热采井中油套管钢的腐蚀行为

Corrosion Behavior of Oil Casing Steels in Thermal Recovery Well

采用高温高压反应釜模拟稠油热采CO_(2)和H_(2)S腐蚀环境,研究了热采井油套管钢110H、L80-3Cr、L80-9Cr和L80-13Cr在此环境中的腐蚀行为。结果表明,在单一CO_(2)腐蚀环境中,随着温度的升高,4种油套管钢的均匀腐蚀速率均增大,80℃时随着油套管钢中铬含量的增加,均匀腐蚀速率降低。在CO_(2)和H_(2)S共存腐蚀环境中,油套管钢的均匀腐蚀速率随CO_(2)和H_(2)S分压比p(CO_(2))/p(H_(2)S)的变化呈现不同的规律:80℃时,随着p(CO_(2))/p(H_(2)S)增大,110H和L80-3Cr的均匀腐蚀速率逐渐增大,而L80-9Cr和L80-13Cr呈现先增大后减小的趋势;150℃时,随着p(CO_(2))/p(H_(2)S)增大,4种油套管钢的均匀腐蚀速率先增大后减小。在300℃和350℃的CO2和H_(2)S共存腐蚀环境中,L80-9Cr和L80-13Cr的耐蚀性远远优于L80-3Cr和110H。

The corrosion behavior of oil casing steels 110H,L80-3Cr,L80-9Cr and L80-13Cr was studied in CO_(2) and H_(2)S environment of heavy oil thermal recovery simulated by high-temperature and high-pressure autoclave.The results show that the uniform corrosion rates of four kinds of oil casing steels increased with the increase of temperature in solo CO_(2) corrosion environment,and at 80℃they decreased with the increase of Cr content in the oil casing steels.In the corrosion environment of CO_(2) and H_(2)S coexisting the uniform corrosion rates of oil casing steels presented different rules with the change of CO_(2) and H_(2)S partial pressure ratio p(CO_(2))/p(H_(2)S).As the p(CO_(2))/p(H_(2)S)increased at 80℃,the uniform corrosion rates of 110H and L80-3Cr increased gradually,but those of L80-9Cr and L80-13Cr firstly increased and then decreased.As the p(CO_(2))/p(H_(2)S)increased at 150℃,the uniform corrosion rates of the all oil casing steels showed a tendency of first increase and then decrease.In the CO_(2) and H_(2)S coexisting environment at 300℃and 350℃,the corrosion resistance of L80-9Cr and L80-13Cr were much better than those of L80-3Cr and 110H.