil is 39° API units (personal

communication, Harrison, 2012). The estimated original oil in place (OOIP) is about

27 MMbbl, however, 5.4 MMbbl were produced through primary recovery and 2.3

MMbbl through secondary recovery. The total percentage (primary and secondary) of

the OOIP is 28%. As of 2011, the field produces approximately 12,000 barrels per

year (Figure 47). That suggested that the recovery efficiencies were only about 28% of

OOIP. In this field, however, original oil in place may be overestimated due to the

patchy distribution of reservoir facies (see below).

92

10,000South Buckeve Oil Field Dundee .Annual Production

a 1,000SB

©

e

•OilProd

6.0% Annual Decline

•BrineProd

uso^cornr^rHLncnror^r-iLncrinor^T-iLncriro<tf«3-«3-mir>«3i£><x>r-.rôooooocr>cr>oooocScScriOCiCiCT^cricricôcôc^côoor-tr-t.-Ht-<*-l<-l*-lT-<<Hr-l»H«-l»-<r-l«-l»-4fMr\jr>J

Production Year

10000

1000 §

Figure 47. Performance history of the South Buckeye Dundee reservoir showing theannual oil production (green curve) and annual water production (bluecurve) associated with annual decline (pink line). Pilot waterfloodingbegan in 1980 (from Harrison, 2012).

Mount Pleasant Field

The Mount Pleasant oil field was the first commercial Dundee field in

Michigan, and was discovered in 1928 in Mt Pleasant Township, Midland County,

Michigan. Mt Pleasant Field lies in both Isabella and Midland Counties (T18-14N-

2W), Michigan (Mortl, 1991).When the Mount Pleasant Field was discovered in the

central basin, serious attention from the petroleum industry became directed toward

the Michigan Basin (Addison, 1940). The depth of the Dundee reservoir is at 3,545 ft

(1,080 m). After fifty five years of production, several producers commenced a pilot

secondary recovery program that water-flooded portions of the field (personal

93

communication, Harrison, 2012). However, the size of these pilot projects is small,

and only limited data on the performances of these pilot projects is publicly available.

The Mount Pleasant Field produces oil from fenestral reservoir facies with an

average porosity and permeability of 9% and 195md, respectively. Average thickness

of the pay zone is approximately 40 feet. The reservoir unit of the field is thought to

extend over approximately 7310 acres. Since discovery, 589 wells have been drilled

in the field. Cumulative production from this reservoir exceeds 29 MMbbl of through

2011. There are currently only 10 producing wells, 4 water injection wells, 2

observation wells, and 573 wells were plugged and abandoned. Average gravity of

produced oil is 41.2° API units (personal communication, Harrison, 2012). The

estimated original oil in place (OOIP) is about 66.8 MMbbl, with 28.3 MMbbl

produced through primary recovery and 1.2 MMbbl produced through secondary

recovery. Only 44% of the original oil in place has been recovered from Mount

Pleasant Field during the primary and secondary production phase. As of 2011, the

field produces approximately 15000 barrels per year (Figure 48).

Mount Pleasant Oil Field Dundee Annual Production10000 1 600

1000

a 100

10

900l\HIO'J»(NICO<t(10lMlCO"J03•a-^LnLnkOicioi-^r^oooooociciOOOcicioiffidicifficriciiowmijiciooo•—I i—li-trHrHtHrHi-lr-lr-li-I (H r-l rH (M (N CM

Production Year

Figure 48. Performance history of the Mount Pleasant Dundee reservoir showing theannual oil production (green curve) and annual water production (blue

94

curve) associated with 4.5% annual decline (pink line). Pilotwaterflooding began in 1980 (from Harrison, 2012).

Enhanced Oil Recovery (EOR) Potential

Enhanced oil recovery (EOR) is a term used for a wide variety of techniques

for increasing the amount of crude oil that can be extracted from an oil field. Gas

injection (including CO2) and water injection for pressure maintenance is presently

the most commonly used approach to enhance recovery (Grammer et al., 2008).

Recovery efficiency, which is also called oil efficiency factor, is expressed as a ratio

of recovered oil to original oil in place (Larue, 2004, Eq. 1).

cumulative productionEq. 1. Recovery Efficiency = ——-—— * 100

original oil in place

In this study, the Dundee Limestone produces oil predominately from three

different reservoir types; the stromatoporoid boundstone (patch reef), crinoidal

grainstone (shoal), and fenestral peloidal grainstone/packstone (peritidal). These

reservoir facies have an average thickness of the pay zone is 11 feet, 20-30 feet, and

40-60 feet, respectively. Cumulative production from a patch reef reservoir in South

Buckeye Field exceeds 7.7 MMbbl with primary recovery efficiencies of

approximately 20% (Eq.l). Production from the South Buckeye Field declined

significantly in the primary phase of production possibly due to either the reefs have

reached or are nearing their economic limit in the primary phase of hydrocarbon

production or reservoir pressure from the gas expansion drive is nearly depleted.

However, the South Buckeye Field has been converted to secondary recovery

operations, primarily through water injection for pressure maintenance, conducted in

95

the late 1980s (Figure 47), with additional recovery of approximately 45 % of the

primary recovery. Overall, the higher production from the patch reef facies indicates a

good response to secondary waterflood operations. The good response is attributed to

good overall reservoir quality and interconnectivity of the pore system in the patch

reef facies. Therefore, more recoverable oil can be extracted from the patch reef facies

based on the reservoir properties and estimated OOIP. However, the limited lateral

continuity of the patch reef facies and problematic OOIP estimates probably makes

this reservoir facies less efficient for EOR compared with other two facies (3 and 7).

The total recoverable oil reserves from shoal reservoir facies in the West

Branch Field are estimated to be about 26.4 MMbbl. The shoal reservoir facies has

produced in excess of 9 MMbbl in primary recovery and nearly 4.7 MMbbl from

secondary waterflood. The enhanced oil recovery pilot and field-wide waterflood

projects in the West Branch Field has achieved significant secondary waterflood oil

recovery. This facies generally produces from a uniform pore type (interparticle

porosity) and has high porosity and moderate permeability with an average of 7% and

14md, respectively. The good reservoir efficiency in the shoal facies is attributed to

the lateral continuity of the facies and good interconnectivity of this facies due to the

nature of the pore system (pore-throat size distribution) as well as of the amount of

porosity. Pore-throat size distribution is one of the important factors determining

permeability because the smallest pore throats are the bottlenecks that determine the

rate at which fluids pass through a rock (Kopaska-Merkel, 1991). The shoal reservoir

facies appears to possess good reservoir quality and good vertical and lateral

continuity on the basis of core analysis, production performance and core to log

correlation. Therefore, the shoal reservoir facies is a good candidate for enhanced oil

recovery to produce bypassed oil from shoal reservoir facies in the Dundee limestone.

96

Production in the Mount Pleasant Field started in the late twenties and the

field began experiencing steep production rate declines (Figure 48). After fifty years

of production, the field was converted to a pilot waterflood program. The field

production characteristics, including the heterogeneous nature of the field (i.e.,

especially porosity and permeability), may contribute to the different reservoir

performance. Distribution of porosity and permeability for three selected wells (

Pfund 1, permit # 36259; McClintic 3, permit # 36367; and Mt Pleasant Unit Tract

55, permit # 39770) demonstrate that (Figure 49) the fenestral reservoir (facies 7)

within the Dundee Limestone is thought to have a dual permeability system: a higher

permeability component consisting of interconnected vugs and solution-enhanced

fractures and stylolites seams, and a lower permeability component consisting of

microporosity and interparticle porosity. Through the primary production phase, fluids

move more easily through the higher permeability component. However, a large total

volume of hydrocarbons are stored in the lower permeability component. In light of

reservoir quality shown in porosity vs. permeability cross plot, the better production

probably resulted from the better reservoir quality zones (Figure 49). Additionally, the

estimated primary recovery efficiency in the Mount Pleasant Field is 42%, indicating

that the higher permeability component of the dual porosity system is being swept

very efficiently. The pilot waterflood program in the field resulted in low recovery

efficiency (<2% of OOIP) because the oil in the lower permeability reservoir type has

been ineffectively swept by the injected fluid.

Importantly, the remaining oil in the Mount Pleasant Field is concentrated in

the low permeability component and would be a target for waterflood or CO2

enhanced oil recovery (EOR). The injected fluid (water or CO2) flows at a faster rate

through the high-permeability grainstone intervals and at a lower rate in the low-

97

permeability of microporosity and interparticle porosity grainstone intervals,

effectively bypassing much of the oil in the lower permeability component. This

suggests that the microporosity and interparticle porosity are excellent targets for

waterflood or CO2 enhanced oil recovery because they have moderate porosity, low

permeability, and high initial oil saturation (Appendix D).

In North Buckeye, Wise, and Mt Pleasant fields production comes from one

uniform reservoir type, the fenestral reservoir facies. Analysis of this reservoir facies

was only documented in the Mt Pleasant Field because of better available data

control. It is inferred that this degree of the reservoir properties and reservoir

geometries can be applied to both the Wise and North Buckeye fields. The insights

from the geologic reservoir characterization and field production history provide an

understanding of the reservoir architecture, pore networks, and flow units within the

Dundee Limestone in six fields. It is this foundation that gives some context to areas

with better reservoir development and economic waterflood or CO2 EOR potential.

The geological framework, production performance, and operational understanding

should provide useful guidance for future waterflood or C02 EOR potential

expansion. Fundamentally the fenestral facies performance differently than grainstone

or patch reef. North Buckeye and Wise fields both perform like Mount Pleasant does.

98

10000Porosity vs. Permeability for Facies 7

4

6 8 10

Porosity %

♦Permit #36259

•Permit # 39770A Permit#36367

14 10

Figure 49. Example of three selected wells of the fenestral facies showing theheterogeneity (porosity and permeability) within a single well. Note thatthe fenestral reservoir facies has a dual permeability system, a higherpermeability component consisting of interconnected vugs and solution-enhanced fractures and stylolites seams (blue circle), and a lowerpermeability component consisting of microporosity and interparticleporosity (red circle).

99

CHAPTER VII

CONCLUSIONS

This study evaluates the depositional and diagenetic controls on reservoir

quality within several Dundee Limestone oil fields in order to identify reservoir-prone

facies and predict their distribution. The distribution of reservoir facies in the Dundee

Limestone is controlled by primary depositional processes in conjunction with a suite

of diagenetic processes. In the fifteen wells described in this study, seven distinct

depositional facies have been identified in the Dundee, as well as Rogers City. These

facies were placed into an idealized vertical succession in order to evaluate a

sequence stratigraphic model oh the basis of an inferred depositional model from

deepest/open marine to shallowest/tidal flat.

Oil production occurs from at least three different reservoir facies; 1)

Crinoidal grainstone; 2) Stromatoporoid boundstone; and 3) Fenestral peloidal

grainstone/packstone in different Dundee fields. The other four facies 1) Crinoidal

skeletal wackestone; 2) bioturbated peloidal grainstone/packstone; 3) Coral-

stromatoporoid rudstone; and 4) Skeletal wackestone, which most commonly form

seals and baffles. This is largely due to their disconnected pore space, consisting

primarily of limited distribution of interparticle, moldic and vuggy pores. Facies 3 and

5 very rarely have reservoir potential when molds are dissolved and the isolated vugy

porosity is interconnected by stylolitization and fracturing.

Examination of conventional core analysis data from the hydrocarbon

reservoir facies indicates that these facies have variable porosity and permeability

relationships. The correlation between porosity and permeability of the reservoir

facies are known to be poor in the Dundee limestone due to the varying connectivity

of different pore types. Reservoir quality in these fields is controlled by lithologic

100

variations and the spatial heterogeneity in diagenetic processes. Variations in

diagenetic alterations such as porosity, permeability and lithology, could produce

zones with different reservoir properties and so different petrophysical behaviors. The

combination of porosity and permeability data in terms of reservoir quality provides a

convenient starting point to address the differences between facies and between

reservoir zones.

This study provides additional information on the opportunities for

implementing water flooding or C02 enhanced oil recovery (C02-EOR). With similar

subsurface reservoirs, waterflood or enhanced recovery initiatives should understand

the reservoir quality and geometry to evaluate the potential of preferential sweep of

unrecovered hydrocarbon. The implementation of EOR in more laterally continuous

reservoir (i.e., fenestral peloidal grainstone/packstone facies) should be more efficient

and effective than typically spatially isolated reservoir facies such as patch reef facies

of the South Buckeye Field. For example, the patch reef reservoir (facies 2), has

distinct petrophysical reservoir properties and also has distinct reservoir geometry

properties, in particular laterally discontinuous patch reef facies. This characteristic

results in less efficient for EOR potential.

101

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103

Outcrop and Modern Analogs in Reservoir Modeling: American Association ofPetroleum Geologists, Memoir 80, p. 1-22.

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Halley, R.R., and Schmoker, J.W., 1983, High porosity Cenozoic carbonate rocks ofsouth Florida: progressive loss of porosity with depth: American Association ofPetroleum Geologists, Bulletin, v. 67, p. 191-200.

Haq, B. U., and Schutter, S. R., 2008, A Chronology of Paleozoic Sea-Level Changes,Science, v. 322, no. 5898, p. 64-68.

Harrison III, W. B., 1991, South Buckeye Field, in M. S. Wollensak, ed., Oil and GasField Manual of the Michigan Basin: Michigan Basin Geological Society, v. 2,p. 85-93.

Hinze,W. J and Merrit, D. W., 1969, Basement Rocks of the Southern Peninsula ofMichigan, in Studies of the Precambrian of the Michigan Basin: Michigan BasinGeol. Soc. Field Excursion Guidebook, p. 28-59.

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104

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Michigan Basin: American Association of Petroleum Geologists, Bulletin, v. 90,p. 1787-1801.

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105

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Appendix ACore Descriptions

108

Permits 19693

Oxy USA Inc., Mcnerney, B E13. Wise FieldIsabella County Michigan

Depth Interval: 3678.5' - 3717'Rogers City:

The Rogers City facies is dense, low porosity and permeability. The boundarycontact between Rogers City and Dundee is marked by irregular surface (stylolite).

3678.5'-3683': Ls, dark gray, crinoidal/skeletal wackestone, Fl, occasionallyinterbedded with packstone, containing fossil fragments such as crinoids,gastropods, brachiopods, ostracods, and intraclasts. It has stylolite structure,has low porosity and permeability which acts as a cap rocks in the mostDundee intervals. Its contact with lower Dundee Limestone is marked byirregular surface. The depositional environment is interpreted as an openmarine.

Dundee Limestone:

3683'3684': Ls, gray buff, fenestral, peloidal grainstone/packstone, F7, this faciesmade up largely of peloids. The skeletal grains include casts of fossilfragments, gastropods, ostracods, bivalves. Stylolites are very common in thisfacies, oil stain. The only sedimentary structures are fenstrae, smalllaminations, and cyanobacterial mat. This interval is very pores. Thedepositional environment is high energy peritidal.

3684'-3687.5': Ls, brown- grey, skeletal wackestone, F6, with casts of gastropods,bivalves, forams, peloids, ooids, crinoids, ostracod fragments, and calcareoussponges. No visual porosity was observed. It has stylolites and some fractures.Partially dolomitization of carbonate mud was observed. The depositionalenvironment is low energy shallow lagoon.

3684.9', 3685.2' (Thin-section) Skeletal Wackestone. Containsforams,ostracods, bivalves.

3687.7' (Thin-section) Skeletal Wackestone it haspeloids, ooids,crinoids.

3687.5'-3692': Ls, grey buff, fenestral, peloidal grainstone/packstone, F7. Grainsinclude peloids, with casts of fossil fragments, gastropods, ostracods, bivalves.The sedimentary structures associated with this facies are fenstrae, smalllaminations, and cyanobacterial mat. Porosity within this facies is dominantlyfenestral and interparticle, high permeability and porosity, main reservoir in

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this field. The vugs are partially filled with calcite crystals. Stylolites arecommon throughout this facies, oil stain, the depositional environment isperitidal.

3688.8', 3689', 3689.3' (Thin-section)Peloidal grainstone/packstone.

3692'-3695.5': Ls, brown-gray, skeletal wackestone F6, skeletal grains includegastropods, bivalves, ostracod fragments, forams, and minor stromatoporoids.No visual porosity. The stylolites and some fractures are observed. Thedepositional environment is interpreted as a low energy lagoon.

3693.1' (Thin-section) Skeletal Wackestone.

3695.5'3698': Ls, grey buff, fenestral, peloidal grainstone/packstone, F7. Thisinterval is largely made of peloids, and with casts of fossil fragments,gastropods, ostracods, bivalves. The sedimentary structures associated withthis facies are fenstrae and small laminations, and cyanobacterial mat. Porositywithin this facies is dominantly fenestral and interparticle, main reservoir inthis field. The vugs are partially filled with calcite crystal cement. Stylolitesare common throughout this facies, oil stain and the depositional environmentis interpreted as peritidal

3698'-3700': Ls, brown-gray, very fined grain, skeletal wackestone, F6 with casts ofgastropods and ostracod fragments. No visual porosity, it has stylolites andsome vertical fracture (5-8cm). The depositional environment is low energylagoon.

3700'3709.5': Ls, gray buff, fenestral, peloidal grainstone/packstone, F7. Thisfacies consist of peloids, gastropods, ostracods, bivalves. This interval is veryporous. The sedimentary structures associated with this facies are fenstrae andsmall laminations, and cyanobacterial mat. Porosity within this facies isdominantly fenestral and interparticle porosity, main reservoir in this field.The vugs are partially filled with calcite crystal cement. Stylolites are commonthroughout this facies, oil stain, and the depositional environment is peritidal.

3700.8' (Thin-section) Peloidal grainstone

3709.5'-3711': Ls, gray buff, skeletal wackestone, F6, fined grained, fossilfragments, bivalves, gastropods, ostracods, forams and ooids??. The styloliteshave bladed dolomite along vertical lines. This interval has low permeabilityand porosity.

3709.3' (Thin-section) skeletal wackestone.

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3711'-3714.5': Ls, grey buff, fenestral, peloidal grainstone/packstone, F7, mainlymade up of peloids, and with casts of fossil fragments, gastropods, ostracods,bivalves. The sedimentary structures associated with this facies are fenstraeand small laminations, and cyanobacterial mat. Porosity within this facies isdominantly fenestral and interparticle porosity, main reservoir in this field.Stylolites are common throughout this facies, oil stain, and the depositionalenvironment is peritidal.

3712'-13' (Thin-section) fenestral peloidal grainstone.

3714.5'-3717': Ls, brownish gray, very fined grain, skeletal wackestone, F6, skeletalgarains include gastropods, ostracod fragments, forams very abundant. Sparsevugy and moldic porosity that partially filled with calcite cements, stylolitesare very common. The depositional environment is low energy lagoon.

3716.6' (Thin-section) Skeletal Wackestone.

Ill

Permit#35461

Oryx Energy Co., Sierra Land CO., INC 1, Mt PleasantMidland County Michigan

Depth Interval: 3530'-3615'

Rogers City:

3530'-3544': Ls dark gray, crinoidal/skeletal wackestone, Fl, consists of crinoids,and other fossil fragments, intraclasts, has stylolite structure and has very lowporosity and permeability, which act as cap rocks in the most Dundeeintervals. This facies representing open marine environment.

Dundee Limestone:

3544'-3554': Ls, light to brownish gray, fenestral peloidal grainstone/packstone,F7, and the observed grains within this facies include coral and spongesfragments. The sedimentary structures found in this facies include tidallaminations, and fenestral structure. Porosity within this facies is dominantlyfenestral and moldic porosity, and forms a main reservoir in this field.

3554'-3556': Ls, light to brownish gray, skeletal wackestone, F6, with casts ofbivalves, ostracod fragments, and calcareous sponges (stromatoporoid). Novisual porosity, it has stylolites and some fractures. The depositionalenvironment is low energy shallow lagoon.

3560'-3563': Missing interval.

3563'-3565': Ls, light to brownish gray, skeletal wackestone, F6, with casts ofbivalves, ostracod fragments, and calcareous sponges (stromatoporoid). Wispyand suture stylolites and some fractures, oil stain. The depositionalenvironment is low energy shallow lagoon.

3565'-3569': Ls, light to brownish gray, fenestral peloidal grainstone/packstone,F7, and the observed grains within this facies include coral and spongesfragments. The sedimentary structure observed in this facies is fenestralstructure. Very fine to fine sand grain, porosity within this facies is dominantlyfenestral and moldic porosity, high permeability and porosity, main reservoirin this field. The vugs are partially filled with calcite crystal cement, stylolitestructure, the depositional environment is peritidal.

3569'-3570.5': Ls, light to brownish gray, skeletal wackestone, F6, with casts ofbivalves, ostracod fragments, and calcareous sponges (stromatoporoid). Thisfacies is u interbedded with peloidal grainstone facies #7. It has low and highamplitude stylolites and some fractures, oil stain. The depositionalenvironment is low energy shallow lagoon.

112

3570.5'-3574': Ls, light to brownish gray, fenestral peloidal grainstone/packstone,F7, and the observed grains within this facies include coral and spongesfragments. The sedimentary structures found in this facies include, tidallaminations, and fenestral structure very limited. Very fine to fine sand grain,porosity within this facies is dominantly fenestral porosity, high permeabilityand porosity, main reservoir in this field. The vugs are partially filled withcalcite crystal cement, stylolite structure, the depositional environment isperitidal.

3574'-3577': Ls, light to brownish gray, skeletal wackestone, F6, it is highlybioturbated with casts of bivalves, ostracod fragments, and calcareous sponges(stromatoporoid) at 3680'. No Visual porosity, it has low and high amplitudestylolites and some fractures, oil stain. The depositional environment is lowenergy shallow lagoon.

3577'-3579': Ls, light to brownish gray, fenestral peloidal grainstone/packstone,F7, and allochems grains within this facies include coral and spongesfragments. The sedimentary structures found in this facies include, tidallaminations, and fenestral structure very limited. Very fine to fine sand grain,porosity within this facies is dominantly fenestral and moldic porosity, highpermeability and porosity, main reservoir in this field. The vugs are partiallyfilled with calcite crystal cement, stylolite structure.


3581' -3584.5': Ls, light to brownish gray, fenestral peloidal grainstone/packstone,F7, and the skeletal grains include coral and sponges fragments. The mainsedimentary structures are tidal laminations, and fenestral structure. Very fineto fine sand grain, porosity within this facies is dominantly fenestral andmoldic porosity, high permeability and porosity, main reservoir in this field.The depositional environment is peritidal.

3584.5'-3585.5: Ls, light to brownish gray, skeletal wackestone, F6, with casts ofbivalves, ostracod fragments, and calcareous sponges (stromatoporoid). Wispyand suture stylolites and some fractures, oil stain. The depositionalenvironment is low energy shallow lagoon.

3585.5-3588': Ls, light to brownish gray, fenestral peloidal grainstone/packstone,F7, and the observed grains within this facies include coral and spongesfragments. The sedimentary structure observed in this facies is fenestralstructure. Very fine to fine sand grain, porosity within this facies is dominantlyfenestral and moldic porosity, high permeability and porosity, main reservoir

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in this field. The vugs are partially filled with calcite crystal cement, stylolitestructure, the depositional environment is peritidal.

3588'-3590': Ls, light to brownish gray, skeletal wackestone, F6, with casts ofbivalves, ostracod fragments, and calcareous sponges (stromatoporoid). Thisfacies is u interbedded with peloidal grainstone facies #7. It has low and highamplitude stylolites and some fractures, oil stain. The depositionalenvironment is low energy shallow lagoon.

3590'-3594': Ls, light to brownish gray, fenestral peloidal grainstone/packstone,F7, and the observed grains within this facies include coral and spongesfragments. The sedimentary structure observed in this facies is fenestralstructure. Very fine to fine sand grain, porosity within this facies is dominantlyfenestral and moldic porosity, high permeability and porosity, main reservoirin this field. The vugs are partially filled with calcite crystal cement, stylolite.


