The performance of various corrosion inhibitors has been tested in flow loop at high temperature and high flow velocity. The experimental conditions were 60-150°C, 1 bar CO2, pH 5 and 0.1-1% NaCl. The flow velocity was varied between 1 and 9 m/s, corresponding to wall shear stress values between 5 and 135 Pa respectively. The general
observation was that changes in flow velocities had negligible
effect on the inhibited corrosion rate. No inhibition failure related to flow was observed. As corrosion product layers formed on the specimens, separating the contributions of inhibitor and corrosion product film with respect to protective effect became difficult. A test of flow sensitivity under film forming conditions may reflect the flow persistency of the corrosion product films rather than that of the inhibitor. It was found that temperature is a critical parameter for the tested inhibitors. The inhibited
corrosion rate generally increased with increasing temperature. The effect of temperature was dependent on the inhibitor formulation.
Keywords: CO2 corrosion, corrosion inhibitors, corrosion testing, high temperature, flow velocity