P110S碳钢在高Cl^(-)高酸性气体分压下的腐蚀行为

Corrosion Behavior of P11oS Carbon Steel Under High Cl^(-) High Acid Gas Partial Pressure

模拟了西北塔河油田极端苛刻的环境,通过高温高压反应釜模拟试验,失重法、显微组织观察,腐蚀产物物相分析等考察了在高Cl^(-)含酸性气体条件下,温度和CO_(2)分压对P110S碳钢腐蚀行为的影响。结果表明:P110S碳钢的腐蚀速率随着温度的升高先增大后减小再增大,随着CO_(2)分压的升高先增大后减小,腐蚀速率分别在210℃和CO_(2)分压8 MPa时达到最大。当温度为150℃或CO_(2)分压为8 MPa时,FeCO3晶体开始从溶液中析出,在P110S碳钢表面形成了保护性的产物膜,有效抑制了基体的全面腐蚀,降低了腐蚀速率。此外,溶液中高浓度的Cl-极易导致产物膜发生剥落与破裂,造成严重的点蚀。

The extremely harsh environment of Tahe Oilfield in Northwest China was simulated.The effects of temperature and partial pressure of CO_(2) on the corrosion behavior of Pl1oS carbon steel under the condition of high Cl^(-) containing acid gas were investigated through simulation test in high temperature and high pressure reactor,weight loss method,microstructure observation,phase analysis of corrosion products.The results showed that the corrosion rate of PlloS carbon steel first increased,then decreased and then increased with the increase of temperature.With the increase of CO_(2) partial pressure,the corrosion rate firstly increased and then decreased.The corrosion rate reached the maximum at 210℃and CO2 partial pressure of 8 MPa respectively.When the temperature was 150℃ or the partial pressure of CO_(2) was 8 MPa,FeCO_(2) crystal began to precipitate from the solution,forming a protective product film on the surface of Pl1oS carbon steel,effectively inhibiting the overall corrosion of the matrix and reducing the corrosion rate.In addition,the high concentration of Cl^(-) in the solution could easily lead to the peeling and cracking of the product film,causing serious pitting corrosion.