The Northern North Sea field is expected to yield the equivalent of 15,000 barrels of oil a day. It connects via subsea pipes into Total’s Alwyn field from where the gas is pumped ashore to the Scottish mainland.
Islay is south-east of the giant Ninian field, straddling the boundary line between the UK and Norwegian sectors.
The field, discovered in 2008, holds the equivalent of 17 million barrels of oil. The water depth is only 120 metres.
Total has a strategy for the North Sea which involves using existing offshore facilities to reach and tap other satellite discoveries. The company said Islay would help to further extend the life of its Alwyn production hub.