元素硫对825合金在高温高压含CO2/H2S环境中腐蚀行为的影响  

Effect of Elemental Sulfur on the Corrosion of 825 Alloy in High Temperature and High Pressure Environment Containing CO2/H2S

作　　者：李科 李天雷[1,2] 施岱艳 李九一[3] 郑子奇 钟显康[3,4] LI Ke;LI Tian-lei;SHI Dai-yan;LI Jiu-yi;ZHENG Zi-qi;ZHONG Xian-kang(Southwest Branch of China Petroleum Engineering construction Co.,LTD,Chengdu 610041,China;Sichuan Branch,Key Laboratory of Petroleum Tubing Mechanics and Environmental Behavior,China National Petroleum Corporation,Chengdu 610041,China;School of Petroleum and Natural Gas Engineering,Southwest Petroleum University,Chengdu 610500,China;State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Chengdu 610500,China)

机构地区：[1]中国石油工程建设有限公司西南分公司,成都610041 [2]中国石油天然气集团公司石油管力学和环境行为重点实验室四川分室,成都610041 [3]西南石油大学石油与天然气工程学院,成都610500 [4]油气藏地质及开发工程国家重点实验室,成都610500

出　　处：《装备环境工程》2020年第11期10-17,共8页Equipment Environmental Engineering

摘　　要：目的研究元素硫对825合金在高温高压含CO2/H2S环境中腐蚀行为的影响,为评价825合金在高温高压含CO2/H2S和元素硫环境中的适应性提供依据。方法将825合金分别置于含元素硫和不含元素硫的模拟气田环境中,进行高温高压含硫实验。采用失重法、高温高压电化学法、扫描电镜和能谱测试方法对825合金的均匀腐蚀、局部腐蚀、电化学腐蚀、微观形貌和化学组成进行表征,揭示元素硫对825合金在高温高压含H2S和CO2环境中腐蚀行为的影响规律。结果在不含元素硫的环境中,825合金的均匀腐蚀速率仅为0.0217 mm/a,无局部腐蚀现象产生,也没有检测到明显的点蚀噪声信号;在含元素硫的环境中,825合金的均匀腐蚀速率高达0.469 mm/a,具有明显的局部腐蚀特征,且点蚀噪声信号显著,与光学照片观察结果一致。结论825合金在高温高压含元素硫和氯离子环境中容易发生局部腐蚀,这主要是由于元素硫在水溶液中发生水解反应,在局部区域生成了H2S和H2SO4,在高温和氯离子的耦合作用下,显著地加剧了825合金的腐蚀,腐蚀产物以氧化物和硫化物为主。The work aims to study the effect of elemental sulfur on the corrosion behavior of 825 alloy in high temperature and high pressure environment containing CO2/H2S and provide a basis for evaluating the adaptability of 825 alloy in high temperature and high pressure environment containing CO2/H2S and elemental sulfur.The 825 alloy was respectively placed in the simulated gas field environment with and without elemental sulfur for high temperature and high pressure sulfur-containing experiments.The uniform corrosion,local corrosion,electrochemical corrosion behavior,micro-morphology and chemical composition of 825 alloy were characterized by weight loss method,high temperature and high pressure electrochemical method,scanning electron microscope and energy spectrum test,and the influence of elemental sulfur on the corrosion behavior of 825 alloy in high temperature and high pressure environment containing H2S and CO2 was revealed.In the environment without elemental sulfur,the uniform corrosion rate of 825 alloy was only 0.0217 mm/a,and there was no local corrosion phenomenon and no obvious pitting noise signal was detected.In the environment containing elemental sulfur,the uniform corrosion rate of 825 alloy was as high as 0.469 mm/a,and there were obvious local corrosion characteristics and significant pitting noise signal,which was consistent with the observation results of optical photos.825 alloy is prone to local corrosion in high temperature and high pressure environment containing elemental sulfur and chloride ions,which is mainly due to the hydrolysis reaction of elemental sulfur in aqueous solution.During hydrolysis reaction,elemental sulfur produces H2S and H2SO4 in local areas,which significantly aggravates the corrosion of 825 alloy under the coupling action of high temperature and chloride ions,and the corrosion products are mainly oxides and sulfides.

关 键 词：元素硫 825合金 电化学噪声 局部腐蚀 高温高压电化学 H2S/CO2 

分 类 号：TG172[金属学及工艺—金属表面处理]