Effects of chloride content on CO2 corrosion of carbon steel in simulated oil and gas well environments

• DOI: 10.1016/j.corsci.2014.03.025
• Publication Date: 2014-03-23T12:10:44Z
• Authors: Q.Y. Liu; L.J. Mao; S.W. Zhou
• Keywords: Carbon steel; Immersion; Partial pressure

Abstract Effects of chloride content on CO2 corrosion of carbon steel have been studied by immersion tests and electrochemical measurements combined with scanning electron microscopy, X-ray diffraction and analysis of polarization curves. Results show that maximum CO2 corrosion rate is reached with increasing Cl− content at a constant temperature and partial pressure. CO2 corrosion is a mixed-controlled process, i.e., both activation and mass-transfer steps with increasing Cl− content. Increasing Cl− content can reduce CO2 solubility. Moreover, Cl− can destroy corrosion product films and change morphology of corrosion product films, but it has no effect on the composition of the corrosion product.