基于有限元法的半球形点腐蚀损伤P110油管剩余强度分析  

Residual Strength Analysis of P110 Oil Pipe with Hemispherical Pitting Corrosion Based on Finite Element Method

作　　者：张江江[1] 袁樾 曾文广[1] 郭玉洁[1] 李芳[1] 邓宽海[2] 范春玲 林元华[2] ZHANG Jiang-jiang;YUAN Yue;ZENG Wen-guang;GUO Yu-jie;LI Fang;DENG Kuan-hai;FAN Chun-ling;LIN Yuan-hua(Northwest Oilfield Company,SINOPEC,Urumqi 830011,China;State Key Laboratory of Oil and Gas Reservoir Geology and Development(Southwest Petroleum University),Chengdu 610500,China;Chongqing Pressure Vessel Manufacturing Co.,Ltd.,Chongqing 402560,China)

机构地区：[1]中国石化西北油田分公司,新疆乌鲁木齐830011 [2]油气藏地质及开发工程国家重点实验室(西南石油大学),四川成都610500 [3]重庆欣雨压力容器制造有限责任公司,重庆402560

出　　处：《材料保护》2021年第11期39-47,共9页Materials Protection

基　　金：国家自然科学基金“交变温度、压力及其耦合作用下套管—水泥环—地层完整性研究”(51904261);国家自然科学基金“H_(2)S/CO_(2)溶解度测试、预测及其与油套管完整性的相关性研究”(51274170)资助。

摘　　要：油管服役环境中CO_(2)、H_(2)S等各种腐蚀性物质共存,点腐蚀时有发生,其直接后果是降低了油管的剩余强度,成为制约管柱完整性的重要因素之一。对点腐蚀油管进行剩余强度分析,利于油管的安全运行,可为工程技术人员现场评价油管适用性与完整性提供理论依据。为此,采用ABAQUS软件,基于API 579标准,建立了48种半球形点腐蚀损伤油管三维模型,并对模型进行了验证。模拟并得到了油管外径、壁厚,点腐蚀缺陷分布、数量、深度对油管剩余强度的影响规律。结果表明:(1)相同点腐蚀参数下,88.9 mm油管的剩余强度下降率比73.0 mm油管的平均低3.09%,其设计规范中的傅立叶系数更小,油管安全性更高;(2)油管轴向上点腐蚀缺陷分布是降低油管剩余强度的主要因素;(3)油管点腐蚀缺陷个数更多,其承压能力不一定更低,但在排除点腐蚀分布影响下,承压能力一定更小;(4)随着点腐蚀深度的加深,油管的剩余强度迅速减小,极易发生穿孔事故。CO_(2),H_(2)S and other corrosive substances coexist in the service environment of oil pipes,so pitting corrosion of the oil pipe occurs frequently.Reducing the residual strength of the oil pipe is the direct consequence,which will become one of the important factors that restrict the integrity of the pipe string.Residual strength analysis of pit-corroded oil pipes is beneficial to the safe operation of oil pipe,and it can provide theoretical reference basis for engineers and technicians to evaluate tubing suitability and integrity of the oil pipe on site.Therefore,basing on API 579 standard and using ABAQUS software,48 types of hemispherical pit-corroded oil pipes’3D models were established,which were validated.Then,the influence law of tubing outer diameter,wall thickness,distribution,number and depth of pitting corrosion defects on residual strength of oil pipelines was simulated and obtained.Results showed that(1)on average,the decrease rate of the residual strength of the 88.9 mm oil pipe was 3.09%lower than that of the 73.0 mm oil pipe under the same pitting corrosion parameters,the Fourier coefficient in the design specification for 88.9 mm oil pipe was smaller and the oil pipe safety was higher.(2)The distribution of pitting corrosion defects on the axial direction of the oil pipe was the main factor that reduced the residual strength of the oil pipe.(3)When there were more pitting corrosion defects in oil pipes,and their pressure bearing capacity was not necessarily lower;but after eliminating the influence of pitting corrosion distribution,the pressure bearing capacity must be smaller.(4)The deeper the pitting corrosion was,the residual strength of the oil pipe decreased rapidly,and the perforation accident was easy to happen.

关 键 词：P110油管 点腐蚀 剩余强度 API 579 ABAQUS有限元法 傅立叶系数 

分 类 号：TE88[石油与天然气工程—油气储运工程]