Wintershall in discovery near North Sea’s Vega field

STAVANGER, Norway -- Wintershall Norge, operator of production license 248 F, is in the process of completing the drilling of four wells in the North Sea.

The wells are wildcat well 35/11-20 S, appraisal well 35/11-20 A and wildcat well 35/11-20 B. Due to technical issues, well 35/11-19 S had to be abandoned, and well 35/11-20 S was drilled about 50 m southwest of 35/11-19 S.

The wells were drilled about 5 km southeast of Vega field in the North Sea and 100 km southwest of Florø.

The primary and secondary exploration targets for well 35/11-20 S were in Late Jurassic reservoir rocks (intra Heather formation sandstone). The well did not encounter reservoir rocks in the primary exploration target. The well encountered an 8-m oil column in the secondary exploration target at the top of an intra Heather formation sandstone with poor reservoir quality and a total thickness of about 70 m.

The objective of well 35/11-20 A was to delineate the oil discovery in intra Heather formation sandstone, and to prove petroleum in Middle Jurassic (Brent group) and Early Jurassic (Cook formation) reservoir rocks. The well encountered a total oil column of 33 m in intra Heather formation sandstone, of which 19 m were of good reservoir quality. Due to technical issues, it was not possible to reach the Brent group and Cook formation.

Well 35/11-20 B was drilled to further delineate the oil discovery in intra Heather formation sandstone. The secondary target was to prove petroleum in Middle Jurassic (Brent group) and Early Jurassic (Cook formation) reservoir rocks. The well encountered a total oil column of 46 m in intra Heather formation sandstone, of which 29 m were of moderate reservoir quality. A total oil column of 19 m was encountered in the Tarbert formation in the Brent group, of which 10 m were of moderate reservoir quality. The Cook formation was encountered with a total thickness of about 170 m with predominantly poor reservoir quality and only traces of petroleum.

Preliminary estimates place the size of the discovery between 1.5 and 4.5 MMcm of recoverable oil equivalents. The licensees will evaluate the discovery along with other nearby discoveries with a view toward a potential development.