Wildcat well proves North Sea reservoir suitable for carbon storage

Harbour Energy Norge and its partners have confirmed a reservoir in the Norwegian part of the North Sea suitable for CO2 injection and storage following the drilling of a wildcat well.

As part of the Havstjerne storage project, the 9/6-1 well was drilled in a water depth of 90 meters, around 30 kilometers southeast of the Yme platform and around 120 kilometers southwest of Farsund using Odfjell Drilling’s DeepSea Nordkapp semi-submersible rig.

The objective was to investigate whether Middle Jurassic and Middle and Upper Triassic reservoir rocks in the Havstjerne project are suitable as a CO2 storage site. The well was drilled to a vertical depth of 3,366 meters below sea level and was terminated in the Skagerrak Formation in the Upper Triassic.

According to the Norwegian Offshore Directorate (NOD), formation pressure data indicate that the rocks in the Sandnes and Bryne formations are located in a regional hydrostatic pressure gradient for this area. Extensive volumes of data have been acquired from the reservoir and caprocks, and an injection test conducted, with preliminary results positive.  

The well has been permanently plugged and abandoned, with the data now to undergo further analysis. The results are set to become part of the basis for future decisions regarding investment in the Havstjerne storage project.

Well 9/6-1 is the first well drilled in the exploration licence EXL 006, awarded in May 2023, and the fourth drilled to investigate potential commercial storage of CO2 on the Norwegian continental shelf (NCS).

Havstjerne’s Phase 1 is expected to enable the storage of 42.75 million tons of CO2-equivalent over the first 10 years. This effort is projected to avoid 42 million tons of CO2-equivalent emissions, with a relative greenhouse gas (GHG) avoidance potential of 98%.

Harbour Energy has a 60% operated interest in the Havstjerne CO2 storage licence, acquired through its acquisition of the Wintershall Dea asset portfolio in 2024. The remaining 40% is held by Stella Maris CCS, recently acquired by Yinson Production from Altera Infrastructure.

A couple of weeks ago, Equinor drilled two appraisal wells in the Norwegian sector of the North Sea, confirming suitable properties for CO2 injection and storage.