A floating production storage and offloading (FPSO) unit is a floating vessel used by the offshore oil and gas industry for the production and processing of hydrocarbons, and for the storage of oil. An FPSO vessel is designed to receive hydrocarbons produced by itself or from nearby platforms or subsea template, process them, and store oil until it can be offloaded onto a tanker or, less frequently, transported through a pipeline. FPSOs are preferred in frontier offshore regions as they are easy to install, and do not require a local pipeline infrastructure to export oil. FPSOs can be a conversion of an oil tanker (like the Seawise Giant) or can be a vessel built specially for the application. A vessel used only to store oil (without processing it) is referred to as a floating storage and offloading (FSO) vessel. The first of a related type, floating liquefied natural gas vessels, went into service in 2016. Types FPSOs are classified into the following types. Floating storage and offloading (FSO) Floating production storage and offloading (FPSO) Floating drilling production storage and offloading (FDPSO) Floating storage regasification unit (FSRU) A floating storage and offloading unit (FSO) is essentially a FPSO without the capability for oil or gas processing. Most FSOs are converted single hull supertankers. An example is Knock Nevis, ex Seawise Giant, which for many years was the world's largest ship. It was converted into an FSO for offshore use before being scrapped. At the other end of the LNG logistics chain, where the natural gas is brought back to ambient temperature and pressure, a specially modified ship may also be used as a floating storage and regasification unit (FSRU). A LNG floating storage and regasification unit receives liquefied natural gas (LNG) from offloading LNG carriers, and the onboard regasification system provides natural gas exported to shore through risers and pipelines. , there are 33 FSRUs in the world, of which some relocate to higher-priced areas. History Oil has been produced from offshore locations since the late 1940s. Originally, all oil platforms sat on the seabed, but as exploration moved to deeper waters and more distant locations in the 1970s, floating production systems came to be used. The first oil FPSO was built in 1977 on the Shell Castellon field, located in the Spanish Mediterranean. Today, over 270 vessels are deployed worldwide as oil FPSOs. On July 29, 2009, Shell and Samsung