残余应力对套管抗挤强度影响的有限元分析

EFFECTS OF RESIDUAL STRESS ON CASING COLLAPSE RESISTANCE

在套管的生产过程中会产生残余应力 ,这种残余应力将大大降低套管的拉伸屈服极限及压缩屈服极限 ,进而降低套管的抗挤强度。长期以来 ,这个问题一直没有引起人们的充分重视而加以克服。根据弹性力学理论 ,建立了套管的力学模型 ,通过有限元分析和计算 ,得到了存在残余应力情况下套管的抗挤强度。研究表明 ,残余应力在很大程度上影响着套管的抗挤强度 ,因此 ,为了提高套管的抗挤强度 。

During the production of casing,it will give birth to residual stress.This kind of residual stress will decrease the tensile yield limit and compressive yield limit of casing greatly.As a result,it will decrease casing collapse resistance.For a long time,the problem has not been regarded and resolved.Based on the elastic theory,the mechanical model of casing has been established.Analyzed and calculated by the Finite Element Method,the casing collapse resistance with the existence of residual stress has been obtained.Research shows that the residual stress effects casing collapse resistance in a great degree.Therefore,in order to increase casing collapse resistance,casing residual stress should be decreased as far as possible.