套管变形的弹塑性有限元分析

在考虑油田注水因素产生的压力变动及不均匀性因素的基础上，通过建立存在上下油层压力差以及两向地应力差的带有射孔的套管受力模型，采用有限元方法研究了地下一段套管的损坏变形情况．分析结果表明，随着各种外载的逐渐增加，套管水平截面逐渐由圆形变成椭圆形，在最大地应力处套管有凹入，在最小地应力处套管有凸出．有关结果将对套管损坏的进一步研究与防治具有一定的理论意义。

Elastic-plastic finite element analysis of casing deformation

Considering pressure change and unevenness owing to affusion of oil field, failure deformation of specified position on the casing underground has been analyzed using finite element method by establishing a mechanics casing model with perforation. The model is under the condition of pressure difference between upper and lower oil layer and ground stress difference between two vertical directions on the plane. It is obtained that casing section transforms from circle to ellipse with the gradual increase of external load. Concave of the failure deformation occurs on the position exerted maximum ground stress and bulge of the failure deformation occurs on the position exerted minimum ground stress. All analysis results have some theoretical helps to detailed researches on casing failure and prevention.