3598'-3607': Ls, light to brownish gray, fenestral peloidal grainstone/packstone,F7, and the observed grains within this facies include coral and spongesfragments. The sedimentary structures found in this facies include, tidallaminations, and fenestral structure very limited. Very fine to fine sand grain,porosity within this facies is dominantly fenestral porosity, high permeabilityand porosity, main reservoir in this field. The vugs are partially filled withcalcite crystal cement, stylolite structure, the depositional environment isperitidal.

3607'-3610': Ls, light to brownish gray, skeletal wackestone, F6, with casts ofbivalves, ostracod fragments, and calcareous sponges (stromatoporoid). It haslow and high amplitude stylolites and some fractures, oil stain. Thedepositional environment is low energy shallow lagoon.

3610'-3615': Ls, light to brownish gray, fenestral peloidal grainstone/packstone,F7, and the observed grains within this facies include coral and spongesfragments. The sedimentary structures found in this facies include, tidallaminations, and fenestral structure very limited. Very fine to fine sand grain,porosity within this facies is dominantly fenestral porosity, high permeabilityand porosity, main reservoir in this field. The vugs are partially filled withcalcite crystal cement, the depositional environment is peritidal

♦ This core was depth-shifted up 5 feet to match the wire-line logs

114

Rogers City:

Permit#35764

Oryx Energy Co., Ames, C W 1, Mt PleasantMidland County Michigan



Dundee Limestone:

3534'-3543': Ls, light to brownish gray, fenestral peloidal grainstone/packstone,F7, and the observed grains within this facies include coral and spongesfragments. The sedimentary structures found in this facies include smallcyanobacterial mats, tidal laminations, and fenestral structure. Very fine tofine sand grain, porosity within this facies is dominantly fenestral and moldicporosity, and forms a main reservoir in this field. This facies has beendeposited in peritidal environment.


3545' -3548': Ls, light to brownish gray, fenestral peloidal grainstone/packstone,F7, and the observed grains within this facies include coral and spongesfragments. The sedimentary structures found in this facies include smallcyanobacterial mats, tidal laminations, and fenestral structure. Very fine tofine sand grain, porosity within this facies is dominantly fenestral and moldicporosity, high permeability and porosity, main reservoir in this field. Thedepositional environment is peritidal.


3550'-3557': Ls, light to brownish gray, fenestral peloidal grainstone/packstone,F7, and the observed grains within this facies include coral and spongesfragments. The sedimentary structure observed in this facies is fenestralstructure. Very fine to fine sand grain, porosity within this facies is dominantlyfenestral and moldic porosity, high permeability and porosity, main reservoir

115


3557'-3560': Ls, light to brownish gray, skeletal wackestone, F6, with casts ofbivalves, ostracod fragments, and calcareous sponges (stromatoporoid). Wispyand suture stylolites and some fractures. The depositional environment is lowenergy shallow lagoon.

3560'-3568': Ls, light to brownish gray, fenestral peloidal grainstone/packstone,F7, and the observed grains within this facies include coral and spongesfragments. The sedimentary structure found in this facies is fenestral structure.Very fine to fine sand grain, porosity within this facies is dominantly fenestraland moldic porosity, high permeability and porosity, main reservoir in thisfield. The depositional environment is peritidal.



3577'-3579': Ls, light to brownish gray, skeletal wackestone, F6, it is highlybioturbated with casts of bivalves, ostracod fragments, and calcareous sponges(stromatoporoid). No Visual porosity, it has low and high amplitude stylolitesand some fractures, oil stain. The depositional environment is low energyshallow lagoon.

3579'-3584': Ls, light to brownish gray, fenestral peloidal grainstone/packstone,F7, and the observed grains within this facies include coral and spongesfragments. The sedimentary structures found in this facies include, tidallaminations, and fenestral structure very limited. Very fine to fine sand grain,porosity within this facies is dominantly fenestral and moldic porosity, highpermeability and porosity, main reservoir in this field. The vugs are partiallyfilled with calcite crystal cement, stylolite structure, the depositionalenvironment is peritidal.

116


3587'-3589': Ls, light to brownish gray, fenestral peloidal grainstone/packstone,F7, and the observed grains within this facies include coral and spongesfragments. The sedimentary structures found in this facies include tidallaminations, and fenestral structure very limited. Very fine to fine sand grain,porosity within this facies is dominantly fenestral and moldic porosity. Thevugs are partially filled with calcite crystal cement, stylolite structure, thedepositional environment is peritidal.


117

Permit#36227

Oryx Energy Co., Sokolowski, C T 1, Mt PleasantMidland County Michigan

Depth Interval: 3544'-3609'Dundee Limestone:

3544'-3548': Ls, light to brownish gray, fenestral peloidal grainstone/packstone,F7, and the observed grains within this facies include coral and spongesfragments. The sedimentary structures found in this facies include tidallaminations, and fenestral structure. Porosity within this facies is dominantlyfenestral and moldic porosity, and forms a main reservoir in this field.


3551' -3561': Ls, light to brownish gray, fenestral peloidal grainstone/packstone,F7, and the skeletal grains include coral and sponges fragments. The mainsedimentary structures are tidal laminations, and fenestral structure. Very fineto fine sand grain, porosity within this facies is dominantly fenestral andmoldic porosity, high permeability and porosity, main reservoir in this field.The depositional environment is peritidal.




3574'-3585': Ls, light to brownish gray, fenestral peloidal grainstone/packstone,F7, and the observed grains within this facies include coral and spongesfragments. The sedimentary structure found in this facies is fenestral structure.

118

Very fine to fine sand grain, porosity within this facies is dominantly fenestraland moldic porosity, high permeability and porosity, main reservoir in thisfield. The depositional environment is peritidal.



3591'-3597': Ls, light to brownish gray, skeletal wackestone, F6, it is highlybioturbated with castsof bivalves, ostracod fragments, and calcareous sponges(stromatoporoid). No Visual porosity, it has low and high amplitude stylolitesand some fractures, oil stain. The depositional environment is low energyshallow lagoon.

3597'-3600: Ls, light to brownish gray, fenestral peloidal grainstone/packstone,F7, and allochems grains within this facies include coral and spongesfragments. The sedimentary structures found in this facies include, tidallaminations, and fenestral structure very limited. Very fine to fine sand grain,porosity within this facies is dominantly fenestral and moldic porosity, highpermeability and porosity, main reservoir in this field. The vugs are partiallyfilled with calcite crystal cement, stylolite structure.


3601' -3603': Ls, light to brownish gray, fenestral peloidal grainstone/packstone,F7, and the skeletal grains include coral and sponges fragments. The mainsedimentary structures are tidal laminations, and fenestral structure. Very fineto fine sand grain, porosity within this facies is dominantly fenestral andmoldic porosity, high permeability and porosity, main reservoir in this field.The depositional environment is peritidal.

119



120

Rogers City:

Permit#36259

Oryx Energy Co., Pfund-1, Mt PleasantMidland County Michigan



Dundee Limestone:

3539'-3553': Ls, light to brownish gray, fenestral peloidal grainstone/packstone,F7, and the observed grains within this facies include coral and spongesfragments. The sedimentary structures found in this facies include tidallaminations, and fenestral structure. Very fine to fine sand grain, porositywithin this facies is dominantly fenestral and moldic porosity, highpermeability and porosity, main reservoir in this field. The vugs are partiallyfilled with calcite crystal cement, stylolite structure, the depositionalenvironment is peritidal.


3555'-3563': Ls, light to brownish gray, fenestral peloidal grainstone/packstone,F7, and the observed grains within this facies include coral and spongesfragments. The sedimentary structures found in this facies include tidallaminations, and fenestral structure. Very fine to fine sand grain, porositywithin this facies is dominantly fenestral and moldic porosity, highpermeability and porosity, main reservoir in this field. This facies wasdeposited in peritidal environment.

3563'-3565': Limestone, light to brownish gray Ls, skeletal wackestone, F6, withcasts of bivalves, ostracod fragments, coral and calcareous sponges(stromatoporoid). Wispy and suture stylolites and some fractures. Thedepositional environment is low energy shallow lagoon.

3565'-3569': Ls, light to brownish gray, fenestral peloidal grainstone/packstone,F7, and the observed grains within this facies include coral brachiopods andsponges fragments. The sedimentary structures found in this facies includetidal laminations, and fenestral structure. Very fine to fine sand grain, porosity

121

within this facies is dominantly fenestral and moldic porosity, highpermeability and porosity, main reservoir in this field3569'-3571': Ls, light tobrownish gray, skeletal wackestone, F6, with casts of bivalves, ostracodfragments, coral and calcareous sponges (stromatoporoid). Wispy and suturestylolites and some fractures. The depositional environment is low energyshallow lagoon.

3571'-3579' Ls, light to brownish gray, fenestral peloidal grainstone/packstone,F7, and the observed grains within this facies include coral brachiopods andsponges fragments. The sedimentary structures found in this facies includesmall cyanobacterial mats, tidal laminations, and fenestral structure. Very fineto fine sand grain, porosity within this facies is dominantly fenestral andmoldic with minor stylolitic porosity, high permeability and porosity, mainreservoir in this field. The vugs are partially filled with calcite crystal cement,stylolite structure, the depositional environment is peritidal

3579'-3581': Ls, light to brownish gray, skeletal wackestone, F6, very fine-grained,with casts of bivalves, ostracod fragments, coral and calcareous sponges(stromatoporoid). This facies interpreted as storm deposit. Stylolite structure iscommon, no visual porosity. Low porosity and permeability based on the coreanalysis date. The depositional environment is low energy shallow lagoon.

3581'-3583': Ls, light to brownish gray, fenestral peloidal grainstone/packstone,F7, and the observed grains within this facies include brachiopods, coral,sponges fragments, stromatoporoid rich. The sedimentary structures found inthis facies include small cyanobacterial mats, tidal laminations, and fenestralstructure. Very fine to fine sand grain, porosity within this facies is dominantlyfenestral and moldic with minor stylolitic porosity, high permeability andporosity, main reservoir in this field. The vugs are partially filled with calcitecrystal cement, stylolite structure, the depositional environment is peritidal.

3583'-354.5: Limestone, light to brownish gray Ls, skeletal wackestone, F6, veryfine-grained, with casts of bivalves, ostracod fragments, coral and calcareoussponges (stromatoporoid it about 10 cm). This facies interpreted as stormdeposit. Wispy and suture stylolites is common, no visual porosity. Lowporosity and permeability based on the core analysis date. The depositionalenvironment is low energy shallow lagoon.

3584.5'-3587': Ls, light to brownish gray, fenestral peloidal grainstone/packstone,F7, and the observed grains within this facies include coral brachiopods andsponges fragments, stromatoporoid. The sedimentary structures found in thisfacies include small cyanobacterial mats, tidal laminations, and fenestralstructure. Very fine to fine sand grain, porosity within this facies is dominantlyfenestral porosity, high permeability and porosity, main reservoir in this field.

122

The vugs are partially filled with calcite crystal cement, stylolite structure, thedepositional environment is peritidal.

3587'-3589': Limestone, light to brownish gray Ls, skeletal wackestone, F6, veryfine-grained, with casts of bivalves, ostracod fragments, coral and calcareoussponges (stromatoporoid it about 10 cm). This facies interpreted as stormdeposit. Stylolite structure is common, no visual porosity. Low porosity andpermeability based on the core analysis date. The depositional environment islow energy shallow lagoon.

3589'-3604': Ls, light to brownish gray, fenestral peloidal grainstone/packstone,F7, and the observed grains within this facies include coral brachiopods andsponges fragments and stromatoporoid rich at 3598'-3600'. The sedimentarystructures found in this facies include small cyanobacterial mats, tidallaminations, and fenestral structure. Very fine to fine sand grain, porositywithin this facies is dominantly fenestral and moldic porosity, highpermeability and porosity, main reservoir in this field. The vugs are partiallyfilled with calcite crystal cement, stylolite structure, the depositionalenvironment is peritidal.

3604'-3606.5': Ls, light to brownish gray, skeletal wackestone, F6, very finegrained, with casts of bivalves, ostracod fragments, coral and calcareoussponges. This facies interpreted as storm deposit. Stylolite structure iscommon, no visual porosity. Low porosity and permeability based on the coreanalysis date. The depositional environment is low energy shallow lagoon.

3606.5'-3634': Ls, light to brownish gray, fenestral peloidal grainstone/packstone,F7, and the observed grains within this facies include coral brachiopods andsponges fragments, stromatoporoid at 3642.5' (12cm). The sedimentarystructures found in this facies include small cyanobacterial mats, tidallaminations, and fenestral structure. Very fine to fine sand grain, porositywithin this facies is dominantly fenestral and moldic porosity, highpermeability and porosity, main reservoir in this field. The vugs are partiallyfilled with calcite crystal cement, stylolite structure, the depositionalenvironment is peritidal.

3634'-3636': Ls, light to brownish gray, skeletal wackestone, F6, very fine-grained,with casts of bivalves, ostracod fragments, coral and calcareous sponges. Thisfacies interpreted as storm deposit. Wispy and suture stylolites is common, novisual porosity. Low porosity and permeability based on the core analysis date.The depositional environment is low energy shallow lagoon.

3636-3639': Ls, light to brownish gray, fenestral peloidal grainstone/packstone,F7, and the observed grains within this facies include coral brachiopods andsponges fragments. The sedimentary structures found in this facies include

123

small cyanobacterial mats, tidal laminations, and fenestral structure. Very fineto fine sand grain, porosity within this facies is dominantly fenestral andmoldic porosity, high permeability and porosity, main reservoir in this field.The vugs are partially filled with calcite crystal cement, stylolite structure, thedepositional environment is peritidal.


3644'-3650': Ls, light to brownish gray, fenestral peloidal grainstone/packstone,F7, and the observed grains within this facies include coral brachiopods andsponges fragments. The sedimentary structures found in this facies includesmall cyanobacterial mats, tidal laminations, and fenestral structure. Very fineto fine sand grain, porosity within this facies is dominantly fenestral andmoldic with minor stylolitic porosity, high permeability and porosity, mainreservoir in this field. This facies interpreted as peritidal environment.


3652'-3657': Ls dark gray, crinoidal/skeletal wackestone, Fl, consists of crinoids,and other fossil fragments, intraclasts, has stylolite structure and has very lowporosity and permeability, which act as cap rocks in the most Dundeeintervals. This facies representing open marine environment. Floodingsurface @3652.5-3654(diverse fauna include crinoids and finger coral,sponges, and stromatoporoid debris)

124

Rogers City:

Permit#36367

Oryx Energy Co., Mcclintic-3, Mt PleasantIsabella County Michigan



Dundee Limestone:





3596'-3599': Ls, light to brownish gray, fenestral peloidal grainstone/packstone,F7, and the observed grains within this facies include coral and spongesfragments. The sedimentary structure observed in this facies is fenestralstructure. Very fine to fine sand grain, porosity within this facies is dominantlyfenestral and moldic porosity, high permeability and porosity, main reservoir

125





3604'-3607': Ls, light to brownish gray, fenestral peloidal grainstone/packstone,F7, and the observed grains within this facies include coral and spongesfragments. The sedimentary structures found in this facies include, tidallaminations, and fenestral structure very limited. Very fine to fine sand grain,porosity within this facies is dominantly fenestral porosity, high permeabilityand porosity, main reservoir in this field. The vugs are partially filled withcalcite crystal cement, stylolite structure, , the depositional environment isperitidal.



126

3614'-3617': Limestone, light to brownish gray Ls, skeletal wackestone, F6, it ishighly bioturbated with casts of bivalves, ostracod fragments, and calcareoussponges (stromatoporoid). No Visual porosity, it has low and high amplitudestylolites and some fractures, oil stain. The depositional environment is lowenergy shallow lagoon.






♦ This core was shifted up 5 feet.

127

Rogers City:

Permit#36387

Oryx Energy Co., Miller, Viola 1, Mt PleasantIsabella County Michigan


3560'-3588: Ls dark gray, crinoidal/skeletal wackestone, Fl, consists of crinoids,and other fossil fragments, intraclasts, has stylolite structure and has very lowporosity and permeability, which act as cap rocks in the most Dundeeintervals. This facies representing open marine environment.

Dundee Limestone:




3606'-3614': Missing interval.


3616'-3618': Ls, light to brownish gray, fenestral peloidal grainstone/packstone,F7, and the observed grains within this facies include coral and spongesfragments. The sedimentary structure observed in this facies is fenestral

128

structure. Very fine to fine sand grain, porosity within this facies is dominantlyfenestral and moldic porosity, high permeability and porosity, main reservoirin this field. The vugs are partially filled with calcite crystal cement, stylolitestructure, the depositional environment is peritidal.





129

Rogers City:

Permit#39770

Oryx Energy Co., Mt Pleasant Unit Tract 55Isabella County Michigan

Depth Interval: 3557' - 3617'

3557'-3572': Ls dark gray, crinoidal/skeletal wackestone, Fl, consists of crinoids,minor bivalves, trilobites, fossil fragments, intraclasts, has stylolite structureand has very low porosity and permeability, which act as cap rocks in the mostDundee intervals. This facies representing open marine environment.

3574.4' (Thin-section) Crinoidal wackestone.

Dundee Limestone:

3572'-3577': Ls, light to brownish gray, fenestral peloidal grainstone/ packstone,F7, and the grains within this facies includes peloids and sparsely gastropodsand bivalves, trilobites, and other fossil fragments. The sedimentary structuresfound in this facies include small cyanobacterial mats, tidal laminations, andfenestral structure. Very fine to fine sand grain, porosity within this facies isdominantly fenestral and moldic porosity, main reservoir in this field. Thedepositional environment is peritidal.

3575' (Thin-section) peloidalpackstone

3577'-3579': Ls, light to brownish gray, skeletal wackestone, F6, with casts ofgastropods, bivalves, forams, peloids, crinoids, ostracod fragments, andcalcareous sponges (stromatoporoid) at 3578'. No Visual vugy porosity, it hasstylolites and some fractures. Partially dolomitization of carbonate mud. Thedepositional environment is interpreted as a low energy shallow lagoon.

3579' -3590': Ls, light to brownish gray, fenestral peloidal grainstone/packstone,F7, this interval occasionally interbedded with skeletal wackestone at 3584',grains within this facies includes mainly peloids and sparsely gastropods andbivalves, trilobites, and other fossil fragments. Porosity within this facies isdominantly fenestral, moldic and interparticle porosity, main reservoir in thisfield. The vugs are partially filled with calcite crystal cement, stylolitestructure common throughout the core. The sedimentary structures found inthis facies include small cyanobacterial mats, tidal laminations, and fenestralstructure, the depositional environment is peritidal.

3585.9', 3589.1' (Thin-section) peloidal grainstone

130

3590'-3593': Ls, light to brownish gray, skeletal wackestone, F6, consist ofgastropods, ostracods, bivalves, trilobites. Low porosity and permeability,stylolites are very common throughout the core.

3592.2' (Thin-section) skeletal wackestone

3593'-3597': Ls, light to brownish gray, fenestral peloidal grainstone/packstone,F7, grains includes mainly peloids and sparsely gastropods and bivalves. Thesedimentary structures found in this facies include small cyanobacterial mats,tidal laminations, and fenestral structure. Very fine to fine sand grain, porositywithin this facies is dominantly fenestral and interparticle porosity, mainreservoir in this field. The vugs are partially filled with calcite crystal cement,stylolite structure, the depositional environment is peritidal.

3593.9' (Thin-section)peloidal grainstone

3597'-3600': Ls, light to brownish gray, skeletal wackestone, F6, consists ofgastropods, ostracods, bivalves, and trilobites and corals, stylolites, no visualporosity. The depositional environment is low energy shallow lagoon.


3600'-3607': Ls, light to brownish gray, fenestral peloidal grainstone/packstone,F7, the grains present in this facies include mainly peloids and sparselygastropods and bivalves, ostracods, trilobites. Porosity within this facies isdominantly fenestral and moldic porosity, main reservoir in this field. Thevugs are partially filled with calcite crystal cement, stylolite structure commonthroughout the core. The sedimentary structures found in this facies includesmall cyanobacterial mats, tidal laminations, and fenestral structure, thedepositional environment is peritidal.

3607'-3610': Ls, light gray, skeletal wackestone, F6, consists of gastropods,ostracods, bivalves, trilobites, and peloids. Low porosity and permeability,calcite cements, it has stylolite and vertical fractures at 3609'. Thedepositional environment is low energy shallow lagoon.

3606' (Thin-section) skeletal wackestone

3610'-3616' Ls, light to brownish gray, fenestral peloidal grainstone/packstone,F7, and grains include mainly peloids and sparsely gastropods and bivalves,ostracods, trilobites. Porosity within this facies is dominantly fenestral andinterparticle, forms a main reservoir in this field. The vugs are partially filledwith calcite crystal cement, stylolite structure common throughout the core.The sedimentary structures found in this facies include small cyanobacterial

131

mats, tidal laminations, and fenestral structure, the depositional environmentis peritidal.

3610.5' (Thin-section) peloidalpackstone

3616'-3617': Ls, light to brownish gray, skeletal wackestone, F6, very fine-grained,consist of gastropods, ostracods, bivalves, peloids, and trilobites, stylolitestructure are common, no visual porosity. Low porosity and permeabilitybased on the core analysis date. The depositional environment is low energyshallow lagoon.

♦ This core was shifted up 3 feet

132

Permit#39771

Oryx Energy Co., Mt Pleasant Unit Tract 46, Mt PleasantIsabella County Michigan


Rogers City:


Dundee Limestone:







133



3614'-3617': Ls, light to brownish gray, fenestral peloidal grainstone/packstone,F7, and the observed grains within this facies include coral and spongesfragments. The sedimentary structures found in this facies include, tidallaminations, and fenestral structure very limited. Very fine to fine sand grain,porosity within this facies is dominantly fenestral porosity, high permeabilityand porosity, main reservoir in this field. The vugs are partially filled withcalcite crystal cement, stylolite structure, , the depositional environment isperitidal.




♦♦♦ This core was shifted up 8 feet.

134

Permit # 36730

Summit Petroleum Corp., Fitzwater 6. South buckeye FieldGladwin County Michigan

Depth Interval: 3560'-3624'Rogers City:

3560'-3562': Ls, dark gray, crinoidal/skeletal wackestone, Fl, contains crinoids,bryozoans, brachiopods, ostracods, undifferentiated fossils, intraclasts, smallfractures filled with calcite cement. It has stylolite structure and has very lowporosity and permeability according to the core analysis which acts as caprocks in the most Dundee intervals.

Dundee Limestone:

3562'-3564': Burrowed peloidal grainstone/packstone, F2. This facies is observedon top of the Dundee just below the Rogers City. The skeletal grains of thisfacies include brachiopods, crinoids, bivalves, ostracods, trilobites, bryozoans,corals, and phylloid algae. Burrows are the only sedimentary structure presentin the skeletal peloidal grainstone facies. Peloids are observed as majorcomponents of this facies. Wispy and suture stylolites are common throughoutthis facies. It is commonly fine to medium-grained and moderately sorted. Themajor porosity types include interparticle, intraparticle porosity. It is a non-reservoir facies due to its low porosity and permeability.

3563' (thin-section)peloidal grainstone/packstone

3564'-3670.5': Ls, gray-brownish gray, stromatoporoid boundstone, F5. Bioclastswithin this facies include massive and tabular stromatoporoids, corals,brachiopods, crinoids, bryozoans, and trilobites. Minor intercalations ofcrinoidal grainstone and skeletal peloidal grainstone are occasionallyassociated with this facies. Stylolites are common throughout this facies.Porosity of this facies includes growth framework, vuggy, and intraparticleporosity and also some interparticle porosity in the grainstone facies. It is themain reservoir in South Buckeye field.

