1/6-4 is a wildcat exploration wellbore in the North Sea, drilled by A/S Norske Shell, entered Dec 29, 1975, to 3,810 m in the Tor Fm.
- 3,810
- m total depth
- 72
- m water depth
- Dec 29, 1975
- entered · completed Apr 9, 1976
- Tor Fm
- at total depth · Late Cretaceous
- —
- m of core
- 133
- °C bottom-hole temperature
SODIR FACTPAGES · RECORD UPDATED FEB 20, 2026 · RELEASED APR 9, 1978
On file for this wellbore
What the Directorate holds from this wellbore. Each opens the section that lists it.
Drilling
- Drilling facility
- CHRIS CHENERY · Semisub steel
- Drilling days
- 103
- Kelly bushing elevation
- 33 m
- Maximum inclination
- 0°
- Drilling permit
- 144-L
- Licensing round
- 1-A
- Plugged and abandoned
- —
- Core samples available
- Yes
- Cuttings samples available
- Yes
- Position · ED50
- 56.74779° N, 2.70657° E
Well history
WRITTEN BY THE NORWEGIAN OFFSHORE DIRECTORATE
General
Well 1/6-4 was drilled in the southernmost part of the Breiflabb Basin in the North Sea. The objective was to evaluate a large low relief base Tertiary - Late Cretaceous structure with potential reservoirs both in the Danian - Late Cretaceous Chalk and in the Paleocene Sands. The primary target was the Chalk (Ekofisk and Tor formations).
Operations and results
Wildcat well 1/6-4 was spudded with the semi-submersible installation Chris Chenery on 29 December 1975 and drilled to TD at 3810 m in the Late Cretaceous Tor Formation. The drilling of 1/6-4 was beset with rig mechanical problems, most notably failures in the mooring system induced by adverse North Sea weather. All in all 34 days (ca 33%) of the total rig time on the well was counted as down time. The well was drilled with bentonite/seawater spud mud down to 437 m and with lime/Drispac/seawater mud from 437 m to TD.
Top Rogaland Group, Balder Formation, came in at 3110 m. A Paleocene sandstone, Andrew Formation was penetrated from 3197 to 3253 m. Top Shetland Group, Ekofisk Formation, came in at 3374 m. The Balder Formation (Tuff marker) had some residual hydrocarbons up to 30%. This was substantiated by gas readings and some shows of fluorescence in ditch cuttings. The underlying Andrew Formation sandstones were found 100% water-bearing. Both the Danian and Maastrichtian were fully water bearing based on petrophysical analyses. This was in agreement with the lack of oil/gas shows while drilling in this section.
No cores were cut and no wire line fluid samples were taken.
The well was permanently abandoned on 9 April 1978 as a dry well with shows.
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Around this wellbore
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About this data
Norwegian Offshore Directorate (Sodir) FactPages, mirrored nightly and used under the Norwegian Licence for Open Government Data (NLOD). Depths are metres along the wellbore from the kelly bushing unless a row gives its own unit; older cores are filed in feet. A zero the Directorate files for an unmeasured pressure, density, or temperature is shown as a dash.
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