The Agar-Plantain discovery is located 12km east of the Beryl field in the UK North Sea. Image courtesy of Apache Corporation.
Alvheim FPSO offers a potential development option for the Agar-Plantain field. Image courtesy of Aker BP.
Agar-Plantain is expected to produce first oil in early-2021. Image courtesy of Faroe Petroleum.

The Agar-Plantain oil discovery is located in the North Sea, within the South Viking Graben area of the UK Continental Shelf (UKCS).

The discovery is jointly owned by operator Azinor Catalyst (25%), Cairn (50%) and Faroe Petroleum (25%).

Development of the offshore field is expected to begin in 2020 with first oil production expected in early-2021.

Agar-Plantain location

Agar discovery and the Plantain prospect are located close to the UK/Norwegian median line, in the UKCS blocks 9/9d and 9/14a of the license P1763.

The potential Agar-Plantain offshore field development area lies 12km east to the Beryl field and 14km west to the Alvheim hub in the North Sea.

Agar-Plantain oil discovery details

The Agar field was discovered with the drilling of the 9/14a-15A well by Azinor in 2014, which encountered an 11m column of oil in Eocene Frigg Formations sands.

The analogous Frosk oil discovery well 24/9-12 S in PL340 license of the Norwegian Continental Shelf was made by AkerBP in 2018, which suggested the presence of a minimum of 30 million metric barrels of oil equivalent (Mmboe) of recoverable oil resources.

The exploration for Plantain, another Eocene oil prospect, was started following the Eocene Agar and Frosk oil discoveries.

Agar and Plantain are estimated to contain up to 98Mmboe of combined recoverable oil resources.

Agar-Plantain exploration details

Drilling for the Agar-Plantain using the Transocean Leader semi-submersible drilling rig began in August 2018, while exploration results were announced in November 2018.

The exploration drive led to the drilling of a successful exploration well in licence P1763. The initial wellbore of the exploration well 09/14a-17B was drilled to a total depth of 2,254m. A side-track 09/14a-17BZ up-dip was then drilled for appraisal of the 2014 Agar oil discovery.

The sidetrack was drilled to a depth of 1,962m and encountered a 20m gross interval of very high-quality oil-bearing sands.

Plantain discovery well was drilled to a depth of 2,066m and encountered 27m of net hydrocarbon-bearing reservoir sandstones of the Eocene Lower Frigg Formation.

Development options for the Agar-Plantain discovery

Agar-Plantain development options include a tie-back to either the Beryl Bravo operated by Apache or the Alvheim floating, production, storage and offloading vessel (FPSO) operated by Aker BP. A stand-alone FPSO tie-back is also being considered for the project.

The net present value (NPV) of the Agar-Plantain development is estimated to be $624m.

Transocean Leader drilling rig details

Transocean Leader is a harsh environment semi-submersible drilling rig developed in 1987. Classified as a DNV+1A1It, it is an Aker H-42 non-self-propelled semi-submersible rig capable of operating at a water depth of 5,500ft.

The 361ft-long, 274ft-wide and 130ft-deep rig has a displacement of 44,457 million tonnes (Mt). The maximum drilling depth of the rig is 25,000ft.

The rig is equipped with two Cameron T 18-3/4in 15,000psi double-ram preventers and two Hydril GX 18-3/4 inch 10,000psi annular preventers.

Transocean Leader comprises four Niigata Liaaen 2,600kW compass thrusters and a Kongsberg SDP-Posmoorata DP system. Other equipment includes 90 marine risers, 12 tensioners, a 500 PSI rated diverter, and a 23ft-long 32ft-wide moonpool.

Beryl Bravo platform and Alvheim FPSO details

Beryl Bravo is an eight-legged fixed steel jacket platform at a water depth of 119m in Block 9/13a of the UK North Sea. It serves the Beryl offshore field located 335km north-east of Aberdeen, which is operated by Apache Corporation.

Alvheim is a Norwegian oil and gas field situated at a water depth between 120m and 130m in the central part of the North Sea. Operated by Aker BP, the field produces oil and gas through the Alvheim FPSO.

Oil from the FPSO is transported in shuttle tankers, while gas is exported via the Scottish Area Gas Evacuation (SAGE) system to St Fergus in Scotland.

Contractors involved

RPS provided environmental permitting, as well as health, safety and environment (HSE) support to Azinor for the exploration project.

The drilling rig contract was awarded to Diamond Offshore Drilling in 2017.