3565' (thin-section) StromatoporoidBoundstone

3570.5'-3572.5: Ls, brownish gray, crinoidal grainstone, F3, consists of crinoids,peloids, bivalves, trilobites, ostracods, bryozoans, brachiopods. It is very finegrained and moderately sorted. The crinoidal grainstone facies is usually foundbelow the stromatoporoid boundstone facies and sometimes it is interbeddedwith burrowed skeletal peloidal grainstone facies. Wispy and suture stylolites.Porosity of this facies includes intraparticle and interparticle and moldicporosity (interpreted as a secondary reservoir facies).

135

3571' (thin-section) Crinoidal Grainstone

3572.5'-3590.5': Ls, gray-brownish gray, stromatoporoid boundstone, F5. Bioclastswithin this facies include massive and tabular stromatoporoids, corals,brachiopods, crinoids, bryozoans, and trilobites. Minor intercalations ofcrinoidal grainstone and skeletal peloidal grainstone are occasionallyassociated with this facies. Porosity of this facies includes growth framework,vuggy, and intraparticle porosity and also some interparticle porosity in thegrainstone facies.

3587' (thin-section) StromatoporoidBoundstone

3590.5'-3600': Burrowed peloidal grainstone/packstone F2. The skeletal grains ofthis facies include brachiopods, crinoids, bivalves, ostracods, trilobites,bryozoans, corals, and phylloid algae. Burrows are the only sedimentarystructure present in the skeletal peloidal grainstone facies. Peloids areobserved as major components of this facies. Stylolites are commonthroughout this facies. It is commonly fine to medium-grained and moderatelysorted. The major porosity types include interparticle, intraparticle porosity. Itis a non-reservoir facies due to its low porosity and permeability.

35793' (thin-section) peloidal grainstone/packstone

3600'-3602': Crinoidal grainstone, F3, consist of crinoids, peloids, bivalves,trilobites, ostracods. It is very fine-grained and moderately sorted. Wispy andsuture stylolites. The crinoidal grainstone facies is usually found below thestromatoporoid boundstone facies and sometimes it is interbedded withburrowed skeletal peloidal grainstone facies. Porosity of this facies includesintraparticle porosity and also some interparticle and moldic porosity(interpreted as a secondary reservoir facies).

3602'-3608.5': Burrowed peloidal grainstone/packstone, F2. The skeletal grains ofthis facies include brachiopods, crinoids, bivalves, ostracods, trilobites,bryozoans, corals, and phylloid algae. Burrows are the only sedimentarystructure present in the skeletal peloidal grainstone facies. Peloids areobserved as major components of this facies. It is commonly fine to medium-grained and moderately sorted. This facies is interbedded with thestromatoporoid boundstone facies at 3610' and also the crinoidal grainstonefacies. Stylolites are common throughout this facies. The major porosity typesinclude interparticle, intraparticle porosity. It is a non-reservoir facies due toits low porosity and permeability.

3608.5'-3610.5' Coral-stromatoporoid rudstone/rudstone, F4. This facies variesfrom fine to medium-grained, well sorted, with skeletal graindebris consistingof crinoids, bivalve, brachiopods, finger and tabulate corals, sponges, and

136

stromatoporoid fragments, were deposited in grainy or muddy matrix. Porositytype within this facies is predominantly intraparticle and interparticle.

3609' (thin-section) ReefFlank

3610.5'-3617': Burrowed peloidal grainstone/packstone, F2. The skeletal grains ofthis facies include brachiopods, crinoids, bivalves, ostracods, trilobites, bryozoans,corals, and phylloid algae. Burrows are the only sedimentary structure present in theskeletal peloidal grainstone facies. Peloids are observed as major components of thisfacies. It is commonly fine to medium-grained and moderately sorted. This facies isinterbedded with the stromatoporoid boundstone facies at 3610' and also the crinoidalgrainstone facies. Stylolites are common throughout this facies. The major porositytypes include interparticle, intraparticle porosity. It is a non-reservoir facies due to itslow porosity and permeability

3617'-3624': Crinoidal grainstone, F3, consists of crinoids, peloids, bivalves,trilobites, ostracods. It is very fine-grained and moderately sorted. Wispy andsuture stylolites. The crinoidal grainstone facies is usually found below thestromatoporoid boundstone facies and sometimes it is interbedded withburrowed skeletal peloidal grainstone facies. Stylolites are commonthroughout this facies. About foot or so there is fining up sediments whichindicate to a storm deposit (at 3620'). Porosity of this facies includesintraparticle, interparticle, intercrystalline porosity (interpreted as a secondaryreservoir facies).

3623' (thin-section) Crinoidal Grainstone3624' (thin-section) Crinoidal Grainstone

137

Permit# 43383

Summit Petroleum Corp., Nusbaum Kern 3-W. South buckeye FieldGladwin County Michigan


3526'-3547': Ls, dark gray, crinoidal/skeletal wackestone, Fl, contains crinoids,bryozoans, brachiopods, ostracods, undifferentiated fossils, intraclasts, smallfractures filled with calcite cement. It has stylolite structure and has very lowporosity and permeability according to the core analysis which acts as caprocks in the most Dundee intervals.

353 7.4' (thin-section) Crinoidal wackestone

Dundee Limestone:

3547'-3552': Burrowed peloidal grainstone/packstone, F2, this facies is observedon top of the Dundee just below the Rogers city. The skeletal grains of thisfacies include brachiopods, crinoids, bivalves, ostracods, trilobites, bryozoans,corals, and phylloid algae. Burrows are the only sedimentary structure presentin the skeletal peloidal grainstone facies. Peloids are observed as majorcomponents of this facies. It is commonly fine to medium-grained andmoderately sorted. The major porosity types include interparticle, intraparticleporosity. It is a non-reservoir facies due to its low porosity and permeability.

3548.9 (thin-section)peloidal grainstone/packstone

3552'-3554' Coral-stromatoporoid rudstone/rudstone, F4. This facies varies fromfine to medium-grained, well sorted, with skeletal grain debris consisting ofcrinoids, bivalve, brachiopods, finger and tabulate corals, sponges, andstromatoporoid fragments, were deposited in grainy or muddy matrix. Porositytype within this facies is predominantly intraparticle and interparticle.

3554'-3662': Ls, gray - brownish gray, stromatoporoid boundstone, F5. Bioclastswithin this facies include massive and tabular stromatoporoids, corals,brachiopods, crinoids, bryozoans, and trilobites. Occasionally interbeddedwith crinoidal skeletal grainstone facies at 3570', 3571', and 3576'. Porosityof this facies includes growth framework, vuggy, and intraparticle porosityand also some interparticle porosity. It is the main reservoir facies.

3562'-3563: Ls, brownish gray, crinoidal grainstone, F3, consist of, crinoids,peloids, bivalves, trilobites, ostracods, bryozoans, brachiopods. Very finegrained and moderately sorted. The crinoidal grainstone facies is usually foundbelow the stromatoporoid boundstone facies and sometimes it is interbeddedwith burrowed skeletal peloidal grainstone facies. Wispy and suture stylolites

138

are common. Porosity of this facies includes intraparticle interparticleintercrystalline porosity (interpreted as a secondary reservoir facies).

3562' (thin-section) Crinoidal Grainstone

3563'-3667.3': Ls, gray - brownish gray, stromatoporoid boundstone, F5, theskeletal grains within this facies include massive and tabular stromatoporoids,corals, brachiopods, crinoids, bryozoans, and trilobites. Porosity of this faciesincludes growth framework, vuggy, and intraparticle porosity and also someinterparticle porosity.

3564.4' (thin-section) Stromatoporoid Boundstone.

3577.3'-3573': Burrowed peloidal grainstone/packstone, F2. This facies isobserved on top of the Dundee just below the Rogers City. The skeletal grainsof this facies include brachiopods, crinoids, bivalves, ostracods, trilobites,bryozoans, corals, and phylloid algae. Burrows are the only sedimentarystructure present in the skeletal peloidal grainstone facies. Peloids areobserved as major components of this facies. It is commonly fine to medium-grained and moderately sorted. The major porosity types include interparticle,intraparticle, limited distribution of vuggy, moldic, and intercrystallineporosity. It is a non-reservoir facies due to its low porosity and permeability.

3569.9' (thin-section) peloidal grainstone/packstone

3573'-3582': Crinoidal grainstone, F3, consist of crinoids, peloids, bivalves,trilobites, ostracods. It is very fine-grained and moderately sorted. Thecrinoidal grainstone facies is usually found below the stromatoporoidboundstone facies and sometimes it is interbedded with burrowed skeletal

peloidal grainstone facies. Porosity of this facies includes intraparticle, andinterparticle porosity (interpreted as a secondary reservoir facies).

3574.7' (thin-section) Crinoidal Grainstone

3582'-3586': Burrowed peloidal grainstone/packstone, F2. This facies is observedon top of the Dundee just below the Rogers City. The skeletal grains of thisfacies include brachiopods, crinoids, bivalves, ostracods, trilobites, bryozoans,corals, and phylloid algae. Burrows are the only sedimentary structure presentin the skeletal peloidal grainstone facies. Peloids are observed as majorcomponents of this facies. It is commonly fine to medium-grained andmoderately sorted. The major porosity types include interparticle, intraparticle,and intercrystalline porosity.

3583.5' (thin-section) peloidal grainstone/packstone


139

Permit#32780

Summit Petroleum Corp., State Buckeye B-6, North Buckeye FieldGladwin County Michigan

Depth Interval: 3589' - 3667'Rogers City:

3589'-3609.5': Ls, dark grey, Crinoidal/ Skeletal wackestone Fl, contain fossilfragments such as crinoids, gastropods, brachiopods, ostracods, andintraclasts. Small fractures filled with calcite cements, the depositionalenvironment is open marine (subtidal). It has stylolite structure and has verylow porosity and permeability according to the core analysis which acts as caprocks in the most Dundee intervals.

3602.8' (Thin-section) crinoidal wackestone.

Dundee Limestone:

3609.5'-3643': Ls, buff to tan, fenestral peloidal grainstone/packstone, F7, veryfine grained, and moderately sorted, fenestrae dominant and oil stained. Thisfacies is largely made up of peloids. Skeletal grains within this facies includebrachiopods, bivalves, ostracods, gastropods, crinoids, stromatoporoids at3635, and corals rich at 3646.5. The sedimentary structures found in this faciesinclude small cyanobacterial mats, tidal laminations, and fenestral structure(vertical and horizontal fenestrae), stylolite structures. Porosity within thisfacies is dominantly fenestral porosity, high permeability and porosity, mainreservoir in this field.

3616. '2, 3620.8', 3629.6' (Thin-section) Fenestral peloidalpackstone


3643'-3646': Ls, brown- gray, skeletal wackestone, F6, with casts of gastropods,bivalves, forams, peloids, ooids, crinoids, ostracod fragments, and calcareoussponges. No Visual porosity was observed. It has stylolites and some fractures.Partially dolomitization of carbonate mud was observed. The depositionalenvironment is low energy shallow lagoon.

3646'-3656': Coral-stromatoporoid rudstone/rudstone, F4. This facies variesfrom fine to medium-grained, well sorted, with skeletal grain debris consistingof crinoids, bivalve, brachiopods, finger and tabulate corals, andstromatoporoid fragments, were deposited in grainy or muddy matrix. Porositytype within this facies is predominantly intraparticle and interparticle with aminor intercrystalline component.

3649.6' (Thin-section) skeletal trilobite wackestone

140

3651' (Thin-section) crinoidal skeletal grainstone

3656'-3666': Stromatoporoid boundstone, F5. Bioclasts within this facies includemassive and tabular stromatoporoids, corals, brachiopods, crinoids, bryozoans,and trilobites. Occasionally interbedded with crinoidal skeletal grainstonefacies. Porosity of this facies includes growth framework, vuggy, andintraparticle and also some interparticle porosity in the grainstone facies,fractures augment, moderate to high porosity/permeability. Main reservoir inSouth Buckeye field.

3656.6', 3660' (Thin-section) stromatoporoid boundstone: consists ofcrinoids, brachiopods, bryozoans, corals, and trilobites. Growthframework porosity occurs.

3663' (Thin-section) skeletal grainstone: consists of, crinoids, andbrachiopods, corals, and trilobites.

3666'-3667': Ls, very dark gray, Coral-stromatoporoid rudstone/rudstone, F4.This facies varies from fine to medium-grained, well sorted, with skeletalgrain debris consisting of crinoids, bivalve, brachiopods, finger and tabulatecorals, and stromatoporoid fragments, were deposited in grainy or muddymatrix. Porosity type within this facies is predominantly intraparticle andinterparticle with a minor intercrystalline component.


141

Permit#52002

Summit Petroleum Corp., Salla, John 9-11 HD, North Buckeye FieldGladwin County Michigan


3598'-3599: Ls, dark grey, Crinoidal/ Skeletal wackestone Fl, contains fossilfragments such as crinoids, gastropods, brachiopods, ostracods, andintraclasts. Small fractures filled with calcite cements, the depositionalenvironment is open marine (subtidal). It has stylolite structure and has verylow porosity and permeability according to the core analysis which acts as caprocks in the most Dundee intervals.

Dundee Limestone:

3599'-3624': Ls, buff to tan, fenestral peloidal grainstone/packstone, F7, very finegrained, and moderately sorted, fenestrae dominant and oil stained. This faciesis largely made up of peloids. Skeletal grains within this facies includebrachiopods, bivalves, ostracods, gastropods, crinoids, and stromatoporoids.The sedimentary structures found in this facies include small cyanobacterialmats, tidal laminations, and fenestral structure (vertical and horizontalfenestrae), stylolite structures. Porosity within this facies is dominantlyfenestral porosity, high permeability and porosity, main reservoir in this field.

3624'-3625.5': Ls, brown- gray, skeletal wackestone, F6, with casts of gastropods,bivalves, forams, peloids, ooids, crinoids, ostracod fragments, and calcareoussponges. No Visual porosity was observed. It has stylolites and some fractures.Partially dolomitization of carbonate mud was observed. The depositionalenvironment is low energy shallow lagoon.

3625.5'-3633': Missing interval

3633'-3644': Ls, buff to tan, fenestral peloidal grainstone/packstone, F7, very finegrained, and moderately sorted, fenestrae dominant and oil stained. This faciesis largely made up of peloids. Skeletal grains within this facies includebrachiopods, bivalves, ostracods, gastropods, crinoids, and stromatoporoids.The sedimentary structures found in this facies include small cyanobacterialmats, tidal laminations, and fenestral structure (vertical and horizontalfenestrae), stylolite structures. Porosity within this facies is dominantlyfenestral porosity, high permeability and porosity, main reservoir in this field.

3644'-3646': Ls, brown- gray, skeletal wackestone, F6, with casts of gastropods,bivalves, forams, peloids, ooids, crinoids, ostracod fragments, and calcareoussponges. No Visual porosity was observed. It has stylolites and some fractures.

142

Partially dolomitization of carbonate mud was observed. The depositionalenvironment is low energy shallow lagoon.

3646'-3650': Coral-stromatoporoid rudstone/rudstone, F4. This facies variesfrom fine to medium-grained, well sorted, with skeletal grain debris consistingof crinoids, bivalve, brachiopods, finger and tabulate corals, andstromatoporoid fragments, were deposited in grainy or muddy matrix. Porositytype within this facies is predominantly intraparticle and interparticle with aminor intercrystalline component.

3650'-3656': Stromatoporoid boundstone, F5. Bioclasts within this facies includemassive and tabular stromatoporoids, corals, brachiopods, crinoids, bryozoans,and trilobites. Occasionally interbedded with crinoidal skeletal grainstonefacies. Porosity of this facies includes growth framework, vuggy, andintraparticle and also some interparticle porosity in the grainstone facies,fractures augment, moderate to high porosity/permeability. Main reservoir inSouth Buckeye field.

3656'-3658': Ls, buff to tan, fenestral peloidal grainstone/packstone, F7, very finegrained, and moderately sorted, fenestrae dominant and oil stained. This faciesis largely made up of peloids. Skeletal grains within this faciesstromatoporoids. The sedimentary structures found in this facies include smallcyanobacterial mats, tidal laminations, and fenestral structure (vertical andhorizontal fenestrae), stylolite structures. Porosity within this facies isdominantly fenestral porosity, high permeability and porosity, main reservoirin this field.

♦> This core was shifted up 5 feet

143

Permit#35720

Jordan Energy Exploration Co Lie, Hutsonl-2., ButmanGladwin County MI


The Rogers City facies is dens, grey-dark gray Ls, low porosity and permeability. Theboundary contacts between the Rogers City and Dundee is marked by irregularsurface (stylolite).

3656-3674.5 Limestone, gray-dark gray Ls, crinoidal/skeletal wackestone, Fl, fineto medium-grained muddy packstone with burrows, bivalves, corals,intraclasts, suture stylolites, chert nodules, no visual porosity. Intercalatedwith crinoidal bioturbated packstone at 3660.3-62, 3664-65. This faciesrepresenting open marine environments.

Dundee Limestone

3674.5-3686: Ls, gray-brownish gray, stromatoporoid boundstone, F5. Bioclastswithin this facies include massive and tabular stromatoporoids, corals,brachiopods, crinoids, bryozoans, and trilobites. Minor intercalations ofcrinoidal grainstone and skeletal peloidal grainstone are occasionallyassociated with this facies. Stylolites are common throughout this facies.Porosity of this facies includes growth framework, vuggy, and intraparticleporosity and also some interparticle porosity in the grainstone facies. It isrepresenting a good reservoir based on the Neutron porosity log.

144

Permit#28399

DEVELOPMENT CO., Grow 4, West BranchOgemaw CO, MI


2540'-2573.5': Ls dark gray, crinoidal/skeletal wackestone, Fl, consists of crinoids,and other fossil fragments, intraclasts, has stylolite structure and has very lowporosity and permeability, which act as cap rocks in the most Dundeeintervals. This facies representing open marine environment.

Dundee Limestone:

2573.5'-2582': Ls, light to brownish gray, skeletal wackestone, F6, with casts ofbivalves, ostracod fragments, coral and calcareous sponges (stromatoporoid).Wispy and suture stylolites and some fractures. The depositional environmentis low energy shallow lagoon.

2582'-2591': Ls, light to brownish gray, burrowed peloidal grainstone/packstone,F2, this facies is observed on top of the Dundee just below the Rogers city.The skeletal grains of this facies include brachiopods, crinoids, bivalves,ostracods, trilobites, bryozoans, corals, and phylloid algae. Burrows are theonly sedimentary structure present. Peloids are observed as major componentsof this facies. It is commonly medium to fine-grained and moderately sorted.Wispy and suture stylolites, oil stained. This facies was deposited in protectedshallow marine environment.

2591'-2616': Ls, brownish gray, crinoidal grainstone, F3, consist of, crinoids,peloids, bivalves, trilobites, ostracods, bryozoans, brachiopods. Very finegrained and moderately sorted. The crinoidal grainstone facies is usually foundbelow the stromatoporoid boundstone facies and sometimes it is interbeddedwith burrowed skeletal peloidal grainstone facies. Porosity of this faciesincludes intraparticle, interparticle, and moldic porosity (interpreted as asecondary reservoir facies).

2616'-2625': Ls, light to brownish gray, burrowed peloidal grainstone/packstone,F2, this facies is observed on top of the Dundee just below the Rogers city.The skeletal grains of this facies include brachiopods, crinoids, bivalves,ostracods, trilobites, bryozoans, corals, and phylloid algae. Burrows are theonly sedimentary structure present. Peloids are observed as major componentsof this facies. It is commonly medium to fine-grained and moderately sorted.Wispy and suture stylolites, oil stained. This facies was deposited in protectedshallow marine environment.

145


2648'-2652': Ls, light to brownish gray, skeletal wackestone, F6, with casts ofbivalves, ostracod fragments, coral and calcareous sponges (stromatoporoid).Wispy and suture stylolites and some fractures. The depositional environmentis low energy shallow lagoon.


2662'-2670': Ls, light to brownish gray, burrowed peloidal grainstone/packstone,F2, this facies is observed on top of the Dundee just below the Rogers city.The skeletal grains of this facies include brachiopods, crinoids, bivalves,ostracods, trilobites, bryozoans, corals, and phylloid algae. Burrows are theonly sedimentary structure present. Peloids are observed as majorcomponentsof this facies. It is commonly medium to fine-grained and moderately sorted.Wispy and suture stylolites, oil stained. This facies was deposited in protectedshallow marine environment.


2682'-2704': Ls, light to brownish gray, coral-stromatoporoid rudstone F4. Thisfacies varies from fine to medium-grained, well sorted, with skeletal graindebris consisting of crinoids, bivalve, brachiopods, finger and tabulate corals,sponges, and stromatoporoid fragments, were deposited in grainy or muddymatrix. Porosity type within this facies is predominantly intraparticle andinterparticle.

146

2704'-2716': Ls, light to brownish gray, skeletal wackestone, F6, with casts ofbivalves, ostracod fragments, coral and calcareous sponges (stromatoporoid).Wispy and suture stylolites and some fractures. The depositional environmentis low energy shallow lagoon.

147

Appendix B

Core Descriptions Charts and Graphics

148

LEGEND

Grain Types, sedimentaryStructures, and Porosity Typesfff Stylolitic

(| Burrowed

=00: Fenestral Textures

•r$fi/ Brachiopod

A Gastropod

/^J Stromatoporoid

\f Brvozoan

@ Coral

^^ Undifferentiated Fossils

000 Peloids

-^ Crinoids

BC Intercrystalline Porosity

BP Interparticle Porosity

WC Intracrystalline Porosity

\Yp Intraparticle Porosity

PW Framework Porosity

MO Moldic

VUG Vug

-Dundee-Rogers City contact

Total Depth

Thin Section

Limestone

Idealized Vertical Succession of Seven FaciesFenestral Peloidal Grainstone/Packstone (Peritidal)

F5

F3

Skeletal Wackestone (Lagoonal)

Stromatoporoid Boundstone (Patch reef)

Coral-stromatoporoid (loatstone to rudstone (Reef Flank)

Crinoidal Grainstone (Shoal)

Bioturbated Peloidal Grainstone/Packstone (Protected shallow marine)

Crinoidal/Skeletal Wackestone (Open marine)

149

Permit # 35461Oryx Energy Co., Sierra Land CO., INC 1, MT Pleasant, Midland CO, Ml

Formation: Dundee Limestone Depth Interval: 3530'-3615'

151

Permit # 36259Oryx Energy Co., Pfund-1, MT Pleasant, Midland CO, Ml


156

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Permit # 36367Oryx Energy Co., Mcclintic-3, MT Pleasant, Isabella CO, Ml


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Permit # 43383Summit Petroleum Corp., Nusbaum Kern 3-W, S Buckeye, Gladwin CO, Ml


166

Permit #32780Summit Petroleum Corp., State Buckeye B-6, N Buckeye, Gladwin CO, Ml


167

Permit #52002Summit Petroleum Corp., Salla, John 9-11 HD, N Buckeye, Gladwin CO, Ml


*This corewasShifted up 5 ft]

169

Permit # 28399

MUSKEGON DEVELOPMENT CO., Grow 4, West Branch, Ogemaw CO, MlFormation: Dundee Limestone Depth Interval: 2540'-2715'

170

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to

Permit # 35720Jordan Energy Exploration CO LLC, Huston 1-2., Butman. Gladwin CO, Ml


174

Appendix CCore Photographs

175

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Figure C.l. Crinoidal skeletal wackestone facies #1. (A) Core photograph, mud nodular texture (Nod) ranging from 1-2 cmin diameter. (B) Slabbed core photograph showing the contact between theupper Rogers City (RGRC) and thelower Dundee Limestone (DUND), separated bymineralized stylolite (Sty). (C) Slabbed core photograph,showing crinoid-rich (Cri).

