Transocean Norge; Source: Transocean

Fresh gas discovery with multiple development routes emerges from North Sea depths

Exploration & Production

Wintershall Dea Norge, a Norwegian subsidiary of Germany’s energy player Wintershall Dea, has expanded its natural gas arsenal with a new gas condensate discovery in the Northern North Sea, thanks to drilling activities undertaken with one of Transocean’s semi-submersible rigs.

Transocean Norge; Source: Transocean

Wintershall Dea and its partners, Petoro and DNO, spudded the Cuvette exploration well within licenses PL248F and PL248GS at the end of April 2024 next to the Vega field in the Norwegian sector of the North Sea with the Transocean Norge semi-submersible rig to target a gas condensate prospect just south of the Vega Central field and infrastructure.

Aside from targeting the Cuvette gas condensate prospect, the exploration well was also expected to test the overlying Upper Jurassic sandstones to glean more insight into the potential of the nearby Orion discovery and several other prospects in the surrounding area.

Anne Grethe Bretting, Wintershall Dea’s Exploration Manager for the North Sea, outlined: “With Gjøa and Vega both in a mature production phase, we and our partners are highly motivated to continue to explore for new discoveries. These discoveries can utilise the spare capacity which will become available in the existing infrastructure in the coming years.”

While disclosing a gas condensate discovery at the Cuvette prospect on June 19, Wintershall Dea confirmed that license partners were going to evaluate the gas condensate discovery’s potential to be fast-tracked into production utilizing existing infrastructure in the Vega/Gjøa area.

“Our strategy is to identify new volumes close to infrastructure that can be quickly developed into new fields. Our goal will now be to establish the commerciality for this new discovery by evaluating development options,” highlighted Roy Davies, Vice President Exploration & Subsurface at Wintershall Dea Norge.

Based on the preliminary results, the Cuvette exploration well encountered gas condensate in sandstones of the Middle and Upper Jurassic age, with estimated recoverable volumes of 9 – 22 million barrels of oil equivalent (mmboe) in the primary Middle Jurassic target and 7 – 16 mmboe in the shallower Upper Jurassic target. 

According to DNO, the partners will consider fast-track production of Middle Jurassic volumes through the Vega Central template along with another option on the table, which is a joint development with three nearby discoveries made in 2015-2016 – Syrah, Orion, Beaujolais – totaling some 15 MMboe gross.

“We are racking up discovery after discovery close to existing gathering and processing infrastructure. Our challenge now is to inject the Norwegian oil sector with a large dose of entrepreneurialism to bring a sense of urgency to partners, infrastructure hosts and regulatory bodies in helping bring our and other discoveries to market,” emphasized Bijan Mossavar-Rahmani, DNO’s Executive Chairman.

More drilling ops coming soon

With the Vega and Nova subsea fields, alongside several operated exploration licenses from its portfolio being close by, Wintershall Dea considers itself one of the key operators in this area of the Northern North Sea. The firm is also a shareholder in the nearby Gjøa platform which serves as the export hub for the surrounding fields in this area.

Ronny Hanssen, Vice President Production & Operations for Wintershall Dea Norge, commented: “Both Gjøa and Vega are in a mature production phase, meaning there is spare capacity that can be utlilised for developing additional discoveries in the coming years. We will continue to explore for hydrocarbons in the area to use this capacity.”

While Cuvette is the latest Wintershall Dea-operated well to be drilled with the Transocean Norge rig during the firm’s period of high activity, the semi-submersible unit has already drilled development wells in the Maria field in the Norwegian Sea, appraised the Bergknapp and Adriana discoveries, and drilled production wells on the Nova field in the North Sea.

However, this is not the end of the rig’s assignment, as it is scheduled to complete the Maria Phase 2 wells during the rest of 2024 and 2025 and begin drilling the Dvalin North development wells in 2026. The semi-sub won a 17-well contract in September 2022 with Wintershall Dea and OMV, which the German player also prolonged with a one-well extension.

The Transocean Norge rig is the first semi-submersible rig that secured the Abate (Power+) notation, designed to reflect the best industry practices in greenhouse gas abatement for offshore units. Harbour Energy has put the wheels in motion to acquire Wintershall Dea‘s entire non-Russian oil and gas portfolio alongside carbon capture and storage assets across Europe.

As a result, the German firm sold its stake in a giant sour gas development off the coast of the UAE to Thailand’s PTTEP in preparation for its business combination with Harbour.