Oil and natural gas wealth in the North Sea is expected to become major financial asset for Scotland on independence, the finance secretary said Wednesday.

"North Sea oil and gas is a fantastic natural asset which has a great future for many decades to come," Scottish Finance Secretary John Swinney said in a statement.

Scotland holds a referendum for independence from the United Kingdom in September. The Scottish government said it could finance itself in part through oil and gas revenues while powering its economy with renewable resources.

Swinney said there may be as much as 24 billion barrels of oil and natural gas reserves left in the North Sea and production is on pace to increase by 14 percent between 2013 and 2018.

The finance minister said Scotland may be the largest oil producer and the second largest gas producer in the European Union.

"Using the industry estimates of production and realistic oil prices it is clear that Scotland's oil industry will continue to make a valuable contribution to our public finances for many years to come," he said.

The British government has questioned Scottish plans for independence, saying the United Kingdom would be better off united.

British oil services company Petrofac lands contract for North Sea work
London (UPI) May 28, 2013 - British oil services company Petrofac said Wednesday it secured a $630 million contract to help energy company EnQuest explore its assets in the North Sea.

Petrofac secured a 10-year operations and maintenance contract for the Thistle, Heather and Northern Producer platforms as well as the EnQuest Producer, a floating production, storage and offloading vessel set for deployment to North Sea field Alma/Galia during the second half of the year.

"We're now looking forward to continuing to work closely with EnQuest to help develop and implement long-term plans for infrastructure management, to maximize returns for the next decade and beyond," Bill Dunnett, managing director for Petrofac's offshore projects division, said in a statement.

There was no statement on the contract from EnQuest.

In March, EnQuest said 2013 production averaged 24,222 barrels of oil equivalent per day, up 6.2 percent from the previous year. For 2014, the company said it expects production to increase by at least 25,000 barrels of oil equivalent per day.