Harbour Energy drilling finds properties suitable for CO2 injection, storage

Harbour Energy Norge AS, operator (60%) of the Havstjerne storage project, confirmed through drilling a reservoir suitable for injection and storage of carbon dioxide (CO₂) in the North Sea, the Norwegian Offshore Directorate (NOD) said in a release June 2.

The data is subject to further analysis, results of which will become a part of future decisions regarding Havstjerne storage project investment. 

Well 9/6-1 was drilled to a vertical depth of 3,366 m subsea by the DeepSea Nordkapp drilling rig about 30 km southeast of the Yme platform and about 120 km southwest of Farsund. The well was terminated in the Skagerrak formation in the Upper Triassic. Water depth at the site is 90 m.

The well is the first drilled in exploration licence (EXL 006) and the fourth to investigate potential commercial storage of CO₂ on the Norwegian Continental Shelf, NOD said.   

The northwest license, Havstjerne, with an estimated storage capacity of 7 million tonnes/year, was awarded to Wintershall by the Norwegian Ministry of Petroleum and Energy in 2023 and subsequently acquired by Harbour Energy (OGJ Online, Mar. 31, 2023; Dec. 21, 2023). In 2023, Wintershall envisioned a plan to transport CO₂ by ship to the license, which lies 135 km southwest of Stavanger.   

The objective of Well 9/6-1 was to investigate whether Middle Jurassic and Middle and Upper Triassic reservoir rocks in the Havstjerne project are suitable as a storage site for CO₂. 

Well 9/6-1 encountered:

• The Tau formation (caprock), 115 m of homogeneous shale.
• The Egersund formation (caprock), 58 m of sealing shale and dense siltstone. 
• The Sandnes formation (reservoir), 97 m of sandstone, good reservoir quality. 
• The Bryne formation (reservoir), 52 m of sandstone, moderate reservoir quality.
• The Skagerrak formation (reservoir), 200 m of sand- and siltstone of very poor reservoir quality.

Formation pressure data indicates that the rocks in the Sandnes and Bryne formations lie in a regional hydrostatic pressure gradient for this area. 

Extensive volumes of data have been acquired from the reservoir and caprocks. An injection test has also been conducted.

The well has been permanently plugged.