2/5-14 S

General

Well 2/5-14 S was drilled on the Hyme prospect on the west flank of the South-East Tor oil discovery in the southern North Sea. The objectives were to prove commercial amounts of oil in a stratigraphic trap in the Tor and Ekofisk Formations, and to improve the understanding of chalk porosity and fluid properties related to seismic signature. If a discovery was made an appraisal sidetrack well, 2/5-14 A, was planned to kick off from below the 13 3/8" casing shoe. Following the results of the 2/5-14 S well, the sidetrack was not drilled.

Operations and results

Wildcat well 2/5-14 S was spudded with the jack-up installation Mærsk Gallant on 30 December 2008 and drilled to TD at 3845 m (3507.4 m TVD) in the Late Cretaceous Tor Formation. The well was drilled deviated, kicking off from approximately 1200 m. No shallow gas or shallow water flow zones were prognosed and no shallow gas or water flow zones were encountered. Very low penetration rates were experienced in mudstones of the Hordaland and Rogaland Formations. While running the 9 5/8" casing, returns were lost after working the casing through a tight interval from 3025 m to 3042 m. It is believed that the lost mud was forced into a fracture in the formation that remained open and in communication with the well throughout the 8 1/2" section. The well was drilled with seawater and hi-vis pills down to 579 m, with GEM KCl/polymer mud from 579 m to 1560 m, and with Performadril/KCl mud enhanced with 3 - 6% glycol from 1560 m to TD.

The Hordaland Group was encountered at 1739 m (1736.2 m TVD), 53 m TVD deeper than prognosed. The Rogaland Group was encountered at 3338 m (3069.9 m TVD), 5 m TVD shallow to prognosis. Above the main Shetland Group target, three thin