Coalbed methane exploration in the Powder River basin represents an active
play with considerable potential for future expansion and success. Such pot
ential is related to the specific geology and character of the target coals
, which exist in the Paleocene Fort Union Formation at depths of 300-2000 f
t (91-610 m). Although of low rank (lignite-subbituminous), these coals are
volumetrically very large, consisting of thick (50-150 ft;15-45 m), latera
lly extensive seams with significant amounts of late-stage biogenic methane
. Wells drilled to exploit this resource in updip areas have benefited from
dewatering associated with existing coal mining, as well as from existing
pipeline infrastructure. In downdip areas, Fort Union coal beds are artesia
n aquifers and require significant drawdown for gas production. Innovative
drilling and completion practices have been instrumental in lowering costs
and increasing production, thus contributing to the overall success of the
existing-play Production data suggest ultimate recoverable reserves of 0.3-
0.4 bcf per well, making the play economical even at relatively low gas pri
ces.