Figure C.2. Bioturbated peloidal grainstone/packstone facies # 2. (A) Core photograph, showing the burrowed (Bur).

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Figure C.3. Slabbed core photographsof the crinoidal grainstone facies # 3.

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Figure C.5. Patch reeffacies # 5, core photographs of stromatoporoid boundstone showing pillar and lamina structure(yellow arrows).

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Figure C.6. Skeletal wackestone facies # 6. (A) Core photograph ofskeletal wackestone facies associated with stylolites(Sty) and fractures (Fr).

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State Buckeye, 3616'

Figure C.7. Core photographs display fenestral peloidal grainstone/packstone facies # 7 from three fields (Wise, MtPleasant, North Buckeye fields).

Appendix DConventional Core Analysis

Dundee Limestone Formation

183

Permit U 19693

Mcnerney, B E 3, Wise Field,Isabella County Michigan

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3687.5 0.4 6.3 8.3 33.3

3688.5 9.3 6.7 7.7 38.5

3689.5 0.0 6.3 TR 33.3

3690.5 0.2 6.0 TR 43.3

3691.5 0.0 6.3 TR 41.0

3692.5 0.0 6.6 TR 38.9

3693.5 0.0 4.2 TR 62.9

3696.5 0.1 5.5 10.3 77.0

3697.5 TR 4.5 11.5 75.0

3698.5 1.0 8.8 TR 20.3

3699.5 TR 4.2 TR 68.6

3700.5 0.2 6.1 0.0 30.2

3701.5 TR 5.4 TR 33.8

2702.5 TR 5.5 TR 48.3

2703.5 TR 9.8 5.2 23.5

2705.5 0.0 6.8 0.0 34.9

3706.5 0.0 5.6 9.3 74.5

3707.5 0.0 3.4 0.0 61.5

3708.5 3.9 5.0 0.0 36.6

3712.5 0.0 3.2 16.5 66.0

3714.5 0.0 5.3 0.0 79.6

3715.5 0.0 7.1 TR 65.4

3718.5 0.2 10.8 9.4 25.9

3719.5 0.7 7.7 6.8 33.8

3720.5 TR 4.5 TR 76.0

3723.5 TR 3.8 TR 70.5

184

Permit#35461

Sierra Land CO., INC 1, Mt PleasantMidland County Michigan

DEPTH

PERM

MAX

PERM

90

DEG

PORO

GEX

FLUID

SAT

OIL

FLUID

SAT

WATER

DENSITY

GRAIN DESCRIPTION

3536 0.03 0.01 1.0 14.6 29.2 2.70 LM,SL/SHY,SHLAM,STY3537 0.03 0.03 1.3 9.9 49.6 2.68 LM,SHY,FOSS,STY

3538 0.06 0.06 1.8 11.2 45.0 2.71 LM.SHY.SH-

3539 0.05 0.03 1.8 6.6 39.9 2.71 LM

3540 0.05 0.01 1.3 5.9 29.7 2.70 LM,SL/SHY,FOSS,STY

3541 0.02 0.02 0.5 11.0 43.9 2.70 LM,SL/SHY,FOSS,STY

3542 0.17 0.07 0.4 5.7 11.3 2.69 LM,SHY,FOSS,STY

3543 0.03 0.03 0.7 13.6 27.2 2.70 LM,SHY,FOSS,STY

3544 0.53 0.40 0.5 27.0 27.0 2.69 LM,SHY,FOSS,STY

3545 0.02 0.02 0.9 15.4 30.9 2.71 LM,SHY,FOSS,STY

3546 0.13 0.11 0.7 12.5 25.1 2.69 LM,SHY,FOSS,STY

3547 0.07 0.04 0.8 10.5 41.9 2.66 LM,SHY,SH-INCL,FOSS

3548 0.08 0.08 1.4 12.3 24.6 2.71 LM,SHY,FOSS

3549 0.20 0.11 1.0 18.4 18.4 2.68 LM,VF,SL/V,STY

3550 0.25 0.19 8.3 0.0 42.6 2.71 LM

3551 388.00 197.00 8.0 9.0 35.9 2.72 LM

3552 0.22 0.17 6.5 13.4 35.6 2.70 LM

3553 7.10 15.7 9.0 54.2 2.71 LM

3554 0.14 0.12 5.9 23.3 31.5 2.67 LM

3555 4.50 1.40 13.9 3.7 46.3 2.71 LM

3556 6.90 4.70 15.1 23.2 24.5 2.69 LM

3557 7.70 6.60 10.1 15.8 56.2 2.69 LM.V.FOSS

3558 3.50 1.10 8.9 3.6 48.7 2.71 LM

3559 0.16 0.13 4.7 0.0 71.2 2.69 LM

3560 0.77 5.4 0.0 67.9 2.71 LM,VF,V

3561 0.27 0.09 4.1 0.0 67.8 2.72 LM

3562 0.14 0.14 5.2 0.0 53.5 2.70 LM.PP

3563 0.43 0.34 9.3 0.0 65.6 2.71 LM.SH-INCL

3564 0.15 0.09 3.1 0.0 52.0 2.71 LOST CORE

3568 0.08 0.05 4.1 0.0 62.9 2.72 LM.VF

3569 0.12 0.07 3.5 11.2 44.8 2.72 LM,SL/V,FOSS,STY

3570 0.28 0.16 4.2 4.5 49.6 2.71 LM,SHY,VF,V

3571 4.30 2.90 9.6 9.6 38.4 2.70 LM,V,STY

3572 0.74 0.43 8.5 7.0 42.0 2.71 LM.STY

3573 0.55 0.52 6.6 15.8 15.8 2.70 LM.PP.FOSS3574 0.05 0.03 2.7 10.8 48.5 2.72 LM

3575 3.00 1.50 6.0 5.0 40.3 2.70 LM,SL/F,SL/V,PP

3576 1.60 1.40 7.9 17.0 22.7 2.72 LM

3577 0.06 6.5 20.6 20.6 2.73 LM,SL/SHY/STY

185

DEPTH

PERM

MAX

PERM

90

DEG

PORO

GEX

FLUID

SAT

OIL

FLUID

SAT

WATER

DENSITY

GRAIN DESCRIPTION

3578 6.00 0.98 5.3 5.8 40.9 2.71 LM

3579 0.01 3.2 0.0 62.0 2.71 LM

3580 0.01 3.1 0.0 62.0 2.73 LM.STY

3581 0.08 0.08 2.3 0.0 56.3 2.71 LM,SL/SHY,STY3582 0.07 0.03 4.0 6.7 67.3 2.68 LM,SLA/,FOSS,STY3583 0.11 0.09 5.0 3.3 56.4 2.71 LM

3584 7.40 0.30 5.3 4.5 66.8 2.69 LM

3585 0.30 0.29 7.6 3.7 60.0 2.68 LM,SLA/,FOSS3586 0.44 0.40 9.2 3.5 55.4 2.71 LM

3587 0.12 0.10 3.1 9.7 53.3 2.71 LM,VF,SLA/,STY

3588 2.40 1.50 6.0 9.3 34.5 2.71 LOST IN TRANSIT

3590 2.70 0.44 4.7 0.0 53.4 2.71 LM,VF,STY3591 0.08 0.07 2.2 0.0 53.2 2.72 LM,STY

3592 0.06 0.04 1.9 0.0 59.9 2.73 LM.PP.STY

3593 0.06 0.06 3.7 7.4 52.1 2.72 LM

3594 0.53 0.51 7.0 6.7 40.3 2.72 LM

3595 0.13 0.13 5.0 3.8 26.8 2.70 LM,VF,PP,STY

3596 0.05 0.05 2.5 7.5 44.9 2.72 LM.STY

3597 0.10 0.02 1.3 9.0 45.1 2.73 LM.STY

3598 0.05 0.05 2.1 9.5 47.5 2.73 LM,VF,SLA/,FOSS,STY3599 0.12 0.07 2.1 7.5 45.0 2.72 LM.FOSS.STY

3600 0.01 0.01 2.2 5.6 50.5 2.73 LM,SL/ANHY,FOSS3601 0.04 0.01 2.0 0.0 53.8 2.71 LM.PP

3602 0.10 0.07 2.8 0.0 59.2 2.71 LM,VF,SLA/

3603 1085.00 59.00 3.4 0.0 67.9 2.64 LM

3604 0.24 0.24 5.1 3.9 59.1 2.73 LM

3605 0.06 0.06 6.2 4.5 49.8 2.73 LM,PP,FOSS,STY

3606 0.06 0.01 1.3 3.1 61.8 2.70 LM

3607 0.16 0.16 6.0 6.2 41.6 2.70 LM,SL/SHY,SLA/,STY3608 3.70 0.44 4.2 4.7 47.2 2.70 LM,SLA/,FOSS,STY3609 0.01 0.01 4.5 0.0 51.3 2.71 LM,VF,STY3610 0.01 0.01 2.4 0.0 42.1 2.73 LM,VF,STY

3611 0.07 0.01 2.1 0.0 48.3 2.71 LM,VF,PP

3612 0.08 0.08 3.7 0.0 45.6 2.71 LM.PP.STY3613 0.82 0.01 3.4 0.0 29.5 2.71 LM.STY3614 0.01 0.01 1.2 0.0 55.3 2.70 LM,V,FOSS3615 0.20 0.01 4.6 0.0 52.4 2.73 LM,V3616 0.08 0.08 4.0 0.0 57.6 2.70 LM,SLA/,FOSS3617 0.06 0.03 3.1 0.0 49.2 2.72 LM.SLA/

3618 0.06 0.02 1.6 0.0 49.2 2.70 LM

3619 0.03 0.02 3.8 0.0 53.5 2.73 LM.SLA/3620 0.20 0.08 1.9 0.0 48.4 2.72 LM.STY

3621 1.40 0.60 2.5 0.0 50.7 2.73

186

Permit#35764

Ames, C W 1, Mt PleasantMidland County Michigan

DEPTH

PERM

MAX

PERM

90

DEG

PORO

FLD

FLUID

SAT

OIL

FLUID

SAT

WATER

DENSITY

GRAIN DESCRIPTION

3533 0.04 0.02 1.6 27.0 13.5 2.67 LM PP STY

3534 0.11 6.1 20.1 16.3 2.71 LM VF PP FOSS

3535 13 10.00 6.1 11.5 17.5 2.71 LM PP STY

3536 0.11 0.08 9 23.3 13.3 2.71 LM PP STY

3537 0.07 0.04 7.9 5.1 25.7 2.72 LM V STY

3538 0.17 0.08 7.2 43.2 31.7 2.72 LM V FOSS STY

3539 53 44.00 5.2 0.0 35.6 2.71 LM SLA/ FOSS STY

3540 0.08 0.05 3.5 0.0 41.7 2.71 LM SLA/ FOSS STY

3541 0.03 0.03 8.3 21.8 19.4 2.71 LM VF SLA/ FOSS STY

3542 0.17 0.07 4.5 9.3 55.7 2.71 LM VF SLA/ STY

3543 0.02 0.02 4.2 9.9 49.5 2.72 LM SLA/ STY

3544 0.19 0.07 2.9 0.0 65.8 2.71 LM V FOSS STY

3545 7.8 6.30 5.6 16.7 33.5 2.72 LM VF SL/V FOSS STY

3546 0.64 0.41 5.7 7.3 36.6 2.73 LM VF SL/V STY

3547 0.58 0.41 2.5 0.0 50.0 2.72 LM VF PP FOSS STY

3548 0.07 0.02 2.5 0.0 58.6 2.73 LM VF FOSS STY

3549 0.07 0.02 2.2 0.0 58.3 2.68 LM SLA/ FOSS STY

3550 0.84 0.79 2.6 0.0 66.2 2.71 LM VF SL/V FOSS STY

3551 1359 0.10 9.4 7.3 25.1 2.72 LM PP STY

3552 0.02 0.02 8.6 20.9 14.0 2.71 LM VF FOSS STY

3553 0.15 0.15 4 10.5 52.6 2.71 LM SL/SHY

3554 0.07 0.05 8.1 26.1 12.4 2.71 LM VF SLA/ FOSS STY

3555 0.32 0.32 2.4 0.0 43.1 2.70 LM SLA/ FOSS

3556 64 0.07 4.9 0.0 42.0 2.71 LMPP

3557 0.07 0.07 3.4 6.3 56.4 2.70 LM PP FOSS STY

3558 0.31 0.15 6.5 33.8 25.8 2.73 LM PP STY

3559 0.47 0.07 2.3 9.2 55.3 2.72 LM VF PP FOSS STY

3560 3.9 0.07 2.7 7.9 79.0 2.72 LM PP STY

3561 0.76 0.46 2.4 0.0 35.2 2.73 LM SL/V STY

3562 0.13 0.10 1.7 0.0 36.9 2.71 LM SLA/ STY

3563 0.26 0.04 3 0.0 62.4 2.72 LM PP STY

3564 0.58 0.08 1.5 0.0 57.2 2.70 LMSTY

3565 0.22 0.11 1.9 0.0 55.1 2.71 LM SL/F SLA/

3566 0.22 0.15 3.2 0.0 65.4 2.72 LM PP STY

3567 0.14 0.14 2.4 0.0 43.5 2.71 LM PP FOSS

3568 0.04 0.01 3 0.0 42.0 2.71 LM FOSS STY

187

DEPTH

PERM

MAX

PERM

90

DEG

PORO

FLD

FLUID

SAT

OIL

FLUID

SAT

WATER

DENSITY

GRAIN DESCRIPTION

3569 0.22 0.05 0.8 0.0 25.4 2.73 LMSTY

3570 0.01 0.01 1.8 0.0 24.1 2.70 LM FOSS

3571 0.01 0.01 1.9 0.0 43.9 2.71 LM FOSS STY

3572 0.14 0.07 2.1 10.1 50.5 2.72 LM V FOSS

3573 0.02 0.02 3 6.9 55.3 2.71 LM V STY

3574 1.8 0.07 3.4 0.0 61.3 2.72 LMSLA/

3575 0.03 0.03 2.3 0.0 55.3 2.71 LM VF PP STY

3576 0.36 0.22 1.8 0.0 60.8 2.75 LM VF SLA/

3577 0.22 0.01 1.4 0.0 61.8 2.71 LM VF SLA/ STY

3578 0.04 0.04 2.3 9.1 45.5 2.72 LM SLA/ STY

3579 0.04 0.02 3.1 6.9 48.5 2.69 LM VF SLA/ STY

3580 405 1.50 4.9 4.2 50.6 2.72 LM SL/F SLA/ STY

3581 2.1 1.80 2.8 15.3 53.6 2.70 LM V STY

3582 4.3 0.95 4 5.1 45.9 2.69 LMVFSLA/SH-INCL

3583 0.76 0.19 2 0.0 53.4 2.70 LM SLA/ STY

3584 0.01 0.01 2.9 7.2 50.7 2.71 LM PP STY

3585 0.01 0.01 4.1 0.0 35.6 2.72 LM VF PP FOSS STY

3586 0.04 0.02 2.3 0.0 55.0 2.71 LM VF SLA/ FOSS STY

3587 0.05 2 0.0 63.9 2.73 LM VF SL/V FOSS

3588 0.01 1.6 0.0 53.2 2.71 LMVSH-INCLSTY

3589 0.71 0.64 1.7 0.0 25.6 2.72 LM V STY

3590 0.28 0.07 1.3 0.0 32.1 2.71 LM VF S STY

3591 0.09 0.06 0.6 0.0 33.9 2.72 LM VF PP STY

3592 9.7 0.09 1.5 0.0 14.0 2.71 LM VF PP STY

3593 0.42 0.25 1.7 0.0 50.3 2.72 LM VF PP

3594 0.09 0.08 2.2 0.0 49.2 2.73 LM SL/F PP STY

3595 0.28 0.08 2.2 0.0 49.0 2.72

188

Permit#36227

Sokolowski, C T 1, Mt PleasantMidland County Michigan

DEPTH

PERM

MAX

PERM

90

DEG

PORO

FLD

FLUID

SAT

OIL

FLUID

SAT

WATER

DENSITY

GRAIN DESCRIPTION

3545 15.0 12.0 10.3 6.7 38.5 2.7 LM V FOSS STY

3546 983.0 983.0 7.7 5.3 42.1 2.7 LM V FOSS STY

3547 27.0 4.6 6.9 5.9 44.2 2.7 LMSLA/

3548 18.0 16.0 6.5 6.3 53.7 2.7 LMV

3549 135.0 107.0 8.5 8.3 47.2 2.7 LM SLA/ STY

3550 7.0 2.2 7.6 5.4 54.0 2.7 LM V FOSS STY

3551 15.0 7.0 6.4 6.5 48.4 2.7 LM V FOSS STY

3552 1130.0 1130.0 6.8 10.5 42.1 2.7 LM VFV FOSS

3553 0.4 0.2 7.2 2.8 56.7 2.7 LM SLA/ PP

3554 5.6 0.9 8.2 17.3 29.7 2.7 LM PP STY

3555 0.2 0.0 7.3 5.5 22.1 2.7 LM VF PP FOSS

3556 0.5 0.2 8.2 2.5 49.1 2.7 LM V PP FOSS STY

3557 134.0 59.0 9.5 9.7 55.8 2.7 LM CALC V STY

3558 1.1 0.9 12.3 7.2 41.3 2.7 LM V FOSS STY

3559 1.7 1.4 13.2 5.2 41.6 2.7 LMV

3560 3.1 3.1 10.5 6.7 53.4 2.7 LMV

3561 0.8 0.6 6.4 3.2 54.0 2.7 LM VF V STY

3562 0.5 0.4 10.8 8.2 44.0 2.7 LM SLA/ PP FOSS STY

3563 23.0 4.2 10.4 8.6 47.9 2.7 LM CALC V

3564 41.0 5.9 9.3 4.3 54.1 2.7 LM V STY

3565 6.7 2.1 6.4 6.5 65.3 2.7 LM VF SLA/ STY

3566 0.1 0.1 5.3 13.9 55.4 2.7 LM SL/F PP FOSS STY

3567 0.1 0.1 8.1 5.0 40.2 2.7 LM SL/F STY

3568 0.1 0.0 7.6 5.4 54.0 2.7 LMSLA/

3569 8.0 4.2 8.9 8.0 38.7 2.7 LM CALC V STY

3570 6.2 5.2 7.1 5.9 58.5 2.7 LM V STY

3571 905.0 349.0 7.4 9.7 44.4 2.7 LM CALC V STY

3572 1190.0 851.0 6.5 6.3 60.2 2.8 LM CALC V STY

3573 0.1 0.1 9.4 4.3 47.2 2.7 LM SL/F PP STY

3574 1739.0 1739.0 9.4 9.4 47.0 2.8 LM CALC V

3575 1127.0 563.0 8.8 4.6 39.3 2.7 LMV

3576 1.8 1.7 5.4 7.7 38.4 2.7 LM SLA/ FOSS STY

3577 0.2 0.1 8.1 5.0 53.0 2.7 LM SLA/ FOSS STY

3578 0.3 0.2 7.0 5.9 56.1 2.7 LMSTY

3579 0.1 0.1 6.5 6.4 57.4 2.7 LM PP FOSS STY

3580 4.2 0.6 8.5 4.8 52.6 2.7 LM PP STY

189

DEPTH

PERM

MAX

PERM

90

DEG

PORO

FLD

FLUID

SAT

OIL

FLUID

SAT

WATER

DENSITY

GRAIN DESCRIPTION

3581 30.0 13.0 5.2 8.0 55.8 2.7 LM V FOSS STY

3582 31.0 29.0 8.9 4.6 48.1 2.7 LM F V FOSS STY

3583 6.3 4.1 6.9 6.0 57.1 2.7 LM V FOSS STY

3584 1.0 0.1 7.5 0.0 48.8 2.7 LM PP STY

3585 0.1 0.1 6.5 0.0 64.0 2.7 LM V FOSS

3587 0.0 0.0 7.7 5.4 56.6 2.7 LM PP FOSS

3588 0.0 0.0 8.6 0.0 60.5 2.7 LMPP

3589 4.5 1.1 4.3 0.0 43.9 2.7 LM SLA/ STY

3590 0.1 0.0 7.7 5.3 40.1 2.7 LM SLA/ STY

*3591 0.1 6.2 0.0 60.9 2.7 LM CALC V

3592 99.0 2.8 7.1 5.9 59.5 2.7 LM CALC V STY

3593 0.1 0.0 5.1 0.0 49.6 2.7 LM PP STY

3594 0.3 0.2 7.7 5.4 56.7 2.7 LMSTY

3595 0.1 0.1 7.8 2.7 69.4 2.7 LM CALC V STY

3596 0.1 <0.01 6.8 3.1 74.2 2.7 LMSTY

3597 0.0 0.0 7.6 0.0 85.1 2.7 LMSTY

3598 0.1 0.1 5.5 0.0 60.8 2.7 LM VF PP FOSS STY

3599 0.1 0.1 5.3 0.0 53.0 2.7 LM CALC V FOSS STY

3600 0.2 0.1 4.8 0.0 47.2 2.7 LM V STY

3601 0.2 0.2 6.9 0.0 60.1 2.7 LM CALC V

3602 2006.0 2006.0 7.0 0.0 75.6 2.7 LM CALC V FOSS

3603 0.0 0.0 8.1 0.0 53.7 2.7 LM PP STY

3604 9.5 0.8 8.9 0.0 47.9 2.7 LM CALC V STY

3605 6.4 0.7 8.0 0.0 45.6 2.7 LM V STY

*3606 163.0 7.8 0.0 40.0 2.7 LM CALC V

3607 25.0 17.0 8.1 0.0 63.3 2.7 LM V STY

3608 1.5 0.4 8.9 0.0 56.5 2.7 LM V STY

190

Permit#36259

Pfund-1, Mt PleasantMidland County Michigan

DEPTH

PERM

MAX

PERM

90

DEG

PORO

GEX

FLUID

SAT

OIL

FLUID

SAT

WATER

DENSITY

GRAIN DESCRIPTION

3526 0.44 0.06 0.8 19.8 49.6 2.70 LM.SL/SHY.FOSS.STY

3527 0.09 0.08 1.7 23.9 40.9 2.70 LM.SL/SHY.PP,

3528 0.04 0.02 1.4 16.8 42.1 2.69 LM.SL/SHY.STY

3529 0.04 0.02 1.8 16.8 50.4 2.69 LM.STY

3530 0.03 0.03 0.6 15.6 46.9 2.70 LM.SL/SHY.FOSS.STY

3531 0.52 0.26 0.5 49.0 16.3 2.70 LM.SL/SHY.FOSS.STY

3532 0.09 0.04 0.7 44.8 19.9 2.71 LM.SL/SHY.FOSS

3533 0.09 0.09 0.4 32.0 18.3 2.70 LM.SL/SHY.BREC,

3534 0.13 0.10 0.7 43.3 19.2 2.71 LM.SL/SHY.FOSS.STY

3535 0.12 0.04 0.6 32.8 18.7 2.67 LM.SL/SHY.FOSS.STY

3536 1.80 1.10 0.4 25.4 15.7 2.69 LM.SL/SHY.BREC

3537 0.62 0.44 0.7 56.5 12.5 2.68 LM.SLTY.SL/SHY.BRE

3538 0.07 0.07 0.8 19.1 21.8 2.67 LM.SL/SHY.BREC,

3539 0.08 0.07 4.3 7.0 16.0 2.69 LM.V.PP.FOSS

3540 0.16 0.14 2.4 11.2 50.2 2.71 LM.FOSS.STY

3541 1280 1020 13.2 25.6 7.1 2.74 LM.V.FOSS

3542 646 623 13.8 14.7 40.4 2.74 LM.V.FOSS

3543 4847 2999 12.9 0.0 6.3 2.74 LM.VF.V.FOSS

*3544 10 9.0 13.1 75.1 2.71 LM

*3545 166 13.1 6.9 57.1 2.71 LM

3546 1400 1019 12.5 10.4 55.3 2.74 LM.V.FOSS

3547 57 18 11.9 11.9 61.8 2.71 LM.V.FOSS

3548 13 0.28 6.4 13.5 60.1 2.72 LM.VF.V.FOSS

3549 254 178 10.1 5.5 54.9 2.71 LM.V.STY

3550 38 36.00 10.1 17.2 54.5 2.73 LM.V.FOSS

3551 1.60 0.12 5.4 0.0 53.9 2.72 LM.VF.SLA/.FOSS

3552 0.35 0.35 3.6 0.0 65.1 2.73 LM.VF.FOSS.STY

3553 0.29 0.12 4.2 4.6 68.0 2.70 LM.VF.PP.STY

3554 0.08 0.03 3.2 10.8 43.2 2.72 LM.VF.PP.STY

3555 28 19 11.6 15.7 40.4 2.70 LM.V.FOSS

3556 36 18 11.2 26.6 21.9 2.71 LM.V.FOSS.STY

3557 1.80 1.00 11.5 23.3 28.3 2.70 LM.VF.SL/V.PP

3558 1.10 0.36 8.7 13.9 35.8 2.69 LM.SL/SHY.VF.PP

3559 1.10 0.04 4.8 11.7 41.5 2.73 LM.VF.FOSS

3560 23.00 22.00 8.9 17.0 46.2 2.71 LM.V.FOSS

*3561 0.30 5.2 8.7 56.5 2.73 LM

3562 3815 3.90 4.7 9.5 71.0 2.70 LM.VF.FOSS.STY

3565 40.00 20.00 12.1 5.2 36.1 2.72 LM.V.FOSS

3566 0.0 78.1 SAMPLE MISSING

191

DEPTH

PERM

MAX

PERM

90

DEG

PORO

GEX

FLUID

SAT

OIL

FLUID

SAT

WATER

DENSITY

GRAIN DESCRIPTION

*3567 0.01 3.2 21.8 40.9 2.71 LM

3568 6.7 67.4 SAMPLE MISSING

3569 0.12 0.09 2.6 18.9 37.8 2.70 LM.SL/SHY.PP.FOSS3570 1.20 0.34 6.7 7.3 62.1 2.70 LM.PP.FOSS3571 1.40 1.00 8.8 7.9 42.8 2.70 LM.SLA/.FOSS3572 0.94 0.66 8.4 10.9 41.0 2.73 LM.SLA/.FOSS.STY

