Gas-condensate & light oil discovery in the Norwegian North Sea

July 19, 2023

Wellesley Petroleum AS (“Wellesley”) notes the NPD announcement of the drilling results of exploration well 35/10-10 S and appraisal sidetrack well 35/10-10 A, operated by Wellesley. Drilling took place in licence PL1148 (Wellesley 50%, DNO 30%, Equinor 10%, AkerBP 10%) with the Deepsea Yantai rig. The wells were targeting the Carmen prospect and resulted in a commercial hydrocarbon discovery.

Well 35/10-10 S encountered a 210m gas-condensate column in the Ness, Etive and Oseberg formations, 90m of which is in sandstone layers with poor to good permeability. A 70m gas-condensate column was encountered in the Cook Formation, 23 m of which is sandstone with poor permeability. A 13m light oil column was also found in sandstones in the Early Jurassic Amundsen Formation. No formation water was encountered in the well.

Well 35/10-10 A was drilled down-dip, 900 m west of the main bore, and encountered a 240m gas and volatile oil column in Ness, Etive, Oseberg and Cook formations, 50m of which is in sandstone layers with generally poor permeability. The well also encountered water-filled sandstone of good reservoir quality in the Cook Fm. A gas-water contact was not encountered in the well.

Wellesley estimates that the drilling campaign has proved a developable gas-condensate accumulation of 60-100mmboe. 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.

Additionally, information from the 35/10-A appraisal well indicates the possibility for significant upside volumes, with up to 300mmboe potentially being recoverable in and around the accumulation, subject to successful exploration and appraisal activity.

Chris Elliott, CEO of Wellesley, commented:

“Carmen is Wellesley’s sixth commercial discovery in our core Troll area portfolio, and once again validates our geological model for the Middle Jurassic play. Having divested the greater part of our discovered resources in recent months it is very heartening to recharge our portfolio so quickly.

Carmen is well positioned to join and add value to the ongoing area development programme for the other recent discoveries in the greater Troll area. Wellesley will use the early phase development experience gained from our stewardship of the Grosbeak discovery to move the Carmen project forward efficiently. Additionally, we will begin studies to understand the potentially significant upside potential, which may include further exploration and appraisal drilling activity.

Carmen was Wellesley’s first operated HPHT well and we are very pleased to have conducted the operation efficiently and safely. We once again used a Well Management model in combination with a warm rig and a very focused group of drilling service companies who collectively delivered a first-class operation. We are very grateful to all the companies and individuals who contributed to this success.”

2023 FACTBOOK

Our factbook contains the latest management view of the production forecasts from Wellesley’s portfolio.