缓蚀剂联合阴极保护套管的内防腐技术研究  

Research on Internal Corrosion Protection Technology of Corrosion Inhibitor Combined with Cathodic Protection Casing

作　　者：徐建国[1] 陈作明[1] 赵凯峰[1] 陈伟[1] 张鑫鑫 邓菁玉 李宁 王晨 吕祥鸿[2] XU Jianguo;CHEN Zuoming;ZHAO Kaifeng;CHEN Wei;ZHANG Xinxin;DENG Jingyu;LI Ning;WANG Chen;LYU Xianghong(Oil Production Plant,PetroChina Changqing Oilfield,Qingyang 745100,China;School of Material Science and Engineering,Xi’an Shiyou University,Xi’an 710065,China)

机构地区：[1]中国石油长庆油田分公司第二采油厂,甘肃庆阳745100 [2]西安石油大学材料科学与工程学院,陕西西安710065

出　　处：《材料保护》2023年第9期161-168,共8页Materials Protection

基　　金：国家自然科学基金青年科学基金项目(51902254);陕西省自然科学基础研究计划(2016JM5064,2018JQ5108)资助。

摘　　要：针对油井套管的内腐蚀问题,采用高温高压失重试验及极化曲线、交流阻抗谱和恒电位极化等电化学测试技术,结合有限元模拟计算,研究了固体缓蚀剂联合阴极保护的套管内防腐技术及其协同促进机制。结果表明:固体缓蚀剂现场加注浓度为120 mg/L时,其对J55套管的缓蚀率为85.91%,满足标准要求,但腐蚀速率仍然较高,为0.3079 mm/a;该固体缓蚀剂为阴极型缓蚀剂,阴极保护可显著促进缓蚀剂粒子的吸附阻滞效果,外加-50 mV阴极极化电位后,缓蚀剂吸附极化电阻由505.59Ω·cm^(2)增加到1878.50Ω·cm^(2);通过有限元模拟软件计算得到高温铝阳极对J55裸钢管的保护距离仅11.104 m,采用固体缓蚀剂联合牺牲阳极阴极保护措施后,固体缓蚀剂延长了牺牲阳极的保护距离,随着缓蚀剂覆盖率的增加,有效保护距离不断延长,当覆盖率达到98%时,有效保护距离超过100 m;固体缓蚀剂和阴极保护具有协同促进作用,室内实验得到联合作用下J55套管均匀腐蚀速率降低到0.0102 mm/a,缓蚀率达到99.53%,具有优异的保护效果。For the internal corrosion problem of oil well casing,high-temperature and high-pressure weight loss tests,polarization curves,AC impedance spectroscopy,and potentiostatic polarization electrochemical testing techniques were used,combined with finite element simulation calculations,to study the casing internal corrosion protection technology of solid corrosion inhibitors combined with cathodic protection and its synergistic promotion mechanism.Results showed that the corrosion inhibition rate of J55 casing was 85.91%when the on-site concentration of solid corrosion inhibitor was 120 mg/L,meeting the standard requirements,but the corrosion rate was relatively high,which was 0.3079 mm/a.The selected solid corrosion inhibitor belonged to the cathodic corrosion inhibitor.Therefore,cathodic protection could significantly promote the adsorption and retardation effect of corrosion inhibitor particles.After adding-50 mV cathodic polarization potential,the adsorption polarization resistance of corrosion inhibitor increased from 505.59Ω􀅰cm^(2) to 1878.50Ω􀅰cm^(2).The protection distance of the high-tempera-ture aluminum anode to the J55 bare steel pipe was calculated by finite element simulation software,which was only 11.104 m.After applying the solid corrosion inhibitor combined with sacrificial anode cathodic protection,solid corrosion inhibitor extended the protection distance of the sacrificial anode.The effective protection distance continued to extend as corrosion inhibitors coverage increased continuously.When the corrosion inhibitor coverage reached 98%,the effective protection distance was above 100 m.The solid corrosion inhibitor and cathodic protec-tion had a synergistic promotion effect.Indoor experiments showed that under the combined action,the uniform corrosion rate of J55 casing decreased to 0.0102 mm/a,and the corrosion inhibition rate reached 99.53%,demonstrating excellent protective effects.

关 键 词：J55套管腐蚀 固体缓蚀剂 牺牲阳极阴极保护 联合保护 

分 类 号：TG174.4[金属学及工艺—金属表面处理]