天然气工业2024，Vol.44Issue(3)：172-183,12.DOI:10.3787/j.issn.1000-0976.2024.03.015
复合磨损套管爆裂失效机理及剩余强度预测
Burst failure mechanism and residual strength of composite wear casing
摘要
Abstract
Complex oil and gas wells such as ultra-deep wells,horizontal wells and extended reach wells are operated under exceptionally severe conditions,with serious casing composite wear,which poses a great threat to wellbore integrity.Moreover,the residual strength of composite wear casing is difficult to predict accurately.In this paper,based on the Casing Wear Data of Well 501 in the Shunnan block,the north slope of central Tarim Basin and the stress-strain constitutive relationship of P110 tubing,an infinite element mechanical model of composite wear casing is built,which fully considers the wear pattern,clamping angle,wear overlap depth and wear depth caused by the combination of drill pipe body and joint.With this model,the casing elasto-plastic deformation,yielding,crack sprouting,expansion and bursting behavior under various composite wear patterns are simulated,and the stress distribution,residual internal pressure yield strength and bursting strength of casing with different composite wears are obtained.The results indicate that the stress interference weakens the stress concentration when the crescent angle is 0°-90° and enhances the stress concentration when the crescent angle is 90°-180°.This interaction mechanism allows the residual strength of composite wear casing to increase and then decrease as the crescent angle increases.Crack sprouts from the position with the maximum equivalent stress,i.e.the center of the wear crescent,and expands radially from the inner wall to the outer wall of the casing and perpendicular to the maximum circumferential stress.Once a crack initiates,it will expand quickly and induce a burst failure of the casing.The grey correlation analysis is conducted to investigate how the residual strength of casing with composite wear is sensitive to the wear depth,crescent angle,composite wear pattern,and overlap crescent depth.It is clarified that the wear depth is the main controlling factor for the residual strength of casing.The research results can provide technical reference for the design and optimization of casing strength,and be significant for accurately predicting the residual strength of composite wear casing and securing the wellbore safety and integrity.关键词
油气井/复合磨损/套管/失效机理/应力干涉/应力集中/应力交互/剩余强度Key words
Oil and gas wells/Composite wear/Casing/Failure mechanism/Stress interference/Stress concentration/Stress interaction/Residual strength分类
能源科技引用本文复制引用
邓宽海,张明,彭阳,周念涛,姚明远,林元华..复合磨损套管爆裂失效机理及剩余强度预测[J].天然气工业,2024,44(3):172-183,12.基金项目
国家自然科学基金项目"基于CFD模拟和微电位测试的冲刷腐蚀及其启动机理研究"(编号:52074232)、"交变温度、压力及其耦合作用下水泥环完整性研究"(编号:51904261),四川省自然科学基金项目"基于微电位测试和CFD-DEM流固耦合的油井管局部流动腐蚀FILC机理研究"(编号:2022NSFSC0994)、"强交变载荷下套管—水泥环—地层组合体完整性研究"(编号:2022NSFSC0028),研究生教改项目"石油与天然气工程一流建设学科研究生'多元、多层、多径'培养模式研究"(编号:2022JG001). （编号:52074232）
