Most of Canada's reserves are tar sands which are about as pleasant as the name describes - tar mixed with sand. There's a lot of it but it's expensive to extract. So for one thing these reserves are somewhat hypothetical based on the price of oil. The Saudis are profitable at almost any price while new oil sands projects have a break-even cost of somewhere around $90 per barrel. (http://business.financialpost.com/news/energy/how-high-break...)
Even with the normal oil plus tar sands, oil is only Canada's #2 export behind vehicles, 16% of exports. Canada has a well-diversified economy quite unlike Venezuela, Iraq and Saudi Arabia. Iran isn't terrible but oil is still 2/3rds of their exports.
Saudi oil comes out of the ground in a form that you can pretty much barrel and ship, they have it so easy. Canada's oil isn't even oil, it's more like ashphalt.
Even with the normal oil plus tar sands, oil is only Canada's #2 export behind vehicles, 16% of exports. Canada has a well-diversified economy quite unlike Venezuela, Iraq and Saudi Arabia. Iran isn't terrible but oil is still 2/3rds of their exports.