ID: 954
OBJECTID: 954
wlbNpdidWellbore: 2863
wlbName: 34/7-25 S
wlbHistory:

General

Well 34/7-25 S is located near the southern extension of the Tordis field and North of the Gullfaks field in the Tampen area in the Northern North Sea. The main objective of the well was to test the presence of sand and hydrocarbon in a Late Jurassic prospect (the Southern Triangle Upper Jurassic (STUJ) prospect). The STUJ prospect was defined between Base Cretaceous Unconformity (BCU) and a Base Draupne reflector. Secondary objectives were to obtain pressure measurements in the Brent Group, test presence of sand and hydrocarbons in the Cretaceous and in the Paleocene and prove migration route.

Operations and results

Well 34/7-25 S was spudded with the semi-submersible installation Deepsea Bergen on 31 July 1996 and drilled to TD at 3235 m (2596 m TVD) in the Early Jurassic Drake Formation. No significant problems occurred during operations. The well was drilled with spud mud down to 1271 m and with oil based mud (Anco Vert) from 1271 m to TD. No shallow gas was encountered.

Well 34/7-25 S penetrated several sands in the interval from 1250 m to 1700 m within the Hordaland Group. Weak shows were described in the interval 2275 to 2295 m in the Lista Formation. The shows had no odour and no stain in the description, due to oil based mud. The Cretaceous section had only traces of thin sandstone beds in the Shetland Group. The well successfully encountered 27.5 m TVD oil bearing sandstones belonging to the Draupne Formation, with top at 2791 m (2193 m TVD). No OWC was proven. The uppermost 2 m was cemented and had the same log response as the limestone of the Cromer Knoll Group. The next 21 m (2195 - 2216 TVD) showed excellent reservoir properties with porosity around 30% and permeability between 6 and 7 Darcy. This upper massive sandstone was bioturbated and showed a coarsening up character. The lower part of the Draupne Formation comprised sandstones interbedded with more silty parts. This part of the formation had a very high g
wlbHistoryDateUpdated: 2016-07-06T00:00:00