NORWAY · WELLBORES · NPDID 8486
25/4-13 A
Exploration · Appraisal · P&A · Oil/gas · Aker BP ASA · Alvheim · PL 203
25/4-13 A is an appraisal exploration wellbore in the North Sea, drilled by Aker BP ASA, entered Sep 29, 2018, to 2,641 m in the Heimdal Fm.
Discovery 25/4-3 (Gekko) · On the map →
- 2,641
- m total depth · 2,190 m vertical
- 121
- m water depth
- Sep 29, 2018
- entered · completed Oct 9, 2018
- Heimdal Fm
- at total depth · Paleocene
- —
- m of core
- —
- °C bottom-hole temperature
SODIR FACTPAGES · RECORD UPDATED FEB 20, 2026 · RELEASED OCT 9, 2020
On file for this wellbore
What the Directorate holds from this wellbore. Each opens the section that lists it.
Drilling
- Drilling facility
- DEEPSEA STAVANGER · Semisub steel
- Drilling days
- 11
- Kelly bushing elevation
- 30 m
- Maximum inclination
- 52.20000076°
- Drilling permit
- 1703-L
- Licensing round
- 15
- Plugged and abandoned
- Oct 9, 2018
- Core samples available
- Yes
- Cuttings samples available
- Yes
- Position · ED50
- 59.51090° N, 2.07468° E
- Hydrocarbons in
- Heimdal Fm · Paleocene
Well history
WRITTEN BY THE NORWEGIAN OFFSHORE DIRECTORATE
General
Well 25/4-13 A is a geological side-track to 25/4-13 S. The well was drilled to appraise the 25/4-3 Gekko discovery in the Vana Sub-basin in the North Sea. The primary objective was to confirm continuation of reservoir and hydrocarbons in the northern part of the Gekko structure.
Operations and results
Appraisal well 25/4-13 A was kicked off at 941 m in mainwell 25/4-13 S. The well was drilled with the semi-submersible installation Deepsea Bergen to TD at 2641 m (2190 m TVD) m in the Paleocene Heimdal Formation. Operations proceeded without significant problems. The well was drilled with Innovert oil-based mud from kick-off to TD.
Top of the target Heimdal Formation was penetrated at 2541 m (2104 m TVD). The Heimdal sands contained oil and gas but showed a more heterogenous character than in the southern part of Gekko, in well 25/4-13 S. The gas-oil contact was found at 2573.2 m (2131.6 m TVD) based on pressure gradient data, and the oil-water contact at 2582 m (2138 m TVD).
No oil shows are described in the well due to masking by the oil-based mud.
No cores were cut. Fluid samples were taken on wire line with the RDT tool at 2551 m (gas), 2577.02 m (oil), and 2580.07 m (oil). The oil samples were generally of high quality, with an OBM contamination of around 1%, while the gas sample had a contamination in the range 2-6%. Oil analysis show a density of 0.7084 g/cm3 and viscosity of 0.64cP at bubble-point.
The well was permanently abandoned on 9 October 2018 as an oil and gas appraisal well.
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Around this wellbore
This wellbore on Sodir FactPages → · Press release →
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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