连续油管最大下入深度问题初探

在油田使用连续油管柱作业中,求解连续油管的最大下入深度问题时,必须满足最大抗拉强度条件、摩擦阻力条件和屈曲变形条件及其确定的方法和原则。而在下入过程中摩擦综合阻力又是求解的关键。求解摩阻力时,可针对连续油管在井身中不同结构段的不同变形形状,采用求解径向接触反力时求一个螺距内平均接触反力的方法加以解决。按照这种方法,采用安全计算工况,对新疆石油管理局八一井区8607侧钻水平井进行了连续油管冲砂作业时最大下入深度的编程计算,计算结果表明,连续油管的下入深度可满足侧钻水平井冲砂工艺要求。

Investigation in maximum running depth of coiled tubing

To solve the problem of the maximum running depth of coiled tubing, the maximum tensile condition, frictional condition and buckling condition should be satisfied. The key to the solution is the comprehensive frictional drag during string running. This article offers a method for solving the frictional drag, that is, according to the various buckled shapes of coiled tubing in different hole sections, working out the mean contact counterforce in a screw pitch in solving the radial contact counterforce. By using this method, the maximum running depth of coiled tubing in a certain side tracked horizontal hole in sand washing operation is calculated, and the calculated result shows that the running depth of coiled tubing can satisfy the requirement of sand washing technology.