Coal-bed Methane Discoveries in Powder River Basin
MATSON, ROBERT E., Consultant, Butte, MT
The Powder River basin of northeastern Wyoming and southeastern Montana contains the nation's largest supply of subbituminous coal. The coal beds have been mapped with surprising continuity, with thickness of individual beds exceeding 200 ft. The Paleocene Tongue River Member of the Fort Union Formation contains the bulk of the reserves. The coal near surface along the eastern part of the basin is subbituminous C, while in the deeper part and in the northwestern part of the basin the rank is subbituminous B or A.
Commercial exploitation of methane in the Powder River was initiated by Wyatt Petroleum in the Recluse area north of Gillette in 1986. Early production was from sands occurring between major coal beds. Production directly from coal beds along the shallow eastern part of the Powder River basin was achieved by Betop Inc. in the Rawhide field a short distance north of Gillette in early 1989 from five wells. Fifteen additional wells were drilled and completed in the field in late 1990. Other shallow coal-bed methane production has been achieved from the same thick Wyodak coalbed nearby by Martins and Peck Operating, Wasatch Energy, and DCD Inc.
Numerous deeper tests have been drilled and tested by various companies including Coastal Oil and Gas, Materi Exploration, Cenex, Gilmore Oil and Gas, and Betop Inc., none of which has attained commercial success.
Recent exploration in the northwestern part of the basin has resulted in two apparent discoveries.
AAPG Search and Discovery Article #91010©1991 AAPG Rocky Mountain Section Meeting, Billings, Montana, July 28-31, 1991 (2009)