North Sea operator Premier Oil has started drilling on the East Fyne appraisal well in the central North Sea.
Antrim Energy, 35.1% owner in the field, announced the start of the operation today.
It said the well, in the eastern part of the Fyne field, was near to the Erne well, which Antrim found oil in after drilling it before Christmas.
It said it expected the East Fyne appraisal well would be incorporated into a development plan for the Fyne field and an overall strategy for the Greater Fyne area.
An evaluation of the field in 2010 put proved plus probably reserves in Fyne at 21.2million barrels of oil.