井下闭环可控弯接头导向节受力摩擦磨损研究

Research on Forced Friction and Wear of Guide Joint of Downhole Closed-Loop Controlled Bend Sub

导向节是旋转导向钻井工具可控弯接头重要的组成部分。为研究导向节工作过程中钢球在滚道内所受接触应力、摩擦力及磨损的影响,根据Hertz(赫兹)接触理论,运用MATLAB软件计算了导向节中钢球与滚道之间接触应力的大小,建立了钢球与滚道之间的几何模型,分析了转角、轴间摆角和角速度对摩擦力的影响以及对体积磨损率大小的影响规律。研究结果表明:钢球在内滚道产生的接触应力总大于对应的钢球在外滚道产生的接触应力;比较并验证了钢球与保持架间的摩擦力较钢球与滚道间的摩擦力相差较大且变化不明显;根据体积磨损率与转角、轴间摆角、角速度之间的关系曲线,当导向节的旋转外套旋转一周,角速度为50πrad/s时,随着轴间摆角的增大而体积磨损率逐渐减小,当轴间摆角2θ为12°时,体积磨损率随着角速度的增大而增大。研究结果可为可控弯接头整体性能的提高提供指导。

To study the influence of the contact stress,friction and wear of the steel ball in the raceway during the working process of the guide joint,according to the Hertz contact theory,MATLAB software is used to calculate the contact stress between the steel ball and the raceway in the guide joint.The geometric model between the steel ball and the raceway is established,and the influence of the rotation angle and the axial angle on the friction force and the influence factors of the volume wear rate are analyzed.The research results show that the contact stress generated by the steel ball on the inner raceway is always larger than that on the corresponding outer raceway.It is compared and verified that the friction between the steel ball and the cage differ greatly with the friction between the steel ball and the raceway,and the change is not obvious.When the rotating jacket of the guide joint rotates one circle and the angular velocity is 50πrad/s,the volume wear rate gradually decreases with the axial angle.When the axial angle 2θis 12°,the volume wear rate increases with the angular velocity.The research results can provide references for improving the stability of controllable bend sub.