固井水泥环受内压时的弹塑性变形数值模拟  

Numerical Simulation on Elastic-Plastic Deformation of Cement Sheath Under Inner Pressure Condition

作　　者：李明忠[1] 管建平 

机构地区：[1]中国石化华北石油工程有限公司,河南郑州450042

出　　处：《承德石油高等专科学校学报》2017年第4期24-28,共5页Journal of Chengde Petroleum College

基　　金：国家自然科学基金(水热合成型固井材料体系及其高温固化机理研究):5117422;中国石化石油工程技术服务有限公司(水平井细分压裂技术):SG1312-05K

摘　　要：为确定固井水泥环在套管试压和压裂时的弹塑性变形规律,分析微环隙形成机理,基于弹塑性力学原理,根据厚壁圆筒理论,计算水泥环受内压时的弹性变形,并以理论计算结果验证ANSYS有限单元法研究水泥环受力与变形规律的可行性;采用有限单元法,构建物理模型,数值模拟研究水泥环受内压以及泊松比、弹性模量对弹塑性变形规律的影响。针对具体施工与增产措施,该方法可进行水泥环密封完整性的适应性评价,为固井水泥力学性能优化和调整提供参考与依据。Elastic-plastic deformation of cement sheath happens in the condition of casing pressure testing and hydraulic fracturing. If cement sheath has weak capacity for resisting deformation and e- lastic deformation exists, the deformation cannot be fully restored, leading to micro-annulus at the first interface. According to thick-walled cylindertheory, the elastic deformation was analyzed firstly used for testing feasibility about finite element method studying cement sheath＇ s deformation regular- ity by ANSYS software. Numerical simulation on elastic-plastic deformation of cement sheath under internal pressure condition was researched based on finite element method after setting up the physi- cal model. The deformation regularity transferring from elastic to plastic was confirmed and the influ- ence of poisson ratio and elastic modulus on cement sheath＇ s stress and deformation characteristic was discussed further. This method can be used for adaptability evaluation about cement sheath seal integrity at a special operation condition, and furthermore offers reference and basis for optimization about cement slurry＇ s mechanical property.

关 键 词：水泥环 有限单元法 弹性 塑性 泊松比 弹性模量 

分 类 号：TE256[石油与天然气工程—油气井工程]