煤矿井下大口径长距离贯通钻孔可作为输送通道以替代矿井传统井工巷道，相比常规井下大口径钻孔，区别及难点主要在于“点对点”精准贯通、大口径长距离分级高效扩孔，以及全孔段套管敷设并注浆固管。介绍了煤矿井下大口径长距离贯通钻孔成孔关键技术，从RMRS绕障对接技术、分级扩孔技术、排渣工艺技术、全孔段套管敷设技术及注浆固管技术等5个方面深入研究，实现了大口径长距离贯通钻孔高效成孔。在钻孔设计方位轨道多个关键点处钻取的引导直孔内，采用RMRS技术进行超前引导，以实现定向绕障及“点对点”精准贯通；合理优化扩孔级序，采用回拉扩孔工艺以提高扩孔钻进效率；利用“孔内循环+机械辅助”联合排渣工艺提升扩孔钻进排渣效率；选配适用滚珠扶正器，采用“前拉+后推”组合方式实现长距离全孔段套管敷设；采用“环空带压注浆法”进行注浆固管以保障固管质量。基于上述关键技术，构建了大柳塔井与活鸡兔井之间的大口径长距离输水管道，总长度1 932 m，钻孔终孔孔径330 mm，全孔段敷设输水套管尺寸ϕ219 mm×8.94 mm；先导孔成功从2座桥墩之间斜向安全穿过，实际贯通点B_s与设计贯通点B之间水平投影位移偏差0.4 m、垂直剖面位移偏差0.25 m，空间位移偏差0.47 m，基本实现“点对点”连通；注浆固管声幅测井合格率95%，管路实际输水能力达150 m³/h。

The large-diameter and long-distance drilling in coal mines can serve as a transportation channel to replace traditional underground tunnels. Compared with conventional large-diameter drilling, the main differences and difficulties lie in “point-to-point” precise drilling, efficient and rapid reaming of large-diameter and long-distance classification, and full hole section casing laying and grouting for pipe fixation. This article introduces the key technology for drilling holes through large-diameter and long-distance boreholes in coal mines. We will conduct in-depth research on five aspects, including RMRS obstacle avoidance and docking technology, graded hole reaming technology, slag removal process technology, full hole section casing laying technology, and grouting and pipe fixing technology, in order to achieve efficient drilling of large-diameter and long-distance through holes. In the guide straight holes drilled at multiple key points of the drilling design direction track, RMRS technology is used for advanced guidance to achieve directional obstacle avoidance and precise point-to-point penetration; reasonably optimize the drilling sequence and adopt the back pull drilling process to improve the efficiency of drilling; utilizing the combined slag removal process of “intra hole circulation + mechanical assistance” to improve the slag removal efficiency of borehole drilling; optional ball centralizer, using a combination of “forward pull + backward push” to achieve long-distance full hole section casing laying; adopting the “annular pressure grouting method” to ensure the quality of grouting and pipe fixation. Based on the above key technologies, a large-diameter long-distance water transmission pipeline was constructed between Daliuta Well and Huojitu Well, with a total length of 1 932 m, a final borehole diameter of 330 mm, and a water transmission casing size for the entire borehole section ϕ219 mm×8.94 mm; the pilot hole successfully passed diagonally and safely between two bridge piers. The horizontal projection displacement deviation between the actual penetration point B_s and the design penetration point B was 0.4 m, the vertical profile displacement deviation was 0.25 m, and the spatial displacement deviation was 0.47 m, basically achieving point-to-point connectivity; the qualification rate of acoustic amplitude logging for grouting pipes is 95%, and the actual water delivery capacity of the pipeline exceeds 150 m³/h.