School of Geology and Environment, Xi’an University of Science and Technology
China Coal Technology and Engineering Group Xi’an Research Institute (Group) Co., Ltd.

双级双速扩孔工艺技术可以实现煤矿井下顶板高位大直径定向钻孔的一次高效扩孔，克服常规正向多级扩孔技术方法提下钻工作量大、辅助钻进时间长和钻具安全性较差等局限性。扩孔钻头是实施多动力双级双速扩孔技术的关键工具，为进一步提高双级双速扩孔的碎岩效率，对双级双速扩孔钻头的冠部剖面形状、切削齿直径和切削齿结构参数进行优化设计；在此基础上建立了双级双速扩孔钻头和对应地层三维模型、有限元模型，采用动态分析软件模拟研究3种不同钻头直径的碎岩效果；优选一级钻头$phi $165~ϕ152 mm、二级钻头ϕ165 mm的钻头直径配比，利用新设计的双级双速扩孔钻头进行现场试验，完成2个120 mm钻孔一次钻扩至200 mm实钻施工，累积扩孔进尺474 m，扩孔综合钻效为5.6 m/h，最高钻速可以达到7 m/h。结果表明：双级双速一级钻头能够有效减少二级钻头的碎岩难度，延长钻头寿命，满足双级双速工艺要求，大大提高顶板高位大直径综合钻进施工效率。

The two-stage and two-speed reaming technology can realize one time efficient reaming for the high position and large diameter directional drilling of coal mine roof, and overcome the limitations of conventional forward multistage reaming technology and method, such as heavy drilling workload, long auxiliary drilling time and poor drilling tool safety. Reaming bit is the key tool to implement the multi-power two-stage two-speed reaming technology. In order to further improve the rock crushing efficiency of two-stage two-speed reaming, the crown profile shape, cutter diameter and cutter structural parameters of the two-stage two-speed reaming bit were optimized. On this basis, the two-stage two-speed reaming bit and the corresponding formation 3D model and finite element model were established. Dynamic analysis software was used to simulate the rock crushing effect of three different bit diameters. The diameter ratio of the first bit （ϕ165-ϕ152 mm） and the second bit （ϕ165 mm） was selected. The newly designed double-stage double-speed reaming bit was used for field test, and the two 120 mm drill holes were drilled to 200 mm in one time. Cumulative reaming penetration of 474 m, reaming comprehensive drilling efficiency of 5.6 m/h, the maximum drilling rate can reach 7 m/h. The results show that the two-stage two-speed first-stage bit can effectively reduce the difficulty of rock crushing of the two-stage two-speed bit, extend the life of the bit, meet the requirements of the two-stage two-speed process, and greatly improve the integrated drilling efficiency of the top roof with large diameter.

韩佳良，刘建林，唐胜利. 煤矿井下顶板高位大直径定向钻孔双级双速扩孔钻头研究[J]. 煤矿安全，2023，54（9）：194−201

HAN Jialiang, LIU Jianlin, TANG Shengli. Research on double-stage double-speed reaming drill bit for high-position and large-diameter drilling in coal mine roof[J]. Safety in Coal Mines, 2023, 54（9）: 194−201