Throughout the history of gas exploration and development in the U.S., potentially recoverable quantities of methane from unconventional sources such as coalbeds have been largely excluded from potential gas supply surveys. This is attributable to the lack of data about the resource, technology, and economics of its recovery. In order to provide answers, DOE initiated the Methane Recovery from Coalbeds Project (MRCP) to characterise the gas-in-place for various coalbeds and associated sediments.
Preliminary resuits of the DOE Methane Recovery from Coalbeds Project reveal that many of the coal regions in the United States have significant volumes of coalbed methane. Preliminary gas-in-place resource estimates were made based on the volume of coal-in-place and on direct methane-desorption data. It has been conservatively estimated that 14 percent of the 48 conterminous states are underlain by coal-bearing rocks(1). Over 50 wells have helped to update the estimates of methane in these various coal regions. The evaluation of 11 basins by the MRCP reveal that the total resource estimated in-place is between 57 and 285 Tcf· Those basins showing high potential include the Northern Appalachian, Arkorna, Piceance, Warrior, Illinois, and Greater Green River.