针对“U”型通风回采工作面采动卸压瓦斯常规治理方式存在的综合效率低、治理成本高等问题, 以山西晋城矿区某煤矿生产工作面为研究对象，提出采用200 mm大直径高位定向钻孔进行采动卸压瓦斯治理；基于该煤矿顶板大直径高位定向钻孔成孔技术难点分析，选型了关键钻进装备，包括ZDY20000LD型定向钻机、BLY460型泥浆泵车和多动力扩孔钻具；开发了复合强排渣定向钻进技术与多动力一次扩孔技术，实现了复杂地层条件下120 mm高位孔定向钻进与200 mm一次钻扩成孔，综合成孔效率较常规多次分级扩孔方式提高50%以上。瓦斯抽采效果表明：距煤层顶板30~40 m、距回风巷道40 m区域范围是采动裂隙密集发育区，钻孔平均瓦斯抽采体积分数保持在40%以上、最大瓦斯抽采纯量10.94 m³/min，效果显著。

Aiming at the problems of low comprehensive efficiency and high treatment cost in the conventional treatment of mining pressure relief gas in “U” ventilation mining face, taking a mining face in Jincheng Mining Area, Shanxi Province as the research object,200 mm large diameter high-position directional borehole for gas control of mining pressure relief is proposed. Based on the analysis of the technical difficulty of large-diameter high-position directional borehole in the roof of the coal mine, the key drilling equipment are selected, including ZDY20000LD directional drilling rig, BLY460 mud pump truck and multi-power expanding drilling tool. The combined strong slag-discharge directional drilling technology and multi-dynamic single-reaming technology have been developed to realize directional drilling of120 mm high hole and single-reaming of200 mm hole under complex formation conditions, the comprehensive drilling efficiency is more than 50% higher than that of conventional multi-stage expanding. The gas drainage effect shows that the area of 30-40 m away from the roof and 40 m away from the return air roadway is the mining fracture intensive development area. The average gas drainage concentration in the borehole is maintained at more than 40% and the maximum pure amount of gas drainage is 10.94 m³/min, which has remarkable effect.