Effect of CaCO3-saturated solution on CO2 corrosion of mild steel explored in a system with controlled water chemistry and well-defined mass transfer conditions

The effect of Ca2+ on the corrosion product layers when the CO2-containing electrolyte is saturated with respect to CaCO3, as frequently observed in oil production systems, was studied by weight loss, electrochemical techniques, and surface characterizations. An improved experimental set up was used and all experimental parameters reported. Results show that precipitation of corrosion products in solutions with or without CaCO3 was due to the favorable water chemistry obtained at the steel surface compared to the bulk solution. The presence of Ca2+ did not jeopardize the final protectiveness of corrosion product layer, but seemed to delay its growth.