Inhibition Effect of Monoethylene Glycol on CO2 Corrosion of Carbon Steel Subsea Pipeline

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.