| This thesis presents a reservoir simulation analysis of coalbed methane (CBM) production potential of the Illinois Coal Basin. COMET3, a three-dimensional, three phase, finite-difference simulator capable of modeling single, dual and triple porosity models, was used for simulation analyses. The simulation results provide preliminary estimates of CBM production potential of the region.; The results of simulation analyses show that primary CBM recovery potential of the basin is approximately 24% of initial gas-in-place (IGIP), emphasizing the need of enhanced recovery techniques for improving production. Therefore, different enhanced recovery techniques, such as gas injection, horizontal drilling, multi-seam production, and hydraulic fracturing of coal seams, were studied. Gas injection was investigated for three types of gases, namely CO 2, N2 and flue gas. The results of the gas injection study indicated an improvement in CBM recovery, with more than 75% of IGIP being recovered in all three cases. The CO2 injection option resulted in the highest simulated CBM recovery, followed by flue gas and N2 injection, respectively. It was also found that N2 breakthrough occurs much earlier than CO2, which is indicative of the CO 2 sequestration potential in the basin. |
