Venezuela and Saudi Arabia are the countries with the largest and second largest proven oil reserves. As of the start of 2015, which country has the third largest oil reserves?

Yes, Canada. Proven reserves are those quantities of petroleum which, by analysis of geological and engineering data, can be estimated to be commercially recoverable from known reservoirs and under current economic conditions. Because proven reserves include oil recoverable under current economic conditions, nations may see large increases in proven reserves when known, but previously uneconomic, deposits become economic to develop. In this way, Canada's proven reserves increased suddenly in 2003 when the oil sands of Alberta were seen to be economically viable. Similarly, Venezuela's proven reserves jumped in the late 2000s when the heavy oil of the Orinoco was judged economic. So here are the top 10 countries in terms of oil reserves (reserves amounts listed in millions of barrels)

1 Venezuela 297,740

2 Saudi Arabia 268,350

3 Canada 173,625–175,200

4 Iran 157,300

5 Iraq 140,300

6 Kuwait 104,000

7 UAE 97,800

8 Russia 80,000

9 Libya 48,014

10 Nigeria 37,200