Coalbed methane resources of the Appalachian Basin, eastern USA

International Journal of Coal Geology
By: , and 

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Abstract

In 2002, the U.S. Geological Survey (USGS) assessed the technically recoverable, undiscovered coalbed-gas resources in the Appalachian basin and Black Warrior basin Assessment Provinces as about 15.5 trillion cubic feet. Although these resources are almost equally divided between the two areas, most of the production occurs within relatively small areas within these Provinces, where local geological and geochemical attributes have resulted in the generation and retention of large amounts of methane within the coal beds and have enhanced the producibility of the gas from the coal. In the Appalachian basin, coalbed methane (CBM) tests are commonly commercial where the cumulative coal thickness completed in wells is greater than three meters (10 ft), the depth of burial of the coal beds is greater than 100 m (350 ft), and the coal is in the thermogenic gas window. In addition to the ubiquitous cleating within the coal beds, commercial production may be enhanced by secondary fracture porosity related to supplemental fracture systems within the coal beds. In order to release the methane from microporus coal matrix, most wells are dewatered prior to commercial production of gas. Two Total Petroleum Systems (TPS) were defined by the USGS during the assessment: the Pottsville Coal-bed gas TPS in Alabama, and the Carboniferous Coal-bed Gas TPS in Pennsylvania, Ohio, West Virginia, eastern Kentucky, Virginia, Tennessee, and Alabama. These were divided into seven assessment units, of which three had sufficient data to be assessed. Production rates are higher in most horizontal wells drilled into relatively thick coal beds, than in vertical wells; recovery per unit area is greater, and potential adverse environmental impact is decreased.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Coalbed methane resources of the Appalachian Basin, eastern USA
Series title International Journal of Coal Geology
DOI 10.1016/j.coal.2009.12.002
Volume 82
Issue 3-4
Year Published 2010
Language English
Publisher ScienceDirect
Contributing office(s) Eastern Energy Resources Science Center
Description 14 p.
First page 160
Last page 174
Country United States
Other Geospatial Appalachia basin and Black Warrior basin
Online Only (Y/N) N
Additional Online Files (Y/N) N