Figure 6: Share of Organization of the Petroleum Exporting Countries (OPEC) in world crude oil reserves 2012

Classification of crude oil

Crude oil may be referred to as sweet if it contains relatively little sulfur (0.5%) or sour if it contains substantial amounts of sulfur. Sweet crude requires less energy to be extracted and once extracted, yields higher quality gasoline as well as larger quantities of it. Iraq is one of the leading producers of sweet crude. Major locations where sweet crude is found include the Appalachian Basin in Eastern North America, Western Texas, the Bakken Formation of North Dakota and Saskatchewan, the North Sea of Europe, North Africa, Australia, and the Far East including Indonesia.

Sour crude, on the other hand, has a high level of impurities in it, namely sulfur, which must first be removed before being processed into gas and other petroleum based products. Venezuela is a leading producer of sour crude oil. Sour crude is more common in the Gulf of Mexico, Mexico, South America, and Canada. Crude produced by OPEC Member Nations also tends to be relatively sour, with an average sulfur content of 1.77%.

According to IEA top 10 oil producer countries produced over 64 % of the world oil production in 2012. In 2012 total oil production was 4,142 Mt. The top oil producers in 2012 were:

♤ Russia - 544 Mt (13 %)

♤ Saudi Arabia - 520 Mt (13 %)

♤ United States - 387 Mt (9 %)

♤ China - 206 Mt (5%)

♤ Iran - 186 Mt (4 %)

♤ Canada - 182 Mt (4 %)

♤ United Arab Emirates (UAE) - 163 Mt (4 %)

♤ Venezuela - 162 Mt (4 %)

♤ Kuwait - 152 Mt (4 %)

♤ Iraq - 148 Mt (4 %).