Well Slot is a monthly feature where Westwood’s Stephen Coomber looks at drilling activity and rig moves in UK and Norwegian waters.
UK Offshore Well Slot March 2025
As of 28 March, Westwood Global Energy reports there is one exploration and one appraisal well active on the UKCS, at Culzean Deep in the CNS and Crosgan (appraisal) in the SNS.
Since the previous report, operations at the Pensacola (appraisal) and Abbey (appraisal) wells have completed. The Crosgan (appraisal) well spudded.
Central North Sea

The TotalEnergies-operated 22/25a-C8, Z Culzean HPHT development infill well is being drilled from the Culzean wellhead platform and spudded on 26 November, sidetracking on 26 February. It is targeting the Upper-Middle Triassic Skagerrak Formation.
The well will be deepened to an ILX exploration target in the Lower Triassic Smith Bank Formation. Westwood estimates pre-drill resources for the exploration target at 67 mmboe, based on analogues.
Southern North Sea

The 42/14a-3 Crosgan Zechstein appraisal well, operated by ONE-Dyas, was spudded on 22 March with the PROSPECTOR 1 jack-up rig. It is the second appraisal well on Crosgan, targeting the Permian Zechstein Hauptdolomit Formation in a four-way dip closed structure.
The 1990 42/15a-2 Crosgan Zechstein discovery encountered gas and tested at a maximum rate of 1.28 mmscfpd pre-acidisation and 7.6 mmscfpd post-acidisation. The 42/15a-4 appraisal well, drilled in 2023, flowed gas condensate at 114 bcpd and 26.5 mmscfpd. A DST is planned for the new appraisal well. Westwood is currently carrying resources of c. 300 bcf.
The Shell-operated 41/5a-3 Pensacola appraisal well completed on 2 March, having spudded on 17 November with the Valaris 123 jack-up rig. Results have not yet been announced by the JV. The well drilled in a more crestal location than the 2022 discovery. Reported pre-drill 2C resources are 313 bcf gas and 19.8 mmbbl oil (72.6 mmboe).
If commerciality is proven, the discovery will likely be developed with other Zechstein discoveries in the area via a new pipeline to the Teesside gas processing facility. The well is understood to have been cored, with the reservoir encountered being better than anticipated, and a successful DST carried out.
The Petrogas-operated 47/3i-17, Z Abbey appraisal well completed on 17 March, having spudded on 13 November with the Noble Resilient jack-up rig. The well was appraising the 1974 47/3-2 discovery which encountered a tight gas reservoir in the Permian Leman Sandstone Formation. The 47/3i-17Z horizontal sidetrack was kicked off on 19 December.
A five-stage fracc of the well and a 312 hour Extended Well Test (EWT) were successfully completed. The well has been suspended as a gas well. Pre-drill 2P resources are 111 bcf gas and 0.6 mmbbl condensate (19.1 mmboe). No flow rates have been released to date. The successful test will help with development planning as a tie-back to the Tolmount field.
Norway Well Slot March 2025
As of 28 March, Westwood Global Energy reports that there are two exploration wells active on the NCS, with Prince in the NNS and Skarv-E (East) in the Norwegian Sea.
Since the previous report, six exploration wells have been completed with Zagato and Mistral Sør as oil discoveries, Kjøttkake as an oil & gas discovery, and Kokopelli, Kongeørn and Horatio & Polonius as dry wells. The Skarv-E (East) well was spudded.
Barents Sea

The Vår Energi-operated 7122/8-3 S Zagato well was completed on 23 February, having spudded on 17 January, with the COSLProspector semi-sub. The well encountered oil columns in the Middle – Lower Jurassic and Middle – Lower Triassic, with preliminary post-drill resources of 15 – 43 mmboe.
Norwegian Sea

The Aker BP-operated 6507/5-13 Skarv-E (East) well was spudded on 26 February, with the Scarabeo 8 semi-sub. The well is targeting the Middle Jurassic and Lower Jurassic – Upper Triassic. Pre-drill resources are 5 – 15 mmboe.
The 6507/2-8 Kongeørn well, operated by Aker BP, was completed on 21 March, having spudded on 9 February, with the Deepsea Nordkapp semi-sub. The well encountered the Middle-Lower Jurassic targets, but all layers were water-bearing. The well was P&A dry.
The 6406/6-7 S Mistral Sør well, operated by Equinor, was completed on 25 March, having spudded on 22 December 2024, with the Deepsea Atlantic semi-sub. The well encountered a c. 46m gas condensate column in the Middle Jurassic target. The well was P&A gas condensate with post-drill resources of 19 – 44 mmboe.

North Sea
The OMV-operated 35/6-6 Horatio & Polonius well was completed on 22 March, having spudded on 5 February, with the Transocean Norge semi-sub.
The high-impact ILX well encountered the Lower Cretaceous target, which was water-bearing. The well has been P&A dry.
The 35/10-13 S, A Kjøttkake well, operated by DNO, was completed on 27 March, having spudded on 26 January with the Deepsea Yantai semi-sub. The well encountered a 9m gas column and 41m oil column in the Paleocene. The well was P&A oil & gas with post-drill resources of 38.4 – 74.2 mmboe.
The Vår Energi-operated 7/1-3, 4 S Kokopelli well programme was completed on 27 February, having spudded on 23 January with the Deepsea Yantai semi-sub. The high impact well encountered water-bearing Upper Cretaceous chalk reservoir and has been P&A dry.
The OKEA-operated 31/4-A-23 F, G Prince well programme was spudded on 15 November 2024, and is still ongoing from the Brage platform. The wells are targeting the Upper Jurassic. Pre-drill resources of 8 – 52 mmboe.