淮南矿区瓦斯抽采中以孔代巷技术研究与工程实践

摘要

针对淮南矿区顶板岩层复杂地质条件和瓦斯赋存运移特征,开展了以孔代巷技术研究,从采动裂隙发育规律和钻孔瓦斯抽采特征等方面,分析了高位大直径定向钻孔替代高抽巷的技术原理.通过施工勘探孔探明顶板钻遇地层详细信息,以此优化高位定向钻孔层位布置、钻具组合和钻进参数.瓦斯抽采结果表明:煤层顶板以上38 m层位、距轨道巷煤壁26 m钻孔瓦斯抽采流量大、浓度高;随着高位大直径定向钻孔抽采瓦斯纯量增加,工作面上隅角瓦斯体积分数逐步降低,并稳定在0.03％左右;高位大直径定向钻孔瓦斯抽采纯量平均11.07 m3/min,平均体积分数31.39％,与邻近高抽巷瓦斯抽采水平相当.应用结果表明,利用以孔代巷技术进行顶板瓦斯抽采是可行的,研究可为井下瓦斯高效抽采与治理提供借鉴.%According to the complicated geological conditions of the roof strata and the characteristics of gas migration in Huainan Mining Area,the technology research on "borehole in place of roadway" was carried out.The technical principle of the high-position directional borehole with large-diameter in place of high level suction roadway was analyzed from the aspects of the development pattern of mining-induced fracture and the characteristics of borehole gas drainage.Based on the detailed roof strata information obtained by borehole drilling on the roof,one can optimize the layer layout of high-position directional borehole,drilling tool assembly and drilling parameters.The results of gas drainage show that:the borehole above the height of 38 m on the roof with a distance of 26 m with the coal wall of track roadway achieves high flux and high concentration of gas drainage.With the increase of pure gas flow rate in the high-position directional borehole,the gas volume fraction in the upper corner of the working face gradually decreases and stabilizes at about 0.03％.The average gas drainage rate of high-position directional borehole with large-diameter is 11.07 m3/min,with an average concentration of 31.39％,which is comparable to that from the adjacent high level suction roadway.The application shows that the technology of borehole in place of roadway for gas drainage on the roof is feasible.The present research can provide a reference on underground efficient gas drainage and treatment in coal mine.