21. Sudan
Proven reserve: 6,800,000,000 billion barrels
Proven reserve: 6,800,000,000 billion barrels
In 2010, Sudan was considered the 17th-fastest-growing economy in the world and the rapid development of the country largely from oil profits.
However, because of the secession of South Sudan, which contained over 80 per cent of Sudan's oilfields, the country's economic forecast is uncertain.
22. Norway
Proven reserve: 6,680,000,000 billion barrels
Proven reserve: 6,680,000,000 billion barrels
On a per-capita basis, it is the world's largest producer of oil and natural gas outside the West Asia.
23. Ecuador
Proven reserve: 6,542,000,000 billion barrels
Proven reserve: 6,542,000,000 billion barrels
Ecuador's economy has heavily depended on exporting resources such as petroleum, fish, shrimp, timber and gold.
The country's greatest national export is crude oil.
However, fluctuations in world market prices can have a substantial domestic impact.
24. Oman
Proven reserve: 5,500,000,000 billion barrels
Proven reserve: 5,500,000,000 billion barrels
Oil is extracted and processed by Petroleum Development Oman, with proven oil reserves holding approximately steady, although oil production has been declining.
Omani citizens enjoy good living standards, but the future is uncertain with Oman's limited oil reserves.
25. Ghana
Proven reserve: 5,000,000,000 billion barrels
Proven reserve: 5,000,000,000 billion barrels
Although commercial quantities of offshore oil reserves in Ghana were discovered in the 1970s, by 1990 production was still negligible.
In 1983, the government established the Ghana National Petroleum Corporation to promote exploration.
Thereafter, the company reached agreements with a number of foreign firms.
26. Vietnam
Proven reserve: 4,700,000,000 billion barrels
Proven reserve: 4,700,000,000 billion barrels
Though Vietnam is a relative newcomer to the oil industry, it is currently one of the biggest oil producers in Southeast Asia.
27. Egypt
Proven reserve: 4,300,000,000 billion barrels
Proven reserve: 4,300,000,000 billion barrels
Egypt has a developed energy market based on coal, oil, natural gas, and hydro power.
Oil and gas are produced in the western desert regions, the Gulf of Suez, and the Nile Delta.
Egypt has huge reserves of gas, estimated at 1,940 cubic kilometres (470 cu mi), and LNG is exported to many countries.
28. Indonesia
Proven reserve: 4,050,000,000 billion barrels
Proven reserve: 4,050,000,000 billion barrels
The country has extensive natural resources, including crude oil, natural gas.
The country has historically been a member of Organization of the Petroleum Exporting Countries, although it withdrew in 2008 as it was no longer a net exporter of oil.
The country's major export commodities include oil and gas, electrical appliances, plywood, rubber, and textiles.
29. Gabon
Proven reserve: 3,700,000,000 billion barrels
Proven reserve: 3,700,000,000 billion barrels
Gabon's oil revenues comprise roughly 46 per cent of the government's budget, 43 per cent of gross domestic product and 81 per cent of exports.
Oil production is now declining rapidly from its high point of 370,000 barrels per day in 1997.
Some estimates suggest that Gabonese oil will be expended by 2025.
It should be mentioned here that among all of the countries ranked in the 2011 Global Hunger Index, Gabon had the lowest score and thus the lowest level of hunger.
30. Australia
Proven reserve: 1,100,000,000 billion barrels
Proven reserve: 1,100,000,000 billion barrels
Australia has considerable petroleum, natural gas and coal reserves and is one of the few countries belonging to the Organization for Economic Cooperation and Development that is a significant net hydrocarbon exporter, exporting about two-thirds of its total energy production.
Australia was the world's largest coal exporter and the fourth largest exporter of liquefied natural gas in 2009, after Qatar, Malaysia, and Indonesia.