Corrosion inhibition of mild steel in CO2 environments by
sulfiar-containing compounds was studied using various laboratory performance test methods, inhibitor residual analysis techniques and a surface imaging technique. Corrosion rate-time/concentration profiles were obtained for several commercially available sulfur-containing inhibitors together with a proprietary thio compound. The role of chelation and redox chemistry of these inhibitors in corrosion inhibition is discussed in terms of the structure-activity relationship. A number of formulated products with sulfur-containing compounds and other corrosion inhibitors were evaluated for their synergistic effects. Film persistency of various sulfur-containing inhibitors and its effect on
localized corrosion was evaluated. Mechanism of inhibition by sulfur-containing inhibitors including disulfide formation was proposed.
Keywords: thiosulfate, thioglycolic acid, residuals, rotating cylinder electrode, LPR, flow loop, oilfield, CO2