深井套管在CO_(2)环境中腐蚀规律研究  

Study on Corrosion Law of Deep Well Casing in CO_(2) Environment

作　　者：崔国杰 高科超 王啸 刘询 王宁[2] 窦蓬 尚锁贵 赵宇航 CUI Guo-jie;GAO Ke-chao;WANG Xiao;LIU Xun;WAGN Ning;DOU Peng;SHANG Suo-gui;ZHAO Yu-hang(CNOOC China Limited Tianjin Branch,Tianjin 300459,China;College of Safety and Ocean Engineering,China University of Petroleum,Beijing 102249,China)

机构地区：[1]中海石油(中国)有限公司天津分公司,天津300459 [2]中国石油大学(北京)安全与海洋工程学院,北京102249

出　　处：《当代化工》2021年第12期2923-2928,2933,共7页Contemporary Chemical Industry

基　　金：中海石油(中国)有限公司天津分公司,渤中凹陷西南环异常压力条件下钻井提效关键技术研究。

摘　　要：CO_(2)溶于水有极强的腐蚀性,在油田中导致套管发生腐蚀,降低井筒完整性。蓬莱油田是典型的高CO_(2)腐蚀性油田,井底温度与压力要高于其他油田。现利用CO_(2)动态腐蚀实验仪器模拟套管的腐蚀环境,采用控制单一因素改变的方式分别研究CO_(2)腐蚀与温度、CO_(2)分压、时间、电位差和砂之间的关系。结果表明:碳钢在某个温度区间内升高温度后在二氧化碳水溶液中的腐蚀速度加快;随CO_(2)分压的升高,腐蚀速率急剧增大,然后趋于稳定;与电偶腐蚀相比,油井含砂对腐蚀影响更大,1Cr材料对出砂敏感。增加CO_(2)分压后腐蚀电流密度呈先上升再下降趋势;随着温度的升高,油套管钢的腐蚀电位一直减小,腐蚀电流密度先增大后减小。CO_(2) dissolved in water is highly corrosive,resulting in casing corrosion that reduces wellbore integrity in oilfields.Penglai oilfield is a typical high CO_(2) corrosive oilfield,whose bottom hole temperature and pressure are higher than other oilfields.In this paper,CO_(2) dynamic corrosion experimental instrument was used to simulate the corrosion environment of casing,and the relationship between CO_(2) corrosion and temperature,CO_(2) partial pressure,time,potential difference and sand was studied by controlling the change of single factor.The results showed that the corrosion rate of carbon steel in carbon dioxide solution was accelerated after increasing the temperature in a certain temperature range.With the increase of partial pressure of CO_(2),the corrosion rate increased sharply and then tended to be stable.Compared with galvanic couple corrosion,sand content in oil well had greater influence on corrosion,and 1Cr material was sensitive to sand production.After increasing the partial pressure of CO_(2),the corrosion current density first increased and then decreased.With the increase of temperature,the corrosion potential of oil casing steel decreased all the time,and the corrosion current density increased first and then decreased.

关 键 词：油田腐蚀 CO_(2)分压 温度 含砂油田 电化学性能 CO_(2)动态腐蚀实验仪器 腐蚀速率 

分 类 号：TG172[金属学及工艺—金属表面处理]