Print this pageMid-Continent Methane Incorporated (MCMI) has recently completed an extensive assessment of the potential coalbed methane resources across a 40,000-acre lease located in Saline and Williamson Counties of Illinois. The study area is located along the Cottage Grove Fault System.
The 1,000 feet of Pennsylvanian stratigraphy contain an average of 35 feet of total coal in an average of 7 different coal seams. The gas content of the coal was measured from six (6) complete cores (over 100 coal samples) ranging in depths from 300 to 1,000 feet. A total of ten (10) isotherms on individual seams were performed. Diffusivity tests were conducted and measured in the laboratory using xenon gas and core re-equilibration. Cleat density and spacing were measured in the laboratory using CT imaging. Bureau of Mines lost gas estimates were compared to core reequilibration measurements. Over 20 gas quality samples were obtained from coal canister and production tests.
Twelve pilot wells have been completed. Production tests include single coal seam tests, slug tests and interference tests. Pilot tests were used to forecast well spacing. Water quality measurements indicate potential for discharge to surface waters.
The results of the core program indicate significant volumes of gas in place. The results of the pilot program indicate several geological factors may have control over field orientation and production rates. The pilot program was successful in determining the geological factors that will ultimately place the Illinois Basin into coalbed methane commercial production.
AAPG Search and Discovery Article #90926©1999 AAPG Eastern Section Meeting, Indianapolis, Indiana