From Brendan Koerner's The Trillion-Barrel Tar Pit in July's issue of Wired:
[R]ecent improvements in mining and extraction techniques have cut heavy oil production costs nearly in half since the 1980s, to about $10 per barrel, with more innovation on the way.
Even at $30 per barrel of crude, there's plenty of rent in the tar pit. Alberta has 300 billion barrels of the stuff that are accessible using current methods, and another trillion-plus barrels for which promising technologies are being developed. For perspective, consider that the princes and sheikhs of the Middle East control 685 billion barrels.
Koerner's excellent article describes the "alchemy" of processing sticky dirt into refinable crude oil, and the companies and investments involved. Recommended.