The Crude Truth About Oil Reserves: The coming century will overflow with petroleum.
It offends conventional wisdom. It will also seem nasty to the doom-sayers, who for decades have predicted an oil scarcity that never came. But the 21st century is very likely to overflow with oil. There are at least three main reasons for this.

First, oil reserves are finite. This is incontrovertible. But even so, no one knows how finite they are. And since we don't know the total amount of oil resources existing underground, it's impossible to calculate the curve of future supply.

Proved Reserves Of Crude Oil Fall In 2008, Reflecting Low End-Of-Year Prices
The Energy Information Administration’s (EIA) U.S. Crude Oil, Natural Gas, and Natural Gas Liquids Proved Reserves, 2008 reports that proved reserves of crude oil fell by more than 10 percent in 2008, primarily because of low end-of-year prices used to estimate proved reserves, even though discoveries of crude oil rose for the third year in a row. In contrast, proved reserves of natural gas rose by 3 percent in 2008, despite