The full extent of the energy revolution from shale oil and gas is becoming clearer.
The US government’s Energy Information Administration says it estimates global reserves of oil in shale rock deposits will boost world crude resources by 11 percent.
It has calculated there are what it calls “technically recoverable” shale oil reserves totalling 345 billion barrels in 41 countries.
Russia has most – 75 billion barrels, the United States is second with an estimated 58 billion and China is believed to have the equivalent of 32 billion barrels.
Hydraulic fracturing, or fracking, of shale deposits is used to unlock the oil and natural gas which is in the rock.
But while the US government report offers a comprehensive look at global shale potential, it must be remembered that technically recoverable reserves are not a guarantee of supply.
Geology varies in different countries, making it unclear if deposits can be extracted at a reasonable cost.