In order to solve the problem of shallow drilling hole in Changping coal seam,the research on efficient drilling technology in hard-soft composite coal was carried out.According to the characteristics of hard-soft composite coal seam,the drilling technology which uses medium to high speed,wide blade and high helix compound drilling method is put forward.Based on the mechanism of slag discharge of helix drill,two different drilling tools that were φ110/63.5 mm spiral drill pipe +φ120 mm three-wing alloy drill bit and φ95/60.3 mm spiral drill pipe +φ110 mm three-wing scraper PDC drill bit,are designed and manufactured,and the high speed unit head of ZDY6000LR drilling rig is improved.Using ZDY3000LG,ZDY6000LR drilling rigs combined with the manufactured drilling tools,a threestage industrial test was carried out.Accordingly,a helix compound drilling technique which mainly includes the mechanical discharge by means of medium to high speed helix supplemented with fly-ash discharge by using wind power is formed.The rate of resultant boreholes in Changping Coal Mine with depth greater than 150 m is up to 52％ and thus the drilling efficiency in the borehole along the hard-soft composite coal seam has been further improved.%为解决长平矿煤层钻进成孔深度较浅的问题,进行了软硬复合煤体高效钻进技术研究.结合软硬复合煤层特点,提出运用中高速宽叶片高螺旋复合钻进技术进行钻孔施工的工艺.在研究螺旋钻具排渣机理的基础上,设计制造了φ110/63.5 mm螺旋钻杆+φ120 mm三翼合金钻头和φ95/60.3 mm螺旋钻杆+φ110 mm三翼刮刀PDC钻头2种不同的钻具组合;改进了ZDY6000LR钻机的高转速动力头;使用ZDY3000LG、ZDY6000LR钻机与设计制造的钻具组合进行钻孔施工,完成3期现场工业性试验,形成了以中高转速螺旋机械排渣为主、风力排粉为辅的螺旋复合钻进技术,使得长平矿孔深大于150 m的煤层钻孔达到了52％,进一步提高了长平矿软硬复合煤体顺层钻孔效率.
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