Revealing the Deterioration Effect of Scale Inhibitor on the Performance of Corrosion Inhibitor under Dynamic Conditions

Currently, the scale inhibitor (SI) and corrosion inhibitor (CI) have been massively applied in the oil gathering and transportation applications, however, their effect on the corrosion of pipeline steels remained vague. Herein, the corrosion behavior of X65 steel under dynamic condition was systematically studied in a simulated oilfield produced solution containing CO₂/H₂S gases and with/without SI and CI, and the corrosion products formed on surface of X65 were analyzed with multiple characterizations. We find that, the presence of SI could hinder the adsorption of CI molecules on surface of X65, leading to deterioration of the productivity of CI, and then an increase in both the corrosion rate and local corrosion. Therefore, the SI played a certain antagonistic role on the protective property of CI. This work provides a significant guidance on the material selection upon pipeline applications.