The well was drilled by the Transocean Norge drilling rig. (Photo: Transocean)

Wintershall Dea's appraisal well 6507/4-4 S has resulted in a minor increase in the resource estimate for a gas/condensate discovery near the Dvalin field in the Norwegian Sea.

The well was drilled to confirm the size of the previous discovery 6507/4-2 S (Adriana), which was made in 2021.

Preliminary calculations place the size of the discovery at 4-7 million standard cubic metres (Sm3) of recoverable oil equivalent. Before well 6507/4-4 S was drilled, the operator's resource estimate for the gas/condensate discovery was 3-5 million Sm3 of recoverable oil equivalent.

The well was drilled by the Transocean Norge rig 14 kilometres north of the Dvalin field and 270 kilometres north of Kristiansund.

Wintershall Dea is the operator of production licence 211 CS, and Petoro, Aker BP and PGNiG are the other licensees.

Geological information

In 2021, well 6507/4-2 S proved gas/condensate in reservoir rocks from the Cretaceous (the Lysing Formation), as well as gas and oil in reservoir rocks from the Cretaceous (Lange Formation).

The primary exploration target for well 6507/4-4 S was to confirm the size of the discovery in the Lysing Formation (Adriana), including to investigate the reservoir's lateral development.

The primary exploration target for 6507/4-4 A was to confirm the size of the gas/oil discovery in the Lange Formation (Sabina).

Appraisal well 6507/4-4 S encountered a 21-metre gas column in the Lysing Formation with sandstone layers totalling about 16 metres with good to very good reservoir quality. The gas/water contact was proven at 2885 metres below sea level.

The drilling of sidetrack 6507/4-4 A, which aimed to delineate gas and oil discovery 6507/4-2 S (Sabina) in the Lange Formation, had to be aborted due to technical drilling issues.

The licensees will consider tying the discovery into existing infrastructure in the area.

The appraisal well was not formation-tested, but extensive data acquisition and sampling were carried out.

Appraisal well 6507/4-4 S was drilled to a vertical depth of 3039 metres and a measured depth of 3067 metres below sea level, and was terminated in the Lange Formation from the Cretaceous.

Water depth at the site is 446 metres. Appraisal well 6507/4-4 S has been permanently plugged and abandoned.

The appraisal well was drilled by the Transocean Norge drilling rig, which is now headed to production licence 475 BS in the Norwegian Sea (the Maria field), where Wintershall Dea is the operator.

KeyFacts Energy: Wintershall Norway country profile   l   KeyFacts Energy Industry Directory: Norwegian Offshore Directorate