Xi’an Research Institute,China Coal Technology & Engineering Group,Xi’an ,China

针对碎软煤层瓦斯抽采钻孔成孔深度浅、轨迹无法测控、定向钻进困难等问题，提出了采用复合定向与排渣技术施工碎软煤层定向钻孔的技术方案，介绍了其技术原理，开发了泥浆脉冲无线传输技术、复合定向钻进技术、水力正循环与异性钻杆复合排渣技术等关键钻进技术，研制选配了定向钻机、矿用泥浆脉冲随钻测量系统、泥浆泵、螺旋螺杆马达、异形钻杆、过滤钻杆、螺旋无磁钻杆和定向钻头等关键钻进设备，形成了成套技术与装备，并在晋城寺河矿和成庄矿进行了现场试验，在碎软煤层区域内完成定向钻孔4个，最大孔深402 m，总进尺4 808 m，成孔率达到75%，成功覆盖工作面和待掘巷道设计区域，为碎软煤层区域递进式瓦斯抽采治理和一孔两消提供了一种新的技术手段。

According to the shallow hole depth,track without measured and controlled,directional drilling difficult and other disadvantages existed in the available gas extraction borehole drilling technology applied in soft-fragmentized coal seam,directional drilling with mud pulse MWD was put forward.The technical principle was introduced and a complete set of technology and equipment was formed,with the key drilling technologies had been developed,such as mud pulse wireless transmission technology,drilling technology combined rotary with direction,hydraulic positive cycle and heterogeneous drill rod compound slag discharge technology,directional drilling rig,mud pulse MWD system,mud pump,helical screw motor,special drill rod,filter drill rod,spiral non-magnetic drill rod and directional drill were developed and selected.The field test was carried out in Sihe Mine and Chengzhuang Mine,the results show that four directional drilling were successfully completed with the maximum hole depth reached 402 m,total length was 4 808 m,hole forming rate was 75%,predetermined area of work surface and roadway was successfully covered,which will provides a new technical means for progressive gas extraction in soft-fragmentized coal seam and had important significance for safety and high efficiency mining in coal mine.