Statoil Petroleum AS, operator of production licence 272, is in the process of completing the drilling of wildcat wells 30/11-9 S and 30/11-9 A.
The well was drilled about 13 kilometres southeast of the 30/11-8 S discovery and about 35 km south of the Oseberg Sør installation in the North Sea.
The primary exploration target for well 30/11-9 S was to prove petroleum in Upper to Middle Jurassic reservoir rocks (lower part of the Heather and Tarbert formation). The secondary exploration target was to prove petroleum in reservoir rocks in the Middle Jurassic (Ness and Etive formation).
The well encountered gas in a net 90-metre column in the lower part of the Heather formation and in the upper to middle part of the Tarbert formation, both with reservoir properties as expected. The Ness formation was aquiferous and the Etive formation, which lies under the Ness formation, was therefore not explored.
The primary exploration target for well 30/11-9 A was to prove petroleum in Middle Jurassic reservoir rocks (the Tarbert formation). The secondary exploration target was to prove petroleum in Middle Jurassic reservoir rocks (the Ness and Etive formation).
The well encountered oil in a net 40-metre column in the lower part of the Heather formation and the upper part of the Tarbert formation, both with reservoir properties as expected. The Ness formation was aquiferous and the Etive formation, which lies under the Ness formation, was therefore not explored.
Preliminary estimates indicate that the size of the discoveries is between 3 and 7 million Sm3 recoverable oil equivalents.
The wells were not formation-tested, but extensive data acquisition was carried out.
The licensees in production licence 272 will assess the discoveries together with other discoveries in the production licence.
Wells 30/11-9 S and 30/11-9 A were drilled to respective vertical depths of 3637 and 3646 metres below the sea surface, and both were terminated in the Ness formation in the Middle Jurassic.
The wells are the second and third exploration wells in production licence 272, which was awarded in the 2001 North Sea Awards (NST2001) in 2002.
Water depth is 110 metres. The wells will be permanently plugged and abandoned.
Wells 30/11-9 S and 30/11-9 A were drilled by the Ocean Vanguard drilling rig, which will now proceed to production licence 628 in the North Sea to drill wildcat well 25/9-4, where Statoil Petroleum AS is the operator.