The industry regulator, the Oil and Gas Authority, has predicted that 11.9 billion barrels will be extracted by 2050 - a hike of almost 50 per cent from the forecast four years ago, of eight billion barrels.
The figures were greeted by the SNP as “great news”, which “confirmed the major economic potential that North Sea oil reserves have to offer” and raised a new demand for a Scottish oil fund.
But the Scottish Conservatives said that it was the tax policies of the UK government which had encouraged investment in the North Sea, and that there was no appetite for independence in Scotland.
Oil revenues formed a large part of the Yes case for independence during the 2014 referendum, with former First Minister Alex Salmond claiming that there were up to 24 billion barrels of oil still to be extracted and Scotland would experience a “second oil boom”.
However, after the No vote a slump in the global oil price reduced tax revenues to virtually zero - prompting the Scottish Government to scrap its own Oil and Gas Bulletin, which had been the official report on the health of the industry.
According to the OGA, its revised figures were driven by lower production costs, technical advances and 30 new oil fields coming on stream.
Head of performance, planning and reporting at the OGA, Loraine Pace, said: “The 3.9 billion barrels identified is great news with 2018 being a productive year. New discoveries such as Glendronach and Glengorm highlight the future potential of the basin which could be boosted further with new investment, exploration successes and resource progression.”
The regulator, reporting to the Treasury ahead of the chancellor’s spring statement, said oil output last year was up 8.9 per cent last year, the highest UK oil production rate since 2011.
Maureen Watt, Aberdeen South SNP MSP, said: “This is great news for our oil and gas industry. However, we must not be complacent and allow for Scotland’s revenues to be used to cover the costs of Tory tax cuts for rich.
“A portion of oil revenues should be invested in a fund for future generations, as most other oil-producing countries have done – something which will ensure there is a positive economic and social legacy from our oil wealth.
“Of course with a host of industries booming across Scotland, like our food and tourism sectors, Scotland is a hugely wealthy country even without oil and gas. But the only way to ensure that Scotland’s valuable natural resources are invested here in Scotland, and not squandered by Westminster, is through independence.”
However Colin Clark, Scottish Conservative MP for Gordon, said the SNP had “learned nothing from recent history”.
“Whenever there is a boost in production, we are all expected to believe independence is nigh. Yet when there is a downturn, it is the UK Government that must absorb the drop in revenue.
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“The Scottish people rejected independence when oil was $110 a barrel – they are unlikely to change that view at $66.
“The fact is that the policies of this Conservative government have kept taxes stable and encouraged investment in the North Sea. We are seeing the results of that in these very welcome production figures today.”
Scottish Labour’s energy spokesperson, Lewis Macdonald said: “This uptick in forecasts is welcome and both the Tory and the SNP governments must do the upmost to protect jobs in the North Sea. Almost 170,000 jobs were lost due to the collapse in oil prices since 2014 and the response from both governments was nowhere near good enough.
“Instead of going back to the fantasies of the referendum campaign, the SNP should focus on supporting the jobs and prospects we actually have in this vital sector of the economy.”
While UK oil production rose last year, gas production fell by three per cent. The total is expected to fall from this year onwards, but at a slower rate than previously forecast.
Capital expenditure also fell for the fourth successive year, although this trend is expected to be reversed in 2019.