Minor gas discovery and appraisal well southeast of the Kristin field in the Norwegian Sea – 6406/6-6 S and 6406/6-6 A

The wells were drilled about 40 km southeast of the Kristin field in the southern part of the Norwegian Sea. The primary exploration target for the well was to prove petroleum in Middle Jurassic reservoir rocks (the Garn and Ile formation). The secondary exploration target for the well was to prove petroleum in Lower Jurassic reservoir rocks (the Tofte formation).

In the primary exploration target, well 6406/6-6 S encountered gas in a sandstone layer of about three metres, as well as traces of gas deeper in the middle part of the Ile formation, with poor reservoir quality. The gas/water contact was not encountered. The Ile formation is about 145 metres thick, of which about 80 metres are sandstone layers. In the Garn formation, there were thin layers of tight sandstone reservoir totalling 20 metres.

The secondary exploration target in the Tofte formation was about 25 metres of aquiferous sandstone reservoir, mainly with poor reservoir quality.

In appraisal well 6406/6-6 A, the Ile formation was thinner, with a total of about 55 metres of sandstone reservoir, and the quality of the reservoir rocks was confirmed. Technical problems made it impossible to conduct measurements that could confirm a gas column. In the Garn formation, there were thin layers of tight sandstone reservoir totalling 25 metres.

Neither of the wells were formation-tested, but extensive data acquisition and sampling have been carried out in well 6406/6-6 S. Preliminary estimates place the size of the discovery between 0.4 and 2.5 million standard cubic metres (Sm3) of recoverable oil equivalents. The licensees in production licence 255 B will assess the discovery together with other nearby discoveries and prospects as regards further follow-up.

These are the second and third exploration wells in production licence 255 B. The licence was carved out from production licence 255 (awarded in the 16th licensing round) on 19 May 2016. Well 6406/6-6 S was drilled to respective vertical and measured depths of 4784 and 4877 metres below the sea surface, and well 6406/6-6 A was drilled to respective vertical and measured depths of 4659 and 4835 metres below the sea surface. Both were terminated in the Ror formation in the Lower Jurassic.

Water depth is 265 metres. The wells have been permanently plugged and abandoned. Wells 6406/6-6 S and 6406/6-6 A were drilled by the Scarabeo 8 drilling facility, which is now drilling wildcat well 24/9-14 S in production licence 869 in the central part of the North Sea, where Aker BP ASA is the operator.