乙二醇对海底管道CO2腐蚀的抑制作用

Inhibition Effect of Monoethylene Glycol on CO_2 Corrosion of Carbon Steel Subsea Pipeline

海上凝析气田开发普遍采用加注乙二醇(MEG)的方法保护海底湿气管道,抑制水合物形成,对管道内腐蚀也有一定的影响。本工作采用高温高压釜和电化学方法研究了乙二醇对海底管道内部CO2腐蚀的影响,结果表明,乙二醇对CO2均匀腐蚀具有显著抑制作用,抑制效果与国外的经验公式预测结果接近。乙二醇对管道内腐蚀起抑制作用的主要原因可能与降低水的活性、降低FeCO3的溶解性、促进生成腐蚀产物膜等因素有关。

In subsea condensate gas field production,monoethylene glycol（MEG） is often injected to prevent the formation of hydrates in the subsea pipeline,and the MEG affects the internal corrosion of the pipeline to some degree.The effect of MEG on internal corrosion of pipeline in CO2 environment was studied using autoclave testing and electro chemical techniques.The results showed that MEG reduced the general corrosion rate in CO2 environment.The effect was agreed with the predicted result of the empirical formula which was proposed by De Waard et al.The inhibited effect of MEG on internal corrosion would be related to decreasing the activity of water and solubility of FeCO3,which promoted the formation of corrosion product scale.