David G. Hill¹, Charles R. Nelson²

(1) Gas Technology Institute, Chicago, IL
(2) TICORA Geosciences, Inc, Arvada, CO

ABSTRACT: Geologic Characteristics of Frontier Coalbed Methane Plays in North America

Coalbed methane reservoirs currently account for 7% (1.3 Tcf) of total annual U.S. dry natural gas production. To date, most coalbed methane production comes from just three play areas, the Fruitland Formation coal in the San Juan Basin, the Pottsville Formation coal in the Black Warrior Basin and the Pocahontas Formation coal in the Central Appalachian Basin. However, new play areas in the Raton, Uinta and Powder River basins have started producing significant quantities of coalbed methane. These new plays are particularly noteworthy because a decade ago industry viewed the coalbed methane resources in these three basins as having very little commercial development potential.

Industry's recent experiences in the Raton, Uinta and Powder River basins have demonstrated that every coalbed methane play is unique and must be examined, explored and exploited differently. The U.S. lower-48 states contain an estimated 740.5 Tcf of coalbed methane resources. Roughly, 85.9 % (635.9 Tcf) of this enormous coalbed methane resource base is located in frontier play areas, i.e., formations, depth intervals or geographic areas from which there has been no prior large-scale commercial exploitation of coalbed methane resources. This paper will compare industry's historic and current approaches to evaluating the geologic characteristics and development potential of coalbed methane resources in four frontier play areas in North America. These frontier plays are the relatively shallow coal resources in the Illinois Basin and Alberta Plains, the low rank coal resources in the Denver Basin, and the deep (>4,500 ft) coal resources in the U.S. Rocky Mountain region.

AAPG Search and Discovery Article #90906©2001 AAPG Annual Convention, Denver, Colorado