An oil exploration firm has made what it has described as the “largest undeveloped discovery” of oil in UK waters.
Hurricane Energy said one billion barrels of oil could be contained within the Greater Lancaster Area, 60 miles (97km) west of Shetland.
The company hopes to begin production in 2019.
Dr Robert Trice, Hurricane’s chief executive officer, described the find as “exciting times”.
He said: “This is a highly significant moment for Hurricane.
“We believe that the Greater Lancaster Area is a single hydrocarbon accumulation, making it the largest undeveloped discovery on the UK Continental Shelf (UKCS).”
Hurricane discovered oil in two wells which sit about 30km apart.
The company believes the oil they found forms part of the same giant field.
Drilling at the Halifax prospect found a column of oil-bearing rock of at least 1,156m. It has been described as “very significant” in an independent analysis.
Operations had to stop for budget and safety reasons, but Hurricane Energy plans to return for further appraisal.
Shares rose 6% in early trading after the Halifax announcement. In the past year, their value has risen five-fold.
Hurricane Energy has focussed its efforts on what it believes are neglected geological formations known as naturally fractured basement reservoirs.
These occur in a series of drilling blocks west of Shetland, which Hurricane has apparently named after RAF aircraft, also including Typhoon, Whirlwind and Warwick.
Lancaster and Halifax lie between the Schiehallion and Solan fields, west of Shetland, and to the south-east of Foinavon.
Hurricane Energy claims to have found more oil in UK waters than any other exploration company over the past 10 years. All its prospects are wholly owned by the one company.