An FPSO is a floating production system that stores and offloads crude oil at sea.
FPSO stands for floating production, storage and offloading. A converted tanker or purpose-built vessel receives fluids from subsea wells, separates oil, gas, and water, and stores the stabilized crude in large onboard tanks. Shuttle tankers then periodically collect the oil for transport to shore or a refinery.
FPSOs are especially useful in deepwater or remote fields where constructing a permanent pipeline and fixed platform would be costly or impractical. Mooring systems hold the vessel in position, while flexible risers connect it to subsea equipment.
An FPSO is not simply an offshore drilling rig. Drilling rigs primarily drill wells, whereas an FPSO processes and stores production. FLNG vessels perform a similar floating role for liquefied natural gas, and FSRUs regasify imported LNG rather than producing crude oil.