Corrosion Management of Wet Gas Sour Gas Carbon Steel Pipeline with Corrosion Inhibitor and Mono-Ethylene-Glycol in NACE Region 3

Abstract

This paper will present corrosion management of a wet sour gas carbon steel export pipeline using continuous and batch corrosion inhibitors with mono-ethlene-glycol (MEG) as hydrate mitigation strategy in NACE MR 0175/ ISO 15156 region 3 (severe sour). The wet sour gas carbon steel export pipeline corrosion management via continuous CI and batch inhibitors with closed loop MEG regeneration system is rare worldwide. This is especially challenging when the case study may potentially be the longest wet sour gas, large diameter carbon steel pipeline (approximately 207km × 32 inch) in the world thus far. Pipeline corrosion management and hydrate management aspects when being reviewed holistically, it could provide significant cost savings yet safeguarding the overall technical integrity of the pipeline. The overall corrosion management leverages on Shell's many years of JIP and operating experience in sour service including the pipeline material specification, corrosion management, inspection, and maintenance philosophy. Reliable correlation between reservoir properties and uncertainties severe sour service, flow assurance, chemical behavirous, operating experiences etc were considered to best represent the operating envelope for this wet sour gas carbon steel pipeline. This includes the testing and selection of continuous CI and batch inhibitor, corrosion monitoring, operational pigging, maintenance, and inspection requirements throughout the field life.