The Use of Risk-Based Inspection for Aging Pipelines in Sirikit Oilfield

摘要

The Sirikit oilfield located in the north part of Thailand has now been in operation for 28 years and intends to continue production in excess of a further 10 years. The Sirikit oilfield manages 187 intra- field pipelines with total installed length of approximately 417 km. installed from 1983 onwards. A number of the infield pipelines have been in service for more than 20 years and with original design life of 15-20 years, they are reaching the end of or exceeding their original lives. Pipeline degradation due to corrosion leading to spills and production deferment has become critical problem. In addition, frequent and continuous inspection of pipelines to achieve sufficient and reliable inspection data with optimal inspection resource have become increasingly important. In order to keep this oilfield long operational life as well as to assurance sustained pipelines safety and integrity, Sirikit oilfield has implemented the Risk Based Inspection (RBI) to assess a number of 187 infield pipelines with respect to corrosion mechanisms, inspection effectiveness, likelihood of failure and consequence to failure. Pertaining to the results of the implementation, it was a successful implementation for Sirikit assets. The major success was identifying the risk, ensuring that the risk remains as low as reasonably practicable. Optimal inspection plan was also successfully established by extending a number of pipelines inspection intervals from 1 to 2-3 years under some certain conditions and will gradually increase to 4-5 years. The higher level of inspection and scrutiny to reduce potential threats on the pipelines based on what, where, when and how to inspect in order to control and reduce the risk to be within an acceptance level were used. This paper describes the implementation of a risk-based inspection program for the Sirikit oilfield. The paper addresses the RBI matrix, the likelihood attributes, the consequence scores, and the overall risk. Pipelines are plotted on the RBI matrix to develop inspection priorities followed by inspection planning. KRisk-Based Inspection (RBI);; Likelihood of Failure (Lof);; Consequence of Failure (CoF);; Non-Destructive Testing (NDT). Long Range Ultrasonic Testing (LRUT)