Nonlinear Motion Law of Coalbed Gas Seepage under the Combined Effects of Stress and Temperature

摘要

In consideration of the inward (outward) swelling deformation of coal body caused by temperature effect, permeability test of the loaded coal under different temperature conditions and different working conditions was performed with the self-made seepage equipment for thermo-fluid-solid-mechanical coupling of coal containing methane by Henan Province Key Lab of Gas Geology & Gas Control. The variation of coal permeability under the combined effects of stress field and temperature field was investigated, and the gas motion law in the coal samples was also tested. Furthermore, the variation equations of coal permeability under the combined effects of stress field and temperature field, as well as the motion equations describing the nonlinear gas seepage law in coal seams were established. The established equations were proved to fit well with the experimental data, which demonstrated that the motion equations and the research methods were both reasonable. As associated gas of coal, the gas is a kind of clean, efficient energy. Study on the seepage nonlinear motion law of gas in the coal seam is great significance to the mineral gas extraction and the utilization of energy.