Study On The Reasonable Sealing Hole Depth Of 3# Coal Seam Gas Drainage Boreholes In Zhaozhuang Mine

Gas drainage is an important means of gas treatment, gas drainage rely mainly on drilling and sealing ,while the sealing is an important part of the gas drainage, in which the depth of sealing for the gas drainage has a significant influence. On the base of collecting the large amount of geological data, through reading an extensive literature, comprehensively analyzing the factors of gas borehole sealing depth and the relationship between sealing depth and stress distribution of roadway side, obtained gas borehole sealing depth must pass through the roadway relief zone into stress concentration zone. To different geological conditions of coal mine, must calculate the scope of pressure relief zone and stress concentration zone at first, then it can accurately determine the gas drainage boreholes reasonable sealing depth. Through testing the various parameters of physical and mechanical properties of the3 # coal seam's roof and floor of coal and rock samples in Zhaozhuang mine, and using the numerical simulation software, FLAC3D, to simulate the roadway dragging, and combining with field testing of drilling cuttings weight to analyze relief zone and stress concentration zone, and with a comparative analysis of industrial test ,the paper finally summarize a reasonable sealing depth is 8 to10m in the depth of the testing zone.