Integrated Of Key Parameters Of Low Permeability Coal Seam Gas Drainage Drilling Through Layers Of Hebi 4^Th Mine

Gas accident is a major natural disaster which threatens the mine safty, the gas drainage has played a significant role in the mine safety. Although a great quality of research work in the gas drainage of coal mine have been carried out by the specialists at home and abroad, the research work on low permeable coal bed gas drainage still to be limited. Because the low permeable coal bed gas-drainage rate is low, studies on the low permeable coal bed gas drainage parameter, have the important meaning on enhancing the effect of gas drainage through the low permeable coal bed.The thesis focouses on determining the main parameters for low-permeability coal seam gas drainage radius, and affecting the analysis of low-permeability coal seam gas drainage of several major factors. Gas pressure, coal seam permeability plays a key role on coefficienting the impact of drainage radius. First of all, using the theory of gas in the coal seam to analyze the gas pressure, gas flow field parameters arround coal seam gas drilling in theoretical, in order to obtain the theoretical gas drainage radius. On the other hand, numerical simulating different pore size, drainage time, drainage under negative pressure and different gas pressure distribution and flow field distribution surround gas drainage borehole pressure using FLUENT6.3 software. Finally, according to industrial experiments, get the test results of gas pressures, gas drainage radius, and coefficient of permeability about different mining area of Hebi Sino-Thai Mining Co.based on theoretical calculations, numerical simulation results and industrial settlement experimental analysis of the test results to find out that low permeability coal seam gas drainage impact of the main parameters.