基于渭北某矿井煤层底板奥灰水害防治定向钻孔工程，对成孔关键技术进行了研究。研究结果表明：煤层底板以下46 m层位可实现深孔探查；空气钻进工艺可解决孔内排渣不畅及难成孔的问题；通孔钻具可保障套管下至设计深度；利用引导钻头，采用回转钻进工艺可实现深孔下套管；孔内高压注浆、环空静压补浆可确保套管封固质量；滑动定向钻进、回转钻进相结合可提高稳斜段钻进效率；以低于0.5 MPa的钻压在增倾角孔段顺利侧钻开分支；利用不同钻进方法判断含水地质异常体性质；回转钻进方式快速多回次透孔，或大角度定向钻进可穿过易塌孔层位。研究成果为渭北煤田底板奥灰水害防治提供了技术支撑与理论依据。

Based on the directional drilling project for the prevention and control of ordorician limestone karst water disaster in a mine of Weibei, the key technology of hole forming was studied. The results show that the deep hole exploration can be realized in the 46 m layer below the coal seam floor; the method of air drilling can successfully solve the problem of poor slag discharge and difficulty of hole formation. Drilling tools can ensure the casing pipe travels down to the design depth; deep-hole casing can be realized by using a rotary drill process by using a pilot drill; The internal high-pressure grouting and the annulus static pressure filling can ensure the sealing quality of the casting; the combination of slide directional drilling and rotary drilling can greatly improve the drilling efficiency; the branch hole can be successfully drilled in the section of increasing inclination angle with a drilling pressure of less than 0.5 MPa; different drilling methods are used to judge the properties of water-bearing geological anomalies; the rotary drilling method can be used for a fast and multi-passing through holes, or taking directional drilling of large angles to pass through the collapsible section. The research results provide technical support and theoretical basis for the prevention and control of the ordorician limestone karst water disaster in the Weibei coal field.