A new approach in top-of-line corrosion studies in CO2/H2S environment

ABSTRACT The most common way to control Top of line Corrosion (TLC) is to use corrosion inhibitors. A setup was designed to simulate the TLC conditions and measure the corrosion rate in the presence of an Imidazoline-based commercial inhibitor. The base solution was at temperature 70°C and the samples X65 steel were at 5°C and 20°C. Experiments were carried out in atmospheric conditions by purging a mixture of CO2 and H2S gases in proportions of 21% and 79%, respectively. An increase in the TLC rate was measured when the sample temperature increased. The difference between the average corrosion rate measured by weight loss and the instantaneous resulting from Tafel and linear polarisation resistance was significant in this study. Results showed that the surface temperature of the sample has a significant effect on TLC. Although the condensation rate on X65 steel sample with surface temperature of 5°C was about ten times more at 20°C, the corrosion rate was more at higher temperatures.