The Frosk oil field is planned to be developed as a subsea tieback to the Alvheim floating production, storage and offloading (FPSO) facility operating in the central North Sea, Norway.

Aker BP, the operator of the Alvheim field, holds 65% stake in the Frosk field, while the other development partners are Vår Energi (20%) and Lundin Energy Norway (15%).

The Frosk field was discovered in January 2018 and the partners approved the field development concept in the first quarter of 2021. The plan for development and operation (PDO) was submitted to Norway’s Ministry of Petroleum and Energy in September 2021.

The final investment decision (FID) on the £170m ($233m) Frosk field development is expected by the end of 2021.

Frosk field reserves and production

The total recoverable reserves of the field are estimated to be ten million barrels of oil equivalent (Mboe).

First oil from the field is expected in 2023, with the production expected to continue for ten years.

Frosk field location, discovery and appraisal details

The Frosk field is located in block 24/9 in production licence (PL) 340, in the greater Alvheim area of the Norwegian continental shelf.

The field was discovered by the 24/9-12 S wildcat well and was subsequently appraised by the 24/9-12 A and 24/9-15 A appraisal wells in February 2018 and April 2019, respectively. The field’s reservoir comprises Paleocene sandstone in the Heimdal Formation.

Transocean Arctic, a semi-submersible drilling rig, was used to drill the 24/9-12 S and 24/9-12 A wells. The 24/9-12 S discovery well was drilled to a vertical depth of 2,251m, while the 24/9-12 A  appraisal well was drilled to a vertical depth of 2,162m. The 24/9-15 A appraisal well was drilled by Saipem's Scarabeo 8 semi-submersible rig to a vertical depth of 1,810m below the sea surface.

Frosk field development details

The Frosk offshore field development involves the tie-back of two production wells to the Alvheim FPSO by utilising the existing subsea infrastructure of the Bøyla field in the Alvheim area. The Alvheim FPSO is located approximately 25km north-east of the Frosk field.

The Bøyla field, which was developed as a subsea tie-back to the Alvheim FPSO, has been producing since January 2015. Both Bøyla and Frosk fields are located in the same production license.

Test production at the Frosk field

The drilling of the Frosk test producer well was completed in June 2019 and the well was brought on stream in August 2019.

The Frosk test subsea wellhead was connected to the Bøyla ‘M’ production manifold, which is connected to the Alvheim FPSO.

The test production that ceased in 2021 provided information about the Frosk reservoir enabling Aker BP to optimise the Frosk field development plan in terms of the number of wells, drainage strategy, and surface facility requirements.

Alvheim FPSO details

The Alvheim FPSO, operating since 2008, measures 252m long and 42m wide and has an oil storage capacity of 560,000 barrels.

Shuttle tankers transport the stabilised oil from the FPSO to the shore, while gas is transported through a pipeline connecting the Scottish Area Gas Evacuation (SAGE) pipeline system for further transport to the St. Fergus gas terminal in Scotland.

Aker BP aims to produce more than one billion barrels from the Alvheim FPSO through the development of several satellite fields.

To support additional tie-backs to the Alvheim FPSO, a water capacity upgrade project was sanctioned in the fourth quarter of 2020, while a gas debottlenecking project is underway to increase the FPSO’s gas production capacity by 15%.

Aker BP’s alliance partners for the Frosk field development

Aker BP’s drilling and well alliance partners, Odfjell Drilling and Halliburton, are expected to receive contracts to drill and complete the new wells of the Frosk field.

Odjfell Drilling will deploy a semi-submersible drilling rig, while Halliburton will offer well construction services.

Whereas its subsea alliance partners Subsea 7 and Aker Solutions are expected to execute the subsea scope of the Frosk field development.

Alvheim oil and gas field details

The greater Alvheim area consists of the Alvheim, Vilje, Volund, Bøyla and Skogul fields tied back to the Alvheim FPSO.

Skogul field, which commenced operations in 2020, is tied back to the Alvheim FPSO through the Vilje field. The PDO of the Kobra East and Gekko (KEG) project, also located in the Alvheim area, was submitted to Norwegian authorities in June 2021.

The other discoveries in the Alvheim area include Trell & Trine, Froskelår, and Rumpetroll that could be developed as subsea tie-back projects to the Alvheim FPSO.