Sour Top-of-the-Line Corrosion in the Presence of Acetic Acid

Abstract

Abstract Under stratified flow and dewing conditions, internal corrosion can occur at the top of horizontal pipelines where continuous injection of corrosion inhibitors does not have a mitigating effect. This research work presents an experimental study of the influence of the presence of hydrogen sulfide (H2S; up to 0.13 bars) and acetic acid (HAc; up to 1,000 ppm) on carbon dioxide (CO2) top-of-the-line corrosion. The study was performed in a 10 cm (4 in) internal diameter flow loop with system conditions constant at 70°C, 2 bars partial pressure CO2, 3 bars total pressure, 5 m/s gas velocity, and a water condensation rate of 0.25 mL/m2/s. A comprehensive analysis on the effect of these parameters (partial pressure of H2S and concentration of acetic acid) on the type of corrosion product film formed at the top of the line is performed.