Application of gas phase permeability-enhancing fracturing techniques in driving face of coal roadway

Aimed at the problems such as large work volume, long extraction cycle and low gas drainage rate of holes for gas drainage in high-gas seam with low permeabilty in driving face of coal roadway, the paper presented gas phase permeability-enhancing fracturing technique, introduced the gas phase fracturing equipment and the technical principle, the scheme of fracturing operation in working face was determined, the pre-drainage effectiveness after gas phase fracturing was investigated and analyzed. The results show that the quantity of gas drainage of gas phase-fractured hole was four times more than that of ordinary hole, and the quantity of gas drainage of the pre-drainage hole increased by 2.4 times. The practice has proved that gas phase fracturing, as a technology and a technique for safe production in coal mine, is suitable for high gas and soft coal seam with low permeability. Gas phase fracturing has very important theoretical significance and wide application prospect.