Devonian shales of central Appalachian basin: geological controls on gas production

Conference · Wed Mar 01 04:00:00 EST 1989 · AAPG Bulletin (American Association of Petroleum Geologists); (USA)

OSTI ID:5717775

Lowry, P H; Hamilton-Smith, T; Peterson, R M ^[1]

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1. K and A Energy Consultants, Inc., Tulsa, OK (USA)

Gas reserves of the Devonian shales of the Appalachian basin constitute a large, underdeveloped resource producing from fractured reservoirs. As part of ongoing Gas Research Institute research, K and A Energy Consultants, Inc., is identifying geological controls on gas production. Preliminary findings indicate that local gas production is controlled by a combination of structure and stratigraphy. Regional geological review indicates that Devonian sedimentation and structure is influenced by repeated reactivation of basement faults. Site-specific geologic studies indicate that depositional and structural mechanisms vary substantially throughout the basin. Gas production on the eastern margin of the producing area is controlled by an Alleghenian thrust front located by Grenville normal faults. High-capacity wells are associated with tear faults in the thrust sheets. To the southwest, deformation is controlled by both Grenville and Rome trough basement faults. Reactivation of these faults during later orogenic events produced a complex of high-angle reverse and strike-slip faults. Fracturing in the Devonian shales is produced by shearing and flexure associated with these structures. Syndepositional movement of the basement structures influenced the deposition of coarser grained turbidites and tempestites. The combination of fractures and coarser clastic beds provides effective reservoir systems. The shale contains abundant organic material consisting of terrestrial plant debris and marine algal remains. Thermal maturation of this material produced gas which charged the lower reservoir systems. Exploration along reactivated structural trends is an effective strategy for locating Devonian shale gas accumulations. This approach may also apply to other producing strata in the basin.

• OSTI ID: 5717775
• Report Number(s): CONF-890404--
• Conference Information: Journal Name: AAPG Bulletin (American Association of Petroleum Geologists); (USA) Journal Volume: 73:3
• Country of Publication: United States
• Language: English

Related Subjects

03 NATURAL GAS
030200* -- Natural Gas-- Reserves
Geology
& Exploration
APPALACHIAN BASIN
DEVONIAN PERIOD
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GEOLOGIC FAULTS
GEOLOGIC FRACTURES
GEOLOGIC STRUCTURES
GEOLOGIC TRAPS
GEOLOGY
MINERAL RESOURCES
NATURAL GAS DEPOSITS
PALEOZOIC ERA
RESERVOIR ROCK
RESOURCES
ROCKS
SEDIMENTARY BASINS
SEDIMENTARY ROCKS
SHALES