Wellesley Petroleum AS, the operator of production licence 1148, has successfully completed the drilling of wildcat wells 35/10-10 S and 35/10-10 A, located approximately 25 km northwest of the Troll field and 150 km northwest of Bergen in the North Sea.

The primary objective of well 35/10-10 S was to prove petroleum in Middle Jurassic reservoir rocks within the Brent Group's Etive and Oseberg formations. Additionally, the well aimed to confirm the presence of petroleum in the Early Jurassic Cook Formation.

During drilling, well 35/10-10 S encountered a 210 m gas-condensate column in the Ness, Etive, and Oseberg formations, with 90 m of sandstone reservoir showing poor to moderate quality. The Cook Formation yielded a 70 m gas-condensate column, including 23 m of sandstone reservoir with poor quality. The well also revealed a 13 m oil column in the Early Jurassic Amundsen Formation of the Dunlin Group, with 13 m of sandstone reservoir exhibiting poor quality.

Appraisal well 35/10-10 A was drilled lower on the structure, approximately 900 m west of the main well. It identified a 240 m gas-condensate column in the Ness, Etive, Oseberg, and Cook formations, with 50 m of sandstone reservoir showing poor to moderate quality. Water was encountered in the Cook Formation from a depth of 4158 m below sea level.

Preliminary estimates suggest that the discovery holds between 9 and 46 million m3 of recoverable oil equivalent. The licensees plan to initiate early-phase development studies and are considering additional appraisal wells in the area.

Both wells have been permanently plugged and abandoned after being drilled to respective depths of 4030 m and 4212 m below sea level. Extensive data acquisition and sampling were conducted during the drilling operations.

The Deepsea Yantai drilling facility, responsible for drilling the wells, will now proceed to drill wildcat well 25/7-11 S in production licence 984 in the North Sea, where DNO Norge AS operates. The water depth at the drilling site was 360 m.

These wells represent the first and second exploration wells in production licence 1148, which was awarded in APA2021.