The problem is, nobody really knows how much oil is down there. The only thing that's certain: Dead organisms produced (
http://www.livescience.com/environme...l_origins.html) a limited amount of oil long ago, and eventually there won't be enough to sustain the current rate of consumption.
_________________
*Source: LiveScience (
http://www.livescience.com/environme...-prices.html)*
More...