NORWAY · WELLBORES · NPDID 371
25/11-11
Exploration · Appraisal · P&A · Oil · Esso Exploration and Production Norway A/S · Balder · PL 001
25/11-11 is an appraisal exploration wellbore in the North Sea, drilled by Esso Exploration and Production Norway A/S, entered Feb 18, 1981, to 1,960 m in the Ekofisk Fm.
Discovery 25/11-1 Balder · On the map →
- 1,960
- m total depth · 1,960 m vertical
- 126
- m water depth
- Feb 18, 1981
- entered · completed Mar 18, 1981
- Ekofisk Fm
- at total depth · Paleocene
- —
- m of core
- 55
- °C bottom-hole temperature
SODIR FACTPAGES · RECORD UPDATED NOV 4, 2026 · RELEASED MAR 18, 1983
On file for this wellbore
What the Directorate holds from this wellbore. Each opens the section that lists it.
Drilling
- Drilling facility
- GLOMAR BISCAY II · Semisub steel
- Drilling days
- 29
- Kelly bushing elevation
- 25 m
- Maximum inclination
- 4°
- Drilling permit
- 278-L
- Licensing round
- 1-A
- Plugged and abandoned
- —
- Core samples available
- Yes
- Cuttings samples available
- Yes
- Position · ED50
- 59.19644° N, 2.34651° E
- Hydrocarbons in
- Intra Balder Fm Ss · Eocene
- Hydrocarbons in
- Heimdal Fm · Paleocene
Well history
WRITTEN BY THE NORWEGIAN OFFSHORE DIRECTORATE
General
Well 25/11-11 was drilled to appraise the Balder Field on the Utsira High in the North Sea. The objective was to establish the presence of an accumulation of oil sand in the western part of the Balder Field, and evaluate the geologic concept of sand-shale distribution and reservoir quality. The top of the reservoir was anticipated to be at 1708 m MSL.
Operations and results
Appraisal well 25/11-11 was spudded with the semi-submersible installation Glomar Biscay II on 18 February 1981 and drilled to TD at 1960 m in the Danian age chalk of the Ekofisk Formation. The well was drilled with seawater and gel/lignosulphonate.
One main oil sand of Paleocene age (Heimdal Formation) was encountered at 1754 m (1729 m TVD MSL). It was 141.5 m thick and was oil-bearing in the upper 29 m down to an OWC at 1783 m (1758 m TVD MSL). This OWC was in agreement with the general field OWC in the area. Average porosity in the oil sand was 32.6%. Shows of hydrocarbons were also present in a 16 m thick Intra Balder Formation Sandstone with top at 1698 m, and in thin sand stringers within the Sele Formation.
No cores were cut and no wire line fluid samples were taken.
The well was permanently abandoned on 18 March as an oil appraisal.
Testing
No drill stem test was performed.
Around this wellbore
This wellbore on Sodir FactPages →
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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