煤矿井下定向钻孔超长套管下放技术

RIH of over-long casing in underground directional boreholes in coal mines

摘要:

针对煤矿井下定向钻孔超长套管下放成功率低、速度慢的问题，提出开孔段保直钻进、造斜段曲率控制、钻机驱动主动钻杆下放及套管导正等改进技术措施。在阳泉新景矿进行了现场试验，完成了3个满足煤矿井下水力压裂要求的定向钻孔超长套管下放，最大下深达到168 m，套管下放成功率达到100%，下套管平均工效由5.5 m/h最大提高至13.1 m/h，有效地解决了定向钻孔超长套管下放受限的难题。

Abstract:

In view of low success rate and slow speed in RIH of over-long casing in underground directional boreholes in coal mines， technical improvement measures are put forward， such as straight-maintaining drilling in the early section， control of curvature in the deflecting section， lowering of the kelly bar with drill rig， centralization of casing. Field test was carried out in Xinjing Coal Mine of Yangquan， where over-long casing was run in three directional boreholes for underground hydraulic fracturing with the maximum depth up to 168m. The success rate of casing running reached 100%， and the average casing running efficiency increased from 5.5m/h to 13.1m/h， eliminating effectively the limitation of over-long casing running in underground directional boreholes in coal mines.