mississippian madison limestone, uinta mountains – outcrop ...river. note the cavernous nature of...

UTAH GEOLOGICAL SURVEYDEPARTMENT OF NATURAL RESOURCES

L E A D V I L L E L I M E S T O N E R E S E R V O I RC H A R A C T E R I S T I C S

• Net pay – 27 to 225 ft (8-69 m)

• Depositional environments – shallow marine, subtidal, supratidal,intertidal, local buildups or mounds

• Carbonate fabrics - mudstone, wackestone, packstone,grainstone, boundstone (limestone and dolomite)

• Pore types – intercrystalline, moldic, vugs

• Porosity - averages 6-8%, enhanced by natural fracture systems

• Permeability – less than 1 md to 1100 md, averaging 22 md

• Solution breccia and karstified surfaces are common; localcavernous zones

M A D I S O N L I M E S T O N E O U T C R O P C H A R A C T E R I S T I C S

A

A – Location of Mississippian rock outcrops in Utah equivalent to the LeadvilleLimestone. B - Stratigraphic column of a portion of the Paleozoic sectionalong the south flank of the Uinta Mountains (modified from Hintze, 1993).

B

Wayne Co.

Garf ie ld Co.

Grand Co.

Navajo Co.Apache Co.

San Juan Co.

LaPlataCo.

Montezuma Co.

Dolores Co.

San Miguel Co.

Montrose Co.

Ouray Co.

MesaCo.

Emery Co.

COLORADONEW MEXICO

UTAHARIZONA

San Juan Co.

LisbonSoutheast

LittleValley

Lisbon

Big Indian

BigFlat

SaltWash

Cleft

Dry Mesa

UTAH COLO.

N.MEX.ARIZ.

Durango

Cortez

Rico

CrescentJunction

GreenRiver

Monticello

Moab

NUncompahgre uplift

0 20 mi

30 km0

Color

ado

River

River

Green

Paradox Basin

San Juan River

PA

RA

DO

X

FO

LD

A

ND

F

AU

LT

B

EL

T

700

600

400

500

600

700 500

200

400

500

700

300

200

0

300

300

Modified from Parkerand Roberts, 1963

Location of reservoirs that produce oil (green) and gas and condensate (red)from the Mississippian Leadville Limestone, Utah and Colorado. Thickness of

the Leadville is shown; contour interval is 100 ft (modified from Parker andRoberts, 1963). The Leadville Limestone play area is dotted.

Typical gamma ray-sonic log of the Leadville Limestone,Lisbon field discovery well, San Juan County, Utah.

Mississippian Deseret Limestone (Madison equivalent)forming a jagged, vertical cliff, North Fork of the Duchesne

River. Note the cavernous nature of the outcrop.

Typical Madison Limestone exposure of light to darkgray, medium bedded, fine to coarse crystalline,

limestone and dolomite containing fractures,stylolites, and crinoid hash, Whiterocks Canyon.

Vugs and fractures in limestone and dolomitic units,Whiterocks Canyon.

Close-up of open and calcite-filled vugs in limestonematrix, Whiterocks Canyon.

Close-up of small-scale, calcite-filled rectilinearfractures in limestone matrix, Whiterocks Canyon.

A combination of interbedded limestone anddolomite, containing fractures and zones of solution

breccia and vugs, results in a heterogeneousstratigraphic section, Dry Fork Canyon.

Possible small-scale carbonate buildup or mud mound(outcrop is approximately 10 ft [3 m] high), Dry Fork Canyon.

Mississippian Madison Limestone, Uinta Mountains – Outcrop Analogfor the Mississippian Leadville Limestone Reservoir, Paradox Basin

Mississippian Madison Limestone, Uinta Mountains – Outcrop Analogfor the Mississippian Leadville Limestone Reservoir, Paradox Basin