15/9-2

General

Well 15/9-2 was drilled on the Sleipner Vest Field in the North Sea. The primary objective was to test the "beta closure" on the 15/6-3 Sleipner Vest discovery. The target was Middle Jurassic sandstones.

Operations and results

Well 15/9-2 was spudded with the semi-submersible installation Ross Rig on 12 April 1978 and drilled to TD at 3764 m in Late Triassic sediments in the Skagerrak Formation. The main problem in operations was the discovery of a washout in the well head 18 3/4" ax seal area after setting 9 5/8" casing. This was repaired so that drilling could proceed, but it was decided not to do the planned DST due to possible leak. Otherwise, operations proceeded without significant problem. The well was drilled with seawater and gel down to 644 m and with gel and lignosulphonate from 644 m to TD.

The Vestland Group, Hugin Formation was encountered at 3483 m. The Hugin Formation contained gas/condensate down to the OWC between 3652 and 3654 m based on logs and pressure gradients. Weak shows continued down to 3659 m, 2 meters into top Sleipner Formation. Two spots of dead oil and fluorescence on limestone/siltstone cuttings at 2788 and 2812 m in the upper Shetland Group were the only other shows described in the well.

A total of 186.3 m core was recovered in 11 cores from the interval 3498 m to 3692 m. RFT fluid samples were taken at 3490 m ((gas, condensate, water), 3535,7 m (gas and condensate), 3601.6 m (gas, condensate, water), 3640.4 m (gas, condensate, water), 3641 m (gas, condensate, water), 3641.5 m (gas, condensate, water), 3644 m (gas, condensate, water), 3652 m (gas, condensate, water), and 3654 m (water). The condensate gravity in th