COAL BED METHANE POTENTIAL OF THE WESTERN KENTUCKY COAL FIELD

The Western Kentucky Coal Field (WKCF) is the southern tip of the Eastern Interior, or Illinois, Basin. Although some 36 billion tons of coal reserves remain, recent production has been significantly affected by the Clean Air Act Amendments of 1990, which greatly restricts sulfur dioxide emissions. As a result, coal production in western Kentucky between 1991 and 2001 has decreased by 41 %, mainly because most of the coals in the WKCF are high in sulfur content (typically > 3 %). As such, the development of coal bed methane from western Kentucky coals may be one way to exploit this increasingly idled energy resource. Currently, there is a great demand for natural gas in the U.S, as consumption by both the residential and industrial sectors continues to rise. This is especially true in the electric utility industry, which has largely chosen to replace existing capacity, and add new generating capability, with natural gas-fired power plants. Indeed, the U.S. Department of Energy predicts that natural gas consumption by 2025 will have increased more than 30 %, primarily because of the increased use of natural gas for electricity generation. It is likely that coal bed methane, which currently contributes about 10 % of total U.S. gas production, will play an increasingly important role in satisfying this increased need. The high demand and higher price for natural gas has encouraged developers to look at areas previously considered to be uneconomical. The WKCF, and Illinois Basin in general, is one of these areas. Historical gas content data have indicated very low (< 50 scf/ton in many cases) gas contents, which has largely discouraged exploration and development. However, more recently-acquired data have shown that gas contents may be much higher than previously considered, in some instances > 150 scf/ton. Current research in the WKCF is directed at locating areas with high (> 10 m) cumulative coal thickness principally within the Carbondale and Shelburn Formations, which contain the thickest and most laterally-extensive coals in western Kentucky. Older coal-bearing strata assigned to the Tradewater Formation, is also being evaluated, for coal bed methane potential.