Wellesley Petroleum struck a gas-condensate column with its exploration well 35/10-10 S at its Carmen prospect using semisubmersible rig Deepsea Yantai in the Norwegian North Sea. The well encountered a 210-m gas-condensate column in the Ness, Etive, and Oseberg formations, 90 m of which is in sandstone layers with poor to good permeability. A 70-m gas-condensate column was also encountered in the Cook formation, 23 m of which is sandstone with poor permeability. A 13-m light-oil column was also found in sandstones in the Early Jurassic Amundsen Formation. No formation water was encountered in the well.
An appraisal sidetrack, Carmen 35/10-10 A, was drilled down-dip, 900 m west of the main bore, and encountered a 240-m gas and volatile-oil column in Ness, Etive, Oseberg, and Cook formations, 50 m of which is in sandstone layers with generally poor permeability. The well also encountered water-filled sandstone of good reservoir quality in the Cook formation. A gas/water contact was not encountered in the well.
Drilling took place in license PL1148 (Wellesley 50%, DNO 30%, Equinor 10%, Aker BP 10%).
Wellesley estimated that the drilling campaign has proved a developable gas-condensate accumulation of 60 to 100 million BOE. Development planning will now begin to align with the schedules of other developments in the area, including Toppand (Wellesley 5%), Swisher (Wellesley 30%), Grosbeak (Wellesley 5%), and Atlantis.
Information from the 35/10-A appraisal well indicates the possibility for significant upside volumes, with up to 300 million BOE potentially being recoverable in and around the accumulation, subject to successful exploration and appraisal activity.