Resource Assessment and Production Testing for Coalbed Methane Development in the Illinois Basin

The Illinois Basin has over 325 billion tons of remaining coal resources that is estimated to contain 11 trillion cubic feet (Tct), or more, of coalbed methane (CBM). To date, very limited amounts of this CBM have been produced, mainly because historical data have indicated low, uneconomic, gas contents. However, more recently acquired data suggest that gas contents in certain areas within the basin may be much higher than previously thought. As coal production within the basin continues to decline, mainly because of the high sulfur contents of most of the coals, production of CBM may be an effective way to use this vast energy resource to serve the nearby Jlfinois-Indiana primary market in an environmentally sound manner. Development of this resource would also contribute to the energy security of the nation, as a whole. The goal of this project is to obtain fundamental methane-content, permeability, and well-completion data for Jlfinois Basin coals from a selected set of core holes. Project results will encourage and support industry as they attempt to explore for and develop this important energy resource. Six exploration cores will be drilled in selected places in the basin to depths up to 1,500 feet. The well sites will be based on detailed geological analysis to determine the best possible areas for economic CBM. Coal samples from the cores will be placed in desorption canisters and measured for methane content. Certain organic-rich shales, which commonly overly many coals in the basin, will also be cored and tested for methane content. After desorption, the coal samples will undergo further petrographic and geochemical analysis to provide further information about the composition of the coal, and its relationship to CBM potential. Selected samples will also be tested for methane adsorption capacity, which measures the actual methane holding capacity of the coal, and isotope composition to determine the origin of the gas (themogenic versus biogenic). Based on the results of the exploration program, one area will undergo additional closely spaced drilling, and serve as a CBM well-completion test site. Various fracturing methods, designed to enhance the flow of the gas out of the coal, will be tested to determine the best method for maximizing CBM production. An advanced drilling program, which will utilize under-balanced, multi-lateral and multi-level drilling, will also be conducted. This drilling will be the first of its kind for CBM exploration in the Illinois Basin All analyzed data will be made available to the public through publications in electronic and hardcopy formats. Results will be disseminated through a series of regional workshops, publications, and an integrated IBC website. The study will be done under the auspices of the Illinois Basin Consortium (IBC), made up of the state geological surveys of Illinois, Indiana, and Kentucky. The IBC, formed in 1989, has completed a number of cooperative projects since its inception, drawing upon the expertise and resources of each individual state surve •. -