Coal Bed Methane Research in West Virginia's Northern Coalfield

Abstract

Production of coal bed methane from virgin coal beds within the northern West Virginia coalfield is presently limited to several small fields in Wetzel County. Approximately 50 years of periodic activity have yielded wells with reported initial productions of between 30 and 60 mcf per day from the 500-ft-deep Pittsburgh and slightly shallower Sewickley coal beds. Current exploration within this region is focused on multiple-seam completions, utilizing the more predictable areal geology of the Sewickley and Pittsburgh coal beds (Upper Pennsylvanian/Monongahela Group), plus the assumed higher methane potential of the more deeply buried and less well studied Freeport and Kittanning (Middle Pennsylvanian/Allegheny Formation) and the undivided Pottsville Group (Lower to Middle Pennsylvanian) coal beds. Regional gas contents indicate moderately gassy (generally less than 200 ft{sup 3} of gas per ton of coal) coal beds. The West Virginia Geological and Economic Survey is using a Gas Research Institute grant to review available data describing the occurrence of coal, oil, gas, and water in West Virginia's northern coalfield. Subdrainage overburden maps, which eliminate the impact of topography on overburden calculations, have been constructed to assist both regional and local exploration. Limited core samples are available to study the relationship between vitrinite reflectancemore » and gas contents. Similar studies involving gas content versus ash content of in-seam benches are planned. Preliminary coal isopleth maps indicate a greater frequency of occurrence of coal beds in the southern portion of the study area.« less