Development

Johan Sverdrup is a field on the Utsira High in the central part of the North Sea, 65 kilometres northeast of the Sleipner fields. The water depth is 115 metres. Johan Sverdrup was discovered in 2010 and the plan for development and operation (PDO) for Phase I was approved in 2015. The development solution for the first development phase is a field centre with four specialised platforms: living quarters, process, drilling and riser facilities. The four platforms are connected by bridges. The drilling platform has 48 well slots and is prepared for simultaneous drilling, well intervention and production. The field will be operated with power from shore throughout its lifetime. In 2019, production from Phase I started and the PDO for Phase II was approved. The plan comprises a process platform and five subsea templates, in addition to modifications on the riser platform.

Reservoir

The main reservoir contains oil in Upper Jurassic intra-Draupne sandstone and lies at a depth of 1,900 metres. The quality of the main reservoir is excellent with very high permeability. The remaining oil resources are in sandstone in the Upper Triassic Statfjord Group and Middle to Upper Jurassic Vestland Group, as well as in spiculites in the Upper Jurassic Viking Group. Oil was also proven in Permian Zechstein carbonates.

Recovery strategy

The field is produced by water injection as pressure support, as well as gas lift in the production wells. In the first development phase, production wells are placed centrally, high up in the thickest parts of the reservoirs. The water injection wells are placed near the oil-water contact. The distance between the production and injection wells is typically between four and five kilometres. In the second development phase, production and injection wells will be placed in the less central parts of the field.

Transport

Stabilised oil is exported from the riser platform through a new oil export pipeline that is connected to existing underground storage caverns at the Mongstad terminal. The gas is exported from the riser platform to the Kårstø terminal through a new pipeline connected to Statpipe.

Status

The capacities for oil production and water injection in Phase I have been increased in 2021. Phase II started production in December 2022.