Reservoir Characteristics and Gas Production Potential of Woodford Shale in the Southern Midcontinent

IA N A G EO LOG ICAL S UR V E Y 8 1 IN D I A N A U N I VER SI T Y

John B. Comer

Indiana Geological Survey Indiana University 812-855-2687 [email protected]

Distribution of Devonian Black Shale

Williston Basin A nt le r o F B d n la re Michigan Basin Illinois Basin A p p al ac B h as ia in n Permian Basin Anadarko Basin Outcrop belt Mostly subsurface Modified from Juergen Schieber, 2004

Woodford Lithofacies in the Southern Midcontinent

• • • • • •

Black shale Siltstone Dolostone Chert Sandstone Mudstone

• • • • • •

Bypassed settings Proximal and basin centers Proximal and basin centers Distal to open ocean Proximal and locally derived Local

Log Characteristics Texas and New Mexico

Pan American No. 1 Walker Mobil No. 1918 Parks Unit 2 Shell No. 1 Chriesman Shell No. 5 Pacific Royalty

Reference log from Ellison (1950) Comer (1991) Fig. 7

Fractured Woodford Shale Reservoirs

North Aylesworth Field Marshall County, Oklahoma Texaco 1-K Drummond, 11-6S-6E

Comer (1992) location A33; Comer (1987) Fig. 5e

Southeast Joiner City Field Carter County, Oklahoma California No. 1 Mullen, 29-5S-2W

Comer (1992) location A21; Comer (1987) Fig. 5a

3,065 ft 7.8 % TOC 1.0 mm Vertical fractures and 8,983 ft 5.5 % TOC stylolites filled with bitumen Tension gash filled with chert Recrystallized Radiolaria 0.2 mm

Fractured Woodford, Anadarko Basin

Columbia Fuel #1 Rainy Mountain, Kiowa County, Oklahoma, 23-6N-15W, 760 ft

Comer (1992) location A25; Comer (1987) Fig. 4a-d

8.1 % TOC 0.61 % R o Bitumen Calcite Core diameter = 2 inches 1 mm

Fractured Woodford, Permian Basin

Humble No. 43 Yarborough & Allen, Ward County, Texas, Section 66, E. J. Brady Survey Comer (1991) location C2, sample C2-5 Calcite 7175 ft 1 cm 10.1 % TOC 0.55 % R o Type II Kerogen 0.2 mm

Interbedded Black Shale and Chert Lithofacies, Southern Oklahoma

Arbuckle Mountain Uplift outcrop, Murray County, Oklahoma, 1-2S-2E Comer (1992) location OK26, Hwy 110 2 miles north of Dougherty; Comer (1987) Fig. 7a Chert Black Shale Chert Black Shale Chert Black Shale Chert 0.2 m

Black Shale and Chert Petrology, Southern Oklahoma

Comer (1992) location OK35 Arbuckle Mtn Uplift 25-2S-1E; Comer (1987) Fig. 7c Comer (1992) location OK 55 Ouachita frontal zone 4-2N-15E; Comer (1987) Fig. 7b Black Shale

•

Highly compacted

•

Flattened Tasmanites spores (T)

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Amorphous Type II organic matter (AOM)

•

Little or no chert Up to 35 % TOC Chert

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Tasmanites spores (T) uncompacted or slightly flattened (early chert (CT) cementation)

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Amorphous Type II Organic Matter (uncompacted)

•

Well indurated, brittle, and tightly sealed Up to 6.4 % TOC 0.2 mm 0.2 mm

Chattanooga Shale, Ozark Uplift, Belle Vista, Benton County, Arkansas

US 71 12-20N-31W Comer (1992) location AR1

Black Shale – Sandstone Association, Ozark Uplift

Sylamore Sandstone Type Area, 21-15N-11W, Stone County, Arkansas Interbedded black shale and medium-grained supermature quartzarenite 8.5 ft thick; Quartz inherited from Middle Ordovician sandstones

Phosphate

Comer (1992) location AR9 Comer (1987) Fig. 3a-c

Black Shale Oil Residue Black Shale 3.5 % TOC (avg) 0.83 % R o (avg) 0.75 mm Black Shale consists of zones of (1) amorphous marine Type II kerogen (2) (3) terrestrial Type III kerogen mixed marine and terrestrial kerogen Quartz 0.2 mm

Black Shale Characteristics

Mobil No. 1918 Parks Unit 2, Midland County, Texas, Section 14, Block 40, C. F. O’Neal Survey 11,544 ft, 3.1 % TOC Comer (1991) location C1, sample C1-5 1 cm

• •

Parallel laminae Abundant pyrite

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Fine grain size Black color High radioactivity

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Abundant organic carbon

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Amorphous (marine) type II kerogen 11,555 ft 4.2 % TOC Comer (1991) location C1, sample C1-10, Fig. 4a 3 mm

Siltstone Characteristics

Shell A No. 1 Williamson, Gaines County, Texas, Section 110, Block H, D&WRR Survey, 13,064 ft

1 cm

Comer (1991) location C11, sample C11-10

Siltstone Characteristics

• • • •

Shell A No. 1 Williamson, Gaines County, Texas, Section 110, Block H, D&W RR Survey, 13,064 ft Comer (1991) location C11, sample 11-10, Fig. 5h Siltstone Characteristics Subequal random mixture of detrital dolomite (48%) and quartz (52%) Median grain size is 0.05 mm (coarse silt) for both dolomite and quartz Dolomite is angular and abraded with random orientations and uniform texture Siltstone is dense and well indurated

0.1 mm

C (Rippled) B (Flat) A (Graded)

Siltstone Depositional Processes

Silt was deposited by bottom flows Ripple wavelength ~ 1.5 cm Bouma Sequence Scoured Base Humble No. 1 A. E. State, Lea County, New Mexico, 16-15S-33E, 13,768 ft Comer (1991) location C3, sample C3-5, Fig. 5e

3 mm

Lithologic Variations, Texas and New Mexico

Modified from Comer (1991) Fig. 9

Woodford Resource Potential

TOC Nemeha Uplift Catagenesis Northern Oklahoma Platform

{

Anadarko Wich Hollis Basin ita M in tn.

