The primary exploration target for well 35/11-22 S was to prove oil in Middle to Lower Jurassic reservoir rocks (the Brent Group and the Cook Formation). The secondary exploration target was to prove oil in the Statfjord Group in the Lower Jurassic.
In the primary exploration target, the well encountered the Brent Group with a thickness of about 190 m, of which 90 m of effective reservoir rocks with moderate reservoir quality. The thickness of the Cook Formation is about 70 m, of which 50 m of effective reservoir rocks with poor to moderate reservoir quality. Both primary targets are aquiferous.
The secondary exploration target, in the Statfjord group, has a thickness of about 130 m, of which 60 m of aquiferous reservoir rocks with poor reservoir quality.
Well 35/11-22 S also encountered a sandstone-dominated unit in the Heather Formation in the Middle to Upper Jurassic totalling about 30 m, of which 15 m of effective reservoir rocks, mainly with moderate reservoir quality. Oil was proven, but the oil/water contact was not encountered.
Preliminary estimates indicate that the size of the discovery is between 0.2 and 0.7 million standard cubic metres (Sm3) of recoverable oil. The licensees do not consider the discovery to be profitable at present, but will assess this together with other nearby discoveries and prospects with regard to further follow-up.
The well was not formation-tested, but extensive data acquisition and sampling have been carried out.
This is the second exploration well in production licence 248 C. In 2013, this licence was carved out from production licence 248, which was awarded in the North Sea Awards in 1999.
Well 35/11-22 S was drilled to a vertical depth of 3882 m below the sea surface and was terminated in the Statfjord Group.
Water depth at the site is 363 m. The well has been permanently plugged and abandoned.
The well was drilled by the Deepsea Bergen drilling facility, which will now plug an older exploration well in production licence 052 on the Veslefrikk field in the northern part of the North Sea, where Equinor Energy AS is the operator.
Read the article online at: https://www.oilfieldtechnology.com/offshore-and-subsea/15022019/equinor-oil-discovery-in-north-sea/