A floating production, storage and offloading unit (FPSO) is a floating vessel used in the offshore oil and gas industry for the production and processing of hydrocarbons and for the storage of oil. An FPSO is designed to receive hydrocarbons produced by itself or from nearby platforms or subsea platforms, process them, and store the oil until it can be offloaded onto a tanker or, less commonly, transported via pipeline. FPSOs are preferred in frontier offshore regions because they are easy to install and do not require local pipeline infrastructure to export the oil. FPSOs may be converted from an oil tanker (such as the Seawise Giant) or may be a vessel built specifically for the application. A vessel used only to store oil (without refining it) is called a floating storage and offloading vessel (FSO). The first vessels of this type – floating vessels for the transportation of liquefied natural gas – were put into operation in 2016.
Types
FPSOs are divided into the following types.
- Floating Storage and Offloading (FSO)
- Floating Production, Storage and Offloading Unit (FPSO)
- Floating Storage and Offloading Unit (FSOU)
- Floating Storage Regasification Unit (FSRU)
A floating storage and offloading unit (FSO) is essentially an FPSO without the ability to process oil or gas. Most FSOs are converted single-hull supertankers. An example is the Knock Nevis, the former Seawise Giant, which was for many years the largest vessel in the world. It was converted into an FSO for offshore use before being decommissioned.
At the other end of the LNG logistics chain, where the natural gas is returned to ambient temperature and pressure, a specially modified vessel can also be used as a floating storage and regasification unit (FSRU). A floating LNG storage and regasification unit receives liquefied natural gas (LNG) from unloading LNG carriers, and an onboard regasification system exports the natural gas to shore via risers and pipelines. As of 2022, there are 33 FSRUs worldwide, some of which are being relocated to higher-value areas.
Advantages
Floating production, storage and offloading vessels are particularly effective in remote or deepwater locations where offshore pipelines are not cost-effective. FPSOs eliminate the need to install expensive trunk pipelines from a processing plant to an onshore terminal. This can provide an economically attractive solution for small oil fields that may be depleted in a few years and do not justify the cost of installing a pipeline. Once the field is depleted, the FPSO can be relocated to a new location.
New FPSOs have a high initial cost (up to $1 billion) but require limited maintenance. Additionally, their relocation/repurposing capability means they can outlast the production facility by decades. A cheaper alternative for smaller platforms is to convert an oil tanker or similar vessel, costing less than $100 million.
