摘要
分析地层的弹性模量、泊松比以及原场地应力3个主要参数对套管外挤应力的影响,得出不同参数下外挤力系数的数值解。建立了套管外压应力椭圆分布的力学模型,应用ANSYS有限元软件,采用节点函数加载的方式模拟套管屈曲变形与应力椭圆度的关系,对比了套管在均布外压和非均布外压下承载能力的变化。计算结果表明:非均质性原场地应力会大幅降低套管的抗挤能力;随着非均质率增加,Mises应力分布规律也发生了较大的变化。
Three parameters including strata^s elastic modulus, poisson＇s ratio and initial ground stress have been taken into account. By analyzing stratum parameters＇ influence on casing＇s external compres- sional stress,obtained compressional stresses numerical solution under different stratum parameters, the mechanical model with stress elliptic distribution was built. With the help of the finite element software of ANSYS,the relation between stress elliptical degree and buckling deformation by loading nodal function method were analyzed to contrast stress distribution under uniform stress and non-uniform stress. The simulation results showed that the non-uniform ground stress greatly decreased casing＇s collapse resist- ance and the distribution of Mises stress cloud chart greatly changed with the increasing degree of non-u- niformity.
出处
《石油矿场机械》
2013年第4期5-9,共5页
Oil Field Equipment
