Electrochemical Impedance Spectroscopy Study of the Corrosion of 3Cr Pipeline Steel in Simulated CO₂-Saturated Oilfield Formation Waters

The formation and the growth of the corrosion film that forms on 3Cr steel surface in CO₂ environments were characterized and investigated by scanning electron microscopy, energy dispersive spectrometry, quadrant back scattering detector, x-ray photoelectron spectroscopy, and electrochemical impedance spectroscopy (EIS). A model for the formation of the corrosion film is proposed in this paper. The data obtained using the proposed equivalent circuit, which is based on this model, exhibits close agreement with the experimental EIS results, indicating that the proposed film formation model is reliable.