ID: 635
OBJECTID: 635
wlbNpdidWellbore: 1308
wlbName: 2/5-8
wlbHistory:

General

Well 2/5-8 is located on the South East Tor Field in block 2/5 in the Central Trough in the North Sea. The overall outline of the field had previously been defined by the wells 2/5-3 and 2/5-5. The purpose of the well was to test the distribution of high-porosity, re-deposited chalk and productive zones west of the major NS trending crestal fault in the field. It was also planned to test the productivity of the chalk in both the Ekofisk and the Tor Formations on the flanks, confirm reserve calculations for the structure and get good oriented core coverage in both formations.

Operations and results

Appraisal well 2/5-8 was spudded with the semi-submersible installation Dyvi Stena on 18 September 1988 and drilled to TD at 3367 m in the Late Cretaceous Hod Formation. Drilling proceeded without significant problems. The well was drilled with seawater and pre-hydrated gel sweeps down to 370 m and with water based gypsum/polymer non-dispersed mud from 370 m to TD.

Top Ekofisk came in at 3107 m and top Tor Formation at 3204 m. Two cores were cut in the interval 3115 - 3142.5 m in the Ekofisk Formation and another three cores in the interval 3207 - 3291 m in the Tor Formation. The chalk was of a relatively poor reservoir quality both in the Ekofisk and Tor Formation, and oil staining were only found along fracture planes in cores from the Tor Formation. The logs confirmed the negative result from the cores.

No fluid samples were taken in the well.

The well was permanently abandoned on 5 November 1988 as a dry well with shows.

Testing

No drill stem test was performed.

wlbHistoryDateUpdated: 2026-02-24T00:00:00