摘要
为了预测钢材在高温高压CO_2-Cl-共存体系下的腐蚀情况,为某气田在开采周期内推荐安全经济的管材,现根据区块情况,模拟地层水环境,在高温高压条件下对4种常用Cr钢和碳钢进行腐蚀试验。采用腐蚀失重法、扫描电子显微镜(SEM)和能谱分析仪(EDS),探究Cr钢和碳钢的CO_2腐蚀机理、腐蚀严重程度和抗CO_2腐蚀能力。结果表明:在150℃,CO_2分压2.2 MPa(总压30.0 MPa),Cl-含量6 400 mg/L的腐蚀环境中,随着Cr元素含量增加,钢材的抗CO_2均匀腐蚀能力会明显增加,但局部出现向内深入的点蚀坑;由于有Cl-存在,3Cr钢表面无法形成有效的钝化膜,加上气相中含CO_2的高温蒸汽附着在其表面,促进了腐蚀的发生,使3Cr钢的气相腐蚀速率与P110钢的气相腐蚀速率相当,因此在类似的气相腐蚀环境中不推荐使用3Cr钢。
In order to predict the corrosion of steel in high temperature and high pressure CO2- Cl^- coexistence system, and provide the recommended safe materials during producing period for a gas field, the corrosion test of Cr steel and carbon steel under the high temperature and high pressure simulated formation water environment was carried out according to the actual conditions. The CO2 corrosion mechanism, corrosion severity and resistance properties to CO2 corrosion of Cr steel and carbon steel were explored through corrosion weight loss, scanning electron microscopy （SEM） and energy spectrometer （EDS）. Results showed that in the corrosion environment at 150 ℃, CO2 partial pressure of 2.2 MPa （total pressure was 30.0 MPa）, and Cl^- content of 6 400 mg/L, with the increase of Cr content, the resistance properties to CO2 corrosion of steel were significant increased, but the pitting corrosion occurred locally. Due to the presence of Cl^-, the effective passive film did not form on the surface of 3Cr steel. Furthermore, the high temperature steam containing CO2 on the gas phase was adsorbed on its surface, which promoted the occurrence of corrosion. The vapor corrosion rate of 3Cr steel was the same as that of P110 steel. Therefore, it was not recommended to use 3Cr steel in similar vapor corrosion environment.
作者
张智
张泽霖
张怡然
张超
杨玉豪
黄亮
徐一龙
ZHANG Zhi1 , ZHANG Ze-lin1 , ZHANG Yi-ran1 , ZHANG Chao2, YANG Yu-hao2, HUANG Liang2, XU Yi-long2(1. Southwest Petroleum University-State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Chengdu 610500, China; 2. Zhanjiang Branch, CNOOC （China） Co., Ltd., Zhanjiang 524057, China)
出处
《材料保护》
CAS
CSCD
北大核心
2018年第9期113-116,134,共5页
Materials Protection
基金
国家科技重大专项(2016ZX05026002-001)
四川省科技计划(2016JQ0010)
中国石油科技创新基金(2017D-5007-0315)资助
