Two-dimensional modeling of in situ coal gasification. [6 refs]

Predictions of the sweep efficiency of different field processes for in-situ recovery of coal resources are needed to assess the economics of each process. Additionally, the efficient recovery of the total resource requires comparison and evaluation of the processes using these predictions. A preliminary two-dimensional transient computer model that simulates some important features of the in-situ gasification process is described. Simulation results are presented for several example cases of two-well gasifications in heterogeneous medium, which include both forward and reverse combustion modes. The simulation results agree qualitatively with field experiments. Accuracy is currently limited by incomplete representation of physical and chemical phenomena.