6407/10-5

General

Well 6407/10-5 was drilled to test the Portrush prospect, southeast of the Njord Field, in the southern part of the Halten Terrace in the Norwegian Sea. The primary objective was to prove oil in the Late Jurassic sequence (Rogn Formation) in a hanging wall trap downthrown of the Vingleia Fault Complex. The secondary objective was to evaluate potential intra-Melke Formation reservoirs.

Operations and results

Wildcat well 6407/10-5 was spudded with the semi-submersible installation Transocean Barents on 25 August 2015 and drilled to TD at 2890 m in the Late Jurassic Intra Melke Formation Sandstone. A 9 7/8" shallow gas pilot hole was drilled to 452 m. No shallow gas was seen. No significant problem was encountered in the operations. The well was drilled with Seawater and bentonite spud mud down to 452 m, with Seawater/KCl mud from 452 m to 1104 m and with Innovert NS Oil based mud from 1104 m to TD.

A water bearing intra-Lange Formation was penetrated at 2460 m. Top Spekk Formation was encountered at 2518 m. Geochemical analyses show that Spekk Formation is immature and comparatively lean in well position with TOC not more than 2.5 %wt. Top Melke Formation was penetrated at 2646. The Melke Formation contain two sandstones in the intervals 2660 to 2694 m and 2789 m to TD. The two are separated by red-brown coloured claystone. MWD logs and MDT pressure points confirm that all Jurassic reservoirs are water bearing. No definitive hydrocarbon fluorescence was noted throughout the entire well that was distinguishable from oil based mud and mineral fluorescence.

No cores were cut. The MDT was run on wireline for pressure points, but no fluid sample was taken. The aquifer pressure t