高Cl^(-)环空保护液中超级13Cr油管点腐蚀行为研究  

Pitting Corrosion Behavior of Super 13Cr Tubing in High Chloride-containing Annulus Protection Fluid

作　　者：霍宏博 宋闯 刘婉颖[2] 刘东东 张羽臣 何世明[1] HUO Hong-bo;SONG Chuang;LIU Wan-ying;LIU Dong-dong;ZHANG Yu-chen;HE Shi-ming(State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Southwest Petroleum University,Chengdu 610500,China;School of New Energy and Materials,Southwest Petroleum University,Chengdu 610500,China;State Key Laboratory of Offshore oil Exploitation,Tianjin Branch of CNOOC,Tianjin 300459,China)

机构地区：[1]西南石油大学油气藏地质及开发工程国家重点实验室,成都610500 [2]西南石油大学新能源与材料学院,成都610500 [3]中海石油(中国)有限公司天津分公司·海洋石油高效开发国家重点实验室,天津300459

出　　处：《表面技术》2023年第10期206-219,共14页Surface Technology

基　　金：中海石油(中国)有限公司综合科研项目(YXKY-2020-TJ-03);中海石油(中国)有限公司天津分公司"接榜挂帅"科技项目(ZZKY-2022-TJ-JG-03)。

摘　　要：目的 研究超级13Cr管材在油气井服役环境中的点腐蚀失效机制,分析超级13Cr马氏体不锈钢在高温、高Cl^(-)环空保护液、超临界H_(2)S/CO_(2)环境中的点腐蚀失效行为,明确其适用性,并提出相应的腐蚀控制措施。方法 通过分析失效油管的宏观形貌、显微组织、腐蚀形貌及腐蚀产物,判断超级13Cr油管现场失效的原因,结合高温高压反应釜模拟井下腐蚀环境,从平均腐蚀速率、点腐蚀速率等方面揭示超级13Cr油管的点腐蚀失效机理。结果 该超级13Cr材质管柱在受到H_(2)S/CO_(2)污染的环空保护液环境下会发生点腐蚀穿孔失效;通过观察现场失效油管发现,在受到腐蚀性气体污染的高Cl^(-)环空保护液环境中,油管外壁发生了明显的局部腐蚀,油管腐蚀由外壁向内壁扩展,发生了严重的点腐蚀穿孔,并具有一定的H_(2)S应力腐蚀开裂(SCC)特征;在环空保护液环境下,失效油管表面有Cr、O、Cl、S离子聚集,腐蚀受到CO_(2)-H_(2)S共同影响;模拟腐蚀实验结果显示,超级13Cr油管在腐蚀性气体污染的海水基环空保护液环境下具有点腐蚀敏感性,蚀坑深度为80.346μm,点腐蚀速率达到10.34 mm/a。结论 超级13Cr油管在环空保护液中具有优异的抗均匀腐蚀能力,但在受到H_(2)S/CO_(2)污染的高Cl^(-)环空保护液环境中具有明显点腐蚀倾向,建议环空保护液用淡水配制,并进行除氧处理。In recent years,the research on super 13Cr corrosion at home and abroad mainly focuses on uniform corrosion in formation fluid environment and H_(2S) stress corrosion cracking in annulus protection fluid,but rarely considers pitting corrosion failure in annulus protection fluid.At home and abroad,there are few cases of short-term pitting corrosion perforation failures of super 13Cr pipes in annulus protection fluid.This paper aims to study the pitting corrosion failure mechanism of super 13Cr pipes in the service environment of oil and gas wells,and analyze the pitting corrosion failure behaviors of super 13Cr martensitic stainless steel in the environment of high temperature,high chloride-containing annulus protection fluid and supercritical H_(7) S/CO_(2) to make clear the applicability of super 13Cr tubing and put forward corrosion protection measures.Based on the analysis of the macro and micro structure,corrosion morphology and corrosion products of the failed tubing,the failure reason of super 13Cr tubing was determined.Combined with high temperature and high pressure reactors,the downhole corrosion environment was simulated,the mechanism of pitting corrosion loss of super 13Cr tubing was revealed from the aspects of average corrosion rate and pitting corrosion rate.The results showed that the super 13Cr tubing in the failed well had pitting perforation failure in the environment of H_(2)S/CO_(2) polluted annulus protection fluid.Field failure tubing showed that in the environment of high chloride-containing annulus protection fluid polluted by corrosive gas,obvious local corrosion occurred on the outer wall of tubing,and the corrosion expanded from the outer wall of tubing to the inner wall,resulting in pitting corrosion perforation.The failed tubing had certain H_(2)S stress corrosion cracking(SCC) characteristics.There were Cr,O,Cl and S ions on the surface of the failed tubing,and the corrosion was jointly controlled by CO_(2)-H_(2)S.The simulated corrosion test results showed that the super 13Cr tubing

关 键 词：超级13Cr油管 点腐蚀失效 环空保护液 高Cl^(-)环境 腐蚀机理 超临界腐蚀环境 

分 类 号：TE983[石油与天然气工程—石油机械设备]