6508/1-2

General

Well 6508/1-2 was drilled on the Skaugumsåsen prospect in the south-western end of the Helgeland Basin in the Norwegian Sea, about ten kilometres south of the Norne field. The primary objective was to prove petroleum in reservoirs of the Early Jurassic Båt Group. A Secondary objective was to test the reservoir and HC potential of the Paleocene Tare Formation.

Operations and results

A 9 7/8" pilot well 6508/1-U-2 was drilled to 1305 m to check for shallow gas. No indications of shallow gas were seen. Wildcat well 6508/1-2 was spudded with the semi-submersible installation Aker Barents on 20 August 2011 and drilled to TD at 1810 m in the Early Jurassic Tilje Formation. No significant problem was encountered in the operations. The well was drilled with seawater and hi-vis pills down to 1301 m and with Glydril/KCl mud from 1301 m to TD.

The Rogaland Group (Tare and Tang formations) contained some thin hydrocarbon bearing intervals around 1650 to 1660 m. The net pay here was 4.4 m with average porosity of 28%. The zone was overpressured and not in communication with the deeper reservoir zones, and headspace gas analyses from this section indicated the gas was diagenetic, not thermogenic. The top of the main reservoir, the Early Jurassic Ror Formation, was encountered at 1715.5 m underlying the Late Cretaceous Nise Formation. A gas column of 18.2 (1715.5 - 1733.7 m) was present in the Ror Formation, and an oil column of 22.3m was present in the Ror and Tilje Formations down to an OWC at 1756 m. Weak shows continued on the cores down to 1762 m otherwise no shows were seen in this well outside of the hydrocarbon bearing reservoir.

Two cores were cut in the interval 1718.5 m - 1