管道水平定向钻穿越扩孔孔洞形成机理及孔壁稳定性分析

发布时间：2018-04-28 00:43

本文选题：水平定向钻 + 葫芦形孔洞　；参考：《地质科技情报》2017年03期

【摘要】：孔壁失稳是水平定向钻扩孔工程中的瓶颈性问题,扩孔器下沉形成的葫芦形孔洞是孔壁失稳的主要原因。目前,扩孔孔洞孔壁稳定性问题的研究对象多为圆形孔洞而非葫芦形孔洞。基于有限元法建立扩孔器-岩土相互作用的动力学模型,研究了扩孔器下沉形成葫芦形孔洞的机理;此外,开展了葫芦形孔洞的孔壁稳定性研究,并与圆形孔孔壁稳定性进行了对比。研究表明:扩孔器下沉存在极限下沉量,且每级下沉量等于前级扩孔器半径与当前级钻杆半径之差,则实际的孔眼形状为葫芦形;计算值与印度Purna河和渭河穿越工程实际孔高值相对误差值分别为7.39%和9.8%,说明了葫芦形孔洞形成机理具有一定的可靠性;葫芦形孔洞的孔顶坍塌的可能性较圆形孔提高了138%;且孔型对孔腰稳定性的影响小于孔顶稳定性。
[Abstract]:The hole wall instability is the bottleneck problem in the horizontal directional drilling and reaming project, and the hoist hole is the main reason for the hole wall instability. At present, the research object of the stability of the hole wall is the round hole rather than the hoist hole. Based on the finite element method, the dynamic model of the interaction between reamer and rock and soil is established, and the mechanism of the cavities formed by the sinking of the reamer is studied, in addition, the stability of the hole wall of the hoist hole is studied. The stability of the circular hole wall is compared with that of the circular hole wall. The results show that there is a limit subsidence of the reamer, and the subsidence of each stage is equal to the difference between the radius of the former stage and the radius of the current drill pipe, then the actual hole shape is cucurbit-shaped; The relative error between the calculated value and the actual hole height of Purna River and Weihe River crossing project is 7.39% and 9.8% respectively, which shows that the formation mechanism of hoist hole has certain reliability. The probability of hole top collapse of hoist hole is 138m higher than that of circular hole, and the influence of hole shape on the stability of hole waist is smaller than that of hole top.
【作者单位】：西南石油大学机电工程学院;
【分类号】：TE973.4

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