3573 126 0.38 7.2 11.6 62.7 2.70 LM.SL/V.FOSS.STY3574 1198 1136 11.2 11.8 63.0 2.75 LM.VF.V

3575 344 232 10.8 5.3 72.0 2.73 LM.V.FOSS

3576 307 67 8.2 8.5 41.2 2.72 LM.V.FOSS.STY

3577 13 12 7.7 4.8 43.6 2.70 LM.V

3578 0.02 0.01 3.0 8.5 42.6 2.72 LM.VF.PP.FOSS

3579 0.05 0.05 4.4 0.0 67.3 2.72 LM.SL/V.FOSS.STY

3580 322 242 6.7 15.8 34.0 2.70 LM.V.STY

3581 4.10 2.00 6.3 0.0 57.6 2.73 LM.V.FOSS.STY

3582 0.70 0.62 5.6 0.0 56.3 2.70 LM.SLA/.FOSS.STY

3583 0.71 0.69 6.4 10.4 47.6 2.69 LM.PP.FOSS.STY

3584 0.67 0.37 8.0 11.3 35.3 2.69 LM.FOSS

3585 40.00 1.30 7.5 10.8 43.4 2.70 LM.VF.FOSS.STY

3586 0.84 0.42 5.5 10.1 46.2 2.69 LM.PP.FOSS.STY

3587 0.12 0.10 4.8 12.3 55.4 2.70 LM.PP

3588 2.60 0.96 4.7 4.7 46.7 2.71 LM.PP.STY

3589 1126 773 12.8 37.4 30.8 2.74 LM.VF.V

3590 1143 1126 13.3 12.9 31.7 2.74 LM.V.FOSS

3591 45 39 8.0 19.3 45.0 2.70 LM.VF.V.FOSS.STY

3592 3.60 3.00 6.2 14.2 50.4 2.68 LM.V.STY

3593 33.00 15.00 9.7 9.6 41.4 2.71 LM.SLA/.PP

3594 0.80 0.57 7.1 9.6 52.3 2.70 LM.VF.SLA/.PP.STY

3595 1.10 0.40 6.9 7.0 63.2 2.72 LM.SLA/.FOSS

3596 0.53 0.11 6.5 12.8 55.0 2.68 LM.VF

3597 14.00 0.19 4.7 13.3 64.7 2.69 LM.VF.PP

3598 0.90 0.69 5.0 18.0 59.2 2.71 LM.SLA/.FOSS.STY

3599 8.10 4.80 6.7 14.7 48.4 2.69 LM.PP.FOSS

3600 5.60 2.20 9.0 4.1 69.7 2.69 LM.VF.SLA/

3601 0.53 0.43 7.1 0.0 73.4 2.71 LM.FOSS.STY

3602 0.33 0.29 5.1 2.7 57.2 2.69 LM.PP

3603 0.40 0.20 4.1 5.1 46.0 2.72 LM.VF.PP.STY

3604 28.00 1.20 4.3 5.2 44.2 2.72 LM.VF.STY

3605 8.30 7.00 4.8 2.9 63.3 2.69 LM.VF.PP

3606 2.00 0.44 8.4 0.0 67.6 2.72 LM.VF.PP.STY

3607 5201 0.32 8.0 0.0 69.0 2.72 LM.VF.PP

3608 0.61 0.27 7.5 0.0 53.5 2.71 LM.V.FOSS.STY

192

DEPTH

PERM

MAX

PERM

90

DEG

PORO

GEX

FLUID

SAT

OIL

FLUID

SAT

WATER

DENSITY

GRAIN DESCRIPTION

3609 135 20.00 10.1 0.0 68.6 2.69 LM.VF.V3610 7.20 0.86 8.1 0.0 67.9 2.72 LM.CALC.V3611 3.40 0.94 7.9 2.8 74.8 2.71 LM.CALC.VF.V.STY3612 0.46 0.46 8.2 2.8 70.5 2.69 LM,V,FOSS3613 0.34 0.23 6.2 6.0 65.6 2.70 LM,VF,SL/V3614 4.20 1.20 6.6 3.3 59.2 2.71 LM,VF,V,STY3615 3.90 2.00 7.8 2.2 63.4 2.71 LM.VF.V3616 5.70 2.50 8.4 0.0 65.7 2.70 LM,SL/V,FOSS,STY3617 8.40 7.00 8.2 6.3 53.5 2.73 LM,SL/V,FOSS,STY3618 1528 1528 8.8 2.8 59.4 2.73 LM,V,FOSS3619 252 78 8.1 3.8 66.2 2.71 LM,CALC,FOSS,STY3620 2177 1864 8.1 4.0 55.5 2.71 LM,V,FOSS3621 23 15 10.3 2.5 66.0 2.77 LM,V3622 1310 395 9.5 2.8 69.2 2.76 LM,V3623 91 13 9.0 2.5 65.4 2.75 LM,V,STY

*3624 0.06 5.5 3.1 58.0 2.73 LM,V,STY3625 4.40 1.50 7.5 2.8 62.1 2.73 LM,V3626 1.80 0.31 6.7 0.0 61.6 2.72 LM,SL/F,FOSS3627 0.69 0.21 5.6 4.7 66.2 2.73 LM.PP.STY

*3628 0.01 7.6 0.0 58.4 2.73 LM.PP.STY3629 19.00 15.00 8.6 0.0 58.9 2.72 LM,V3630 0.22 0.17 5.9 0.0 60.0 2.71 LM,V3631 0.19 0.16 5.1 0.0 69.9 2.71 LM,V3632 0.19 0.12 3.3 0.0 57.2 2.73 LM.STY

*3633 0.01 3.6 0.0 56.7 2.75 LM.STY3634 1.20 0.98 7.3 0.0 54.4 2.71 LM,SLA/,STY3635 0.14 0.14 6.2 0.0 70.4 2.71 LM,SLA/,STY3636 0.10 0.07 5.0 0.0 56.5 2.73 LM,PP,STY3637 0.09 0.08 4.9 0.0 51.1 2.70 LM.PP

3639 0.01 0.01 3.1 0.0 64.6 2.75 LM,VF,PP,STY3640 0.02 0.01 2.5 0.0 51.6 2.73 LM,SLA/,STY3641 0.11 0.11 5.4 4.0 55.8 2.74 LM,SLA/,STY3642 0.31 0.03 3.1 0.0 65.8 2.70 LM,SLA/,FOSS,STY3643 0.26 0.24 3.5 0.0 48.9 2.74 LM.PP.STY3644 73.00 2.30 9.3 0.0 61.2 2.72 LM.VF.SLA/3645 7.50 5.40 8.1 2.6 57.6 2.68 LM.V.FOSS3646 0.06 0.06 5.6 0.0 55.1 2.73 LM,SL/F,PP3647 0.01 0.01 2.9 0.0 60.5 2.73 LM

3648 0.12 0.01 3.0 0.0 61.6 2.72 LM.STY3649 0.47 0.01 3.9 4.7 60.6 2.72 LM,VF,STY3650 0.03 0.01 4.7 9.8 63.9 2.73 LM.PP.STY

193

Permit#36367

Mcclintic-3, Mt PleasantIsabella County Michigan

DEPTH

PERM

MAX

PERM

90

DEG

PORO

GEX

FLUID

SAT

OIL

FLUID

SAT

WATER

DENSITY

GRAIN DESCRIPTION

3576 0.06 0.02 1.3 32.8 32.8 2.71 LM, FOSS3577 0.04 0.04 1.3 34.1 34.1 2.71 LM, FOSS, STY3578 0.02 0.02 1.1 20.4 40.7 2.71 LM, FOSS, STY3579 0.04 0.04 4.0 74.8 10.7 2.71 LM, FOSS, STY3580 0.16 0.12 2.3 54.7 18.2 2.68 LS, SL/SHY, FOSS3581 0.03 0.01 2.6 64.5 16.1 2.68 LS, SL/SHY, SL/F,3582 0.10 0.06 1.0 21.3 42.6 2.67 LS, SL/SHY, FOSS3583 0.67 0.50 3.5 27.2 36.2 2.72 LM, SL/F, FOSS3584 29.00 26.00 8.6 8.4 47.8 2.72 LM, VF, SLA/, STY3585 7.00 0.05 7.3 25.2 36.4 2.68 LM, VF, SLA/3586 0.03 0.01 2.8 0.0 68.6 2.67 LM, PP, STY3587 0.01 0.01 2.4 0.0 78.6 2.68 LM, SL/F, SLA/,3588 19.00 11.00 9.7 14.6 45.8 2.72 LM, V

3589 3.00 1.30 6.9 24.1 57.3 2.68 LM, V, FOSS3590 1.20 9.1 17.9 47.1 2.70 LM, VF, V, FOSS3591 435 328. 11.0 14.3 39.4 2.69 LM, V, STY3592 4.30 4.10 2.2 9.5 56.9 2.71 LM, VF, SLA/, STY3593 11.00 7.60 8.7 20.9 41.7 2.70 LM, V3594 0.38 0.10 8.5 19.2 40.8 2.71 LM, V, STY

3595 29.00 27.00 8.3 17.1 41.6 2.70 LM, V, STY3596 2.30 2.10 4.9 37.9 29.5 2.70 LM, VF, SLA/3597 0.01 0.01 4.3 51.4 24.5 2.70 LM, VF, SLA/3598 0.01 0.01 7.4 29.1 13.9 2.69 LM, SLA/3599 2.60 0.18 2.1 0.0 50.0 2.72 LM, SL/F, V, STY

3600 0.17 0.14 7.4 19.5 22.3 2.70 LM, V, STY3601 192 171. 10.7 14.8 33.4 2.69 LM, VF, V3602 27 7.3 19.4 25.0 2.68 LM, VF, V3604 LOST CORE

3605 0.15 0.13 7.6 18.6 23.9 2.69 LM, V3606 0.08 0.03 7.3 22.6 33.9 2.70 LM, V, STY3607 0.04 0.04 1.6 0.0 66.7 2.68 LM, VF, SL/V, STY3608 0.14 0.12 2.1 10.3 72.1 2.72 LM, VF, V, STY3609 1.90 5.2 32.0 28.0 2.69 LM, VF, V, PP,3610 0.02 4.9 25.4 21.1 2.71 LM, VF, V, STY3611 0.08 0.05 1.5 14.7 58.7 2.70 LM, STY3612 0.02 0.02 2.3 18.4 64.5 2.70 LM, VF, STY

194

DEPTH

PERM

MAX

PERM

90

DEG

PORO

GEX

FLUID

SAT

OIL

FLUID

SAT

WATER

DENSITY

GRAIN DESCRIPTION

3613 0.25 0.25 2.2 9.8 68.8 2.70 LM, VF, PP3614 0.19 0.14 4.0 23.6 42.0 2.68 LM , VF, FOSS,3615 0.16 0.14 3.8 5.5 60.7 2.72 LM , VF, FOSS,3616 0.19 0.15 4.1 0.0 62.3 2.72 LM , VF, FOSS,3617 0.03 0.01 3.2 0.0 72.3 2.72 LM

3618 0.02 0.02 4.7 15.6 62.4 2.73 LM STY

3619 0.18 0.07 3.7 25.5 45.3 2.71 LM VF, V, STY3620 0.01 0.01 3.6 5.9 71.3 2.71 LM SLA/

3621 0.02 0.01 4.5 9.4 56.5 2.71 LM V, FOSS3622 0.03 0.03 3.9 5.5 77.0 2.72 LM PP, FOSS3623 0.01 0.01 3.6 35.9 41.8 2.72 LM STY

3624 0.03 0.01 2.0 10.8 53.9 2.71 LM VF, SLA/, PP,3625 0.21 0.04 3.5 21.3 42.6 2.71 LM SLA/, FOSS3626 0.05 0.03 2.4 9.0 54.3 2.71 LM PP, FOSS, STY3627 37.00 0.04 2.8 7.5 60.0 2.72 LM VF, PP, FOSS,3628 0.01 2.2 0.0 47.1 2.71 LM SL/ANHY, STY3629 0.13 0.07 2.2 0.0 57.2 2.72 LM PP, FOSS, STY3630 0.01 0.01 1.7 12.6 50.4 2.73 LM PP, STY3631 3.60 2.70 1.7 0.0 61.4 2.73 LM VF, PP, FOSS,3632 0.31 0.12 3.6 6.0 65.6 2.73 LM VF, SLA/3633 0.12 0.04 4.1 10.3 20.7 2.72 LM VF, STY3634 0.80 0.69 1.9 0.0 45.9 2.72 LM VF, STY3635 0.01 0.01 3.4 0.0 31.3 2.72 LM VF, STY3636 0.01 1.7 0.0 62.4 2.73 LM VF, STY3637 0.01 1.7 0.0 63.0 2.73 LM VF, STY3638 0.25 0.04 2.4 8.7 69.6 2.73 LM SLA/

3639 0.02 0.02 2.8 0.0 60.1 2.72 LM SLA/, FOSS3640 2.50 2.00 2.7 0.0 64.1 2.72 LM SLA/, FOSS,3641 17.00 0.01 3.0 7.0 69.7 2.75 LM VF, SL/V, STY3642 0.01 5.5 7.5 29.9 2.72 LM VF, STY3643 0.02 2.6 8.1 48.7 2.71 LM VF, SLA/, STY3644 0.01 2.2 0.0 39.6 2.73 LM VF, STY3645 0.01 1.0 0.0 43.1 2.75 LM VF, PP, STY3646 0.01 0.01 1.5 0.0 56.6 2.69 LM, PP

3647 0.04 0.01 2.2 0.0 38.8 2.71 LM, VF, STY3648 0.04 0.02 3.7 0.0 40.0 2.73 LM, STY

3649 0.05 0.05 2.1 9.9 49.7 2.72 LM, PP, STY3650 0.01 3.3 0.0 70.7 2.72 LM, VF, PP, STY

195

Permit#36387

Miller, Viola 1, Mt PleasantIsabella County Michigan

DEPTH

PERM

MAX

PERM

90

DEG

PORO

GEX

FLUID

SAT

OIL

FLUID

SAT

WATER

DENSITY

GRAIN DESCRIPTION

3561 0.01 0.01 1.8 41.8 23.9 2.71 LS.F/XL.GY3562 0.03 0.03 2.9 44.1 14.7 2.70 LS.F/XL.GY3563 0.01 0.01 1.7 25.3 25.3 2.72 LS,F/XL,GY3564 0.01 0.01 1.5 28.7 28.7 2.71 LS,F/XL,GY3565 0.01 0.01 3.1 30.9 34.3 2.69 LS.F-M/XL.GY3566 0.02 0.02 2.5 17.0 42.6 2.72 LS,F-M/XL,GY3567 0.02 0.02 2.1 20.7 51.8 2.71 LS F-M/XL.GY3568 0.02 0.01 1.9 23.0 45.9 2.72 LS F-M/XL.GY3569 0.03 0.02 1.4 31.0 31.0 2.71 LS F-M/XL.GY3570 0.03 0.03 3.2 13.4 40.1 2.71 LS F-M/XL.GY3571 0.01 0.01 1.6 26.1 26.1 2.71 LS F-M/XL.GY3572 0.02 0.02 1.3 16.6 33.2 2.71 LS F-M/XL.GY3573 0.03 0.01 1.4 31.1 15.5 2.71 LS F-M/XL.GY3574 0.03 0.03 1.7 12.6 50.3 2.70 LS F-M/XL.GY3575 0.01 0.01 1.4 30.7 30.7 2.71 LS F-M/XL.GY3576 0.36 0.04 2.6 37.6 33.4 2.72 LS F/XL.GY3577 0.03 0.02 2.4 17.6 44.1 2.70 LS F/XL.GY3578 0.03 0.03 2.0 10.4 52.2 2.71 LS F/XL.P-P/POR.GY3579 0.04 0.03 1.2 18.3 36.3 2.71 LS F/XL.BUFF3580 0.01 0.01 1.0 20.8 41.6 2.70 LS F/XL,BUFF3581 0.20 0.17 1.2 17.9 35.9 2.70 LS F/XL.GY3582 0.06 0.06 1.4 15.1 15.1 2.70 LS F/XL.GY3583 0.02 0.02 1.3 17.1 34.1 2.70 LS F-M/XL.GY3584 0.08 0.08 1.3 16.0 32.0 2.70 LS F-M/XL.GY3585 0.05 0.04 1.5 28.8 28.8 2.70 LS F-M/XL.GY3586 0.05 0.05 1.9 38.4 22.0 2.70 LS F-M/XL.GY3587 0.04 0.02 1.8 41.8 12.0 2.71 LS F-M/XL.GY3588 0.07 0.06 1.8 40.8 23.3 2.70 LS F-M/XL.GY3589 0.05 0.03 4.7 8.9 39.9 2.71 LS F-M/XL.GY3590 0.14 0.10 3.2 6.6 39.7 2.71 LS F/XL,P/POR,BUFF3591 0.72 0.18 2.1 10.0 59.8 2.71 LS F/XL, P/POR.BUFF3592 0.07 0.05 1.6 13.0 52.1 2.71 LS F/XL, P/POR,BUFF3593 0.09 0.04 2.5 8.6 69.0 2.73 LS F/XL.BUFF3594 0.03 0.01 2.6 0.0 49.8 2.70 LS, F/XL.BUFF3595 0.01 0.00 2.8 7.7 53.6 2.71 LS, F/XL.P/POR.BUFF3596 0.20 0.10 5.0 14.7 33.6 2.72 LS, F/XL, P/POR,BUFF