EXPLANATION Units = %R >6 o Basin Central Oklahoma Platform Oklahoma City Arbuckle Mtn. Uplift Arkoma Basin Ouachita Tectonic Belt Ozark Uplift Little Rock Mississippi Embayment Gulf Coastal Plain Metagenesis

{

2.00 - 5.00 Gas generation <2 Modified from Comer (2005)

OK.

Woodford Resource Potential

In-Place Estimates Based On Hydrogen Mass Balance 600 x 10 12 ft 3 60 x 10 9 bbl 4.4 x 10 12 ft 3 70 x 10 9 bbl 0.24 x 10 12 ft 3 N EXPLANATION ARK.

Probable success - highly fractured Possible success - sparsely fractued or deep Local success - conventional reservoir lithologies or local fractures Poor success - metamorphic or outcrop 0 0 Woodford or equivalent absent TOTAL RESOURCE POTENTIAL Total Estimated Oil-in-Place 130 x 10 9 bbl Total Estimated Gas-In-Place 600 x 10 12 ft 3 100 Miles 160 Km Modified from Comer (2005)

Woodford Resource Potential

THERMAL MATURITY Northwestern Shelf Carlsbad N.M.

Delaware Basin M M EX IC O O Diablo Platform 0 0 0 0 Midland Basin Central Basin Platform Midland TX.

Pecos Arch Val Verde Basin Ouachita Tectonic Belt N 50 Miles Eastern Shelf >6 Cata 4 - 6

{

2 - 4 EXPLANATION Units = %R o 0.35 - 0.60 Early oil generation 0.60 - 1.50 Oil window 1.50 - 2.00 Wet gas and condensate generation 2.00 - 5.00 Gas generation New Mexico Texas Modified from Comer (2005)

35 x 10 9 bbl 0.11 x 10 12 ft 3

Woodford Resource Potential

In-Place Estimates Based On Hydrogen Mass Balance PRODUCTION POTENTIAL N.M.

Carlsbad EXPLANATION Probable success - highly fractured Possible success - sparsely fractured or deep Local success - conventional reservoir lithologies or local fractures Poor success - source beds absent Woodford or equivalent absent Midland 84 x 10 9 bbl 9.0 x 10 12 ft 3 220 x 10 12 ft 3 M EX IC O N TX.

New Mexico Texas 0 50 Miles 0 80 Km TOTAL RESOURCE POTENTIAL Total Estimated Oil-in-Place 120 x 10 9 bbl Total Estimated Gas-In-Place 230 x 10 12 ft 3 Modified from Comer (2005)

Conclusions

• •

Unconventional gas discoveries in Woodford Shale are likely in both the Anadarko and Permian Basins and adjacent provinces where

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Woodford Shale is thermally mature

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Fractures are common

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Competent lithofacies (chert, siltstone, dolostone, sandstone, silty black shale) are abundant Areas having greatest gas production potential and most prospective lithologies are the

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Anadarko Basin in Oklahoma (siltstone and silty black shale)

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Arkoma Basin in Oklahoma and Arkansas (silty black shale)

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Frontal zone of Ouachita fold belt in Oklahoma (chert) Delaware Basin in Texas and New Mexico (siltstone and silty black shale)

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Val Verde and Midland Basins in Texas (siltstone and silty black shale)

Key References

• • • • •

Comer, J. B

., 1991, Stratigraphic analysis of the Upper Devonian Woodford Formation, Permian Basin, West Texas and southeastern New Mexico: Austin, Texas, Bureau of Economic Geology, Report of Investigations 201, 63 p.

Comer, J. B

., 1992, Organic geochemistry and paleogeography of Upper Devonian formations in Oklahoma and northwestern Arkansas,

in

K. S. Johnson, and B. J. Cardott, eds., Source Rocks in the Southern Midcontinent, 1990 Symposium: Norman, Oklahoma, Oklahoma Geological Survey, Circular 93, p. 70-93.

Comer, J. B

., 2005, Facies distribution and hydrocarbon production potential of Woodford Shale in the southern Midcontinent, 110, p. 51-62.

in

B. J. Cardott, ed., Unconventional Energy Resources in the Southern Midcontinent, 2004 Symposium: Norman, Oklahoma, Oklahoma Geological Survey, Circular

Comer, J. B., and H. H. Hinch

Bulletin, v. 71, p. 844-858.

, 1987, Recognizing and quantifying expulsion of oil from the Woodford Formation and age-equivalent rocks in Oklahoma and Arkansas: American Association of Petroleum Geologists

Ellison, S. P

., 1950, Subsurface Woodford black shale, west Texas and southeast New Mexico: Austin, Texas, Bureau of Economic Geology, Report of Investigations 7, 20 p.