Main Cryogenic Heat Exchanger Replacement at Brunei LNG

Introduction This paper addresses the economical and technical justification for the rejuvenation of the existing, 33 years old, Brunei LNG plant to extend its lifetime with a third 20-year contract period to 2033. After an introduction into the history of the development of the Brunei LNG plant, and its growth aspirations for the 21st century, the paper will further focus on the current Asset Reference Plan (ARP) and in particular the technical challenges of the replacement of the Main Cryogenic heat exchangers in four out of the five Brunei LNG production trains. Brunei LNG History The construction of Brunei LNG started in 1968, and first LNG was exported to Japan in 1972. The shareholders of the BLNG plant are the Brunei Government (50%), Mitsubishi Corporation (25%) and Shell (25%). Shell Global Solutions, has also been the technical advisor of the Brunei LNG plant since the initial phases of the project. The BLNG project was the first to use the Propane Mixed refrigerant (C3/MR) process, with spool wound main cryogenic heat exchangers. In the original plant, eleven boilers generated the steam for the turbine driven refrigerant compressors. Treated river water is used as cooling medium in an open cooling cycle. Each liquefaction train has a separate gas treating section that consists of an acid gas removal unit, dehydration unit and mercury removal unit. Originally, the BLNG project included four trains with a design capacity of 1.05 MTPA. During construction, the scope was increased with a fifth train of the same capacity. This fifth train started production in 1974. As the main cryogenic heat exchanger of the fifth train was produced later than the original four, an updated design was installed in train 5. First Rejuvenation Between 1992 and 1994, the first rejuvenation and debottlenecking project was carried out at BLNG. In subsequent years plant debottlenecking projects have been implemented and the production capacity reached a maximum of 7.3 MTPA or almost 140% of initial design capacity by 2003 (Fig. 1).