A Mathematical Model Simulating Flow of Methane and Water in Coal.

摘要

The report covers the development of a mathematical model that describes the flow of methane only and methane and water in a coal bed during mining operations. The flow of methane gas from a coal bed that is being actively mined cannot be measured accurately and must be predicted from the known properties of the bed. In general since most underground structures have water associated with them,the system to be studied may be single-phase (methane gas) or two-phase (methane and water). Because the geometry is complex and the fluids have variable properties as functions of pressure and concentration,the differential equations describing the system are not amenable to analytic solutions but must be solved numerically using high speed computers. The model discussed solves the flow equations for one-or two-phase flow in a heterogeneous anisotropic coal bed. (Author)