Equinor has made an oil discovery near its Heidrun field in the Norwegian Sea through the drilling of wildcat well 6507/8-12 S at the Othello South prospect in production licence 124 B.
The wildcat well was drilled by the Cosl Innovator rig, roughly 4km north of the Heidrun field and around 240km west of Sandnessjøen.
Preliminary assessments suggest that the Othello South discovery holds between 0.15 and two million standard cubic meters (mscm) of recoverable oil equivalent, translating to roughly 0.95–12.6 million barrels of oil equivalent (mboe).
The drilled well aimed to identify the presence of petroleum in reservoir rocks from the Early Jurassic Åre Formation and Late Triassic 'Grey Beds'.
It encountered several oil-bearing sandstone layers within the Åre Formation, measuring a total thickness of 208m.
An oil column approximately 14m thick was found in sandstones with good-to-very good reservoir quality at upper levels.
Deeper sections contained oil-bearing sand with poorer quality that has not yet been volumetrically assessed and presents a potential upside. No oil/water contact was detected during the operation.
Although formation testing was not conducted, extensive data acquisition and sampling were undertaken.
The well reached a vertical depth of 2,477m below sea level and concluded in Red Beds from the Triassic period.
Water depth at the drilling site measures 374m, and plans call for permanent plugging and abandonment of the well.
Meanwhile, the Cosl Innovator drilling unit will relocate to production licence 1014 in the Norwegian Sea to drill well 6610/7-U-3, with a focus on verifying potential shallow gas deposits.
According to the Norwegian Offshore Directorate, the exploration of well 6507/8-12 S is the first in production licence 124 B, which was separated from production licence 124 in September 2024.
Production licence 124 B remains valid until 31 December 2045.
The licence became effective from 1 January 2025, with Equinor serving as the current operator, holding a 25.7% interest.
Other partners include Petoro with a 36.4% interest, ConocoPhillips Skandinavia with 27.91% and Vår Energi with a 10% stake.
Nine exploration wells had previously been drilled within production licence 124's boundaries.
Following the Othello South discovery, Equinor and its partners are considering further development possibilities for the northern section of the Heidrun field.
Operated by Equinor, Heidrun is located in the Haltenbanken area, around 30km north-east of the Åsgard field, at a water depth of approximately 350m.
Heidrun, which was discovered in 1985, was put into production in 1995.
Last December, Equinor and Aker BP discovered hydrocarbons at the Lofn and Langemann prospects in the Sleipner area of the Norwegian North Sea. As per initial estimates, the Lofn prospect holds 3.5–10mscm of recoverable oil equivalent, or 22–63mboe.
