Some Observations on Corrosion of Carbon Steel in Aqueous Environments Containing Carbon Dioxide

Abstract

Experimental results and analyses are reported on the corrosion of carbon steel in CO2-saturated environments that typically represent producing well waters encountered in natural gas reservoirs. Tests were performed at temperatures and pressures up to 95 C (203 F) and 700 kPa (100 psig), respectively. The results indicated that the reduction of the HCO3– ion was significant and is used in part to explain the observed behavior of the steel in CO2 media. Some unusual cathodic polarization characteristics were observed and are believed, from theoretical thermodynamic and kinetic analyses, to be partly a consequence of the cathodic reduction of magnetite and siderite films.