Xi’an Research Institute，China Coal Technology and Engineering Group, Xi’an , China

基于顶板高位定向钻孔抽采瓦斯原理及现有施工技术，针对淮南矿区顶板复杂地层中高位定向钻孔难以有效成孔的问题，提出了采用高压注浆加固地层、扩孔技术疏通钻孔和大倾角快速穿越破碎层段相结合的成孔技术措施，首次在淮南矿区成功施工了3个孔深510 m、孔径153 mm的顶板高位大直径定向钻孔，形成了适用于淮南矿区顶板复杂地层的高位大直径定向钻孔成孔工艺技术，为该类条件矿区工作面瓦斯治理提供了新技术途径。同时针对施工中需频繁起钻扩孔、硬岩中钻进效率低、常规打捞钻具在大直径钻孔中打捞准确度低和下管护孔难度大等问题，提出解决方案，为后续研究提供思路和方向。

Based on the principle and existing technology of gas drainage by high level directional borehole, and with regard to high-level directional borehole which was difficult to be realized in the complex roof strata of Huainan Mining Area, the pore forming technical measure combined with reinforcement strata by high pressure grouting, dredge drilling by reaming technology and rapid crossing broken layer by large angle was put forward. Three roof high-level directional boreholes with 510 m depth and 153 mm bore diameter were successfully actualized for the first time in the Huainan Mining Area. High-level large diameter directional borehole technique which was suitable for complex roof strata in Huainan Mine Area was formed. This technology provided a new technical approach for gas drainage in similar condition mining area. Specific to the problems of frequent reaming, low drilling efficiency in hard rock, low fishing accuracy of conventional fishing tools in large diameter drilling and difficulty of entering bushing, the solutions were proposed, and which provided ideas and directions for subsequent research.