"The Energy of Nations"

Most of us think that both below-and above-ground factors will define the peak, but the peak will be the peak: the most oil that can ever be produced in any one day. Perhaps production wobbles along on a plateau for a while before dropping, but it will never exceed that peak level. If we think of all the theoretically extractable oil under the ground as a tank, what we have to worry about is not so much the size of that tank, but the size of the taps: the actual global production capacity...

The risk debate is not about the oil โ€˜running outโ€™. It will never run out. Oil reserves under the ground... are not the same as oil flows from production pipes at the surface.
— Jeremy Leggett, The Energy of Nations