196

DEPTH

PERM

MAX

PERM

90

DEG

PORO

GEX

FLUID

SAT

OIL

FLUID

SAT

WATER

DENSITY

GRAIN DESCRIPTION

3597 0.06 6.8 0.0 36.7 2.70 LS,F/XL,P/POR,BUFF

3598 0.03 0.03 4.3 4.9 34.0 2.70 LS,F/XL,BUFF

3599 0.26 0.04 2.7 15.8 63.3 2.71 LS,F/XL,P/POR,BUFF3600 0.04 0.01 1.9 0.0 57.2 2.71 LS,F/XL,BUFF

3601 15.00 7.5 12.1 21.5 2.70 LS,F/XL,BUFF3602 0.06 0.01 3.9 10.8 43.3 2.71 LS,F/XL,P/POR,BUFF

3603 275.00 0.01 1.9 0.0 68.8 2.71 LS,F/XL,P/POR,BUFF

3604 0.01 0.01 2.3 0.0 74.7 2.72 LS,F/XL,BUFF

3605 0.01 1.5 0.0 55.2 2.70 LS,F/XL,BUFF

3606 0.23 0.01 2.5 0.0 33.2 2.70 LS,F/XL,P/POR,BUFF

3606 Core Lost

3615 0.08 0.04 2.7 15.8 47.4 2.74 LS.F/XL, P/POR.BUFF

3616 0.16 0.16 0.9 0.0 47.7 2.71 LS,F/XL,BUFF

3617 0.07 0.05 0.9 0.0 45.6 2.72 LS,F/XL,BUFF

3618 0.23 0.01 1.3 16.5 33.1 2.72 LS.F-M/XL.BUFF3619 0.07 0.06 1.3 0.0 32.8 2.72 LS,F/XL,BUFF

3620 26.00 0.68 1.1 0.0 38.2 2.72 LS.F/XL.BUFF

3621 0.42 0.40 1.6 0.0 53.1 2.71 LS,F/XL,BUFF

3622 0.04 0.03 3.2 13.4 26.8 2.74 LS.F/XL.BUFF

3623 0.07 0.05 3.1 7.0 48.8 2.73 LS,F/XL,BUFF

3624 2.5 0.0 42.7 2.72 LS,F/XL,BUFF

3625 1.5 13.9 55.6 2.71 LS,F/XL,BUFF

3626 0.01 2.3 18.7 46.7 2.71 LS,F/XL,BUFF

3627 0.05 0.04 0.7 0.0 29.9 2.71 LS,F/XL,BUFF

3628 1.20 0.20 1.4 30.8 30.8 2.72 LS,F/XL,BUFF

3629 0.09 0.03 2.0 10.7 53.6 2.72 LS,F/XL,BUFF

3630 0.02 0.02 2.5 8.8 61.3 2.73 LS,F/XL,BUFF

3631 0.02 0.02 1.5 0.0 56.6 2.72 LS,F/XL,BUFF

3632 0.15 0.10 3.7 5.8 58.1 2.75 LS,F/XL,BUFF

3633 0.04 0.04 2.9 12.3 49.5 2.74 LS.F/XL.BUFF

3634 0.03 0.03 2.6 8.1 40.3 2.71 LS,F/XL,BUFF

3635 0.15 0.15 4.4 21.4 33.2 2.74 LS,F/XL,BUFF

3636 0.05 0.05 1.9 0.0 45.1 2.72 LS,F/XL,BUFF

3637 0.23 0.13 4.1 10.2 20.3 2.72 LS,F/XL,BUFF

3638 0.17 0.05 2.5 0.0 42.1 2.72 LS,F/XL,BUFF

3639 1.20 0.72 7.6 28.4 21.7 2.74 LS,F/XL,GY

3640 0.24 0.13 1.7 12.4 49.6 2.72 LS,F/XL,BUFF

3641 0.16 0.12 3.2 13.4 40.3 2.72 LS,F/XL,BUFF

3642 1.70 0.23 3.3 12.9 57.9 2.72 LS,F/XL,BUFF

197

Permit#39770

Mt Pleasant Unit Tract 55

Isabella County Michigan

DEPTH

PERM

MAX

PERM

90

DEG

PORO

GEX

FLUID

SAT

OIL

FLUID

SAT

WATER

DENSITY

GRAIN DESCRIPTION

3561 0.2 0.1 1.0 0.0 28.3 2.71 LS,F/XL,GY

3562 0.1 0.1 0.6 0.0 19.3 2.70 LS,F/XL,GY

3563 0.1 0.1 0.3 0.0 34.2 2.70 LS.F/XL.GY3564 0.1 0.1 0.4 0.0 26.9 2.70 LS,F/XL,GY

3565 0.1 0.1 0.5 0.0 33.7 2.70 LS,F/XL,GY

3566 0.1 0.1 0.5 0.0 29.8 2.69 LS,F/XL,GY

3567 0.1 0.1 0.3 0.0 24.6 2.69 LS,F/XL,GY

3568 0.5 0.4 0.2 0.0 40.7 2.69 LS,F/XL,GY

3569 0.8 0.3 0.3 0.0 43.0 2.69 LS,F/XL,GY

3570 0.1 0.1 0.3 0.0 28.5 2.69 LS,F/XL,GY

3571 0.2 0.1 0.3 0.0 52.4 2.69 LS,F/XL,GY

3572 0.1 0.1 0.2 0.0 43.0 2.69 LS,F/XL,GY

3573 0.1 0.1 0.3 0.0 47.0 2.69 LS.F/XL.GY

3574 1.4 1.2 0.3 0.0 45.5 2.65 LS.F/XL.GY

3575 0.1 0.1 0.3 0.0 55.0 2.69 LS.F/XL.GY

3576 9.1 6.2 6.7 18.6 26.9 2.71 LS,F/XL,GY,VUG

3577 231.0 227.0 9.6 17.3 26.0 2.71 LS,F/XL,GY,VUG

3578 45.0 23.0 5.5 16.8 19.2 2.69 LS,F/XL,GY,VUG

3579 0.6 0.3 1.9 23.1 16.5 2.69 LS,F/XL,GY,STY

3580 0.1 0.1 2.7 0.0 61.8 2.71 LS,F/XL,GY

3581 3.2 1.4 2.8 0.0 12.2 2.70 LS,F/XL,VUG,V/F

3582 6.6 4.0 7.2 21.8 19.4 2.71 LS,F/XL,GY,VUG

3583 10.0 4.3 6.9 13.8 24.5 2.71 LS,F/XL,GY,VUG

3584 25.0 21.0 10.1 13.6 24.8 2.70 LS,F/XL,GY,VUG3585 0.1 0.1 6.3 14.1 25.9 2.70 LS,F/XL,GY,VUG

3586 18.0 14.0 9.9 13.8 20.8 2.71 LS,F/XL,GY,VUG

3587 44.0 40.0 9.1 0.0 71.5 2.71 LS,F/XL,GY,VUG

3588 75.0 59.0 11.5 0.0 33.6 2.71 LS,F/XL,GY,VUG3589 528.0 510.0 11.7 11.0 39.3 2.71 LS,F/XL,GY,VUG

3590 992.0 454.0 11.9 13.9 39.8 2.70 LS,F/XL,GY,VUG

3591 337.0 293.0 9.1 13.9 30.1 2.71 LS,F/XL,GY,VUG

3592 0.0 2.7 33.7 19.6 2.70 LS.F/XL.GY3593 0.1 0.1 0.4 0.0 72.2 2.67 LS.F/XL.GY

3594 1.2 1.2 6.4 29.6 50.8 2.70 LS,F/XL,GY,VUG

3595 17.0 14.0 13.9 10.0 24.5 2.82 LS,F/XL,GY,VUG

3596 17.0 13.0 8.3 17.0 30.3 2.70 LS,F/XL,GY,VUG

198

DEPTH

PERM

MAX

PERM

90

DEG

PORO

GEX

FLUID

SAT

OIL

FLUID

SAT

WATER

DENSITY

GRAIN DESCRIPTION

3597 0.1 0.1 4.2 0.0 73.1 2.70 LS,F/XL,GY,STY3598 0.1 0.1 1.8 52.0 14.8 2.69 LS,F/XL,GY,STY3599 28.0 5.8 7.1 0.0 18.5 2.71 LS,F/XL,GY,VUG3600 0.1 0.1 2.7 0.0 26.4 2.69 LS,F/XL,GY,STY3601 0.1 0.1 1.0 0.0 66.4 2.68 LS,F/XL,GY3602 0.1 0.1 0.8 0.0 61.1 2.67 LS,F/XL,GY3603 0.1 0.1 0.8 0.0 71.9 2.70 LS,F/XL,GY,STY3604 14.0 5.4 6.8 0.0 25.3 2.70 LS,F/XL,GY,VUG3605 20.0 19.0 7.7 11.1 19.0 2.70 LS,F/XL,GY,VU3606 0.2 0.1 4.7 33.3 14.8 2.69 LS,F/XL,GY,VUG3607 0.3 0.2 1.3 0.0 51.4 2.68 LS,F/XL,GY,STY3608 0.2 0.2 1.7 0.0 57.0 2.67 LS,F/XL,GY,STY3609 51.0 16.0 1.7 0.0 52.6 2.68 LS,F/XL,GY,STY3610 0.4 0.2 2.1 0.0 48.7 2.68 LS,F/XL,GY,STY3611 0.2 0.2 1.0 0.0 32.5 2.67 LS,F/XL,GY,STY3612 0.1 0.1 3.4 11.6 34.7 2.68 LS,F/XL,GY,VUG3613 12.0 9.6 5.7 13.6 23.3 2.71 LS,F/XL,GY,VUG3614 1.8 1.7 2.6 13.1 18.7 2.70 LS,F/XL,GY,VUG3615 0.1 0.1 1.0 9.3 65.4 2.68 LS,F/XL,GY,STY3616 0.1 0.1 0.5 13.1 45.8 2.68 LS,F/XL,GY3617 0.1 0.1 2.1 16.6 47.4 2.66 LS,F/XL,GY,STY3618 20.0 5.4 5.7 12.8 38.4 2.69 LS,F/XL,GY,STY3619 0.1 0.1 0.7 17.0 50.9 2.66 LS,F/XL,GY3620 0.1 0.1 3.4 16.1 32.3 2.70 LS,F/XL,GY,VUG

199

Permit#39771

Mt Pleasant Unit Tract 46, Mt PleasantIsabella County Michigan

DEPTH

PERM

MAX

PERM

90

DEG

PORO

GEX

FLUID

SAT

OIL

FLUID

SAT

WATER

DENSITY

GRAIN DESCRIPTION

3576 1.6 26.3 26.3 2.71 LS,F/XL,BLK

3577 1.5 0.5 14.7 2.71 LS,F/XL,BLK3578 1.8 0.0 23.3 2.71 LS,F/XL,BLK

3579 1.4 0.0 15.0 2.68 LS,F/XL,BLK

3580 2.6 0.0 18.3 2.72 LS,F/XL,BLK

3581 2.2 0.0 19.8 2.71 LS,F/XL,BLK

3582 1.3 0.0 16.5 2.70 LS,F/XL,BLK

3583 1.5 0.0 14.2 2.72 LS,F/XL,BLK

3584 1.4 0.0 14.9 2.70 LS,F/XL,BLK

3585 1.3 0.0 16.3 2.72 LS,F/XL,BLK3586 1.7 0.0 12.7 2.72 LS,F/XL,BLK

3587 1.7 0.0 12.4 2.71 LS,F/XL,BLK

3588 1.7 0.0 12.8 2.72 LS,F/XL,BLK

3589 2.1 0.0 10.1 2.71 LS,F/XL,BLK

3590 2.1 0.1 10.3 2.72 LS,F/XL,BLK

3591 4.8 19.8 26.4 2.72 LS,F/XL,GY,STY

3592 6.9 13.3 14.8 2.71 LS,F/XL,GY,STY,VUG

3593 5.4 18.3 32.5 2.71 LS,F/XL,GY3594 11.2 33.3 10.5 2.70 LS,F/XL,GY,SLA/UG

3595 4.6 47.1 9.0 2.69 LS,F/XL,GY

3596 5.0 25.1 25.1 2.74 LS,F/XL,GY3597 2.8 26.8 38.3 2.71 LS,F/XL,GY

3598 4.2 17.2 24.6 2.70 LS,F/XL,GY,SL/VUG

3599 8.2 17.4 32.2 2.72 LS,F/XL,GY,VUG

3600 7.7 11.9 34.4 2.71 LS,F/XL,GY,VUG

3601 7.1 12.9 37.2 2.71 LS,F/XL,GY,VUG

3602 15.4 25.7 20.8 2.71 LS,F/XL,GY,VUG3603 9.3 17.2 28.0 2.72 LS,F/XL,GY,VUG3604 4.4 9.5 28.5 2.72 LS,F/XL,GY,SLA/UG

3605 3.3 13.0 39.1 2.73 LS,F/XL,GY,SLA/UG

3606 7.0 20.4 17.5 2.73 LS,F/XL,GY,VUG3607 6.0 23.7 13.5 2.69 LS,F/XL,GY,STY

3608 2.5 49.8 18.3 2.69 LS.F/XL.GY

3609 9.0 44.5 14.5 2.72 LS,F/XL,GY,STY

3610 8.3 45.8 12.4 2.71 LS.F/XL.GY

3611 6.8 53.4 13.0 2.68 LS,F/XL,GY,SLA/UG3612 6.7 27.7 21.5 2.73 LS,F/XL,GY,STY,VUG3613 8.0 17.7 20.2 2.71 LS,F/XL,GY,VUG3614 3.2 23.1 39.5 2.71 LS,F/XL,GY,SL/VUG

200

DEPTH

PERM

MAX

PERM

90

DEG

PORO

GEX

FLUID

SAT

OIL

FLUID

SAT

WATER

DENSITY

GRAIN DESCRIPTION

3615 2.7 7.8 39.1 2.70 LS,F/XL,GY,STY

3616 2.5 37.6 16.7 2.72 LS,F/XL,GY,VUG3617 6.3 19.3 12.9 2.70 LS,F/XL,GY,STY

3618 0.3 2.5 12.6 2.69 LS,F/XL,GY,STY

3619 2.1 0.0 20.0 2.71 LS,F/XL,GY,STY3620 3.5 26.9 23.9 2.70 LS,F/XL,GY3621 4.5 16.3 18.6 2.71 LS,F/XL,GY,VUG3622 3.7 11.2 11.2 2.69 LS,F/XL,GY,STY3623 4.0 30.8 20.5 2.69 LS,F/XL,GY,STY

