34/7-30 S

General

Well 34/7-30 S is located in the western part of the Southern Triangle Upper Jurassic (STUJ) prospect, segment 2. The prospect is situated in the Southern Triangle, which is confined to the south by the Gullfaks Field and to the east and north by the northern extension of the NW-SE trending Gullfaks Fault and southern part of the Inner Snorre Fault. To the west, the main Tordis Fault separates the Southern Triangle from the Tordis Field. Well 34/7-30-S was a "Drill test well". Its main purpose was to perform an acceptance test of Bideford Dolphins "ramrig" operational performance. The re-entry 34/7-30 SR had a conventional purpose: data acquisition in order to appraise oil reserves in the Draupne Sand in STUJ segment 2.

Operations and results

Appraisal well 34/7-30 S was spudded with the semi-submersible installation "Bideford Dolphin" on 26 May 1999 and drilled to 1148 m (1141.8 m TVD RKB) where it was suspended.& The well was re-entered (34/7-30 S R) with the semi-submersible installation "Scarabeo-5" on 11 November 1999 and drilled to 1365 m MD. Due to drilling problems the well was plugged back and a technical sidetrack (34/7-30 S R T2) was kicked off at 1245 m. The well was finally drilled to 2478 m (2269.2 m TVD RKB) into rocks of Late Jurassic age (Heather Formation). Water based PAC mud was used down to 1148 m and &NOVATEC& oil based (olefins) was used from 1148 m to TD. The expected reservoir section, the Upper Draupne Sand, was not found in this well. One core was cut over the possible reservoir interval situated just below the Cromer Knoll Group from 2403 - 2448 m but only claystones and silty claystones of the Heather Formation were penetrated. Five FMT pre-test pressure measurements were attempted between 2399.5 m and 2400.5 m MD. All five pre-tests measurements were tight and no fluid samples were taken. The well was permanently abandoned as a dry appraisal well on 2 December 1999