Preliminary Study on Risk based Inspection (RBI) of Mercury Corrosion at Gas Processing Plant

Traces of elemental mercury in natural gas could cause corrosion to the plant equipments. The objective of this preliminary study is to conduct Risk Based Inspection (RBI) analysis on mercury corrosion at gas processing plant (GPP). The RBI methodology is based on the API RP 580 and API 581 which comprises three main tasks; analyzing the probability of fiillure (poF), determining the consequence of failure (CoF), and evaluating the criticality rating. This analysis focuses on the corrosive effect of mercury to the Pre-Treatment Unit (pTU). Acid Gas Removal Unit (AGRU). and Dehydration Unit (DHU). Based on the preliminary study, a Damage Mechanism Potential and Criticality Assessment of mercury corrosion at GPP are proposed. A total of25 equipments are analyzed in the study whereby 80 percent of the components are in a Medium Risk category and 20 percent is in a Low Risk category. Based on this study, the fmnt-end equipments in GPP could be exposed to a significant risk of mercury corrosion and hence detail analysis is required.