套管-水泥环-地层完备系统力学模型解析解及有限元分析

The Mechanical Model of Analytical Solution for A Complete System of Casing-Cement Sheath-Formation and Its Finite Element Analysis

基于多层组合厚壁圆筒理论,运用弹性力学理论,对套管-水泥环-地层完备系统力学模型计算公式进行了推导,利用有限元软件ANSYS对套管-水泥环-地层完备系统进行了数值模拟计算。研究结果表明,对于套管-水泥环-地层完备系统,其径向应力在套管-水泥环交界面和水泥环-地层交界面上是连续的,其周向应力和Mises应力在套管-水泥环交界面和水泥环-地层交界面上是不连续的;有限元计算结果与理论计算结果的相对误差较小,误差最大的不超过3%,这表明有限元计算结果是可信的,也说明有限元中相关参数和条件的设置较为合理。

Based on the theory of multi-layer combination tubes,the theory of elastic mechanics is applied to derivate calculation formula of the mechanical model of casing-cement sheath-formation system,and a complete system model of casing-cement sheath-formation is simulated by using the finite element software ANSYS.The results of analysis show that as for the casing-cement sheath-formation system,the radial stress is continuous on the interface of casing-cement and interface of cement-formation,but on the interface of casing-cement and interface of cement-formation,the circumferential stress and Mises stress are discontinuous.