Shale gas resources in England may be far greater than previously thought.
The British Geological Survey estimates there may be 1,300 trillion cubic feet of shale gas present in the north of England - double previous estimates.
The BGS said its estimate for shale gas resources in the Bowland Basin region, which stretches from Cheshire to Yorkshire, represented potential resources, but "not the gas that might be possible to extract".
"Shale gas clearly has potential in Britain but it will require geological and engineering expertise, investment and protection of the environment," it said.
Drilling companies have previously estimated that they may be able to extract around 10% of this gas - equivalent to around 130 trillion cubic feet.
The BBC reports that if the estimates are proved correct, that would still suggest recoverable reserves of shale gas far in excess of the three trillion cubic feet of gas currently consumed in Britain each year.
Shale gas is extracted through "fracking" - a process of freeing trapped gas by pumping in a mixture of water, sand and chemicals.
The process has helped boost the domestic energy industry in the United States in recent years, where oil production has risen and gas prices have plummeted.
The British government has also announced a package of reforms to encourage development in the industry.
These include new planning guidelines to make the process of approving new drilling sites more streamlined, and a consultation on tax incentives to encourage exploration.
