Publications

Corrosion Under Insulation – hereinafter referred as CUI – is a hidden integrity threat recently experienced to Belanak FPSO, one of operating fields where Medco E&P Natuna Ltd (MEPN) operating Block B Natuna, in certain level to higher risk where a TIER 3 hydrocarbon leak was observed. It was a wakeup call that the existing CUI inspection best practice covered by routine RBI was considered not effective and needed to revisit. In rolling up the revisit, CUI management strategy was evaluated. After grabbing knowledge sharing from various sources, a new CUI management strategy was established including assigning methodologies (adopting API 581 standard) of assessment, inspection plan, and employing a new inspection technology of Real-time Radiography (RTR). Implementing this new CUI management strategy required a CUI inspection & repair campaign as big volume of higher integrity risk impacted by CUI was identified requiring immediate mitigations. The strategy prioritized the CUI program execution campaign into 3 phases with risk base approaches (priority-1 high risk, priority-2 significant, and priority-3 medium) assigned to total 327 insulated lines, meanwhile 323 lines categorized as low risk and will be managed under routine RBI program. The result of screening inspection revealed CUI defects underneath insulation and defined volume of insulation to be stripped for verification inspection. Final invasive inspection result on priority-1 recorded 49 defects requiring mechanical repairs. All defects was successfully repaired and avoided a catastrophic situation where CUI hydrocarbon leak could have happened. Management recognized that the implementation of new management strategy with inspection technology was working effectively battled CUI threats and lowered integrity risk of Belanak FPSO to low level that safe for continuous operation. Keywords: CUI, management strategy, methodology, inspection technology.