Oil is inflated. There is 1.7 trillion in the Athabasca alone, and 149 years of oil left in Canada alone.
This is a simplistic gesture. Everything is limited by the rate of extraction, and so even as biodiesel production, shale, and tar sands extraction increases - there is still a limit to how fast that can be done. Canada expects to be producing 5mbarrel/day from the Athabasca sands by 2030 - but that's still only 25% of North America's oil needs on a healthy trend. Wells will still be producing oil then, of course - the United States will be producing another 25% on its own from traditional methods if things go well.
But that's still only half, and the rest of the world is either horribly mismanaged, going dry fast, or already spoken for. North America needs to be producing a good portion of half of its oil from alternate means by 2030 - liquefaction, algaculture, shale, and whathaveyou. Only one of those is honestly sustainable.