3624 3.1 41.1 13.7 2.73 LS,F/XL,GY

3625 4.1 54.3 25.8 2.72 LS,F/XL,GY,SL/VUG3626 2.8 25.9 14.8 2.70 LS.F/XL.GY

3627 2.3 9.2 18.3 2.72 LS.F/XL.GY

3628 2.4 8.9 35.5 2.72 LS,F/XL,GY

3629 1.9 11.2 11.2 2.70 LS,F/XL,GY,SLA/UG

3630 1.4 14.9 14.9 2.70 LS,F/XL,GY,SLA/UG

3631 0.3 9.8 29.4 2.71 LS,F/XL,GY,SLA/UG

3632 3.8 11.1 39.0 2.71 LS,F/XL,GY,SLA/UG3633 2.7 15.6 31.2 2.69 LS,F/XL,GY,SLA/UG3634 4.1 10.3 25.7 2.71 LS,F/XL,GY,STY

3635 5.1 18.2 24.3 2.71 LS,F/XL,GY,STY,VUG

3636 2.8 7.5 30.0 2.72 LS,F/XL,GY,STY

201

Permit # 36366

Wheeler, Roland Mt Pleasant FieldIsabella County Michigan

DEPTH

PERM

MAX

PERM

90

DEG

PORO

FLD

FLUID

SAT

OIL

FLUID

SAT

WATER

DENSITY

GRAIN DESCRIPTION

3571 0.16 0.09 2.1 44.8 19.9 2.70 LS,F/XL,BLK

3572 0.06 0.04 2.4 8.9 44.6 2.70 LS,F/XL,BLK

3573 0.07 0.06 3.1 23.9 41.0 2.72 LS,F/XL,BLK3574 0.06 0.06 2.6 29.1 41.5 2.72 LS,F/XL,BLK

3575 0.06 0.05 3.1 30.7 40.9 2.71 LS,F/XL,BLK3576 0.08 0.08 1.9 22.2 22.2 2.72 LS.F/XL.BLK

3577 0.14 0.11 1.5 28.8 14.4 2.72 LS,F/XL,BLK

3578 0.08 0.05 0.9 23.1 23.1 2.71 LS,F/XL,BLK


3581 0.20 0.06 2.4 18.1 36.2 2.74 LS,F/XL,BLK

3582 0.20 0.14 3.0 25.0 28.5 2.78 LS,F/XL,BLK


3585 0.07 0.07 2.9 51.7 7.4 2.74 LS,F/XL,BLK

3586 0.07 0.04 1.8 41.8 12.0 2.72 LS,F/XL,BLK

3587 0.08 0.07 1.2 18.0 18.0 2.72 LS.F/XL.BLK

3588 0.47 0.23 1.0 20.6 20.6 2.72 LS,F/XL,BLK

3589 0.12 0.09 2.9 7.4 59.2 2.74 LS.F/XL.BLK

3590 0.12 0.12 4.1 0.0 45.9 2.72 LS,F/XL,BUFF

3591 1.20 0.54 2.9 0.0 59.5 2.73 LS,F/XL,BUFF

3592 0.33 0.15 3.5 12.1 24.2 2.73 LS,F/XL,P/POR,BUFF

3593 0.01 0.01 2.9 7.3 51.2 2.72 LS,F/XL,BUFF

3594 0.07 0.07 3.8 19.5 27.9 2.73 LS,F/XL,SL/VUG,BUFF

3595 0.55 0.44 4.5 28.2 18.8 2.73 LS,F/XL,P/POR,BUFF

3596 0.09 0.07 3.4 0.0 49.2 2.72 LS,F/XL,BUFF

3597 0.09 0.05 3.2 13.2 46.1 2.74 LS,F/XL,BLK

3598 0.26 0.15 6.2 15.0 16.6 2.74 LS,F/XL,P-P/POR,BLK

3599 0.21 0.18 3.1 13.7 13.7 2.75 LS,F/XL,BLK

3600 0.20 0.20 5.6 16.9 26.2 2.74 LS,F/XL,P-P/POR,BLK

3601 0.05 0.03 4.3 22.0 34.3 2.73 LS,F/XL,P-P/POR,BLK

3602 2.00 0.33 3.8 11.3 45.1 2.74 LS,F/XL,P-P/POR,BLK

3603 7.00 6.40 3.0 7.1 49.4 2.73 LS.F/XL.BUFF

3604 0.17 0.17 2.4 0.0 44.8 2.73 LS.F/XL.BUFF

3605 1.00 0.46 2.9 14.5 36.2 2.72 LS.F/XL.BLK

3606 0.01 5.5 22.5 26.2 2.72 LS,F/XL,P-P/POR,BLK

3607 0.46 0.43 2.2 9.6 38.2 2.72 LS,F/XL,P-P/POR,BLK3608 8.90 6.50 4.2 22.8 20.3 2.74 LS,F/XL,P-P/POR,BLK

3609 1.10 0.72 5.0 14.7 33.6 2.75 LS.F/XL.BUFF

202

DEPTH

PERM

MAX

PERM

90

DEG

PORO

FLD

FLUID

SAT

OIL

FLUID

SAT

WATER

DENSITY

GRAIN DESCRIPTION

3610 1.30 1.00 3.3 12.8 44.8 2.73 LS,F/XL,BLK

3611 0.01 2.7 7.9 55.2 2.72 LS,F/XL,BUFF

3612 0.01 2.6 8.1 40.5 2.71 LS,F/XL,BUFF

3613 0.10 0.09 3.8 19.5 33.4 2.75 LS,F/XL,P-P/POR

3614 0.01 3.3 12.9 45.1 2.73 LS,F/XL,BLK

3615 0.20 0.17 2.9 0.0 59.0 2.70 LS.F/XL.BUFF

3616 0.16 0.14 3.0 0.0 56.4 2.73 LS,F/XL,BUFF

3617 0.10 0.04 5.7 7.4 40.9 2.75 LS,F/XL,BUFF

3618 0.16 0.12 5.9 7.2 43.0 2.77 LS,F/XL,GY

3619 0.01 2.5 8.6 51.7 2.72 LS.F/XL.GY

3620 2.60 0.26 2.1 10.4 20.7 2.74 LS,F/XL,GY/BLK

3621 0.32 0.14 4.2 22.8 50.8 2.73 LS,F/XL,GY/BLK

3622 0.08 0.02 7.3 5.6 22.3 2.74 LS,F/XL,P-P/POR,GY

3623 0.01 5.2 0.0 16.2 2.78 LS,F/XL,GY

3624 0.98 0.01 2.9 7.5 67.3 2.74 LS,F/XL,BUFF

3625 0.54 0.41 2.7 0.0 54.2 2.71 LS,F/XL,BUFF


3628 0.73 0.01 4.4 1.9 68.6 2.76 LS,F/XL,GY/BLK

3629 3029.00 2.20 2.2 0.0 69.4 2.74 LS,F/XL,GY/BLK

3630 0.42 0.42 2.7 0.0 31.1 2.73 LS,F/XL,GY/BLK

3631 0.12 0.07 3.3 0.0 70.9 2.73 LS,F/XL,GY/BLK

3632 0.11 0.09 3.3 0.0 64.2 2.72 LS,F/XL,GY/BLK

3633 0.17 0.15 4.0 0.0 58.9 2.73 LS,F/XL,BUFF/GY3634 0.10 0.10 3.4 0.0 44.1 2.73 LS,F/XL,BUFF/GY

3635 0.04 0.04 1.5 0.0 8.0 2.72 LS,F/XL,BLK

3636 0.04 0.01 3.4 0.0 56.2 2.73 LS,F/XL,GY/BLK3637 0.07 0.07 3.7 11.4 51.1 2.73 LS,F/XL,GY/BLK

3638 147.00 116.00 6.3 6.6 26.5 2.74 LS,F/XL,FOSS,GY

3639 0.16 0.07 2.2 9.9 39.5 2.72 LS,F/XL,GY/BLK

3640 0.29 0.25 1.8 0.0 47.3 2.71 LS,F/XL,GY/BLK

3641 0.03 0.03 1.8 11.6 23.3 2.73 LS,F/XL,GY/BLK

3642 0.04 0.03 1.1 20.5 20.5 2.71 LS,F/XL,GY/BLK

3643 0.04 0.04 1.9 22.2 22.2 2.74 LS,F/XL,GY/BLK

3644 0.10 0.07 2.2 9.7 19.5 2.74 LS,F/XL,GY/BLK

203

Permit # 36258

Van Gaever & Lockwood Mt Pleasant Field

Midland County Michigan

DEPTH

PERM

MAX

PERM

90

DEG

PORO

FLD

FLUID

SAT

OIL

FLUID

SAT

WATER

DENSITY

GRAIN DESCRIPTION

3530 12.00 11.00 9.1 9.9 46.3 2.72 LM V FOSS

3531 502.00 442.00 7.8 11.8 52.4 2.73 LM V FOSS STY

3532 0.28 0.12 4.6 4.5 72.5 2.73 LM V FOSS STY

3533 0.07 0.07 6.2 15.0 43.3 2.72 LM VF FOSS STY

3534 170.00 143.00 8.5 25.4 43.6 2.72 LM V FOSS STY

3535 0.27 0.27 7.0 10.5 59.7 2.72 LM V STY

3536 0.09 0.09 8.5 4.8 45.3 2.72 LM SLA/ STY

3537 33.00 5.50 9.1 10.0 42.1 2.72 LM V FOSS

3538 2.30 1.50 7.2 20.0 45.8 2.72 LM V FOSS STY

3539 0.06 0.06 3.3 0.0 69.6 2.72 LM FOSS

3540 0.13 0.10 3.1 0.0 53.6 2.72 LMSTY

3541 0.08 0.06 3.3 6.3 50.6 2.75 LM PP STY

3542 2.80 1.60 7.1 2.9 63.6 2.73 LM V FOSS STY

3543 0.73 0.25 5.5 13.4 64.9 2.72 LM V STY

3544 0.04 0.04 3.2 6.7 67.5 2.71 LMSTY

3545 0.08 0.06 2.2 0.0 67.5 2.72 LM PP FOSS STY

3546 0.07 0.05 6.3 6.6 49.4 2.72 LM SL/V FOSS STY

3547 1.60 1.60 6.9 0.0 59.4 2.69 LM FOSS

3548 0.19 0.13 5.7 3.7 66.5 2.71 LM FOSS

3549 0.18 0.12 5.0 0.0 72.0 2.71 LM VF PP FOSS

3550 0.01 0.01 3.1 0.0 68.1 2.75 LM PP FOSS STY

3551 0.02 0.02 3.2 0.0 59.4 2.69 LM PP FOSS STY

3552 0.10 0.07 3.5 0.0 66.7 2.70 LM SLA/ STY

3553 4.60 0.58 4.8 4.3 69.3 2.74 LM VF PP FOSS

3554 0.23 0.22 5.4 0.0 56.9 2.71 LM V FOSS

3555 0.13 0.11 3.7 5.6 62.1 2.74 LM SLA/ FOSS

3556 0.17 0.14 5.2 0.0 65.0 2.71 LM PP FOSS STY

3557 0.39 0.33 5.4 7.7 57.7 2.72 LM V FOSS STY

3558 1.20 0.99 4.9 8.6 51.4 2.72 LM SLA/ FOSS STY

3559 0.67 0.66 7.9 2.6 61.8 2.72 LM PP FOSS STY

3560 0.55 0.54 8.0 0.0 63.9 2.72 LM

3561 0.26 0.26 8.3 2.5 69.5 2.75 LMVF

3562 0.15 0.12 2.9 0.0 65.8 2.74 LM PP FOSS STY

3563 0.06 0.06 6.2 0.0 40.9 2.73 LM SLA/ FOSS STY

3564 0.09 0.05 6.1 3.4 68.9 2.72 LM FOSS STY

3565 0.20 0.17 5.8 3.6 67.9 2.72 LMV

204

DEPTH

PERM

MAX

PERM

90

DEG

PORO

FLD

FLUID

SAT

OIL

FLUID

SAT

WATER

DENSITY

GRAIN DESCRIPTION

3566 0.03 0.03 5.7 3.7 66.1 2.71 LM PP FOSS

3567 0.10 0.07 3.2 0.0 74.0 2.71 LMSL/V

3568 0.04 0.04 3.8 0.0 66.9 2.72 LMSLA/

3569 2.10 0.07 3.1 6.8 60.9 2.72 LM SLA/ FOSS

3570 0.29 0.24 6.4 6.5 58.6 2.71 LM SLA/ STY

3571 6.20 5.60 9.4 9.7 32.3 2.71 LM SLA/ STY

3572 0.55 0.42 7.2 12.9 43.0 2.69 LMV

3573 0.65 0.39 8.2 11.3 42.8 2.72 LM PP FOSS

3574 0.19 0.18 3.8 0.0 60.4 2.74 LM SLA/ PP STY

3575 0.05 0.05 2.7 0.0 47.2 2.72 LM PP FOSS

3576 0.07 0.06 5.3 0.0 63.3 2.73 LM SLA/ FOSS

3577 2238 1527 6.7 3.1 49.5 2.75 LMSLA/

3578 1.80 1.80 6.9 3.0 56.9 2.74 LM V STY

3579 0.51 0.05 5.9 7.1 53.2 2.73 LM SL/SHY FOSS

3580 0.21 0.21 4.1 0.0 61.9 2.72 LM SL/F PP FOSS

3581 0.67 0.67 4.7 0.0 62.7 2.71 LMSTY

3582 0.53 0.35 7.1 2.9 51.8 2.72 LM V FOSS

3583 0.23 4.70 7.3 2.9 57.4 2.72 LM SLA/ FOSS

3584 0.51 0.32 5.9 0.0 68.1 2.71 LM V FOSS

205

Permit # 36228

Breedlove Unit Mt Pleasant Field

Midland County Michigan

DEPTH

PERM

MAX

PERM

90

DEG

PORO

FLD

FLUID

SAT

OIL

FLUID

SAT

WATER

DENSITY

GRAIN DESCRIPTION

3543 370 192 3.9 0 42.1 2.71 LM VF V FOSS STY

3544 38 16 5 0 45.8 2.72 LM V PP STY

3545 1.5 0.47 8.9 18.2 47.9 2.7 LMVPP

3546 0.6 0.6 9.3 50.4 19.7 2.7 LMPP

3547 2 1.7 4.5 4.7 79.9 2.71 LM V PP FOSS

3548 63 45 7.8 20.9 47.1 2.7 LM V FOSS STY

3549 0.39 0.36 3.3 0 39 2.7 LM V STY

3550 236 11 7.9 15.4 48.8 2.71 LM V FOSS STY

3551 332 27 7.2 0 53.6 2.72 LM V FOSS STY

3552 17 0.72 8.5 16.9 53.1 2.7 LM V FOSS STY

3553 0.23 0.09 6.2 20.2 43.8 2.71 LM V STY

*3554 0.01 3.8 11.2 67.1 2.71 LM V PP STY

3555 0.03 0.03 4.8 8.8 61.3 2.71 LM PP FOSS

3556 0.05 0.05 3.1 0 54.4 2.72 LM

*3557 50 11.9 10.1 48.8 2.71 LM VFV FOSS STY

3558 1.2 0.49 10 21.6 49.4 2.71 LM V FOSS STY

*3559 0.1 4.5 32.5 32.5 2.71 LMPP

3560 0.07 0.03 2.7 0 71.8 2.71 LM SLA/ PP STY

3561 2.8 1 2.6 0 73.8 2.72 LM SLA/ PP STY

3562 0.19 0.11 4 0 62.1 2.71 LM PP STY

*3563 0.05 2.6 0 80.3 2.71 LMVF

*3564 71 12.2 11.4 39 2.71 LM VF V FOSS STY

*3565 0.93 13 9.2 50.5 2.71 LMVFVSH-INCL

3566 0.48 0.45 6.4 3.2 54.5 2.72 LM

3567 0.61 0.5 14 8.4 50.4 2.71 LM

*3568 0.84 13.2 26.9 41.8 2.71 LM

*3569 0.34 7.7 2.6 71.4 2.7 LM SL/F PP

*3570 0.07 8.6 0 63.7 2.71 LM SL/F PP

3571 0.04 0.04 8.1 0 40.1 2.72 LMPP

*3572 0.35 8.6 8.2 54.2 2.71 LM VF STY

*3573 0.1 9.5 42.4 46.7 2.7 LM PP FOSS

3574 LOST CORE

3581 13 11 9.4 17.2 38.7 2.7 LMVSH-INCL

3582 4.8 2.9 7.7 37.7 35 2.68 LM V FOSS

3583 0.1 0.04 3.8 0 49.2 2.69 LM SL/SHY SLA/ FOSS

*3584 0.01 2.5 0 84.7 2.72 LM FOSS STY

*3585 0.01 2.9 7.4 66.5 2.71 LM SH-INCL FOSS

3586 5.7 5.3 12 14.8 36.2 2.73 LM SL/SHY SLA/ FOSS

3587 1.8 1.6 11.9 22.8 22.8 2.7 LM V FOSS

206

DEPTH

PERM

MAX

PERM

90

DEG

PORO

FLD

FLUID

SAT

OIL

FLUID

SAT

WATER

DENSITY

GRAIN DESCRIPTION

3588 1.9 0.84 4.1 40.7 30.5 2.69 LM SL/SHY V FOSS

3589 0.43 0.43 10.4 33.6 35.4 2.67 LM V FOSS

3590 15 2.7 3.8 11.1 50 2.7 LM V FOSS STY

3591 0.04 0.03 6 3.5 62.6 2.72 LM

3592 0.09 0.07 6.6 3.2 66.5 2.73 LM

3593 0.1 0.01 2.1 10 60 2.71 LM SHLAM STY

3594 562 0.27 3 0 69.8 2.72 LM VF FOSS

3595 2.7 0.05 3.8 0 68.1 2.72 LM VF FOSS STY

3596 246 183 3.4 0 43.3 2.7 LMVSH-INCLSTY

3597 3.7 0.09 6.1 6.8 58.1 2.72 LMVSH-INCLSTY

3598 15 14 5.2 0 43.3 2.71 LMVSH-INCLSTY

3599 0.03 0.01 5.3 3.9 66.7 2.7 LM V FOSS

3600 260 199 5.3 0 66.5 2.71 LM V FOSS

3601 3.7 0.5 5.8 3.8 60.9 2.7 LM V FOSS

3602 0.13 0.05 5.8 7.2 60.8 2.7 LMPPV

3603 0.28 0.2 11.2 18.7 30.2 2.72 LM V FOSS STY

3604 1.4 0.33 6 12 51.3 2.72 LMVFV

3605 4.7 0.23 6.5 3.2 47.4 2.71 LM VF V PP FOSS

3606 0.89 0.33 4.9 0 42 2.71 LM VF PP FOSS STY

3607 0.1 0.03 2.8 0 68.2 2.72 LMM

3608 0.08 0.08 2.2 0 57.5 2.71 LM SL/V FOSS STY

3609 0.03 0.03 1.8 0 58 2.73 LMPP

3610 0.06 0.04 7.6 0 64 2.72 LM PP STY

3611 0.14 0.1 7.2 9.9 36.9 2.71 LM SLA/ FOSS STY

3612 0.37 0.37 9.4 7.6 41.1 2.71 LM SLA/ FOSS STY

*3613 0.08 8.8 0 55.8 2.72 LM V FOSS

3614 280 228 10 7.1 42.4 2.73 LM V FOSS

3615 1 0.91 11.3 1.8 58.6 2.71 LM V PP FOSS STY

3616 0.77 0.44 10.8 3.7 52 2.73 LM V FOSS STY

3617 0.08 0.08 7.8 2.6 57.9 2.71 LMSLA/ FOSS

3618 3 2.1 7.5 5.5 57.7 2.69 LM SLA/ PP FOSS STY

3619 266 232 7.9 5.2 54.6 2.74 LM V FOSS

*3620 0.14 8.2 2.5 57.5 2.71 LM V PP FOSS

207

Permit # 36204

Gwaltney, V M Mt Pleasant FieldIsabella County Michigan

DEPTH

PERM

MAX

PERM

90

DEG

PORO

FLD

FLUID

SAT

OIL

FLUID

SAT

WATER

DENSITY

GRAIN DESCRIPTION

3597 0.13 0.05 1.3 16.5 33.0 2.71 LM,SHY,FOSS3598 1.70 1.50 2.1 46.2 20.5 2.69 LM,SL/SHY,SHLAM

3599 0.07 0.04 1.3 32.2 16.1 2.67 LM,SHY,FOSS,STY3600 0.16 0.10 2.9 51.7 7.4 2.69 LM, SHY, FOSS

3601 0.77 0.62 1.9 50.7 22.5 2.65 LM,SHY,SHLAM,FOSS3602 0.56 0.14 1.9 51.7 11.5 2.67 LM,SHY,SHLAM,FOSS

3603 0.27 0.06 1.2 17.8 35.6 2.69 LM, SHY, SHLAM,

3604 0.08 0.05 2.4 9.0 44.8 2.70 LM, SL/SHY,VF.FOSS,

3605 0.14 0.14 1.6 13.7 54.9 2.68 LM,VF

3606 0.12 0.06 2.0 10.6 42.6 2.70 LM,SL/SHY,STY

3607 0.08 0.05 1.0 0.0 21.0 2.70 LM.SL/SHY

3608 0.13 0.09 1.8 12.0 48.1 2.71 LM,SL/SHY,FOSS

3609 0.43 0.37 2.7 27.9 39.8 2.70 LM,VF,PP,STY

3610 0.04 0.04 2.1 10.2 51.2 2.70 LM.FOSS

3611 0.39 0.10 2.7 15.8 39.4 2.72 LM/VF

3612 0.10 0.05 1.8 12.2 48.9 2.67 LM

3613 0.09 0.03 2.0 10.6 52.8 2.67 LM,VF

3614 0.13 0.11 2.4 9.1 54.4 2.69 LM.PP.STY

3615 4.40 2.90 0.8 0.0 28.4 2.68 LM.VF.STY

3616 0.09 0.08 1.1 0.0 20.3 2.70 LM.STY

3617 0.06 0.03 1.9 0.0 66.5 2.67 LM.STY

3618 0.08 0.04 2.6 8.3 58.2 2.70 LM.PP.STY

3619 0.37 0.21 8.5 4.7 16.5 2.71 LM,SLA/,STY

3620 1.40 1.20 4.9 19.2 29.8 2.70 LM,SLA/,STY

3621 0.05 0.03 3.9 10.9 38.0 2.71 LM.PP.STY

3622 0.04 0.04 2.6 8.2 65.3 2.70 LM.PP.STY

3623 0.27 0.07 4.2 10.1 50.4 2.70 LM.PP.STY

3624 0.49 0.17 1.3 0.0 16.1 2.70 LM.PP.STY

3625 0.30 0.30 2.3 0.0 54.8 2.73 LM.STY

3626 0.16 0.13 4.3 29.2 19.5 2.70 LM.SLA/.STY

3627 0.05 0.01 3.0 14.0 34.9 2.69 LM.PP.STY

3628 0.08 0.05 3.6 20.7 53.2 2.71 LM.FOSS3629 8.00 0.99 1.9 0.0 66.5 2.72 LM.VF

3630 0.29 0.07 2.7 7.8 54.9 2.69 LM.VF.PP.STY3631 0.10 0.07 4.2 30.2 20.1 2.70 LM.PP

3632 0.54 0.41 3.8 24.9 27.7 2.70 LM.PP.STY

3633 0.01 2.4 0.0 54.1 2.72 LM

3634 0.43 0.21 2.9 0.0 51.6 2.72 LM.VF.STY

3635 0.19 0.14 1.8 0.0 48.2 2.72 LM.FOSS

208

DEPTH

PERM

MAX

PERM

90

DEG

PORO

FLD

FLUID

SAT

OIL

FLUID

SAT

WATER

DENSITY

GRAIN DESCRIPTION

3636 0.07 0.03 4.5 9.3 28.0 2.70 LM.PP.STY

3637 0.06 0.03 2.9 14.8 51.8 2.70 LM.PP

3638 0.07 0.03 2.0 0.0 54.4 2.71 LM

3639 0.02 0.01 3.5 12.0 36.1 2.70 LM.SHLAM

3640 0.25 0.13 3.3 6.4 32.0 2.71 LM.PP.STY

3641 0.06 0.03 1.7 0.0 51.3 2.70 LM.VF.FOSS

3642 0.01 3.1 7.0 63.2 2.73 LM

3643 2.9 7.3 58.5 SAMPLE MISSING

3644 1.4 15.3 30.5 SAMPLE MISSING

3645 0.13 0.12 1.7 12.3 24.6 2.75 LM.SL/SHY.VF

3646 0.01 2.2 9.9 49.4 2.72 LM

3647 3.20 1.10 1.9 0.0 57.0 2.71 LM.VF.STY

3648 2.3 9.4 56.5 LM,FOSS,TBFA

3649 0.16 0.01 3.2 6.7 40.0 2.70 LM.VF.STY

3650 0.01 0.01 1.7 25.3 25.3 2.72 LM

3651 0.01 0.01 2.5 8.5 51.2 2.69 LM.SL/SHY.VF

3652 0.20 0.13 2.7 7.8 54.9 2.70 LM.VF.STY

3653 0.13 0.08 3.4 22.1 50.5 2.71 LM.VF.STY

3654 0.10 0.07 2.3 9.2 45.8 2.69 LM.VF.STY

3655 0.06 0.06 2.2 9.7 19.5 2.72 LM.SL/SHY.STY

209

Permit # 36049

Mcclintic # 4 Mt Pleasant Field

Isabella County Michigan

DEPTH

PERM

MAX

PERM

90

DEG

PORO

GEX

FLUID

SAT

OIL

FLUID

SAT

WATER

DENSITY

GRAIN DESCRIPTION

3559 0.03 0.01 2.6 28.5 40.7 2.71 LM, SHY, FOSS, STY

3560 0.11 0.10 1.5 28.1 28.1 2.70 LM , SHY, FOSS, STY

3561 0.08 0.08 1.7 44.6 25.5 2.69 LM , SHY, FOSS, STY

3562 0.09 0.07 1.1 20.2 40.4 2.71 LM SHLAM, FOSS

3563 0.03 0.03 1.2 17.6 35.2 2.69 LM FOSS

3564 0.05 0.04 1.5 29.5 29.5 2.70 LM FOSS, STY

3565 0.04 0.04 1.9 50.3 22.4 2.68 LM SL/F, SHLAM,

3566 0.09 0.07 1.8 47.1 23.5 2.69 LM SL/SHY, SHLAM,

3567 0.07 0.07 2.7 47.4 31.6 2.65 LM SL/SHY, SHLAM,

3568 0.07 0.07 1.8 41.0 23.4 2.63 LM SL/SHY, SHLAM,

3569 0.71 0.42 4.0 10.6 47.9 2.69 LM V, FOSS

3570 0.55 0.54 6.9 17.9 26.9 2.71 LM V, FOSS, STY

3571 0.77 0.76 10.2 35.2 15.7 2.70 LM VF, SLA/, FOSS

3572 0.14 0.14 2.8 0.0 53.7 2.72 LM VF

3573 43.00 0.03 2.5 0.0 68.2 2.71 LM VF, PP, STY

3574 2.50 1.50 10.0 32.4 58.6 2.71 LM V, FOSS, STY

3575 10.00 7.50 9.5 30.1 45.1 2.71 LM V, FOSS, STY

3576 11.00 7.00 10.7 23.3 33.6 2.70 LM V, FOSS, STY

3577 0.96 0.95 7.7 15.9 37.2 2.71 LM V, STY

3578 0.67 0.67 8.1 35.4 32.9 2.69 LM SLA/, STY

3579 4.10 4.00 3.9 5.4 75.6 2.71 LM VF, SLA/, STY

3580 733 586 9.0 13.7 52.3 2.71 LM SL/F, V, STY

3581 2957 25.00 8.7 10.3 43.7 2.71 LM VF, V

3582 237 123 10.8 14.8 42.6 2.71 LM V

3583 12.00 2.90 7.8 18.3 39.2 2.69 LM VF, V, STY

3584 0.09 0.04 5.8 16.2 28.8 2.71 LM PP

3585 0.50 0.48 8.0 61.4 12.8 2.68 LM PP

3586 0.02 0.01 2.6 28.6 16.3 2.73 LM VF, PP

3587 4112 0.07 4.6 16.1 55.3 2.73 LM VF, PP

3588 44.00 22.00 8.3 19.5 43.9 2.72 LM

3589 1.30 1.10 4.6 15.9 45.3 2.70 LM VF, SLA/, STY

3590 280 0.05 6.0 24.1 27.5 2.71 LM VF, PP

3591 0.01 0.01 4.3 29.5 49.1 2.70 LM

3594 0.25 0.14 9.2 32.6 13.0 2.66 LM SLA/

3595 22.00 0.64 3.7 5.8 40.4 2.71 LM PP

3596 0.03 0.01 3.6 0.0 47.4 2.67 LM SL/SHY, SLA/

3597 0.80 0.39 4.8 8.6 30.2 2.70 LM V, STY

3598 6.6 6.2 21.8 TBFA

3599 4.00 0.62 5.5 17.0 53.0 2.66 LM, V, STY

210

Permit # 35680

Foster, Mary W Mt Pleasant FieldMidland County Michigan

DEPTH

PERM

MAX

PERM

90

DEG

PORO

FLD

FLUID

SAT

OIL

FLUID

SAT

WATER

DENSITY

GRAIN DESCRIPTION

3551 0.01 0.01 2.2 45.5 9.1 2.70 LM SHY SL/PYRC

3552 0.09 0.01 1.8 38.9 11.1 2.70 LM SHY FOSS STY

3553 0.16 0.05 0.7 0.0 28.6 2.69 LM SL/SHY FOSS

3554 0.04 0.03 3.6 52.8 11.1 2.70 LM SL/SHY FOSS

3555 0.04 0.04 1.8 50.0 11.1 2.67 LM SHY FOSS STY

3556 0.03 0.03 1.9 43.8 11.1 2.68 LM SHY FOSS STY

3557 0.07 0.07 2.4 54.2 8.3 2.68 LM SHY FOSS STY

3558 0.03 0.03 3.3 39.4 45.5 2.70 LM SL/SHY FOSS

3559 0.04 0.01 1.5 53.3 13.3 2.70 LM SL/SHY SL/F

3560 7.30 4.70 9.7 21.6 28.9 2.71 LM CALC V SHR S

3561 3.30 3.10 11.2 25.0 32.1 2.70 LMVSHRFOSS

3562 4.30 4.00 15.5 31.7 17.1 2.69 LMV SL/F SHR

3563 0.37 0.30 3 50.0 6.7 2.70 LM SL/SHY VF

3564 0.04 0.01 0.6 0.0 66.7 2.70 LMVF

3565 14.00 13.00 10 12.0 26.0 2.71 LM V SHR STY

3566 0.62 0.11 6.1 19.7 31.1 2.70 LM VF SLA/ PP STY

3567 1.20 0.02 4.1 53.7 22.0 2.70 LM VF PP FOSS STY

3568 0.55 0.34 1.5 26.7 13.3 2.70 LM VF PP SHR FOSS

3569 0.12 0.12 0.6 0.0 33.3 2.74 LM SL/SHY SL/F

3570 0.24 0.12 3.2 21.9 18.8 2.74 LM SL/SHY VF PP

3571 0.10 0.06 3.5 37.1 37.1 2.70 LM SL/SHY SL/F PP

3572 0.08 0.05 2.5 40.0 16.0 2.70 LM PP FOSS STY

3573 0.63 0.18 2.2 40.2 17.9 2.70 LM SL/F SL/V PP

3574 15.00 10.00 5.1 7.8 56.9 2.72 LM VF V FOSS

3575 22.00 8.10 4.9 8.2 24.5 2.71 LM PYRC V STY

3576 20.00 13.00 11.1 10.5 22.7 2.70 LMV SHR

3577 14.00 8.00 3.9 56.4 15.4 2.67 LMV SHR

3578 0.73 0.64 1.9 36.8 21.1 2.70 LM VF PP SHR STY

