连续油管侧钻开窗钻头扭矩的计算

Analysis of Bit Torque in Coiled Tubing Sidetracking

连续油管侧钻技术较好的解决了由于地层因素、套管本身质量等原因致使停产、套管损坏井的问题。但由于连续油管刚度有限,且受井下马达输出扭矩的限制,容易造成马达失速,导致损坏,因此钻头扭矩的精确计算对井下开窗作业有着很大的意义。基于连续油管侧钻开窗的特点,对开窗工具了进行合理选择,对侧钻时钻头的受力进行了较为细致的分析。通过Matlab软件进行编程计算,得出了钻头在前进过程中某一钻压下的扭矩变化曲线。通过对曲线的分析,找到了扭矩变化的原因,为侧钻过程中钻压的选择提供了一定的理论依据,使得钻头不会因为扭矩过大而锁死乃至损坏钻具,提高开窗效率。

The production halts and casing failure problems,which are caused by formation factors and the quality of casing is better solved by coiled tubing side tracking technology. Based on the feature of coiled tubing side tracking,the reasonable tools are chosen,and the load on the bit is carefully analyzed. The curve of torque related to bit pressure is generated when drilling forward,programming is made by using Matlab. Through analyzing this curve,the reason of the change in torque is identified,which provides a theoretical basis for the choice of drilling pressure. This is very important in avoiding the dead lock or even the breaking down of drilling assemble of bit,it improves the efficiency of sidetracking window.