Rystad Energy estimates US has 264 billion barrels of oil
The Norwegian energy consultancy Rystad Energy said US reserves are slightly larger than Russia (256B barrels) and Saudi Arabia (212B barrels) accounting for existing fields, discoveries and fields yet to be discovered.
The study said that more than half of US oil is in unconventional shale fields with Texas alone holding 60 billion barrels.
At current production, Rystad estimates there is 70 years of recoverable oil in the world, or 2092 billion barrels.
I'm skeptical of these reports. Shale is a complete game changer and there are no reliable estimates of what might be recoverable with shale technology in markets that haven't been drilled.
In any case, the hope is that within the next 50 years, the demand for oil is far lower because it's been replaced by alternatives.