Results of coalbed-methane drilling, Meadowfill Landfill, Harrison County, West Virginia

The U.S. Environmental Protection Agency funded drilling of a borehole (39.33889°N., 80.26542°W.) to evaluate the potential of enhanced coalbed-methane production from unminable Pennsylvanian coal beds at the Meadowfill Landfill near Bridgeport, Harrison County, W. Va. The drilling commenced on June 17, 2004, and was completed on July 1, 2004. The total depth of the borehole was 1,081 feet (ft) and contained 1,053.95 ft of Pennsylvanian coal-bearing strata, and 27.05 ft of Mississippian strata.

A total of 37.02 ft of high-volatile A and B bituminous Pennsylvanian coal was cored and desorbed from the Harlem, Brush Creek, Upper Freeport, Upper Kittanning upper split, and Upper Kittanning coal beds and the Clarion coal zone. Intact coal intervals were desorbed for a maximum period of 92 days before they were crushed to approximately 10-mesh to determine residual gas amounts. Crushed coal was desorbed for a period of 36 days. Measured gas content, on a dry, ash-free basis, ranged from 79.69 standard cubic feet per ton (SCF/ton), or 2.49 cubic centimeters per gram (cc/g), for the Harlem coal bed to 223.21 SCF/ton, or 6.98 cc/g, for the Clarion coal zone.

Methane contents of desorbed gas from coal samples in the Meadowfill Landfill study area ranged from 14.87 to 98.73 percent (corrected for air contamination) for the Harlem coal bed and Clarion coal zone, respectively. Proportions of methane to the sum of the higher molecular weight hydrocarbons ranged from about 40 to 340 as the desorbed gas contained only a small percentage of higher weight hydrocarbons. Coalbed methane from the Upper Kittanning upper split and the Upper Kittanning coal beds is thermogenic in origin with isotopic composition of carbon (carbon 13, ¹³C) in methane (expressed as δ¹³C in units of parts per thousand (per mil) relative to the Vienna Peedee belemnite (VPDB) standard) ranging from -46.6 to -48.7 per mil. Coalbed methane from the Brush Creek and Upper Freeport coal beds and the Clarion coal zone contains some biogenic methane with δ¹³C values ranging from -51.05 to -51.56 per mil.