6609/10-2

General

Well 6609/10-2 was drilled in the Helgeland Basin in the Norwegian Sea. The main objective was to test the hydrocarbon potential of the Lower Jurassic Båt Group in the Trolla Prospect, with the Early Jurassic Tilje and Åre formations as the main targets. The Middle Jurassic Garn and Ile formations were secondary targets. Well 6609/10-2 was planned as a vertical exploration well with TD 200 m into the Triassic Grey Beds at approximately 2525 m MD-RKB.

Operations and results

Wildcat well 6609/10-2 was spudded with the semi-submersible installation Songa Delta on 5 September 2009 and drilled to TD at 2528 m in the Late Triassic Grey Beds. A water kick was taken at 1640 m, in a thin permeable zone below seismic resolution. The well was closed in with an observed shut-in pressure of 1.43 sg EMW. The water kick was circulated out before displacing the well to kill mud and drilling continued. The well was drilled with spud mud down to 352 m, with AQUAMUL KCl/Polymer mud from 352 m to 1237 m, and with AQUACOL KCl/Polymer/glycol mud from 1237 m to TD.

The Fangst Group was present in form of 37 m thick Ile Formation and 45 m of Ror Formation, despite its presence being highly uncertain prior to drilling. The Tilje Formation was encountered at 2054 m while top Åre Formation was encountered at 2142 m. The main Båt Group reservoir was 367 m thick of which 182 m (50 %) was net sand according to log interpretation. Except for increased background gas readings when penetrating Jurassic coal seams, no hydrocarbons were detected in the reservoir section. Results from the analysis of Isotube gas samples confirmed the absence of hydrocarbons in the well. No hydrocarbon shows were recorded in the well.

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