Scotland, heading for a September 2014 independence referendum, could hold enough shale gas resources to cover UK gas needs for more than 30 years, a new geological report published by the British government has shown.

But Scotland's roughly 80 tr cbm of gas is only around 6% of the country's potential, with the rest mainly in the Bowland Shale region across northern England.

In its third report focusing on areas with high potential, the British Geological Survey said the populous Midland Valley area of Scotland holds around 6 billion barrels of shale oil.

Energy Minister Michael Fallon set the findings squarely in the context of Scotland potentially splitting from Britain.

"Only the broad shoulders of the United Kingdom can attract investment in new energy sources and maintain the UK's position as one of the world's great energy hubs - generating energy and generating jobs," Fallon said.

Britain is betting on the development of shale gas to help curb its growing dependence on imports and to stem a decline in oil and gas tax receipts as output from the mature North Sea basin falls rapidly.

Scotland already produces the bulk of Britain's oil and gas and estimates for future conventional fossil fuel production show this is set to continue.

In total, the three BGS reports on unconventional oil and gas resources showed Britain has around 1,409 trillion cubic feet of shale gas and 10.4 billion tonnes of shale oil in place.

These estimates are based on scarce data, however, and further exploratory drilling needs to be undertaken to determine how much shale oil and gas can actually be recovered, BGS stressed.

The shale gas industry is gearing up for the UK's first onshore oil and gas licensing round in six years that will allow companies to bid for permits in shale oil and gas areas.

Some of the companies active in Britain's shale market are IGas, Egdon Resources and Cuadrilla.