Numerical Simulation Of Gas Drainage Parameter From Boreholes And Application In Tenghui Coal Mine Of201Face

In order to enhance gas extraction rate of201face and prevent the disaster causedby coal and gas outburst, so that it could take security environment of Tenghui colliery.According to the fluids in porous media of the law of conservation of mass, take paralleldrilling around coal seam of gas flow field for the study, establish to the drillingpre-pumping coal seam gas seepage model, and analysis the numerical solution. Finally,it could attach to reduce the amount of construction, improve the drainage rate, shortenthe eliminate outburst period as well as rapid secure excavation though the study ofparallel drilling along Coal Seam.To analysis single coupling hole by COMSOL Multiphysics Software, to analysisthe different conditions of drainage time, suction pressure of the drainage, permeabilityof coal seam, coal seam gas pressure, drill hole diameter of extraction radius and theamount of drilling gas extraction, get various factors on the influence of pre-pumpingthe coal seam gas. And the conditions of three holes, different hole spacing on theinfluence of gas pressure distribution, The following conclusions, With the increase ofdrainage time, drainage affected area increases; suction pressure of the drainage has alittle impact on extraction radius, but have a greater impact on the amount of gas extract;Permeability of coal seam has a significant impact on extraction hole radius and volumeof gas extraction, extraction radius was reduced to a downward trend with the low ofpermeability; Coal seam gas pressure has a little effect to drill hole diameter ofextraction radius, but has a greater impact on the amount of drilling gas extraction; Atthe same time, the hole diameter has a greater impact on the extraction radius and theamount of gas extraction, as the diameter increases, the extraction radius and the amountof gas extraction will be greater. In the case of three holes, gas pressure of the holespacing of5m drop faster than the hole spacing of2m and7m, The best extractionresults and removing outburst more fully.