CO_2凝析气藏气井油套管腐蚀原因分析及常用钢材腐蚀性评价

Cause analysis of corrosion on oil tube and casing in gas well of CO_2 condensate reservoir and corrosiveness evaluation of common steel materials

对黄桥CO2凝析气藏气井油套管腐蚀特征及原因进行了分析,并选择N-80、3Cr和9Cr等3种油套管常用钢材进行了CO2腐蚀室内动态评价试验。试验结果表明:N-80钢材腐蚀十分严重,3Cr钢材腐蚀较严重,9Cr钢材腐蚀较轻。建议CO2凝析气藏气井油套管采用9Cr管材,若采用N-80、3Cr管材,必须采取防腐措施。试验结果对黄桥CO2凝析气田完井管材的选择具有指导意义,对其他CO2气田开发也具有借鉴意义。

Corrosion characteristics and causes were analyzed in oil tube and casing in gas wells of Huangqiao CO2 condensate reservoir, and in-house performance evaluation experiment was conducted by using of common steel materials, N-80, 3Cr and 9Cr. Results show that N-80 steel materials are most seriously corroded, 3Cr steel materials are seriously corroded, and 9Cr steel materials are lightly corroded. It is recommended to use 9Cr oil tube and casing in gas well of CO2 condensate reservoir. If N-80 or 3Cr steel materials have to be used, corrosion protection measures should be taken. The experiment is meaningful in completion of Huangqiao material selection for well CO2 condensate field and also can be referred in the development of other CO2 gas field.