Oil and gas discovery near the Balder field in the North Sea - 25/8-20 S, 25/8-20 B and 25/8-20 C

The wells were drilled about 6 kilometres north of the Balder field in the central North Sea, 165 kilometres west of Haugesund.

The primary exploration target for wildcat well 25/8-20 S was to prove petroleum in the Eiriksson Formation from the Early Jurassic Age and the Skagerrak Formation from the Late Triassic Age.

The secondary target for the well was to prove petroleum in the Hermod Formation from the Paleogene Age.

The primary exploration target for wildcat well 25/8-20 B was to prove petroleum in injectite sands from the Paleogene Age (the Horda, Balder and Sele Formation) and to prove petroleum in the Skagerrak Formation in a nearby fault segment to well 25/8-20 S.

The primary exploration target for appraisal well 25/8-20 C was to prove petroleum and study the spread of the reservoir to injectite sands from the Paleogene Age.

Well 25/8-20 S encountered an oil column of about 30 metres in the Skagerrak Formation, of which 10 metres of sandstone with moderate to good reservoir quality. The oil/water contact was not proven.

The well encountered a total of about 45 metres of water-bearing sandstone with very good to extremely good reservoir quality in the Eiriksson Formation.

In the Hermod Formation, the well encountered 50 metres of water-bearing sandstone with extremely good reservoir quality.

Well 25/8-20 B encountered a gas column of about 30 metres and an oil column of 55 metres in Eocene injectite sands, of which 10 metres was sandstone of extremely good reservoir quality. The oil/water contact was encountered about 1780 metres below sea level.

The well also encountered oil in sandstone intervals of poor to moderate quality in the upper part of the Skagerrak Formation, which has a gross thickness of 95 metres. The oil/water contact was not proven. Pressure data in the water zone indicates communication in the Skagerrak Formation with 25/8-20 S.

Well 25/8-20 C encountered a gas column of about 40 metres and an oil column of about 55 metres in Eocene injectite sands, where about 35 metres was massive sandstone with extremely good reservoir quality. The gas/oil and oil/water contacts were encountered at the same depth as in 25/8-20 B.

Preliminary estimates of the size of the discovery are between 9 and 21 million standard cubic metres (Sm3) of recoverable oil equivalent. The licensees have assessed the discoveries as commercial and will consider tie-in to existing infrastructure in the Balder area.

The wells were not formation-tested, but extensive data acquisition and sampling have been performed.

These are the tenth, eleventh and twelfth exploration wells in production licence 027. The production licence was awarded in the 2nd licensing round in 1969.

Well 25/8-20 S was drilled to respective vertical and measured depths of 2374 and 2699 metres below sea level, and was terminated in the Skagerrak Formation.

Well 25/8-20 B was drilled to respective vertical and measured depths of 2353 and 2664 metres below sea level, and was terminated in the Skagerrak Formation.

Well 25/8-20 C was drilled to respective vertical and measured depths of 1880 and 2026 metres below sea level, and was terminated in the Sele Formation from the Paleocene Age.

Water depth at the site is 128 metres. The wells have been permanently plugged and abandoned.

The wells were drilled by the Scarabeo 8 drilling facility, which will visit the shipyard in Ølen before it drills development well 7122/7-D-2 H in production licence 229 in the Barents Sea, where Vår Energi AS is the operator.