N80钢在模拟减氧空气驱生产井中的腐蚀行为  

Corrosion Behavior of N80 Steel in Simulated Oxygen-reduced Air Flooding Production Well

作　　者：周凯丽 史宝成[1] 薛琨 潘建澎 张兴凯 刘凯 伍丽娟 ZHOUKaili;SHIBaocheng;XUEKun;PANJianpeng;ZHANGXingkai;LIUKai;WULijuan(Hubei Key Laboratory of Drilling and Production Engineering for Oil and Gas,Yangtze University,Wuhan 430110,China)

机构地区：[1]长江大学油气钻采工程湖北省重点实验室,湖北武汉430110

出　　处：《热加工工艺》2024年第14期87-92,共6页Hot Working Technology

基　　金：国家科学自然基金项目(51974033);油气钻采工程湖北省重点实验室开放基金资助项目(YQZC202103)。

摘　　要：为了探究N80钢在减氧空气驱生产井中的腐蚀行为,基于灰色关联分析法,分析了国内某减氧空气驱生产井的腐蚀主控因素,并以油藏模拟结果作为室内模拟参数,采用动态失重法结合金相显微镜、XRD、3D形貌等相关表征,研究了不同生产时期N80钢的腐蚀行为。结果表明:氧含量对减氧空气驱生产井腐蚀的敏感性最大,在含氧工况下,N80钢的腐蚀速率显著增加,氧含量3%(0.3 MPa)时的腐蚀速率是不含氧的5倍左右。在驱油初期,腐蚀为CO_(2)主导的局部腐蚀,腐蚀产物主要为致密的FeCO_(3)。随着注气时间的延长,井筒内为CO_(2)/O_(2)均衡环境,腐蚀转变为二者共同作用,腐蚀产物为FeCO_(3)和疏松多孔的Fe_(2)O_(3)。在持续注气3年后,生产井内为高O_(2)+低CO_(2)环境,致密的FeCO_(3)遭到破坏,腐蚀坑横向发展,腐蚀转变为由O_(2)主导的全面腐蚀。In order to explore the corrosion behavior of N80 steel in oxygen-reduced air flooding production wells,the main controlling factors of corrosion in a domestic oxygen-reduced air flooding production well were analyzed based on the grey relational analysis method.Taking the reservoir simulation results as laboratory simulation parameters,the corrosion behavior of N80 steel in different production periods was studied by dynamic weight loss method combined with metallographic microscope,XRD,3D morphology.The results show that the oxygen content is the most sensitive to the corrosion of the production well with oxygen-reduced air flooding.Under the oxygen containing condition,the corrosion rate of N80 steel increases significantly,and the corrosion rate when the oxygen content is 3%(0.3 MPa),which is about 5 times than that without oxygen.In the initial stage of oil displacement,the corrosion is localized corrosion dominated by CO_(2),and the corrosion products are mainly dense FeCO_(3).With the prolongation of gas injection time,the wellbore is in a balanced environment of CO_(2)/O_(2),and the corrosion transforms into the combined action of the two.The corrosion products are FeCO_(3)and loose and porous Fe_(2)O_(3).After 3 years of continuous gas injection,the production well is in a high O_(2)+low CO_(2)environment,the dense FeCO_(3)is destroyed,the corrosion pit develops laterally,and the corrosion transforms into a general corrosion dominated by O_(2).

关 键 词：N80钢 减氧空气驱 生产井井筒 灰色关联度分析 O_(2)/CO_(2)腐蚀 

分 类 号：TG172[金属学及工艺—金属表面处理]