Abstract: Coal-Bed Gas Potential in Ohio: Case Study of the Nelms Project, Harrison County

WOLFE, MARK E.
Ohio Division of Geological Survey, Columbus, OH

The coal bed gas production potential in Ohio has not been adequately evaluated. Regional estimates of the total coal-bed gas in place for eastern Ohio exceed 2 trillion cubic ft.

Commercial production of coal-bed gas in Ohio began in 1992 at the abandoned Nelms No. 1 underground mine located in Green Township, Harrison County. By 1998, gas production from several converted mine vents was as much as 3 million cubic ft per day.

The gas at the Nelms mine is produced from the Lower Freeport (No. 6A) coal bed of the Pennsylvanian Allegheny Group. Average depth to the top of the coal is 525 ft. Coal thickness averages 65 inches. The Lower Freeport (No. 6A) is a blocky, bituminous coal that has a rank of high-volatile A and is typically found as a single bench.

The Nelms project is located on the eastern flank of a north-southtrending structural feature that has been mapped on both the overlying Pittsburgh (No. 8) coal and the underlying Mississippian Berea Sandstone. Air-photo and satellite lineaments support the suggestion that structure and fracturing played important roles in coal-bed gas reservoir development.

Eastern Ohio contains multiple deep, relatively thick coals, as well as historically hydrocarbon productive sandstones, which may have potential for multiple zone completion. The thousands of abandoned underground coal mines in the state may also have coal-bed gasproduction potential in areas where geologic and hydrogeologic conditions are favorable.

AAPG Search and Discovery Article #90930©1998 AAPG Eastern Section, Columbus, Ohio