I am no expert on oil exploration but i remember reading somewhere that the cost of extraction of oil in Iraq and Saudi is somewhere between $ 2- $5 per barrel !!!!!! So even at $ 30 they were making a killing.
As far as Canadian Oil is considered, as desi driller has said it is mostly "Oil Sands" ..... this is expensive to extract, so is vailable at over $ 100 a barrel. There are environmental concerns ....... but then only time will decide which is going to prevail ... economic concerns or environmental copncerns.

On another note, Mexico produces more oil then Canada (presently)....... but you dont see people running to Mexico !!!!!!!