Confirmed gas/condensate discovery in the North Sea (35/10-16 S)
Well 35/10-16 S was drilled by the Deepsea Yantai rig. (Photo: Odfjell drilling)
6/22/2026 Wellesley Petroleum and its partners have completed the drilling of appraisal well 35/10-16 S. The well confirms the gas/condensate discovery 35/10-10 S ("Carmen").
The well was drilled about 25 kilometres northwest of the Troll field and 35 kilometres east of the Kvitebjørn field.
Preliminary calculations show that the discovery is between 3.4 and 17 million standard cubic metres (Sm3) of recoverable oil equivalent (o.e.). This corresponds to between 21 and 107 million barrels of oil equivalent.
This is the third well drilled in production licence 1148, which was awarded in 2022 (APA 2021).
The licensees in production licence 1148 are Wellesley Petroleum (operator), DNO, Equinor, and Aker BP.
Moving forward, the licensees will explore opportunities to develop "Carmen" back to existing infrastructure in the area. Additional wildcat wells may also be drilled.
Well 35/10-16 S was drilled by the Deepsea Yantai rig, which will now drill appraisal well 35/7-2 on the "Afrodite" discovery in production licence 293.
Geological information
The objective of 35/10-16 S was to delineate the "Carmen" discovery in wells 35/10-10 S and 35/10-10 A, drilled in 2023. These wellbores encountered hydrocarbon-bearing reservoir rocks in the Ness, Etive and Oseberg formations (the Brent Group) from the Middle Jurassic, in addition to hydrocarbon-bearing reservoir rocks in the Cook Formation from the Early Jurassic.
A 14.6-metre gas/condensate column was encountered in the lower part of the Ness Formation, with reservoir rocks of poor to very good quality. The gas/water contact was not encountered.
In the Etive Formation, a 41.3-metre gas/condensate column was encountered in reservoir rocks of poor to moderate reservoir quality. The gas/water contact was not encountered.
In the Oseberg Formation, a 5-metre gas/condensate column was encountered in reservoir rocks of poor to moderate reservoir quality. The gas/water contact was encountered at 3966 metres below sea level.
In the Cook Formation, reservoir rocks with poor to moderate reservoir properties and a thickness of 31.6 metres were encountered. The reservoir was aquiferous with hydrocarbon shows.
The well was drilled to a vertical depth of 4153 metres below sea level in the Amundsen Formation.
Water depth at the site is 365 metres. The well has been permanently plugged and abandoned.
Updated: 6/22/2026