基于摩擦系数的连续油管钻桥塞力学特性研究

Research of the Mechanics Characteristic of the Coiled Tubing Drillable Bridge Plug Base the Friction Coefficient

为明确摩擦系数对连续油管水平井最大钻塞深度的影响,对直井段采用软杆模型,弯曲井段采用刚杆模型,结合屈曲状态分析,设计了连续油管临界锁死判别准则,实现了不同摩擦系数情况下连续油管底部保持一定钻压的最大下入深度计算。研究结果表明:连续油管的屈曲一般发生在垂直井段。增加连续油管最大钻塞深度的有效办法是减小摩擦系数和减小底部钻压;同时会减小螺旋屈曲程度,但会一定程度上增加注入头载荷。研究内容和研究结果对连续油管钻塞作业提供一定的理论参考。

In order to identify the influence of the friction coefficient on the maximum depth of the coiled tubing drillable bridge plug in horizontal well,and the vertical segments used the soft-string model,the curved well segments used the stiff-string model,combined with the analysis of the buckling state,designed the critical lock-up criterion of coiled tubing. The maximum depth of the coiled tubing is calculated with the different friction coefficient and the bit pressure. The research results show that,the buckling of the coiled tubing occurred in the vertical segments commonly. The Effective methods of increasing the maximum depth of the coiled tubing drillable bridge plug were the decreasing of friction coefficient and the bit pressure. At the same time,the degree of helical buckling was reduced,but the load of injection head was increased in a certain extent. The research contents and research results provide the theoretical reference for the coiled tubing drillable bridge plug.