抽油杆含缺陷区域电化学腐蚀规律研究  

Research on Electrochemical Corrosion of Sucker Rod with Defects

作　　者：周云凤 刘少胡[1] 马卫国[1] 黄小光[2] 冉小丰[1] 曲宝龙[3] Zhou Yunfeng;Liu Shaohu;Ma Weiguo;Huang Xiaoguang;Ran Xiaofeng;Qu Baolong(School of Mechanical Engineering,Yangtze University;College of Pipeline and Civil Engineering,China University of Petroleum(East China);School of Chemistry&Environmental Engineering,Yangtze University)

机构地区：[1]长江大学机械工程学院 [2]中国石油大学(华东)储运与建筑学院 [3]长江大学化学与环境工程学院

出　　处：《石油机械》2023年第5期76-85,共10页China Petroleum Machinery

基　　金：国家自然科学基金项目“连续管缺陷处细观-宏观损伤失效机制研究”(51974036)。

摘　　要：目前国内同时考虑多因素环境下对抽油杆CO_(2)腐蚀影响的研究较少。为此,基于COMSOL多物理场耦合分析的方法和任意拉格朗日-欧拉法展开模拟含缺陷抽油杆CO_(2)腐蚀规律研究,并结合某油田SN区块抽油杆腐蚀情况进行了分析。研究结果表明:随着温度的升高,抽油杆CO_(2)腐蚀速率先增大后减小;抽油杆腐蚀速率随CO_(2)分压的增大而增大,当其分压增大到0.5 MPa后,腐蚀速率增长放缓,最后趋于平稳;腐蚀速率随pH值的增大而减小,当温度为80℃时,抽油杆腐蚀速率降低90.7%;当抽油杆缺陷长度为1 mm时,腐蚀电位幅度变化最大,此时的腐蚀深度最深(1.3 mm)。研究结论可为含缺陷抽油杆在电化学腐蚀环境下使用寿命预测和安全评价提供理论支撑。In China,the corrosion of sucker rod cannot treat the CO_(2) corrosion under multi-factor conditions.In this paper,the CO_(2) corrosion of sucker rod with defects was simulated by using the COMSOL multi-physicalfield coupling analysis method and the arbitrary Lagrange-Euler method,and verified with the sucker rods from the SN block of an oilfield.The results show that the CO_(2) corrosion rate of sucker rod increases and then decreases as the temperature rises.The CO_(2) corrosion rate of sucker rod increases as the partial pressure of CO_(2) rises,and increases slowly after the partial pressure of CO_(2) reaches 0.5 MPa unit it becomes stable.Moreover,the CO_(2) corrosion rate of sucker rod decreases as the pH value increases,by 90.7%when the temperature is 80℃.The sucker rod with a defect length of 1 mm exhibits the largest variation of corrosion potential amplitude,corresponding to the largest corrosion depth(1.3 mm).The research results provide theoretical support to predict the service life and safety assessment of sucker rod with defects in electrochemical corrosion environment.

关 键 词：抽油杆 CO_(2)腐蚀 腐蚀模型 腐蚀速率 缺陷长度 

分 类 号：TE983[石油与天然气工程—石油机械设备]