Evaluation of high shear inhibitor performance in CO2-containing flow-induced corrosion and erosion-corrosion environments in the presence and absence of iron carbonate films

Carbon steel pipeline degradation occurs as a result of erosion-corrosion during oil and gas production. Sand particles contribute to this effect when they are present in conjunction with a high flow velocity. In carbon dioxide (CO 2 ) environments, and under certain conditions, the corrosion rate of the steel can be reduced by the formation of a protective iron carbonate (FeCO 3 ) layer. This work assesses the ability of FeCO 3 to protect the underlying steel in flow-induced corrosion and erosion-corrosion environments. Autoclave tests are performed at 60 °C and 100 bar in a 1 wt%NaCl CO 2 -saturated solution for a duration of 48 h to develop 60 µm thick FeCO 3 films. The film-covered samples were then transferred into a submerged impinging jet (SIJ) apparatus to assess their ability to resist both flow-induced corrosion and erosion-corrosion environments at 25 °C and a flow velocity of 15 m/s (both with and without 1000 mg/L sand). Tests were also conducted in the presence of a commercially available corrosion inhibitor to evaluate the interaction. Results indicate that the FeCO 3 layer is able to considerably suppress corrosion of the carbon steel substrate. Experiments in the presence of both the FeCO 3 film and corrosion inhibitor demonstrated that there is a notable synergistic effect between these two components in providing resistance to erosion-corrosion.