Study on directional drilling pre drainage technology of strip gas in coal roadway of outburst coal seam
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Abstract
In order to alleviate the tight connection between mining and excavation in outburst coal seam and realize the goal of rapid outburst elimination before coal roadway excavation, aiming at the problems of long construction period and high cost of traditional gas drainage and outburst elimination methods, this paper proposes to use directional drilling to pre extract the strip gas in outburst coal seam coal roadway, and use air composite directional drilling technology to solve the problem of directional long drilling in outburst coal seam.The matching air compound directional drilling equipment is developed and selected.The test results of Qinglong coal mine show that the drilling effect of the technical equipment is remarkable, and the technical problems existing in the drilling construction process, such as accurate control of drilling trajectory, efficient slag removal of downward inclined hole and normal operation of air screw drilling tool, have been overcome.The directional long drilling hole has large gas flow and high concentration, of which two million m3 of gas has been extracted in 21608 trackside drilling yard.21601 trackside drilling site has reached the gas drainage standard and has been safely excavated after passing the regional effect inspection.The research results provide a new idea for coal roadway strip outburst elimination in broken soft outburst coal seam.
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