Deputy director of R&D department, Wuhan Rules & Research Institute
China Classification Society
14:30 - 15:00
Wednesday, 18 September 2019
T1.5 Converting Small-scale LNG Carrier for Floating Storage Unit (FSU)
The combination of Liquefied Natural Gas (LNG) Floating Storage Unit (FSU) and Floating Regasification Unit (FRU) to form the function of Floating Storage and Regasification Unit (FSRU) is a feasible alternative to onshore LNG receiving terminal. Due to the shallow of sea channel, shortage of wharf, limit of operating range and other restrictions, especially for some islands in Southeast Asia, converting the small-scale LNG carrier to FSU can realize the storage of LNG alongside the quay and become one of the solutions for supplying the natural gas to peak-shaving station and power plant. Taking CNOOC 30k cubic meters LNG carrier, M.V. “HAI YANG SHI YOU 301”, converting to a FSU at BENOA harbor in Indonesia as an example, the design scheme of “FSU+FRU”, characters of ship type and actual port conditions were considered, the connections compatibilities of manifold and Emergency Shutdown (ESD) system were evaluated in accordance with the guidelines of SIGTTO, the selection of berthing fenders between ship to ship as well as ship to shore was analyzed based on the OCIMF recommendations, the optimization of mooring plan was calculated based on the hydrodynamic analysis of AQWA. Hazard Identification (HAZID) analysis on layout and LNG transfer system were carried out in combination with the characteristics of frequent LNG transfer from shuttle carrier to FSU and continuous discharge from FSU to FRU, 54 hazard sources were identified by means of the 20 guiding words. Safety zones for LNG ship to ship (STS) and ship to shore transfer operation was calculated by Quantitative Risk Assessment (QRA) based on the consequence simulation by the three-dimensional computational fluid dynamics software FLACS. Recommendations for further mitigation measures were proposed based on the existing safety measures, suggestions for equipment operations and daily maintenance were given as well. “Hai Yang Shi You 301” using as FSU has successfully operated for 2.5 years in Bali Island, it has completed 37 times LNG ship to ship transfer and delivered 760,000 cubic meters LNG to FRU during the period. This paper provides a useful reference and best practice to the industry for the project design and safety operation on converting a small-scale LNG carrier as FSU.