温度和Cl^(-)浓度对完井液中Cr13油管的电化学腐蚀的影响  

Effects of temperature and chloride ion concentration on electrochemical corrosion of Cr13 tubing in completion fluid

作　　者：张伟 曹文凯 阳俊龙 ZHANG Wei;CAO Wenkai;YANG Junlong(Shanghai Haikai Anti-Corrosion Engineering Technology Branch,CNOOC Changzhou Paint and Coatings Industry Research Institute Co.,Ltd.,Shanghai 200120,China;School of Chemistry and Chemical Engineering,Guangxi University,Nanning 530004,China;Zhanjiang Branch,CNOOC EnerTech-Drilling&Production Co.,Zhanjiang 524057,China)

机构地区：[1]中海油常州涂料化工研究院有限公司、上海海铠防腐工程技术分公司,上海200120 [2]广西大学化学与化工学院,广西南宁530004 [3]中海油能源发展股份有限公司工程技术湛江分公司,广东湛江524057

出　　处：《石油化工腐蚀与防护》2023年第4期1-5,共5页Corrosion & Protection In Petrochemical Industry

基　　金：中海石油(中国)有限公司科研项目“新型油管隔热防腐涂料技术研究”(CCL2019ZJFN1165)。

摘　　要：油田环境地质复杂,导致产油过程中的油套管极易发生腐蚀。在油田进入注水期之后,井下油管服役工况更加复杂、环境更加恶劣,会造成输油管壁发生严重的腐蚀。针对Cr13不锈钢油管,研究温度和Cl^(-)浓度对完井液中Cr13电化学腐蚀的影响。在模拟现场实际工况的基础上,测试了温度为40~80℃、Cl^(-)质量分数为10000~18000μg/g的完井液中Cr13的开路电位、电化学阻抗谱和极化曲线。研究结果表明Cr13的开路电位较负(-0.75~-0.59 V),表现出较高的腐蚀倾向性;极化曲线阳极区呈现活性溶解状态,未发生钝化,表明Cr13的电化学反应活性很高;电化学阻抗随温度和Cl^(-)浓度增加而减小,表明Cr13表面钝化膜稳定性减弱。采用注水、注缓蚀剂和防腐涂层等措施对预防输油管腐蚀十分有效。The complex geological condition of oilfield results in corrosion of tubing and casing during oil production.During the water injection period,working condition of underground oil pipes become more severe,which can cause serious corrosion at the wall of oil pipeline.The effects of temperature and chloride ion concentration on the electrochemical corrosion of Cr13 stainless steel tubing in completion fluid was studied.According to the actual working condition,the open circuit potential,electrochemi⁃cal impedance spectroscopy and polarization curve of Cr13 in completion fluid were measured at the temperature of 40~80℃and chloride ion mass fraction of 10000~18000μg/g.The results demonstrated that the open circuit potential of Cr13 was relatively negative(-0.75~-0.59 V),exhibiting a high corrosion tendency;the anode region of the polarization curve showed an active dissolution state without passivation,indicating the electrochemical reaction activity of Cr13 was very high;the electrochemical impedance decreased with the increase of temperature and chloride ion concentration,and the stability of the passivation film on the surface of Cr13 weakened.Therefore,methods of water injection,corrosion inhibitors,and anti⁃corrosion coatings were very effective in preventing corrosion of oil pipelines.

关 键 词：电化学腐蚀 温度 Cl^(-) Cr13不锈钢油管 

分 类 号：TE983[石油与天然气工程—石油机械设备]