Norway greenlights Yggdrasil, Valhall PWP-Fenris projects

June 9, 2023
The Norwegian Parliament (Storting) has approved Aker BP’s plans for development and operation for two big projects in the North Sea.

Offshore staff

OSLO, Norway  The Norwegian Parliament (Storting) has approved Aker BP’s plans for development and operation for two big projects in the North Sea.

Estimated capex for Yggdrasil and Valhall PWP-Fenris is more than NOK165 billion ($15.22 billion). Construction of the facilities will take place at yards in Egersund, Stavanger, Haugesund, Stord, Verdal and Sandnessjøen.

Yggdrasil, covering the Hugin, Fulla and Munin license groups, is a multi-field development in the area between the Aker BP-operated Alvheim and Equinor-led Oseberg field centers. The other partners are Equinor and PGNIG Upstream Norway.

Reserves in the area have risen to more than 700 MMbbl following the recent Øst Frigg Beta/Epsilon oil discovery, now thought to contain 53-90 MMboe recoverable.

Øst Frigg, comprising the Alpha and Beta structures, was discovered in the 1970s as a gas field overlying a 10-m oil layer. While Elf produced the gas in the 1980s and 1990s, the oil was untapped but the location was also uncertain.

Aker BP began drilling investigations in early 2022 with a sidetrack to Øst Frigg Alpha drilled from the Grefsenkollen well. According to subsurface manager Tor-Ole Jøssund, “The result showed a bit of oil on top, and some oil trapped under a barrier, but it was too spread out to recover. This wasn’t the result we were hoping for.”

A revised plan involved drilling horizontally in Beta and also included Epsilon.

The Øst-Frigg Beta/Epsilon wildcat well had a vertical main track and three horizontal sidetracks. Saipem’s semisub Scarabeo 8 started drilling in April, with the first sidetracks targeted at Beta to prove oil and appraise the discovery, followed by a sidetrack to Epsilon.

Most of the Beta well was used to reach Epsilon structure. The final casing was landed in the reservoir followed by drilling of the horizontal section toward Epsilon and lastly toward the Gamma structure.

Over a two-week period, the rig drilled more than 6,000 m, both open hole and horizontally. Analysis of the data suggests a 10% increase over the previous resource estimate.

“Drilling 6 km horizontally…requires precision and the ability to constantly assess risk against reward based on a continuous stream of data, as exploration wells have higher uncertainty than regular wells,” said drilling superintendent Hanna Tronstad. “We’re also doing this with a rig that’s new to Aker BP.”

The program was monitored from the company’s new drilling operations center, with geosteering applied to optimize well placement in the oil-bearing layer, using a resistivity map developed based on measurements from tools downhole.

The entire Yggdrasil area will be remotely operated from an onshore ops center and control room in Stavanger, with unmanned platforms, new technology and data-driven decisions and work processes, and power from shore.

Detailed engineering is progressing, and all main contracts have been awarded, with construction set to start this fall.

Construction for Valhall PWP-Fenris in the southern North Sea should begin shortly. Aker BP’s partners in this development are Pandion Energy (Valhall) and PGNiG Upstream Norway (Fenris, 50 km from the Valhall field center).

The program calls for a new centrally located production and wellhead platform (PWP) bridge linked to the field center, and an unmanned platform on Fenris that will be connected to PWP through subsea pipelines.

“This development will enable access to new, highly profitable volumes on Valhall and Fenris with considerable upside potential,” said senior vice president Valhall Ole Johan Molvig.

Aker BP estimates the reserves for the joint project at 230 MMboe, alongside continuing production of existing Valhall reserves (137 MMbbl). The development will use the existing power from shore system.

The company is now also establishing Valhall as a gas hub with production from Fenris raising gas exports from Valhall to Europe and more than doubling gas processing capacity.


Courtesy SBM Offshore's "Full-year Results 2023" presentation
Courtesy Energean's "January 2024 Trading & Operations Update"
Courtesy BW Energy's "Fourth quarter and full year 2023 Presentation"