偏磨套管破裂强度三维弹塑性有限元分析  

Collapse strength analysis of eccentric wear casing based on a three-dimensional elastic-plastic finite element method

作　　者：陈占锋[1,2] 朱卫平[1,2] 狄勤丰[1,2] 李世强[1,2] 

机构地区：[1]上海大学上海市应用数学和力学研究所,上海200072 [2]上海市力学在能源工程中的应用重点实验室,上海200072

出　　处：《石油钻采工艺》2013年第6期1-4,共4页Oil Drilling & Production Technology

基　　金：国家自然科学基金项目(编号:51174130);上海市优秀学术带头人项目(编号:12XD1402500);上海市部分地方院校能力建设重点项目(编号:12160500200);上海领军人才基金项目资助

摘　　要：为了更真实地模拟套管在内压下的破裂过程及影响因素,基于弹塑性大变形理论,建立套管三维有限元模型,对偏磨套管的破裂问题进行了研究。结合实验数据,提出了新的判断套管破裂的强度准则,给出了"月牙形"模型中偏磨率和"偏心筒"模型中偏心率的关系,并讨论了偏磨半径和偏磨率对偏磨套管破裂强度的影响。结果显示,套管内壁应力达到极限强度作为套管破裂的强度准则较为准确;偏磨半径对套管破裂强度影响较小;破裂压力随偏磨率的增加近似呈线性下降。研究结果可为套管柱设计提供理论支持。In order to simulate the process of casing collapse and analyze the influence factor more realistically, a three-dimensional finite element model for casing was established and the eccentric wear casing collapse problem under internal pressure was studied, based on elastic-plastic large deformation theory. According to the experimental data, a new strength criterion to judge casing collapse was proposed, and the influence of partial wear radius on collapse strength was analyzed. A relationship between the eccentric wear rate in the ＂crescent-shaped＂ model and the eccentricity in ＂eccentric cylinder＂ model was given and the influence of the eccentric wear radius and the eccentric wear rate on collapse strength was discussed. Results showed that, the ultimate stress on casing inner wall was relatively accurate as the collapse strength criterion. Eccentric wear radius had little impact on casing collapse strength. Besides, the collapse pressure almost linearly decreased with the increase of the eccentric wear rate. This paper provides a theoretical support for casing string design.

关 键 词：套管 偏磨 破裂压力 有限元法 强度准则 

分 类 号：TE931.2[石油与天然气工程—石油机械设备]