WESTERN KENTUCKY COALS: POTENTIAL FOR COALBED METHANE AND GAS ADSORPTION

The Illinois Basin has not been developed for Coalbed Methane (CBM) production. If exploration is to progress and production occur in this area, it is necessary to determine both gas content and other parameters for the Kentucky portion of the Illinois Basin.

This research is part of a larger project conducted by the Kentucky Geological Survey (KGS) to evaluate the CBM production of Pennsylvanian-age western Kentucky coals in Ohio, Webster, and Union counties using methane adsorption isotherms, direct gas desorption measurements, and chemical analyses of coal and gas. The research will investigate relationships between CBM potential and petrographic, surface area, pore size, and gas adsorption isotherm analyses of the coals. Maceral and reflectance analyses were conducted at the Center for Applied Energy Research. Surface area and pore size of the coals were analyzed using a Micrometrics ASAP 2020 and the carbon dioxide isotherm analyses were conducted using a volumetric adsorption apparatus in a water temperature bath at the Indiana Geological Survey (IGS).

Site specific correlations for the Kentucky part of the Illinois Basin will be determined using the various analyses previously mentioned. The data collected will be compared with previous work in the Illinois Basin and will be correlated with the data and structural features in the basin. The Webster and Union County part of Western Kentucky may be unique with regard to the origin of CBM because gas composition and carbon and hydrogen isotopic data suggest mostly thermogenic origin of coalbed gas in contrast to its dominantly biogenic character in Ohio County, Kentucky.