Known reserves of Natural gas were thought to be sufficient for 60 to 120 years. Now with shale gas being produced in large quantities, the IEA has revised known reserves upwards to 250 years — and they could be further revised upwards.
The world may have twice as much natural gas than previously thought, according to the rich nations’ think tank the International Energy Agency (IEA). The world may have 250 years of gas usage at current levels thanks to “unconventional gas” from shale and coal beds, Anne-Sophie Corbeau, senior gas expert at the IEA told BBC News.
Estimates may even be revised upwards. Studies are underway into newly-recoverable sources, Ms Corbeau said. But she stressed that the totals were highly uncertain, and depended on price, technology and the accessibility of supplies.
“The gas story is huge,” she told BBC News. ”A few years ago the United States was ready to import gas. In 2009 it had become the world’s biggest gas producer. This is phenomenal, unbelievable.” The US achieved the change through a technological breakthrough in which firms found a way of using tiny explosions to free gas previously trapped in a common rock – shale.
Miss Corbeau said other nations were now rushing to replicate the US success by exploiting gas currently trapped in various types of rock where it was thought to be impossible to access.
She said conventional natural gas supplies were assured for 60 years – with maybe a further 60 years if engineers could get to other supplies. She admitted there is great uncertainly about how much unconventional gas is possible to exploit, but said the best estimate is that new sources will stretch gas supplies to 250 years at current levels.
“The resources are really huge,” she said.
“We probably have 920 trillion cubic metres – that is more than 300 times the current annual demand for gas. ”Not all of this will be recoverable, but any country that develops new gas supplies will have a global impact on gas availability and price, as gas markets are all inter-connected.”