Drilling has started at i3 Energy’s Serenity field in the outer Moray Firth.
The company has confirmed that the Borgland Dolphin semi-submersible rig arrived at prospect and spudded the SA-01 well.
The well has best-estimate resources of 197million barrels of stock-tank oil initially in place.
Serenity is the second of a three-well drilling campaign for i3, which last month drilled a pilot well at the Liberator field.
It will then be followed up by an appraisal well at the nearby Liberator West extension.
London-listed i3 believes Serenity could be developed as an extension of the neighbouring Tain discovery, operated by Repsol Sinopec Resources UK.
Chief executive Majid Shafiq said: “We are excited to be drilling this potentially high-impact well at Serenity which could add materially to i3’s reserves and resources and may become a fast-tracked development alongside the neighboring Tain oil field.
“The Borgland Dolphin continues to perform very well with operations running smoothly to date and we look forward to updating the market as our well objectives are achieved.”