There are alternative means for natural oil mining (e.g. Sand Oil)- as long as prices where below $50 a barrel, the production costs of alternative methods were not economical.
As prices of oil sky high, you can see the Oil Sand industry booming. The Alberta province of Canada has the worlds largest Sand-Oil reserves - they say Canada can produce enough oil for the world-wide consumtion for the next 50 years (at least)
For more details see: Albeta Sand Oil