Sampath Bukkaraju

OTC-26007-MS Top of Line Corrosion: An Evaluation of Critical Parameters that Drive Mitigation Methods and System Design in Deepwater Gas Systems

Top of Line Corrosion (TOLC) occurs in deepwater wet gas systems when water vapor condenses on the upper internal walls of the flowline due to the heat exchange occurring between the hot fluid and the colder environment. The condensed liquid becomes enriched by the corrosive species naturally present in the gas stream and assumes a low pH because it does not contain any buffering species such as bicarbonate or iron. The predominant concern is carbon dioxide (CO2), which reacts with water to form carbonic acid (H2CO3), although hydrogen sulfide (H2S) and organic acids can also present significant challenges and drive the corrosion process.