煤层顶板裂隙高位定向长钻孔安全高效抽采技术的研究与应用

放顶煤开采期间，上覆岩层受到矿压的影响，形成冒落带、裂隙带、弯曲下沉带，工作面采空区遗煤和围岩涌出的大量瓦斯飘浮在上方裂隙带区域，造成瓦斯聚集并向外涌出，形成了安全隐患，因此必须将该区域瓦斯抽出来；以往治理采空区瓦斯主要采用顶板裂隙高位钻场、顶板高抽巷等措施，但是这2种方法施工成本较高，且施工周期长，对生产接替影响较大。煤层顶板裂隙高位定向长钻孔安全高效抽采采用大功率钻机+定向钻进技术，在裂隙带施工控制整个回采范围的长钻孔，减少采空区和邻近层瓦斯向工作面空间的流动，真正实现了“以孔代巷”，既节省了成本，又缩短了工期，还提高了采空区瓦斯抽采的连续性、稳定性，减少了采空区瓦斯向外涌出，提升了瓦斯抽采效果，促进了煤矿安全高效发展。

Research and application of safe and high-efficiency drainage technology with high-level directional long holes in coal roof cracks

During top coal mining，the overlying rock strata is affected by the mineral pressure，forming caving zones，fissure zones and bending subsidence zones.A large amount of gas gushing from the leftover coal and surrounding rocks in the working face goaf floats in the upper fissure zone.This caused the gas to gather and gush out，forming a hidden safety hazard.Therefore，the gas in this area must be pumped out；in the past，the gas control in the goaf area mainly adopted measures such as roof crack high drilling site and roof high drainage，but these two methods of construction the cost was high，and the construction period was long，which had a greater impact on production succession.The high-position long directional boreholes in the roof cracks of coal seams were safely and efficiently drained.The high-power drilling rig+directional drilling technology was adopted to construct the long boreholes in the cracked zone to control the entire mining area，reducing the flow of gas from the goaf and adjacent layers to the working face space.The real realization of "replacement of tunnels with holes" not only saved costs，but also shortened the construction period，but also improved the continuity and stability of gas drainage in the goaf，reduced the gas outflow from the goaf and improved the effect of gas drainage had promoted the safe and efficient development of coal mines.