Corrosion Behavior of X52 Steel in High Pressure CO<sub>2</sub> Environment

Abstract

Research in high pressure CO2 environment is important in oil and gas industry due to potential development of high pressure CO2 gas fields. Current understanding limits the use of carbon steel pipeline material in this high pressure CO2 environment due to excessive corrosion rates predicted by corrosion prediction software. The aim of this work is to elucidate the corrosion behavior of X52 steel in high pressure CO2 environment. Electrochemical methods of linear polarization resistance (LPR), electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization techniques were employed to study the CO2 corrosion mechanism at high pressures of 10-60 bar at ambient temperature. Surface morphology and chemical composition of corrosion film was studied by using scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results obtained showed that the corrosion rates at high pressures were significantly influenced by CO2 pressure. However FeCO3 and F3C were the main component of the corrosion product film.