Evaluating the Western Kentucky Coal Field for Economic Coal Bed Methane: An Update

Eble, Cortland F. and James A. Drahovzal
Kentucky Geological Survey, University of Kentucky, Lexington, KY

The Western Kentucky Coal Field is the southern tip of the Eastern Interior, or Illinois, Basin. An estimated 36 billion tons of coal remain in the Western Kentucky Coal Field, some of which may contain economically recoverable quantities of methane gas. This could be very important, considering that this important energy resource has been severely impacted by stringent SO2 emissions limits, with a 41 % decline in coal production occurring during the last decade.

Geologic analysis over the past 15 years indicates that economic coalbed methane will most likely be found in Carbondale and Shelburn Formations coals, as these beds are the thickest, and most laterally continuous coal beds in the Western Kentucky Coal Field. Principal target beds include the Davis through Baker coals. Some older Tradewater Formation coals, which are known to be locally thick (e.g., Mannington) may contain economically recoverable gas as well. An analysis of 20 borehole records from Webster and Union Counties indicates an average of 17 feet, and in some cases more than 25 feet, of coal thickness in the Davis through Baker interval. An overburden map on the Springfield coal indicates that a considerable amount of the Springfield exists at depths of 500 feet, or more, across a large part of the coal field. An even larger area has at least 200 feet, or more, of cover, demonstrating that the principal target coal beds have sufficient cover for coal bed methane production across most of the Western Kentucky Coal Field.

AAPG Search and Discovery Article #90031©2004 AAPG Eastern Section Meeting, Columbus, Ohio, October 3-5, 2004