33/9-14

General

Well 33/9-14 was drilled on the Statfjord Nord Field on Tampen Spur in the North Sea. The primary objective of the well was to verify the lateral and vertical distribution of sand within a thick Volgian sequence and to prove oil below 2690 m MSL in this sequence (deepest oil in Volgian, well 33/9-8). The Brent Group was a secondary target.

Operations and results

Appraisal well 33/9-14 was spudded with the semi-submersible installation Deepsea Bergen and drilled to TD at 2982 m in the Early Jurassic Drake Formation. There were signs of shallow gas from 408 409 m, but the gas bearing sands created no problems. No significant problem was encountered in the operations. The well was drilled with seawater/gel down to 414 m, with gypsum/polymer mud from 414 m to 2670 m, and with gel/lignosulphonate mud from 2670 m to TD.

The reservoir (interpreted as Kimmeridgian age Intra Draupne Formation Sandstone) came in as prognosed at 2674 m. The oil/water contact was taken from the logs to be at 2747 m, while pressure gradients suggest the contact could be five meter higher up. Intermittent weak shows were described down to 2800 m, else no shows were described in the well. The reservoir properties were very good with porosities up to 30 %. The Brent Group, Ness Formation came in at 2777 m. It was water wet.

Six cores were cut in the Intra Draupne Formation Sandstones and the Brent Group in the interval 2680 to 2879 m. The recovery was generally good except for core 3, for which only 0.5 m was recovered. The core-log depth shift was 3.0 to -3.5 m for all cores. FMT fluid samples were taken at 2757 m and at 2798.4 m.

The well was permane