CO2增采环境下X70管线钢的应力腐蚀开裂行为研究

Study of Stress Corrosion Cracking Behavior of X70 Pipeline Steel in CO2 Enhanced Mining Environment

李俊池 谢飞

Junchi Li Fei Xie

辽宁石油化工大学 石油天然气工程学院，辽宁 抚顺 113001

College of Petroleum Engineering，Liaoning Petrochemical University，Fushun Liaoning 113001，China

在CO2增采（CCS?EOR）环境下，研究了X70管线钢在不同CO2压力下的腐蚀开裂行为及其机理。 使用高压反应釜及模拟采出水溶液，对现场环境进行了模拟；通过电化学实验，研究了X70管线钢在CCS?EOR环境下的腐蚀速率与腐蚀机理；通过慢应变速率拉伸实验，研究了模拟环境下X70管线钢的腐蚀开裂行为；通过扫描电镜，分析了不同CO2压力下X70管线钢的腐蚀开裂机理。 结果表明，X70管线钢的腐蚀速率随着CO2压力的增加而增加；X70管线钢表面产生的腐蚀产物膜不能保护金属基体，而且加剧局部腐蚀；在腐蚀产物膜的影响下，CO2压力的增高使X70管线钢应力腐蚀敏感性增加，X70管线钢腐蚀开裂同时受金属表面裂纹的影响。

In the environment of CO2 enhanced recovery (CCS?EOR), the corrosion cracking behavior and mechanism of X70 pipeline steel under different CO2 pressures were studied. The on?site environment was simulated by using a high?pressure reactor and a simulated produced aqueous solution; the corrosion rate and corrosion mechanism of X70 pipeline steel in the CCS?EOR environment were investigated by electrochemical experiments; the corrosion cracking behavior of X70 pipeline steel under simulated environment was investigated by slow strain rate tensile experiments; finally, the corrosion cracking behavior of X70 pipeline steel under different CO2 pressure was analyzed by scanning electron microscope. The results show that the corrosion rate of X70 pipeline steel increases with the increase of CO2 pressure; the corrosion product film produced on the surface of X70 pipeline steel can not protect the metal matrix, and intensify the local corrosion; under the influence of the corrosion product film, the increase of CO2 pressure makes X70 pipeline steel stress corrosion susceptibility increases; and the corrosion cracking of X70 pipeline steel is also affected by the metal surface cracks.

国家自然科学基金项目(51604150);辽宁省自然科学联合基金资助项目(2020?HYLH?14)

10.12422/j.issn.1672-6952.2023.01.007