Abstract: Coalbed Methane Development in the Virginia Portion of the Central Appalachian Basin
NOLDE, JACK E., and DAVID B. SPEARS
The Virginia portion of the central Appalachian basin is only 7 percent of the basin area, yet contains nearly 95 percent of the basin's coalbed methane wells. This is because of geologic factors such as presence of multiple high-gas-content coal beds and thick overburden. Historical experience in degassing deep coal mines through vertical boreholes also favored development of the resource.
The most attractive methane-producing coal beds are in the Lower Pennsylvanian Lee, Pocahontas, and Norton Formations and limited to Buchanan, Dickenson, Russell, and Wise Counties. These coal beds are the Pocahontas No. 3 and 6, Little Fire Creek, Lower Horsepen, Beckley, War Creek, Middle and Upper Horsepen, and the Jawbone. These beds range from 0.5 to 7 feet in thickness.
Coalbed-methane well drilling and production have increased dramatically since 1988, in part because of non-geologic factors. The federal tax credit a part of the Crude Oil Windfall Profit Tax Act of 1980 was nearly 50 percent of the well head price of natural gas in Virginia in 1990. This was a profitable incentive for developers. The Virginia Gas and Oil Act of 1990 provided for forced pooling of coalbed methane royalties, resolving ownership uncertainties that previously constrained development. Introduction of multiple bed completion technology, developed in the Black Warrior basin, increased average per-well production. Starting March 1, 1997 there are 821 wells producing coalbed methane. In 1995, 681 wells yielded 30,355,870 Mcf of gas, nearly 61 percent of the annual natural gas production.
AAPG Search and Discovery Article #90939©1997 AAPG Eastern Section and TSOP, Lexington, Kentucky