We are not likely to run out of oil of any quality any time soon. However we are facing the looming prospect of a production peak, something which is largely a human and logistical phenomenon, rather than a geological one.
Oil production will likely soon peak, resulting in a bumpy plateau for a while, before beginning its inevitable descent towards full exhaustion. The only real argument is on the timing and severity of the decline. Production will peak and decline because of depletion in existing fields – especially of the giant and supergiant fields most of which are now getting very old. The lack of new discoveries sufficiently large enough to offset existing depletion in these very large fields, and satisfy an increasing demand for oil driven by exponential economic and population growth, plus the poor development and production prospects for unconventional substitutes such as tar sands, heavy oil, coal, and shale etc.
