Development of Coal-Gas Production Simulators and Mathematical Models for Well-Test Strategies. Final Report January 1984-May 1986

摘要

Mathematical models have been developed to simulate the transient two-phase flow of methane gas and/or water through coal seams. The models predict gas and water contents throughout the coal seam as a function of time and gas and/or water productions by unstimulated vertical wells and by wells connected to induced fractures. The models are available as a series of computer programs, written in a structured dialect of FORTRAN. In these programs, the coal seam is modeled as a dual-porosity medium which incorporates time-dependent, nonlinear desorption of methane from the coal matrix. The models have been used to support a variety of activities in the GRI methane from coalbeds program including assessment of economic potential from the Warrior Basin, Alabama and the Piceance Basin, Colorado, to evaluate well test procedures, and to investigate the effects of pressure-dependent permeabilities and desorption characteristics.