This paper presents the results of an experimental investigation undertaken to generate some of thebasic data on flow characterization of selected Illinois Basin coals.The experimental study includedmeasurement of permeability of coal cores subjected to in situ conditions of stress,temperature andpressure.The results obtained to date suggest that the permeability of most Illinois coals should beconsidered medium to high compared to other CBM producing basins in the US.Furthermore,thepermeability of coal reservoirs should be expected to vary significantly with continued production of CBMas a result of changes in the effective stress and pore pressure.The variation would be even moresignificant if CO2 is injected to enhance the production of CBM and/or for carbon sequestration since thepermeability of coal to CO2 is lower to begin with.Hence,with continued gas recovery,CBM productionwould change significantly and this should be taken into consideration when planning such operations.Finally,the capacity of coal to retain methane and CO2 was measured for the coals tested.The resultsshow that,for the pressure range permissible in the region,CO2 sequestration potential of the coals isthree to five times the amount of incremental methane recovered.
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