摘要
Gas flow patterns during draining of gas from a coal seam during mining are discussed.The coal seam is treated as a dual medium with both pores and cracks.The seepage,diffusion,and desorption processes are treated using a gas flow equation that describes flow around drill holes.MATLAB is used to solve the differential equations.The permeability tracer test results from a mined coal seam are used to study the variation in gas drainage from a coal seam during mining.The results show that mining can increase the permeability of a coal seam,which then increases the gas drainage.There are inflection points in this variation over time.A close relationship between this variation and the rate of change in coal seam permeability is observed.
Gas flow patterns during draining of gas from a coal seam during mining are discussed.The coal seam is treated as a dual medium with both pores and cracks.The seepage,diffusion,and desorption processes are treated using a gas flow equation that describes flow around drill holes.MATLAB is used to solve the differential equations.The permeability tracer test results from a mined coal seam are used to study the variation in gas drainage from a coal seam during mining.The results show that mining can increase the permeability of a coal seam,which then increases the gas drainage.There are inflection points in this variation over time.A close relationship between this variation and the rate of change in coal seam permeability is observed.
基金
funded by the State Key Basic Research Program of China(No.2011CB201206)
the National Science and Technology Significant Special Project(No.2011ZX05040-001)
