气田高压注水过程中井身应力分布特征的流-固耦合分析

Fluid-solid Coupling Analysis of Stress Distribution Characteristics in High-pressure Water Injection Well

套管对于维持井壁稳定有十分重要的作用。但是在高压注水井中,日益严重的油田套管损坏现象使得套管损坏机理研究已经成为当前油气田注水急需解决的问题。以四川盆地中部气田水回注井的井筒为分析对象,建立了考虑注水压力、岩石孔隙压力及三维地应力的仿真模型,将井筒分解为由地层、水泥环、套管和射孔段组成的整体系统,在不同注水压力条件下,分别对套管、水泥环、地层岩石的应力场分布进行了流-固耦合体的有限元模拟计算。根据计算结果,可分析各组成部份的应力变化特征,从而得出注水井的安全注入压力,对于防止套损及水泥环、地层破裂现象具有重要指导意义。

It is very important to use casing for the wellbore stability and prevention of oil polluted in oil region. Various references show that the casing damage phenomenon is increasing seriously. The casing damage mechanism research is one of the urgent problem to be solved. Sichuan basin gas field in the middle reinjection well perforated casing as prototype, considering fluid structure interaction algorithms,creat three-dimensional porous medium finite element model and formation cementring casing as a whole system.Computer simulation indicates it is a useful method to use fluidstructure coupling model to simulate perforated casing.And the result is in good accordance with field management,at the sametime pressure limit in high-reinjection well can get .