Bonga without the topside

https://www.ship-technology.com/projects/bonga-fpso/

Let us make some definitions,

FPSO, FSO, PP.

FPSO (Floating Production Storage and Offloading) and FSO (Floating Storage and Offloading) systems today have become the primary method for many offshore oil and gas producing regions around the world.

An FPSO is a floating production system that receives fluids (crude oil, water and a host of other things) from a subsea reservoir through risers, which then separate fluids into crude oil, natural gas, water and impurities within the topsides production facilities onboard. Crude oil stored in the storage tanks of the FPSO is offloaded onto shuttle tankers to go to market or for further refining onshore.

Most FPSOs/FSOs are ship-shaped and can be secured to the seabed via a variety of mooring systems, the choice of which is determined by the specific environment. They are suitable for a wide range of water depth, environmental conditions and can be designed with the capability of staying on location for continuous operations for 20 years or longer.

https://www.modec.com/business/floater/fpso/

So the major difference between a FPSO and FSO is that one can produce, store, and off load crude while the other can only store and off load. The two of them are floaring on the water, bouyed into positions by strong anchors.

Some platforms can process oil and gas but can not store, so these ones are the production platforms, that need FSO to complete cycle of storing and offloading. At the extreme end of this spectrum are FDPSO - Floating drilling production storage and offloading vessels.

In the liquefied gas sector, there are FSRU - Floating storage and regasification unit.

The first oil FPSO was built in 1977 on the Shell Castellon field, located in the Spanish Mediterranean.[7] Today, over 270 vessels are deployed worldwide as oil FPSOs.[8]

On July 29, 2009, Shell and Samsung announced an agreement to build up to 10 LNG FPSOs,[9] at the same Samsung Yard. Flex LNG appeared to construct smaller units.[10]

One of the world's largest FPSO is the Kizomba A, with a storage capacity of 2.2 million barrels (350,000 m3). Built at a cost of over US$ 800 million by Hyundai Heavy Industries in Ulsan, Korea, it is operated by Esso Exploration Angola (ExxonMobil). Located in 1200 meters (3,940 ft) of water at Deep water block 200 statute miles (320 km) offshore from Angola, Central Africa in the Atlantic Ocean, it weighs 81,000 tonnes and is 285 meters long, 63 meters wide, and 32 meters high (935 ft by 207 ft by 105 ft).[22]

https://en.wikipedia.org/wiki/Floating_production_storage_and_offloading

Floating Production Storage and Offloading (FPSO) vessels certainly have the wow factor: their sheer size, processing power and capability of operating for decades without pause make them impressive facilities - and invaluable to the oil and gas industry. We take a look at the largest, oldest and deepest FPSO vessels in the world.

FPSOs have become the primary operating systems for many offshore oil and gas producing regions across the globe. These ship-shaped vessels are quite the structural engineering feat: designed to suit a variety of environmental conditions and water depths, they are capable of staying on location for continuous operations upwards of 20 years. FPSOs collect fluids from subsea reservoirs through risers (rigid or flexible pipes). These fluids are then separated into crude oil, natural gas, water and impurities within production facilities onboard. Crude oil is stored in internal tanks before being offloaded onto shuttle tankers for distribution. Currently, there are approximately 183 operating FPSOs: here we take a look at the largest, the oldest and the deepest in the world.

Weighing in at 220,000 tonnes with a storage capacity of 2.3 million barrels, the Egina FPSO is the largest in the world, by capacity. Operated by TotalEnergies, the $3 billion vessel is 330 metres long, 61 metres wide and 34 metres tall, and is currently moored at the Egina oil field, 200km off the coast of Nigeria. Connected to 44 subsea wells, this immense facility can produce up to 208,000 barrels of oil per day and is responsible for almost 10% of Nigeria’s total oil production.

https://www.brunel.net/en-au/blog/oil-and-gas/record-breaking-fpsos

Grandfather of all FPSOs, the Arco Ardjuna vessel was built in 1973 and is yet to retire, making it the longest serving FPSO in the world. Operated by Pertamina, the 48-year-old vessel is moored at the Ardjuna Oil Field in the Java Sea, approximately 95km from Jakarta. At the time of its construction, the 53,734 tonne FPSO was one of the largest vessels in the world.

https://www.brunel.net/en-au/blog/oil-and-gas/record-breaking-fpsos

Shell’s Turritella vessel sets the record for the world’s deepest FPSO, reaching to impressive depths of 2,900 metres. Located in Stone’s Field in the US Gulf of Mexico, this FPSO copes with extreme weather conditions in an area known for severe storms and hurricanes. Purpose-built for Stone’s Field, the vessel boasts the world’s largest disconnectable buoy, allowing it to quickly sail away in the event of hurricanes and later re-connect to resume operation. In yet another record breaker, it the first vessel to combine a disconnectable buoy with steel ‘lazy wave’ risers – an innovation which absorbs the impact of large waves, steadying the vessel and enhancing production performance at extreme depths.

https://www.brunel.net/en-au/blog/oil-and-gas/record-breaking-fpsos