Premier Oil has started drilling an appraisal well at its Tolmount East discovery in the Southern North Sea.
The operator is aiming to confirm estimates that the prospect, around 40 miles from the Yorkshire coast, holds between 220 to 300 billion cubic feet of gas.
The Ensco 123 rig was contracted to drill the appraisal well which spudded on Thursday, August 8, according to information on the Oil and Gas Authority website.
Tolmount East has the potential to “add significantly” to the wider Tolmount field which contains approximately 520billion cubic feet of gas and is due for production in the fourth quarter of 2020.
Premier is also assessing the possibility of a further development in Tolmount Far East.