15/6-2

General

Well 15/6-2 was drilled in the Ve Sub-basin in the North Sea, ca 5 km north of the Sleipner Field. It is the replacement well for 15/6-1, which was junked for technical reasons. The objective was to evaluate a deep-seated structure in the Scottish-Norwegian Graben. The target was Eocene to Paleocene sandstones.

Operations and results

Wildcat well 15/6-2 was spudded with the drill vessel on 9 September 1971 and drilled to TD at 3131 m in the Shetland Group. No drilling problems were encountered, however, due to deviation problems around 1311 m a planned FIT was aborted, as the tool would not go beyond this depth. Initial drilling from the sea floor to 1330 m was with seawater and gel. Below 1330 m, a fresh water Spersene XP-20 mud system was used.

The Paleocene section contained abundant potential sandstone reservoirs (Heimdal Formation) with thin beds of clay becoming marly below 2390. Significant shows were encountered in the interval 2223 to 2236 m in the upper Heimdal Formation. The cuttings, sidewall and conventional cores corroborated the shows. Weak shows were recorded also on numerous sidewall cores between 2303 and 2604 m. However, other evidence did not substantiate these shows and the reservoir was assumed water wet below 2236 m. The Danian (2676 to 2735 m, Våle Formation) consisted of a sequence of thinly interbedded sandstones, clays, shales and chalky limestones. No shows were reported in this section. The Late Cretaceous section, from 2735 m to 3106 m, was predominantly limestone with thin interbeds of shale. Thin interbeds of sandstone were also noted. There were no shows in the Late Cretaceous.

Three cores were cut. Core 1 was cut from 2236 to 2242 m with 10