高产气井油管柱双重非线性流致振动模型研究

针对高产气井流体流动诱发油管柱振动引起的破坏问题,采用微元法、能量法结合哈密顿变分原理建立油管柱纵横向耦合非线性流致振动模型,基于弹塑性体接触碰撞理论,建立油套管非线性接触碰撞模型,并将其引入流致振动模型中,得到高产气井油管柱双重非线性流致振动模型。采用有限元法和Newmark-β法求解油管柱的双重非线性流致振动模型,与文献的实验数据和只考虑接触碰撞单非线性模型计算结果对比,验证了本文所建立的油管柱流致振动模型的正确性和优越性。根据现场高产气井参数,采用相似原理,开展了气井油管柱流致振动模拟试验,测得油管柱振动响应数据,与理论模型计算结果对比,再次验证了油管柱双重非线性流致振动模型的正确性。所建立的非线性流致振动模型可为高产气井油管柱安全设计提供有效的分析工具。

Bi-nonlinear Fluid-induced Vibration Model of Tubing String in High-yield Gas Well

In view of the damage caused by fluid induced tubing string vibration in high-yield gas wells, the micro element method, energy method and Hamilton variational principle are used to establish the longitudinal and transversal coupling nonlinear fluid-induced vibration (FIV) model of tubing string. Based on the contact collision theory of elastic-plastic body, the nonlinear contact-collision model of tubing string is established and introduced into the fluid induced vibration model to obtain the bi-nonlinear model of tubing string in high-yield gas wells. The bi-nonlinear FIV model of tubing string is solved with the finite element method and Newmark—$beta$ method. Compared with the experimental data in literatures and the calculation results of single nonlinear model only considering contact impact, the correctness and superiority of the FIV model of tubing string are verified. According to the parameters of a high-yield gas well in the field, a simulation test of fluid induced vibration of the gas well tubing string is carried out by using the similar principle. The vibration response data of the tubing string is measured and compared with the calculation results of the theoretical model, which again verifies the correctness of the bi-nonlinear FIV model of the tubing string. The nonlinear FIV model established in this paper can provide an effective analysis tool for the safety design of tubing string in high-yield gas well.