Vår Energi and Equinor mull over oil discovery tie-back to existing Barents Sea FPSO

Following a new oil discovery near an asset that is already in operation, Norway’s oil and gas player Vår Energi and its Norwegian state-owned partner, Equinor, are in the process of contemplating a tie-back of their latest discovery to the existing floating production, storage, and offloading (FPSO) unit in the Barents Sea.

According to the Norwegian Offshore Directorate (NOD), Vår Energi and Equinor have proven oil in appraisal well 7122/8-2 S, which was drilled in the Barents Sea to delineate the Countach discovery in Lower Jurassic and Middle Triassic reservoir rocks in the Realgrunnen Subgroup and the Kobbe Formation, respectively, near the Goliat field.

The well was drilled by the COSL Prospector semi-submersible rig, which secured a two-year contract in September 2023 with Vår Energi in the Barents Sea and started the job in the third quarter of 2024. This deal comes with three years of options, resulting in a maximum duration of five years.

The contract builds on the cooperation between Vår Energi and Equinor, enabling the duo to secure access to the rig for the 2024-2026 period. With a drilling depth of 7,500 meters, the COSL Prospector rig is of GG5000 design and can operate in water depths up to 1,500 meters.

The appraisal well is the tenth in the same production license 229, awarded in 1997, as Goliat. While the initial discovery was proven in 2022 in Lower Jurassic and Middle Triassic reservoir rocks, before the drilling of the well 7122/8-2 S, the operator’s resource estimate for the discovery was 1.3-4.8 million standard cubic meters of recoverable oil equivalent.

The well encountered a 35-meter oil column in the upper part of the Kobbe Formation in sandstone layers totaling 19 meters with good reservoir quality, but the oil/water contact was not proven. NOD underlined that sandstone layers totaling 27 meters in the middle and lower part of the Kobbe Formation were aquiferous.

Furthermore, the reservoir in the Realgrunnen Subgroup had very good to good reservoir quality and a total thickness of 5 meters but was water-filled. In addition, an oil column totaling 217 meters was proven in the Klappmyss Formation, in thin sandstone layers with moderate to poor reservoir quality.

The preliminary estimates place the size of the discovery in Klappmyss at 0.3-0.8 million standard cubic meters of recoverable oil equivalent. Even though the well was not formation-tested, extensive data acquisition and sampling were carried out.

The appraisal well 7122/8-2 S was drilled to respective vertical and measured depths of 3,120 meters and 3,209 meters below sea level and was terminated in the Havert Formation in the Lower Triassic. The water depth at the site is 406 meters. The well will be permanently plugged and abandoned.

Vår Energi, which is active in the area surrounding Goliat, is continuing its hydrocarbon exploration efforts in production licenses 229 and 1131. As confirmed by the Norwegian player, the appraisal well’s preliminary estimate places the size of the discovery between 1.6 and 8.3 million standard cubic meters of recoverable oil equivalent.

The size of the discovery now corresponds to 10-52 million barrels and the licensees are considering tying it back to existing infrastructure on Goliat, where oil is offloaded from the FPSO Goliat to shuttle tankers for transport to the market.

The future gas export is planned via the Snøhvit pipeline for the liquid natural gas (LNG) processing facility at Melkøya near Hammerfest, contributing to plans aimed at extending the lifetime of the field. To this end, several infill wells were drilled since start-up. In 2021 and 2023, the discoveries 7122/6-3 S (Rødhette) and 7122/8-1 S (Countach) were made in the area north of the Goliat field.

However, more infill and exploration wells are on the agenda in the coming years. The Goliat field, discovered in 2000 with production beginning 16 years later, is located 50 kilometers southeast of the Snøhvit field. Eight subsea templates with 32 well slots are tied back to the FPSO Goliat.

Moreover, Goliat was granted a plan for development and operation (PDO) exemption for the Snadd reservoir in 2017 and the Goliat West segment in 2020, enabling production from these accumulations to begin in 2017 and 2021, respectively.

Johan Castberg, a project under development in the Barents Sea, in which Equinor and Vår Energi are also partners together with Petoro, recently saw a revision of its start-up timeline, getting pushed back to January/February 2025 from the end-2024, because of adverse weather conditions during the final stage of commissioning and start-up.

The FPSO Johan Castberg was anchored at the field in September 2024. The project cost increased to 2.2 billion 2024-NOK, or approximately $206.5 million, since last year, when it rose by over $1.2 billion from the previous year’s estimate. As the FPSO has been hooked up to the subsea facility, the project is approaching start-up, with all wells required to meet the plateau capacity of 220,000 barrels of oil equivalent per day (kboepd) drilled and ready for production.

While 14 wells have been drilled, 12 are ready to be put in operation mode, which is sufficient to bring the field to plateau production. The estimated recoverable volumes in Johan Castberg are between 450 to 650 million barrels of oil.