Brasse Field, Offshore Norway

The reservoir of the Brasse Project contains oil, gas, and natural gas liquids (NGL) in the Upper Jurassic Sognefjord Formation.

The field is expected to contain 30 millions barrels of oil equivalent (mmboe). Around two-thirds of the reserve is oil, and the rest is gas and NGL.

Ownership

OKEA holds a 45.5576% stake in the licence which hosts the Brasse Field. Norwegian oil and gas operator DNO has 50% interest, while M Vest Energy owns the remaining 4.4424%.

In November 2023, Lime Petroleum, a 91.65% subsidiary of Rex International, signed sale and purchase agreements with DNO and OKEA to acquire minority interest in PL740.

As agreed, Lime will buy 10.7212% interest from DNO Norge and 6.2788% from operator OKEA to own a total of 17% in the production licence.

Subject to government approvals, the deal is slated to be completed in early 2024.

Brasse Discovery and Appraisal

The Brasse Discovery was proven in 2016 and, subsequently, it was delineated by four wells.

The wildcat exploration well, 31/7-1, was drilled by a semi-submersible rig called Transocean Arctic in May 2016 to test the Brasse prospect on the northern portion of the Bjørgvin Arch.

The wildcat well was drilled to a total depth of 2,780m in the Early Jurassic Johansen Formation. The Sognefjord Formation was encountered at a depth of 2,154m and the siltstones/sandstones of the formation contained gas and oil.

According to Norwegian Offshore Directorate, the campaign identified hydrocarbons columns of 18m gas and 24.4m of oil.

The four appraisal wells drilled for the project were 31/7-1 A, 31/7-2 A, 31/7-2 S, 31/7-3 A.

The 31/7-1 A was a geological sidetrack to the wildcat well located on the northern portion of the Bjørgvin Arch.

The well was drilled using Transocean Arctic in June 2016 to a total depth of 2,530m in the Middle Jurassic Fensfjord Formation. It encountered gas and oil bearing Sognefjord Formation sandstones / siltstones with a gross vertical hydrocarbon column of 5.5m gas and 24.4m oil.

The 31/7-2 A appraisal well was drilled in July 2017 to appraise the Brasse Discovery and find the lateral development of the Sognefjord Formation to the east of the primary well bore and prove the presence of hydrocarbons, pressure gradients, and fluid contacts.

31/7-2 S appraisal well was drilled via the semi-submersible installation, Deepsea Bergen, to a total depth of 2,450m in the Middle Jurassic Tarbert Formation. The objective was to prove the continuity of the reservoir and hydrocarbon columns and contacts in the southern portion of the Brasse structure.

The 31/7-3 A appraisal well was drilled on 31/7-1 Brasse discovery to assess the reservoir characteristics and look out fluids contact in the north-western part of the discovery.

Another well 31/7-3 S drilled in November 2018 turned out to be dry.

Brasse Field Development

In August 2023, OKEA and DNO agreed on a fast-track development concept for the discovery. The move cleared the way for detailed studies to connect the Brasse field to the Brage field.

The project is expected to be developed as a tie-back to the Brage Platform, located 13km away. Important commercial terms for the tie-in have been agreed by the partners.

The proposed plan will lead to fewer topside modifications on the Brage Platform and simplification of the design of the production wells, thereby reducing the final cost of the project.

The partners aim to submit the Plan for Development and Operation (PDO) to the Norwegian authorities in early 2024.

Contractor Involved

Offshore Drilling Contractor Transocean provided Transocean Arctic semi-submersible installation to drill wells for the offshore prospect.