地应力方向对椭圆套管强度的影响规律分析  

Analysis of the Influence Law of Ground Stress Direction on Elliptic Casing Strength

作　　者：李增亮[1] 蔡俐娜[1] 王木乐[2] 赵新学[2] 赵传伟[1] 

机构地区：[1]中国石油大学(华东)机电工程学院 [2]中原油田采油工程技术研究院

出　　处：《石油机械》2013年第11期14-16,20,共4页China Petroleum Machinery

基　　金：国家科技重大专项"高含硫气井套管修复技术研究"(2011ZX05017-003-04)

摘　　要：在考虑套管初始椭圆度和非均匀水平地应力作用位置的基础上,通过建立套管-水泥环-地层受力模型,采用弹塑性有限元方法对具有初始椭圆度套管的抗挤毁强度与非均匀水平地应力作用位置的关系进行分析,并与绝对圆形套管数值分析结果进行对比。研究结果表明,套管抗挤毁强度与非均匀地应力的作用方向有关。当最大水平地应力作用方向与套管长轴方向平行时,初始椭圆度将增大套管的抗挤毁强度;当最大水平地应力作用方向与套管长轴方向垂直时,初始椭圆度将降低套管的抗挤毁强度。可以通过合理正确地利用地应力的作用位置来提高套管的抗挤毁强度,进而延长套管的使用寿命。The initial casing ellipticity and the action location of uneven horizontal ground stress were first con- sidered and the casing-cement sheath-formation force model was established. The elasto-plastic finite element meth- od was used to make an analysis of the relation of the collapsing strength of casing with initial ellipticity to the action position of uneven horizontal ground stress. The analysis was then compared with the numerical analysis of absolute circular casing. The research findings show that the casing collapsing strength is related to the action direction of un- even ground stress. When the maximum horizontal ground stress is parallel to the casing long-axis direction, the ini- tial ellipticity will increase the casing collapsing strength. When the maximum horizontal ground stress general serv- ice direction is perpendicular to the casing long-axis direction, the initial ellipticity will decrease the casing collap- sing strength. The action location of ground stress can be used reasonably and correctly so as to improve the casing collapsing strength and to lengthen the service life of casing.

关 键 词：套管 椭圆度 地应力方向 有限元分析 影响规律 

分 类 号：TE925[石油与天然气工程—石油机械设备]