petrophysical characterization of the barnett shale: progress report

Petrophysical Characterization of Petrophysical Characterization of the Barnett Shale: Progress Reportthe Barnett Shale: Progress Report

Jeff KaneJeff KaneBureau of Economic GeologyBureau of Economic Geology

PBGSP Annual PBGSP Annual MeetingMeetingFebruary 27-28, 2006February 27-28, 2006

Jeffrey A. Kane, Bureau of Economic Geology , PBGSP Annual Meeting, 2/27-28/2006, Austin, TXJeffrey A. Kane, Bureau of Economic Geology , PBGSP Annual Meeting, 2/27-28/2006, Austin, TX

OverviewOverview

• Database constructionDatabase construction• Geophysical log analysis modelGeophysical log analysis model• Texas United Blakely #1Texas United Blakely #1• SummarySummary


Database constructionDatabase construction

• Wireline database:Wireline database:• 7 wells with geochemical data7 wells with geochemical data

• 2 with log data2 with log data• 1 with mineralogy data1 with mineralogy data• 1 with limited P & P data1 with limited P & P data• 1 with capillary pressure data1 with capillary pressure data• 2 with core descriptions2 with core descriptions


Database constructionDatabase construction

• Many of these core data were recently provided by Dan Many of these core data were recently provided by Dan Jarvie of Humble Geochemical Services.Jarvie of Humble Geochemical Services.


Geophysical log modelingGeophysical log modeling

• A quick historical perspectiveA quick historical perspective• Mineralogical model Mineralogical model • Kerogen issuesKerogen issues


Geophysical log modeling – some historyGeophysical log modeling – some history

• Much of the methodology used today to come from work Much of the methodology used today to come from work performed on the T.P. Sims #2 core (ResTech, 1991)performed on the T.P. Sims #2 core (ResTech, 1991)

• This methodology derives from work done earlier on the This methodology derives from work done earlier on the Devonian Shale (GRI, 1989)Devonian Shale (GRI, 1989)

• Few data have been published subsequently.Few data have been published subsequently.


Geophysical log modeling - MineralogyGeophysical log modeling - Mineralogy

Mineralogy distributionW. C. Young #2

0

10

20

30

40

50

60

70

80

90

Total Clay Quartz K-Feldspar Plagioclase Calcite Dolomite Pyrite Apatite

Volume (%)

Q1 Min Median Max Q3


Geophysical log modeling - KerogenGeophysical log modeling - Kerogen

Kerogen is a wildcard Kerogen is a wildcard • It appears as porosity on logsIt appears as porosity on logs• It has a nominal density of about 1.0 to 1.2 g/cc It has a nominal density of about 1.0 to 1.2 g/cc

(but it is probably more variable)(but it is probably more variable)• It has a hydrogen index of about 0.65 to 0.70 It has a hydrogen index of about 0.65 to 0.70

(water = 1.0)(water = 1.0)



k

Sk C

CSTOCW

)(11 ×−

=

(from Guidry and Olszewski, 1990) where:Wk is the weight of kerogenTOC is the weight fraction of total organic carbon S1 is the weight fraction of free oilCS1

is the weight fraction of carbon in the free oil

Ck is the weight fraction of carbon in the kerogen

Guidry and Olszewski (1990) suggest 0.87 and 0.75 for CS1 and Ck

respectively. Jarvie (1999) recommends a value of 0.83 for CS1.



where:Vk is the volume fraction of kerogenWk is the weight of kerogenB is the bulk densityk is the kerogen density

k

Bkk

WV

×

=



• The preceding is from derived from core data, not log The preceding is from derived from core data, not log datadata

• Initially, correlations have to be developed to estimate Initially, correlations have to be developed to estimate kerogen volume from logskerogen volume from logs

• This work is currently in progressThis work is currently in progress


Geophysical log modeling Geophysical log modeling

• We have a mineralogical model of clay, quartz, calcite, We have a mineralogical model of clay, quartz, calcite, dolomite, pyrite, apatite, kerogen, and fluids (water and dolomite, pyrite, apatite, kerogen, and fluids (water and gas)gas)

• We have a set of logs that have known or estimated We have a set of logs that have known or estimated responses to each of these model pointsresponses to each of these model points

