H_2S/CO_2环境中CO_2,pH值和Cl^-对P110套管钢电化学腐蚀的影响  

Electrochemical Corrosion Behavior of P110 Casing Steel in Environment Containing Dissolved H_2S and CO_2

作　　者：邓洪达[1,2] 李春福[2] 曹献龙[1] 贾宝贵[3] 

机构地区：[1]重庆科技学院冶金与材料学院,重庆401331 [2]西南石油大学油气藏地质及开发工程国家重点实验室,四川成都610500 [3]塔里木油田公司监督管理中心,新疆库尔勒841000

出　　处：《材料保护》2009年第3期18-22,92-93,共5页Materials Protection

基　　金：中国石油天然气集团公司十五期间应用基础研究项目(06A40301)

摘　　要：针对目前高含H2S和CO2环境井下管材电化学腐蚀研究不深入的现状,采用动电位扫描技术分析了在H2S/CO2环境中环境腐蚀影响因素(CO2,pH值和Cl-)对P110套管钢电化学腐蚀行为的影响。在溶解H2S和CO2且pH=2.7的含Cl-溶液中,当混合气体中CO2含量分别为17%,34%,50%时,腐蚀电流密度(Jcorr)分别为0.32849,0.29573,0.23709mA/cm2,在含50%H2S环境中,腐蚀电流密度为0.27289mA/cm2。与单一含H2S腐蚀环境相比,在酸性环境中CO2促进金属腐蚀,而在近中性环境中,CO2抑制金属腐蚀。在含Cl-溶液中,pH值降低,Jcorr增加,而在不含Cl-溶液中,pH值降低,Jcorr降低。在pH=2.7的溶液中,当Cl-存在时,Jcorr提高;而在pH=5.9溶液中,当Cl-存在时Jcorr降低。The effects of environment corrosion factors including C02,pH value and Cl～ on the electrochemical corrosion behavior of P110 casing steel in the environment containing dissolved H2 S and CO2 were studied by potentio -dynamic scanning technique. Results indicate that in the solution containing dissolved H2S/CO2 and Cl-with a pH value of 2.7,the corrosion current density (Jcorr) was measured to be 0.328,0.296 mA/cm2 ,and 0.237 mA/cm at a mixed gas com-position of 50% H2S/17% C02,50% H2S/34% C02,and 50% H2S/50% CO2,respectively. And Jcorr was recorded as 0. 273 mA/cm2 in the environment containing 50% H2S. Compared to that in the solution containing H2S alone,Jcorr increased in acidic H2S/CO2 solution and decreased in nearly neutral H2S/CO2 solu-tion. Moreover,Jcorr increased with decreasing pH value of the so-lution in the presence of Cl-,and it decreased therewith in the absence of Cl-. In addition,Cl-led to increase of Jcorr in the so-lution of with a pH value of 2.7,while it caused decrease of Jcorr in the solution with a pH value of 5.9.

关 键 词：电化学腐蚀 腐蚀机理 套管钢 H2S CO2 

分 类 号：TG172.6[金属学及工艺—金属表面处理]