ABSTRACT: Coalbed Methane Exploration and Results: Richmond Basin, Virginia

KNOX, LARRY M., JOSEPH L. COOPER, MICHAEL N. HUGENTOBLER, and MANUEL J. VALLE, Amoco Production Company, Houston, TX

Limited well information combined with data from old mine workings initially suggested significant potential for commercial coalbed methane development within the Richmond basin of Virginia. Estimates of the gas resource ranged as high as 39.6 billion cubic meters m (1.4 tcf) for the 400 sq. kilometers (100,000 ac) basin.

In mid-1989 to early 1990, Amoco Production Company cored six holes to test this potential: the shallowest 550 m (1806 ft) and the deepest 1215 m (3988 ft). Three cores were drilled to basement. Coals were penetrated at depths ranging from 366 m (1200 ft) to 892 (2928 ft). Comprehensive field and laboratory analyses of the coals yielded sufficient gas content and saturation for commercial coalbed methane potential. However, seam thicknesses and total net coal thicknesses appeared quite variable and unpredictable.

This information, combined with the previously existing data, suggests a complex structural and depositional history for the coal sequences. Cultural development compounds this problem in parts of the basin, making many areas inaccessible for exploration and development. As a result it is highly unlikely that any area exists of sufficient size to allow any commercial coalbed methane development within the Richmond basin.

AAPG Search and Discovery Article #91012©1992 AAPG Annual Meeting, Calgary, Alberta, Canada, June 22-25, 1992 (2009)