Research On Borehole Sealing Technology Of Gas Extraction With One Grouting

This thesis analyzes the borehole sealing principle, proposed gas drainage drilling and efficient drilling seal method, developed a belt pouch both ends block and one end grouting sealing device, and conducted site visits to its sealing effect, the following conclusions:Effective drilling seal must put sealing slurry into the borehole drilling and plastic zones can improve the effect of gas drainage.The sealing device of "both ends block and one end grouting" effectively improves the gas extraction concentration of cross-seam borehole and along the coal seam borehole. After F group of Eight Mine cross-seam borehole extract gas 30d, the concentration of drilling reach 70% to 83%, bedding perforation extraction after 30d, concentrations above 60%; ten mine amyl group cross-seam borehole extract gas 30d, concentration about 60%, F group cross-seam borehole about 65%, bedding hole above 32%; 13 Mine F group cross-seam borehole extract gas after 30d, concentration is above 15%; No.8 Mine, No.10 Mine and No.13 Mine cross-seam borehole sealed hole are 4～10m,1～11m,10-18m can drainage high concentration gas; Eight and ten mines cross-seam borehole respectively sealing 15～23m and 11～19m can drainage high concentration gas.Therefore, the proposed sealing parameters of "both ends block and one end grouting" are 4～12m, bedding drilling sealing parameters are 12～20m.