Active studies have been made on the offshore LNG receiving terminal by many people around world. Especially in USA, many actual LNG receiving terminal projects are under progress and some are under engineering and construction stages. Among the candidates, the LNG Regassification Vessel (LNG RV) would be the first offshore LNG receiving facility. The successful operation of the LNG RV would accelerate the similar application by proving technical and commercial grounds. The LNG RV adopts onboard regasification (regas) and turret facilities in addition to the conventional LNG carrier. The regas process is mainly composed of the LNG feed pumps, high pressure LNG pumps, vaporizers, and send-out equipment, which are similar to those of a land-based LNG receiving terminal. The regas capacity of the vessel is approximately 500 mmscfd. The first LNG RV has been delivered to her ship owner in January 2005 after successful completion of the gas and regas trial. The first commercial operation will start later March, 2005. So, at the time of this paper presentation, the operation of the first cargo would have completed in the Gulf of Mexico. The experiences gained from the first LNG RV implementation could be a step stone for the future offshore LNG terminal technologies.
Considering most of the feed gas for the LNG is produced in offshore and most LNG is imported via sea, it might be natural that many people in the LNG industry would consider offshore LNG facilities as alternatives for the land-based ones. However, despite of rapid expansion of the LNG industry and the abundance of the offshore LNG facility concepts, no physical offshore LNG facility is existent so far. Two major sectors of the offshore LNG facility would be LNG FSRU (Floating Storage and Regasification Unit) and LNG FPSO (Floating Production Storage and Offloading). Both the LNG FSRU and FPSO concepts are well-known and now approaching implementation stages. In the environment, the successful completion of the LNG RV, the first offshore LNG facility, would be an important achievement in the LNG technology. The purpose of this paper is to introduce the LNG RV status to those who are interested in and have contributed to the offshore LNG technology.
LNG RV is a vessel with combined functions of the conventional LNG carrier, offshore mooring turret and regasification (regas) facilities. As the vessel has onboard regas facility, the regasified natural gas (NG) can be connected directly to a commercial pipeline trunk. Therefore the process does not need any land-based LNG receiving and regas facilities. The basic concept of the LNG RV is shown in Fig 2. Though the LNG RV concept is unique, the technologies used in LNG RV are based on proven conventional ones. The long operation records of the ocean-going LNG vessels have proved the reliabilities of the onboard equipment and the LNG containment system. The similar onboard turret systems have been used for many years for crude oil shuttle tanker applications.