Almost all coal beds contain gases within internal pore spaces and fractures. These gases, which consist mostly of methane, are generally hazardous to mining operations and may form explosive mixtures with oxygen where they are not properly vented from underground coal mining operations. In places, the gas is so abundant that it constitutes an economic resource and is produced from wells. Wells are drilled into unmined coal, which is then fractured artificially in order to release the gas to the well bore in relatively large quantities. Alternatively, wells drain mine gases from the broken down rock (gob) associated with underground coal mining.

Coalbed methane (CBM) occurs in coal beds of Mississippian and Pennsylvanian (Carboniferous) age in the Appalachian basin, which extends almost continuously from New York to Alabama. In general, the basin includes three structural subbasins: the Dunkard basin in Pennsylvania, Ohio, and northern West Virginia; the Pocahontas basin in southern West Virginia, eastern Kentucky, and southwestern Virginia; and the Black Warrior basin in Alabama and Mississippi. For assessment purposes, the Appalachian basin was divided into two assessment provinces: the Appalachian Basin Province from New York to Alabama, and the Black Warrior Basin Province in Alabama and Mississippi. By far, most of the coalbed methane produced in the entire Appalachian basin has come from the Black Warrior Basin Province.

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