Analysts in Australia say the extraction of oil from a major shale oil source discovered in South Australia is at least 10 years away.
Linc Energy of Queensland said independent studies have confirmed a major shale oil source in South Australia's far north, which officials have estimated could be worth $A20 trillion.
The company said up to 233 billion barrels of oil are estimated to be trapped in the shale, which prompted a jump in the firm's share price.
However, Patersons Securities analyst Alexis Clarke said these initial figures should be treated lightly.
Shale oil is more costly to extract and more controversial than conventional crude and involves fracking, in which water is pumped in to break up the shale.