6407/7-8

General

The 6407/7-8 Noatun well is located in the Gimsan Basin, ca 15 km north of the Njord Field in the Norwegian Sea. The main objective of the well was to prove hydrocarbons in the Ile and Tilje Formations (Noatun C prospect). The structure was expected to contain gas and condensate.

Operations and results

An 8 1/2" pilot hole (6407/7-U-1) was drilled to 810 m due to a shallow gas warning.

Wildcat well 6407/7-8 was spudded with the semi-submersible installation West Alpha on 18 June 2008 and drilled to TD at 5138 m (5105 m TVD) in the Early Jurassic Åre Formation. No overpressured shallow gas was observed by the ROV at the wellhead or by the MWD while drilling the 8 1/2" pilot hole, the 36" hole or the 26" hole. From ca 800 m to ca 3600 m the well was drilled with a ca 8.5 degree deviation, leading to measured depth at TD being 33 m more than true vertical depth. Due to high temperatures in the reservoir section the MDT wire line operations proved difficult and several runs and Mini-DST's failed or did not give valid data. The well was drilled with Spud mud down to 1109 m, with Glydril mud from 1109 m to 2452 m, and with Versatherm oil based mud from 2452 m to TD.

The well penetrated rocks of Quaternary, Tertiary, Cretaceous, and Jurassic age. A 50 m thick sandstone section was penetrated in the upper Springar Formation and some thin sandstone stringers were penetrated in the Lange Formation, otherwise lithology was mudstone. All sands above BCU were dry. The well proved gas/condensate in both the Fangst and Båt Groups. Gas readings were considered relatively high in the Tertiary with a maximum of 5.3% at 2084 m in the Rogaland Group. The gas levels also inc