As COSL rig wraps up drilling ops at North Sea well, preparations underway for next one

September 5, 2025, by Melisa Cavcic

Norway’s oil and gas player Vår Energi is setting the stage to spud the next well on its list off the coast of Norway after drilling its second well in the North Sea with one of COSL Drilling Europe’s semi-submersible rigs.

The rig owner explains that the COSL Pioneer rig has completed its second well for Vår Energi at the Balder field, BT-4, which is seen as a complicated multilateral well. This 2010-built semi-submersible rig is designed to operate at water depths of up to 750 meters.

COSL Drilling Europe highlighted: “This was a technically challenging project, where the COSL Pioneer team for the first time made use of control mud level, which was part in delivering an outstanding performance.

“This achievement reflects the skill, dedication, and teamwork of everyone involved, both offshore and onshore and our commitment to delivering safe, efficient, and low-carbon drilling solutions.”

With drilling activities at the second well out of the way, the rig is moving on to the F Template. As a result, the team is preparing to spud well number three. Following a drilling permit, Vår Energi drilled a dry well on the Kokopelli prospect earlier this year with the same rig.

Once it confirmed a final investment decision (FID) for the Balder Phase VI project to sustain long-term, high-value production through the FPSO Jotun, the Norwegian operator brought the FPSO online to extend the life of the Balder field in the North Sea.