Pennsylvania Coalbed Methane Update
Markowski, Antonette K.
Interest in the economic value and development of natural gas from coalbeds in Pennsylvania grew during the late 1980s, resulting in a dramatic increase in production a decade later. Major growth in coalbed methane (CBM) as an unconventional source of natural gas continued from 1999 to 2008. This occurred in part because of increased knowledge of the CBM reservoir, improvement in drilling technology, higher gas prices, more favorable national economic conditions, and the need to expand our domestic energy resources. Since then, the number of new well permits decreased in 2009 owing to the global recession and focus on the Middle Devonian Marcellus shale gas play. However, commercial quantities of CBM are still being produced in seven counties of the southern and southwestern portions of the Main Bituminous field.
According to the Pennsylvania Department of Environmental Protection and the Pennsylvania Geological Survey Wells Information System, there are a total of about 1,275 CBM wells in various stages of completion as of October 2012. The following coals of the Monongahela Group, Conemaugh Group, Allegheny Formation, and Pottsville Formation are among the principal CBM targets: Sewickley, Pittsburgh, Bakerstown (Upper and Lower), Brush Creek, Mahoning, Freeport (Upper and Lower), Kittanning (Upper, Middle, and Lower), Clarion, Brookville, and Mercer (Upper, Middle, and Lower). The most recent and complete annual production data compiled for 2008 reveals that CBM reached an all-time high of 11.6 billion cubic feet (Bcf). This could heat more than 168,100 households for a year. Currently, new production figures for 2009 through 2011 are being investigated to establish trends.
Total CBM resource estimates were quantified by the following sources: (1) Geomega, Inc. (1983 unpublished report)-2,654 Bcf for Pennsylvania anthracite and bituminous coal; (2) Gas Research Institute (1988)-51 trillion cubic feet (Tcf) gas-in-place for southwestern Pennsylvania and northwestern West Virginia; and (3) United States Geological Survey (1996)-11.5 Tcf economically recoverable for the Northern Appalachian coal basin (Pennsylvania, Ohio, Maryland, and northern West Virginia). CBM, an energy source that rivals conventional natural gas in composition and heating value, continues to make a valuable contribution to our domestic energy mix on state and national levels.
AAPG Search and Discovery Article #90163©2013AAPG 2013 Annual Convention and Exhibition, Pittsburgh, Pennsylvania, May 19-22, 2013