Applications of Reservoir Simulation to in Situ Coal Gasification

摘要

The results of the Hanna IVB in situ coal gasification test suggest a relationship between the preignition high permeability zones and the subsequent flame front propagation. As a result, this paper addresses the problem of the effect of nonuniform permeability on the air flow patterns in a water saturated coal seam. Specifically, the nonuniformities addressed are those caused by: (1) the existence of horizontal high permeability zones in an otherwise homogeneous, isotropic coal; (2) the change in permeability and flow path caused by well completions and location; and (3) the existence of orthotropic permeability. The results indicate that the most favorable condition for reverse combustion linking in underground coal gasification exists when the process wells are aligned with the high permeability direction of an orthotropic coal. The results also demonstrate the importance of proper well completion. (ERA citation 06:016386)