33/6-3 S

General

Well 33/6-3 S was drilled in the Marulk Basin in the Northern North Sea in order to test the extension of the 34/4-10 oil discovery across a saddle point to a structural high in the south-west. The objective was to evaluate sandstones in the Statfjord Formation, the Beta Statfjord South prospect. The well was planned as a near-HPHT well.

Operations and results

Appraisal well 33/6-3 S was spudded with the semi-submersible installation Songa Delta on 17 April 2012 and drilled to TD at 4444 m (4200 m TVD) 65 m into the Late Triassic Lunde Formation. The well was drilled directionally (S-shaped well with a sail angle through the 12 1/4” interval (2496 to 4015 m) of approximately 38.5 deg. The well was drilled with seawater down to 1364 m, with Carbo-Sea oil based mud from 1364 m to 2496.5 m, and with Magma-Teq oil based mud from 2496.5 m to TD.

Top of the Statfjord Formation (primary target) was penetrated at 4266 m (4023 m TVD), 6m TVD shallower than prognosis. The Lunde Formation (Hegre Group) was recorded at 4379 m (4135.2 m TVD). The petrophysical interpretation of the logging data recorded a gross Statfjord Formation reservoir of 112.5 m with 35.9 m net water bearing reservoir (average porosity of 13.0% and average SW of 96.7%). The only shows recorded in the well were poor oil shows in cuttings and two sidewall cores, all in the Statfjord Formation sandstones from 4230 m to 4376 m. Formation pressure and temperature data confirmed the central fault terrace was not in the HPHT regime and that it was in a lower pressure regime to the 34/4-11 and 34/4-13S fault terraces.

No conventional cores were cut in the well. Six RCI formation fluid samples were acquired at the top of th