• We can construct a set of equations to describe these We can construct a set of equations to describe these relationships relationships


Geophysical log modeling Geophysical log modeling

• This leads to a set of simultaneous equations that allow This leads to a set of simultaneous equations that allow us to solve for the volumes of the geologic constituents us to solve for the volumes of the geologic constituents presentpresent

• This is fundamentally the same approach used by This is fundamentally the same approach used by programs such as programs such as ELANELAN™ ™ andand OPTIMA™ OPTIMA™

• We use the We use the GeologGeolog™ package ™ package MultiMin™MultiMin™


Overview of what the logs show Overview of what the logs show

Texas Blakely #1 wireline log analysisTexas Blakely #1 wireline log analysis


Texas United Blakely #1Texas United Blakely #1


CaliperIN6 16

Total gamma rayGAPI0 300

Corrected gamma rayGAPI0 300

7100

7200

7300

7400

DEPTHFEET

Potassium%-5 5

ThoriumPPM0 40

UraniumPPM-10 30

Neutron porosityV/V0.3 -0.1

Bulk densityG/C32 3

Shallow focussed logMMHO0.2 2000

Medium inductionOHMM0.2 2000

Deep inductionOHMM0.2 2000



7090 7250Depth (feet)

0.00

0.05

0.10

0.15

0.20

0.25

2.40

2.45

2.50

2.55

2.60

2.65

2.70

Bulk density (g/c3)

Neutron porosity (v/v)

0.05

0.1

0.15

0 300Total gamma ray (gapi)

0.00

0.05

0.10

0.15

0.20

0.25

2.40

2.45

2.50

2.55

2.60

2.65

2.70

Bulk density (g/c3)


0.05

0.1

0.15



0 300Total gamma ray (gapi)

0.00

0.05

0.10

0.15

0.20

0.25

2.40

2.45

2.50

2.55

2.60

2.65

2.70

Bulk density (g/c3)


0.05

0.1

0.15

0 7Total organic carbon (wt. %)

0.00

0.05

0.10

0.15

0.20

0.25

2.40

2.45

2.50

2.55

2.60

2.65

2.70

Bulk density (g/c3)


0.05

0.1

0.15



CaliperIN6 16



7100

7200

7300

7400

DEPTHFEET

Potassium%-5 5

ThoriumPPM0 40

UraniumPPM-10 30


Bulk densityG/C32 3






7090 7250Depth (feet)

2.30

2.40

2.50

2.60

2.70

0

1

2

3

4

5

6

7

8

Total organic carbon (wt. %)

Bulk density (g/c3)7090 7250

Depth (feet)

0 3 6 9 12 1

50

1

2

3

4

5

6

7

8

Total organic carbon (wt. %)

Uranium (ppm)



CaliperIN6 16



7100

7200

7300

7400

DEPTHFEET

Potassium%-5 5

ThoriumPPM0 40

UraniumPPM-10 30


Bulk densityG/C32 3






Total gamma RayGAPI0 300

7100

7200

7300

7400

Depthfeet Thorium - Potassium Ratio (smoothed)

0.5 50



0.0

0.5

1.0

1.5

2.0

2.5

0

2

4

6

8

10

Thorium (ppm)

Potassium (wt. %)

7050 7450Depth

Feldspars and potassium evaporites

Micas including glauconite

Illite

Mix

ed

la

ye

r c

lay

s

Kaolinite

Heavy Thorium bearing minerals



SummarySummary

• We have just begun to build an extensive Barnett We have just begun to build an extensive Barnett databasedatabase

• We already have a basic model to analyze the Barnett We already have a basic model to analyze the Barnett from wireline logsfrom wireline logs

• Work to date suggest that logs will be of great value in Work to date suggest that logs will be of great value in providing detailed data on Barnett mineralogy and facies. providing detailed data on Barnett mineralogy and facies. More core-based work is necessary to verify this and More core-based work is necessary to verify this and and refine our initial modeland refine our initial model

petrophysical characterization of the barnett shale: progress report

Documents

log data1

limited p p data1

mineralogy data1

geochemical data2

core restech

barnett shale

capillary pressure data2

devonian shale gri