In wet gas transportation pipelines, condensation of water from warm and humid gas on cold pipeline
walls plays a significant role in top of the line (TOL) corrosion. The CO2 TOL corrosion behavior of
carbon steel under low temperature range and high condensation rate conditions was investigated in
autoclaves especially equipped to provoke water condensation on steel samples, hence simulating the
subsea wet gas pipeline environment. One side of the carbon steel samples was exposed to
water-saturated CO2 in the temperature range of 20oC to 45oC at 0.8MPa, the other side was cooled to
as low as 5 oC which caused a relatively high condensation rate. The corrosion rate was determined by
weight loss measurements. The surface morphology and the composition of the corrosion product layers
were analyzed using surface analytical techniques such as Scanning Electron Microscope(SEM) and
Energy Dispersive Spectrum(EDS). In addition, considerations regarding the impact of the condensation
process on the corrosion products were discussed.
Keywords: TOL corrosion, carbon steel, high condensation rate, low temperature