Study of Subsea Pipeline Rehabilitation Strategy in Mature Field by Using Infield Liner Method for Capex And Opex Optimization
Proceedings Publication Date
The study is initiated on transport facility of multi phase flow at one of PHE ONWJ (Indonesian National Oil Company) asset, K-1 platform to KN-1 platform. An 8 inch pipe is being used since 2012 to transport hydrocarbon fluid between the two platforms. In December 2015 and January 2016, several leakages were found during subsea pipeline inspection. It was observed and calculated that the corrosion rate is about 0.3 mm/y, which can be classified a very high rate. With the high corrosion rate at the pipeline, non-corrosive material need to be considered as an effective strategy for pipeline rehabilitation. Infiled liner as one of the pipeline rehabilitation strategy is being assessed on this paper. The infield liner will be compared to the other 3 options, which are flexible pipe, reinforced thermoplastic pipe (RTP), and carbon steel. Each of the option will be assessed by their performance during hydraulic simulation and the economic analysis to obtain the most economical solution for the pipeline rehabilitation strategy. The infiled liner is being assessed for its installation technique and challenges, and the maintainability during operation. As the result, all the options show the ability to perform during the hydraulic simulation. From the economical analysis, infield liner and RTP show similar economics level. The capital cost for both options is US$ 10.2 million with NPV US$ 26.5 million and IRR 80.7%. But after included decommissioning cost, infield liner arise to be the most economical solution for the pipeline rehabilitation strategy. The installation technique of infield liner is using pull through method and it only takes 5 days. No new and specific technique is required to maintain the infield liner during operational phase. It can be concluded that infield liner is the economical and effective solution for pipeline rehabilitation strategy.