The wells were drilled about two km southeast of the 30/11-9 A discovery (Askja East) and 35 km southwest of the Oseberg South facility in the North Sea. The main exploration target for wells 30/11-11 S and 30/11-11 A was to prove petroleum in Upper to Middle Jurassic reservoir rocks (Tarbert formation) in two nearby fault blocks. The secondary exploration target was to prove petroleum in Middle Jurassic reservoir rocks (Ness formation).
30/11-11 S encountered a 25 m oil column in the upper part of the Tarbert formation, of which 22 m had moderate to good reservoir properties. 30/11-11 A encountered a corresponding reservoir in the Tarbert formation, but it is aquiferous with traces of hydrocarbons. The well is classified as dry. Both wells proved sandstones with moderate to good porosity in the Ness formation, but these were aquiferous.
Preliminary estimation of the size of the discovery in well 30/11-11 S is between 0.2 and 0.5 million m3 of recoverable oil.
Data acquisition and sampling have been carried out in both wells.
The 30/11-11 S and 30/11-11 A wells were drilled to respective vertical depths of 3646 and 3334 m below the sea surface and measured depths of 3646 and 3987 m below the sea surface. 30/11-11 S was terminated in the Ness formation and 30/11-11 A was terminated in the Tarbert formation.
The wells are the 12th and 13th exploration wells in production licence 035.
The licence was awarded in the second licensing round in 1969.
Water depth is 106 m. The wells will be permanently plugged and abandoned.
Wells 30/11-11 S and 30/11-11 A were drilled by the Songa Delta drilling facility. The results from the wells will not affect future drilling of the exploration campaign in the area. The campaign will continue with the same drilling facility in the same production licence, with wildcat well 30/11-12 S and potentially 30/11-12 A if the structure warrants an appraisal well.
Adapted from a press release by Louise Mulhall
Read the article online at: https://www.oilfieldtechnology.com/drilling-and-production/13042016/minor-oil-discovery-and-dry-well-southwest-of-the-oseberg-south-field-in-the-north-sea/