强突出煤层穿层抽采钻孔套管护孔钻进技术

Technology of drilling with casing protection hole for cross-layer drainage borehole in strong outburst coal seam

为解决穿层钻孔施工过程中常出现的喷孔、穿煤长度短等难题,在分析穿层钻孔喷孔成因的基础上,提出将套管护孔钻进技术应用于强突出煤层钻孔施工,介绍了其工艺方法与钻具结构、传扭装置、套管钻头等设备,并进行了配套钻机改造和套管选型。应用结果表明:采用套管护孔钻进技术穿越强突出煤层时,钻孔的实际钻屑量与计算钻屑量的比值接近1,证明该技术在控制孔喷以及防治孔突方面具有积极效果,钻孔喷孔强度显著减弱;一次穿煤成功率提高了30%,表明该技术有利于钻孔穿越强突出煤层。

In order to solve the problem of jet orifice and short cross coal seam length during the process of cross-measure borehole,the technology of drilling with casing applied in strong outburst seam on the basis of the causes of borehole strong outburst was proposed in this paper,the structure of drilling tool,torque transmission device,casing shoe,casing and drill rig selection were introduced. The application showed that the technology of drilling with casing had a positive effect on controlling jet orifice and prevention of borehole outburst,and the intensity of borehole strong outburst was significantly weakened when the technology of drilling with casing was applied to cross outburst seam,the practical value and the calculation value of the drilling crumbs amount ratio was around 1,and the one-time success rate of crossing coal seam was increased by 30%,that was the technology was beneficial to drilling in outburst coal seam.