3579 0.20 0.20 11.3 17.7 27.4 2.70 LM SL/F PP STY

3580 4.10 3.30 4.2 21.4 31.0 2.69 LM SHY VF PP STY

3581 1.60 0.86 1.9 0.0 57.9 2.69 LM VF PP SHR STY

3582 0.08 0.05 1.6 0.0 37.5 2.69 LM SL/F PP FOSS

3583 0.06 0.03 1.7 12.3 36.8 2.71 LM PP STY

3584 0.22 0.07 3.8 31.6 36.8 2.70 LMPP

3585 0.03 0.01 2 0.0 40.0 2.71 LM VF PP FOSS

3586 0.87 0.82 9.1 33.0 13.2 2.70 LM PP FOSS

211

DEPTH

PERM

MAX

PERM

90

DEG

PORO

FLD

FLUID

SAT

OIL

FLUID

SAT

WATER

DENSITY

GRAIN DESCRIPTION

3587 0.15 0.13 12.4 29.8 15.3 2.69 LM PP SHR FOSS

3588 0.09 0.03 3.8 18.4 44.7 2.70 LM PP SHR STY

3589 0.01 0.01 2.6 0.0 42.3 2.71 LM VF PP STY

3590 9.60 0.08 4.6 19.6 37.0 2.70 LM VF V FOSS STY

3591 3.80 2.40 4.8 29.7 25.5 2.68 LMV SL/F SHR STY

3592 0.04 0.03 4 41.1 15.4 2.71 LM PP FOSS STY

3593 0.02 0.01 2.8 0.0 69.1 2.71 LM FOSS STY

3594 0.10 0.10 3.4 12.5 37.4 2.70 LM PP FOSS

3595 1.20 0.01 2.1 0.0 70.2 2.72 LM VF STY

3596 0.02 0.02 1 0.0 21.7 2.71 LM PP STY

3597 0.07 0.02 1.6 0.0 43.3 2.71 LM VF PP STY

3598 0.02 0.02 7 5.8 20.3 2.68 LM SL/F PP

3599 0.03 0.03 3.5 11.7 17.6 2.70 LM SL/F PP

3600 0.12 0.03 5.1 8.2 37.1 2.68 LM V STY

3601 0.07 0.03 4.4 9.5 61.6 2.71 LM CALC V SL

3602 0.30 0.09 5.8 7.2 54.3 2.72 LM VF PP SHR

3603 0.16 0.13 2.9 0.0 57.1 2.70 LM SL/ANHY

3604 0.36 0.22 3.3 22.5 54.4 2.71 LMV

3605 0.08 0.03 4.7 9.0 53.9 2.73 LM PP STY

3606 0.11 0.05 2.3 18.8 28.1 2.71 LM VF SHLAM STY

3607 1.40 0.20 3.9 0.0 43.0 2.72 LM SL/F PP

3608 1.30 0.70 3.7 11.4 22.8 2.70 LM VF PP

3609 0.02 0.02 1.2 0.0 17.3 2.69 LM SL/SHY

3610 0.10 0.07 0.9 0.0 23.1 2.69 LMVF

212

Permit # 35540

SMITH, VERA A. Mt Pleasant FieldIsabella County Michigan

DEPTH

PERM

MAX

PERM

90

DEG

PORO

FLD

FLUID

SAT

OIL

FLUID

SAT

WATER

DENSITY

GRAIN DESCRIPTION

3556 0.01 0.01 2.8 14.3 28.6 2.68 LM, SHY, SHLAM,

3557 0.01 0.01 3.2 12.5 46.9 2.67 LM , SHY, SHLAM,

3558 0.01 0.01 2.9 0.0 31.0 2.68 LM SL/F, SHLAM,

3559 0.01 0.01 2 20.0 30.0 2.67 LM FOSS, STY

3560 0.01 0.01 2.4 16.7 16.7 2.69 LM SHLAM, FOSS

3561 0.01 0.01 1.9 21.1 21.1 2.69 LM SL/SHY, FOSS,

3562 0.01 0.01 1.7 47.1 23.5 2.73 LM SL/SHY, FOSS,

3563 0.01 0.01 1 20.0 20.0 2.71 LM FOSS, STY

3564 0.01 0.01 2.5 16.0 32.0 2.7 LM FOSS, STY

3565 0.01 0.01 1.3 15.4 46.2 2.7 LM FOSS, STY

3566 0.01 0.01 1.7 23.5 23.5 2.69 LM SL/SHY, FOSS,

3567 0.01 0.01 2 10.0 30.0 2.69 LM SL/SHY, FOSS,

3568 0.02 0.01 2 35.0 20.0 2.71 LM FOSS

3569 0.01 0.01 1.4 14.3 14.3 2.7 LM FOSS

3570 0.01 0.01 1.9 10.5 31.6 2.7 LM FOSS, STY

3571 0.01 0.01 1.3 15.4 46.2 2.69 LM FOSS, STY

3572 0.01 0.01 1.2 16.7 33.3 2.69 LM FOSS, STY

3573 0.02 0.01 1.2 16.7 33.3 2.7 LM SL/F, STY

3574 0.01 0.01 1.2 0.0 33.3 2.69 LM SL/F, FOSS, STY

3575 0.01 0.01 0.5 0.0 40.0 2.69 LM SL/SHY, FOSS,

3576 0.01 0.01 0.4 0.0 50.0 2.69 LM SL/SHY, FOSS,

3577 0.01 0.01 1.4 14.3 28.6 2.69 LM SL/SHY, FOSS,

3578 0.01 0.01 1 40.0 20.0 2.69 LM FOSS, STY

3579 0.01 0.01 0.9 22.2 22.2 2.68 LM FOSS, STY

3580 0.04 0.01 1.3 30.8 30.8 2.69 LM FOSS, STY

3581 0.01 0.01 0.8 25.0 25.0 2.68 LM SL/SHY, FOSS,

3582 0.01 0.01 1 20.0 20.0 2.68 LM FOSS, STY

3583 0.03 0.01 0.9 22.2 22.2 2.68 LM FOSS, STY

3584 0.01 0.01 1.4 28.6 26.7 2.66 LM SL/SHY, FOSS,

3585 0.01 0.01 1.1 33.3 16.6 2.7 LM FOSS, STY

3586 0.01 0.01 1.1 18.2 18.2 2.69 LM FOSS, STY

3587 0.01 0.01 0.8 25.0 25.0 2.7 LM FOSS, STY

3588 0.03 0.03 2.8 28.6 21.4 2.68 LM SLA/, SH-INCL,

3589 0.02 0.01 2.6 0.0 65.4 2.68 LM PP, STY

3590 0.03 0.01 2.3 0.0 65.2 2.68 LM PP, SH-INCL,

3591 0.03 1.5 0.0 40.0 2.65 LM

3592 0.01 0.01 1.9 0.0 47.4 2.69 LM, SH-INCL

213

DEPTH

PERM

MAX

PERM

90

DEG

PORO

FLD

FLUID

SAT

OIL

FLUID

SAT

WATER

DENSITY

GRAIN DESCRIPTION

3593 0.01 0.01 0.8 0.0 25.0 2.7 LM, SH-INCL, FOSS

3594 0.27 0.12 8.7 10.3 23.0 2.7 LM, V, SH-INCL, STY

3595 0.03 0.01 6.1 14.8 44.3 2.67 LM, PP

3596 0.01 0.01 1.5 0.0 40.0 2.66 LM, PP

3597 0.02 0.01 1.9 10.5 47.4 2.68 LM

3598 0.01 0.01 2 0.0 65.0 2.71 LM, FOSS, STY

3599 0.04 0.01 2.3 0.0 65.2 2.68 LM, PP, STY

3600 0.13 0.09 5.2 7.7 23.1 2.7 LM, V, SH-INCL, STY

3601 0.07 0.02 4.9 8.1 24.5 2.68 LM, V, STY

3602 0.07 0.02 3.3 12.1 51.5 2.68 LM, VF, PP, STY

3603 0.02 0.01 5.8 12.1 27.6 2.66 LM, PP

3604 0.01 0.01 2.5 0.0 60.0 2.69 LM, PP, STY

3605 0.1 5.4 7.4 29.6 2.69 LM, V, STY

3606 0.08 0.04 4.9 14.3 24.5 2.66 LM, V

214

Permit U 36730

Fitzwater 6. South buckeye FieldGladwin County Michigan

DEPTH

PERM

MAX

PERM

90

DEG

PORO

GEX

FLUID

SAT

OIL

FLUID

SAT

WATER

DENSITY

GRAIN DESCRIPTION

3560 0.1 0.1 1.0 1.9 65.2 2.71 LS, F/XL, GY

3561 0.1 0.1 1.1 1.5 62.1 2.70 LS, F/XL, GY

3562 0.1 0.1 0.9 18.3 62.5 2.69 LS, F/XL GY

3563 4.3 0.1 2.1 19.3 65.8 2.70 LS F/XL GY

3564 21.0 21.0 6.5 12.4 42.7 2.70 LS F/XL SLA/UG, FOS,

3565 794.0 449.0 8.1 13.6 44.3 2.70 LS F/XL FOS, GY

3566 944.0 755.0 6.6 9.2 29.4 2.70 LS F/XL FOS, GY

3567 401.0 63.0 7.1 11.8 38.2 2.70 LS F/XL SLA/UG, FOS,

3568 52.0 0.3 3.4 17.8 52.1 2.70 LS F/XL FOS, GY

3569 87.0 32.0 7.1 13.7 41.0 2.69 LS F/XL SLA/UG, FOS,

3570 32.0 26.0 10.3 13.3 39.8 2.69 LS F/XL FOS, GY

3571 51.0 6.7 12.9 16.4 35.3 2.69 LS F/XL FOS, GY

3572 351.0 47.0 15.4 17.7 38.1 2.69 LS F/XL FOS, GY

3573 7.6 1.8 2.8 20.5 44.4 2.69 LS F/XL FOS, GY

3574 1.2 0.4 3.8 12.1 62.8 2.70 LS F/XL FOS, GY

3575 14.0 9.9 4.8 13.3 68.3 2.70 LS F/XL SLA/UG, FOS,

3576 22.0 2.4 5.4 9.3 47.2 2.69 LS F/XL SLA/UG, FOS,

3577 521.0 277.0 10.1 20.3 39.6 2.69 LS F/XL SLA/UG, FOS,

3578 31.0 11.0 7.5 24.8 48.2 2.68 LS F/XL SLA/UG, FOS,

3579 52.0 4.2 10.1 19.6 38.4 2.68 LS F/XL SLA/UG, FOS,

3580 22.0 10.0 4.6 5.5 56.8 2.69 LS F/XL SLA/UG, GY

3581 15.0 13.0 14.2 4.1 42.4 2.72 LS F/XL SLA/UG, FOS,

3582 25.0 12.0 5.4 5.4 56.6 2.69 LS F/XL VUG, FOS,

3583 4.9 4.4 4.1 16.7 60.4 2.67 LS F/XL GY

3584 5.7 5.9 6.8 65.6 2.70 LS F/XL SLA/UG,

3585 6.0 4.8 1.6 6.9 79.9 2.69 LS F/XL SLA/UG, FOS,

3586 25.0 11.0 9.5 4.5 52.5 2.69 LS F/XL SLA/UG, FOS

3587 3.8 2.8 1.1 4.7 55.2 2.69 LS F/XL FOS, GY

3588 0.2 0.2 1.3 4.3 40.6 2.69 LS F/XL FOS, GY

3589 5.1 2.4 5.7 3.2 31.2 2.69 LS F/XL VUG, FOS,

3590 0.2 0.1 2.5 6.8 68.5 2.69 LS F/XL SLA/UG, FOS,

3591 0.1 0.1 1.2 3.3 50.0 2.69 LS F/XL GY

3592 0.1 0.1 1.5 2.6 44.2 2.69 LS F/XL GY

3597 0.1 0.1 1.7 4.7 52.2 2.69 LS F/XL GY

3598 0.1 0.1 1.6 4.0 45.1 2.69 LS F/XL GY

3600 0.4 0.3 4.7 1.8 51.9 2.69 LS F/XL GY

3601 0.1 0.1 3.1 2.1 59.5 2.69 LS F/XL FOS, GY

3622 7.6 4.0 5.8 1.1 49.8 2.69 LS F/XL FOS, GY

3623 1.3 1.3 5.8 1.4 48.5 2.69 LS F/XL FOS, GY

215

Permit# 43383

Nusbaum Kern 3-W. South buckeye FieldGladwin County Michigan

DEPTH

PERM

MAX

PERM

90

DEG

PORO

GEX

FLUID

SAT

OIL

FLUID

SAT

WATER

DENSITY

GRAIN DESCRIPTION

3557 1.9 1.3 5.4 31.6 59.3 2.711 LS

3558 0.1 0.1 0.4 25.3 50.3 2.733 LS

3559 0.7 0.3 2.7 0.0 38.9 2.690 LS

3560 2.6 0.5 2.2 5.9 33.7 2.698 LS

3561 15.0 0.3 2.0 9.1 81.4 2.697 LS

3562 0.1 0.1 2.6 0.0 38.6 2.691 LS

3563 0.6 0.5 3.3 0.0 31.5 2.685 LS

3564 4.2 2.4 2.9 4.9 39.2 2.690 LS

3565 22.0 21.0 15.7 26.9 54.5 2.652 LS, FOSS

3567 5.1 3.2 6.1 17.3 60.6 2.689 LS, FOSS

3568 185.0 34.0 8.3 22.2 30.2 2.693 LS, FOSS

3569 1.6 0.6 2.0 16.1 51.7 2.690 LS, FOSS

3570 14.0 11.0 4.3 21.9 41.9 2.692 LS, FOSS

3571 1.4 1.2 5.4 9.6 30.7 2.696 LS, FOSS

3572 0.5 0.3 4.3 13.6 27.3 2.690 LS, FOSS

3573 14.0 6.8 70.0 12.6 24.6 2.681 LS, FOSS

3574 1.0 30.0 8.5 15.3 27.8 2.677 LS

3575 527.0 456.0 8.7 15.1 32.0 2.678 LS, FOSS

3576 0.1 0.1 2.6 17.8 33.4 2.690 LS

3577 0.1 0.1 1.3 0.0 49.9 2.774 LS

3578 0.2 0.2 2.0 0.0 21.7 2.700 LS

3579 0.4 0.1 2.4 0.0 27.4 2.697 LS

3580 0.1 0.1 1.9 0.0 32.3 2.703 LS

3581 0.1 0.1 1.6 6.8 68.0 2.699 LS

3582 0.4 0.0 1.6 6.7 46.6 2.699 LS

3583 1.0 0.9 2.8 3.7 22.3 2.703 LS

3584 0.3 0.3 3.7 2.9 37.1 2.685 LS

3585 0.9 0.5 2.3 3.2 27.9 2.687 LS

3586 0.5 0.1 1.5 7.3 62.7 2.699 LS

3587 1.4 0.7 4.2 12.5 35.0 2.692 LS

3588 0.2 0.1 1.6 15.5 43.5 2.691 LS

3589 0.1 0.0 1.5 14.8 41.7 2.695 LS

3590 0.2 0.1 3.1 16.7 20.0 2.689 LS

3591 0.4 0.3 1.7 15.7 25.2 2.680 LS

3592 0.1 0.1 1.0 0.0 43.7 2.697 LS

3593 0.1 0.1 0.9 11.8 70.9 2.699 LS

3594 0.8 0.0 1.3 8.2 82.0 2.700 LS

3595 0.0 0.0 1.8 0.0 59.5 2.704 LS

3596 0.2 0.1 1.8 5.9 59.0 2.717 LS

216

Permit#32780

State Buckeye B-6, North Buckeye FieldGladwin County Michigan

DEPTH

PERM

MAX

PERM

90

DEG

PORO

GEX

FLUID

SAT

OIL

FLUID

SAT

WATER

DENSITY

GRAIN DESCRIPTION

3615 0.7 0.1 0.5 15.0 21.7 2.72 LM

3616 156 21 7.2 30.1 40.5 2.76 LM, PYRITE, VGY3617 606 606 11.7 30.7 41.3 2.76 LM, PYRITE, VGY3618 348 217 10.0 32.1 49.3 2.70 LM, VGY3619 899 862 13.2 26.6 40.5 2.73 LM, VGY3620 519 437 11.5 27.9 42.7 2.74 LM, VGY3621 267 233 10.8 27.8 53.7 2.70 LM, VGY

3622 162 159 11.8 27.3 52.8 2.72 LM, VGY

3623 102 99.0 12.1 27.6 53.3 2.73 LM, VGY3624 23 15.0 11.0 14.8 67.9 2.72 LM, VGY

3625 24 19.0 11.1 16.6 76.4 2.73 LM, VGY

3626 19 13.0 12.0 14.8 68.9 2.73 LM, VGY

3627 5 5.0 9.3 17.5 67.4 2.72 LM, VGY

3628 1893 62.0 9.6 14.2 54.8 2.74 LM VGY, V/F

3629 321 250.0 11.1 15.7 60.5 2.71 LM, VGY

3630 373 311.0 10.8 23.8 62.7 2.72 LM, VGY

3631 0.6 9.2 22.5 59.3 2.72 LM, VGY

3632 0.4 9.2 23.1 59.8 2.71 LM, VGY

3633 0.7 0.3 9.6 29.1 66.9 2.71 LM, VGY3634 907 907 12.3 22.3 51.3 2.72 LM, VGY

3635 0.2 5.6 25.3 58.2 2.72 LM, VGY

3636 0.1 9.9 14.2 60.7 2.73 LM, VGY3637 15.0 3.4 8.9 14.3 60.9 2.74 LM, VGY

3638 13.0 8.2 11.4 13.8 59.1 2.75 LM, SLA/GY

3639 13.0 1.2 9.0 25.5 52.8 2.73 LM, VGY

3640 161.0 155 13.1 23.8 49.3 2.74 LM, VGY3641 136.0 120 12.2 24.5 50.0 2.72 LM, VGY3642 3.2 2.7 9.6 37.9 39.3 2.71 LM, VGY3643 0.5 0.4 9.7 37.6 38.9 2.73 LM, VGY

3644 0.3 0.2 6.4 4.3 76.6 2.71 LM, STY, VGY3645 640.0 0.3 6.9 4.1 72.0 2.75 LM, V/F

3646 0.1 5.9 4.0 72.1 2.74 LM

3647 0.1 5.8 4.2 74.3 2.73 LM

3648 0.4 0.1 6.1 14.7 73.2 2.73 LM

3649 3.3 0.1 2.4 13.4 67.2 2.73 LM, SLA/GY3650 0.1 0.1 1.0 12.7 62.7 2.73 LM

3651 0.1 0.1 2.2 13.5 58.7 2.74 LM

217

DEPTH

PERM

MAX

PERM

90

DEG

PORO

GEX

FLUID

SAT

OIL

FLUID

SAT

WATER

DENSITY

GRAIN DESCRIPTION

3652 0.3 0.2 2.0 17.1 71.4 2.73 LM

3653 0.1 0.1 0.9 13.0 60.0 2.73 LM

3654 0.2 0.1 2.0 14.7 64.7 2.73 LM

3655 182.0 0.1 7.0 9.2 52.3 2.77 LM, V/F

3656 0.2 0.1 6.0 10.9 62.1 2.72 LM, STY, SLA/GY, V/

3657 0.1 0.1 5.8 10.1 58.1 2.73 LM, SLA/GY, V/F

3658 0.1 0.1 1.9 10.0 61.3 2.74 LM, SLA/GY, V/F

3659 0.2 0.1 8.0 7.9 47.9 2.72 LM, SLA/GY

3660 0.1 0.1 4.9 10.2 61.7 2.73 LM

3661 0.6 0.1 6.2 6.2 71.8 2.72 LM, SL/VGY.V/F

3662 0.1 0.1 4.5 6.7 77.5 2.71 LM, FOSS, VGY, V/F

3663 0.1 0.1 6.5 3.4 74.2 2.72 LM, FOSS, VGY, V/F

3664 0.1 0.1 6.3 3.0 64.9 2.72 LM, FOSS, SLA/GY

3665 0.1 0.1 6.0 2.9 64.8 2.73 LM, FOSS, SLA/GY

3666 0.8 0.1 11.6 6.4 49.0 2.73 LM, SLA/GY

3667 0.4 0.1 7.6 7.0 53.8 2.72 LM, SLA/GY

3668 0.1 0.1 8.3 7.3 55.4 2.71 LM, VGY

3669 0.1 0.1 11.0 9.6 47.6 2.72 LM, VGY

3670 0.1 0.1 9.0 10.6 52.6 2.73 LM, VGY

3671 0.1 0.1 3.8 18.5 39.2 2.72 LM, VGY

3672 0.1 0.1 0.8 25.8 54.2 2.72 LM, VGY

218

Permit#35720

Hutsonl-2., ButmanGladwin County MI

DEPTH

PERM

MAX

PERM

90

DEG

PORO

GEX

FLUID

SAT

OIL

FLUID

SAT

WATER

DENSITY

GRAIN DESCRIPTION

3656.0-57.0 0.1 0.1 1.1 8.8 88.2 2.71 LS

3657.0-58.0 1.7 0.5 0.5 8.3 78.3 2.70 LS

3658.0-59.0 0.1 0.1 1.0 8.7 87.3 2.70 LS

3659.0-60.0 0.1 0.1 0.8 7.3 82.0 2.70 LS

3660.0-61.0 0.1 0.1 3.0 21.7 46.6 2.70 LS

3661.0-62.0 0.1 0.1 3.0 20.8 44.6 2.69 LS

3662.0-63.0 0.1 0.1 0.7 7.5 82.5 2.70 LS

3663.0-64.0 0.1 0.1 1.3 10.8 72.4 2.71 LS

3664.0-65.0 0.1 0.1 2.3 10.0 68.1 2.70 LS

3665.0-66.0 0.1 0.1 0.5 12.5 78.8 2.70 LS

3666.0-67.0 0.1 0.1 0.7 12.9 77.1 2.71 LS

3667.0-68.0 0.1 0.1 0.9 5.0 91.1 2.70 LS

3668.0-69.0 0.1 0.1 2.7 12.6 74.6 2.72 LS

3669.0-70.0 0.1 0.1 0.8 5.0 88.3 2.70 LS

219

Permit#28399

Grow 4, West BranchOgemaw CO, MI

DEPTH

PERM

MAX

PERM

HORIZ

PORO

GEX

FLUID

SAT

OIL

FLUID

SAT

WATER

DENSITY

GRAIN DESCRIPTION

2578.2 0.10 1.7

2578.8 0.10 3.2

2580.3 0.1 9.0

2581.3 0.2 10.1

2582.5 0.1 5.7

2584.4 0.1 8.1

2587.4 12.3

2587.4 1.0 10.9

2588.5 13.9

2588.7 1.7 12.4

2593.5 4.9 9.2

2597.9 1.8 7.4

2603.0 0.5 7.1

2607.1 7.2

2607.1 0.1 4.8

2608.6 1.1 7.6

2609.6 1.3 8.8

2610.9 0.6 8.6

2613.0 9.1 10.6

2613.2 8.9

2613.3 0.7 6.6

2614.3 6.9 11.7

2615.0 0.6 8.4

2617.2 3.7 10.6

2618.5 0.4 6.2

2621.9 6.2 7.7

2622.9 1.1 6.0

2624.0 13.0 8.9

2626.5 0.1 5.3

2628.4 0.4 5.7

2629.3 0.1 5.6

2930.9 0.4 4.4

2632.1 6.2 7.1

2635.7 8.1

2635.7 112.0 11.3

2636.0 11.3

2636.1 189.0 12.2

220

DEPTH

PERM

MAX

PERM

HORIZ

PORO

GEX

FLUID

SAT

OIL

FLUID

SAT

WATER

DENSITY

GRAIN DESCRIPTION

2639.3 0.5 4.8

2639.8 12.4

2639.8 14.0 10.9

2641.7 12.7

2641.7 5.7 10.7

2644.5 11.3

2644.5 29.0 10.8

2645.0 14.0 13.6

2647.0 2.4 7.5

2649.5 15.0 10.3

2651.5 0.1 6.3

2652.5 5.7 9.7

2655.2 26.0 10.9

2656.3 7.4 9.7

2657.9 0.5 7.6

2660.6 0.3 6.2

2663.1 0.9 9.8

2684.1 54.0 21.8

2687.0 0.1 5.0

2707.5 0.1 1.4

2708.7 0.1 7.7

221

Appendix ECross-sections

Core to Log CorrelationDundee Limestone Formation

222

to

Figure E. 1. A base map with three cross-section lines strike oriented (A-A' and B-B') and dip oriented cross-section (C-C).

to

MT PLEASANT UNIT TRACT 19 MT PLEASANT UNIT TRACT 46

39821 39771

ISABELLAMount Pleasant


Skeletal Crinoidal Wackestone

MCCLINTIC

36820


MCCLINTIC

36367


MAEDER GRACE L

36647


Fenestral peloidal Grainstone/Packstone

EMMONS BROTHERS

37069

A'

RGRC

DUND

Facies 6

Facies 7

ISABELLA

Mount Pleasant

Skeletal Wackestone

Figure E.2. Stratigraphic cross-section (A-A') showing inferred lateral continuity of the fenestral reservoir facies (Aboveblue line) and skeletal wackestone facies (green line). The stratigraphic datum for the cross-section is themajor flooding surface at the top of the Dundee Limestone (Rogers City/Dundee contact). The floodingsurface is marked with red dashed line (FS). RGRC = Rogers City, DUND = Dundee, GR = gamma-ray log,NPHI = neutron porosity log, RHOB = bulk density log.

toto

MT. PLEASANT UNIT TRACT 52 MT PLEASANT UNIT TRACT 55

39824 39770

B



BISHOP J

36854


Skeletal Crinoidal Wackestone

MCCLINTIC STATE CHIPPEWA STATE CHIPPEWA

36815 36884 36910

A <025MI> A <0.16MI> A




Fenestral peloidal Grainstone/Packstone

EMMONS BROTHERS

37069

B'

RGRC

DUND

Facies 6

Facies 7


Skeletal Wackestone

Figure E.3. Stratigraphic cross-section (B-B') showing inferred lateral continuity of the fenestral reservoir facies (Aboveblue line) and the skeletal wackestone (green line). The stratigraphic datum for the cross-section is the majorflooding surface at the top of the Dundee Limestone (Rogers City/Dundee contact). The flooding surface ismarked with red dashed line (FS). RGRC = Rogers City, DUND = Dundee, GR = gamma-ray log, NPHI =neutron porosity log, RHOB = bulk density log.

totoOs

MT. PLEASANT UNIT TRACT 21 MT PLEASANT UNIT TRACT 55 FISHER BROTHERS A SCHROT, JOHN J

40264 39770 37350 36983

C # <1.18MI> A <0.72MI> A <2.40MI> £RHOB


RHOB


RHOB


MIDLANDMount Pleasant

PFUND, W

36259


Skeletal Crinoidal Wackestone Fenestral peloidal Grainstone/Packstone

CLARK UNIT

37028


PLONA UNIT

36931


Skeletal Wackestone

c

RGRC

FloodingSurface

Figure E.4. Stratigraphic cross-section (C-C) showing inferred lateral continuity of the fenestral reservoir facies(Aboveblue line) and skeletal wackestone (green line). The stratigraphic datum for the cross-section is the majorflooding surface at the top of the Dundee Limestone (Rogers City/Dundee contact). The flooding surface ismarked with red dashed line (FS). RGRC = Rogers City, DUND = Dundee, GR = gamma-ray log, NPHI =neutron porosity log, RHOB = bulk density log.

METHNER S MAXWELL

37290

ISABELLA

D'

RGRC

DUND

FloodingSurface?

LUCS

Figure E.5. Stratigraphic cross-section (D-D') showing the inferred flooding surface (FS markedwith red dashed line). The stratigraphic datum for the cross-section is the majorflooding surface at the top of the Dundee Limestone (Rogers City/Dundee contact).RGRC = Rogers City, DUND = Dundee, LUCS= Lucas Formation, GR = gamma-ray log, NPHI = neutron porosity log, RHOB = bulk density log.

227

STROHKIRCH. A

31979


• Skeletal Crinoidal

Wackestone


F5 Stromatoporoid Boundstone


• Coral-StromatoporoidFloatstone


• Skeletal Wackestone


• Fenestral peloidalGrainstone/Packstone

Figure E.6. Stratigraphic cross-section (E-E') showing inferred lateral continuity of the fenestralreservoir facies (Above blue line). The stratigraphic datum for the cross-section isthe majorflooding surface at the top of the Dundee Limestone (Rogers City/Dundeecontact). The flooding surface is marked with red dashed line (FS). RGRC =Rogers City, DUND = Dundee, GR = gamma-ray log, NPHI = neutronporosity log,RHOB = bulk density log.

228

reservoir characterization and enhanced oil recovery

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