连续管钻井个性化PDC钻头降扭机理及试验研究  

Torque Reduction Mechanism and Test Study of PDC Bit Specially Designed for Coiled Tubing Drilling

作　　者：杨高 Yang Gao(Jianghan Machinery Research Institute Limited Company of CNPC)

机构地区：[1]中石油江汉机械研究所有限公司

出　　处：《石油机械》2024年第4期33-40,共8页China Petroleum Machinery

基　　金：国家重点研发计划资助(2021YFB3401400);中国石油集团工程技术研究院有限公司科学研究与技术开发课题“连续管侧钻短半径水平井技术研究”(CPET202305)。

摘　　要：由于连续管自身管径小、柔性大等特性,在进行井下钻进时容易导致摩擦自锁和管柱屈曲,存在钻压施加困难、进尺低下等问题。为提高连续管在低钻压情况下的钻进能力,个性化设计了连续管钻井专用小尺寸PDC钻头。通过单齿切削试验、水平井钻柱微钻头破岩试验、全钻头破岩试验开展小尺寸PDC钻头的降扭机理研究,对比不同齿形对破岩效果的影响。研究结果表明:在PDC切削齿前倾角较小时,破碎相同体积的岩石,宽刃齿所受切削力平均值比常规齿小10.35%~24.56%;同机械钻速情况下,宽刃齿钻头的扭矩小于常规齿钻头,最高降扭37.64%;同转速和钻压情况下,宽刃齿钻头最高降扭28.58%,钻压越大,降扭效果越显著。个性化设计的宽刃齿PDC钻头更适用于连续管实现低钻压、低扭矩、高转速破岩。研究结果可为改善连续管钻井技术在低钻压钻进时的适应性提供新的解决思路和理论支撑。Due to small diameter and high flexibility of coiled tubing,frictional self-locking and buckling easily occur during drilling,resulting in difficult WOB application and inefficient ROP accordingly.In order to improve the drilling ability of coiled tubing under low WOB,a small-sized PDC bit used for coiled tubing drilling was specially designed.By means of cutting test of single cutter,micro-bit and full-bit rock breaking tests of horizontal well drill string,the torque reduction mechanism of small-sized PDC bit was studied,and the influence of different cutter shapes on rock breaking effect were compared.The study results show that when the rake angle of PDC cutter is small,the average cutting force on wide edge cutter is 10.35%to 24.56%smaller than that on conventional cutter when breaking rocks of the same volume.At the same ROP,the torque of a wide edge cutter bit is lower than that of a conventional cutter bit,with a maximum torque reduction of 37.64%.At the same rotary speed and WOB,the maximum torque reduction of a wide edge cutter is 28.58%,and the greater the WOB,the more obvious the torque reduction effect is.The specially designed wide edge cutter PDC bit is more suitable for coiled tubing to realize rock breaking with low WOB,low torque and high speed.The study results provide new solutions and theoretical support for improving the adaptability of coiled tubing drilling technology in drilling with low WOB.

关 键 词：连续管钻井 PDC钻头 宽刃齿 降扭 托压 

分 类 号：TE921[石油与天然气工程—石油机械设备]