Countries With the Most Oil: How the Reserve Ranking Has Changed

The countries with the most oil are Venezuela (303.8 billion barrels of proven reserves), Saudi Arabia (297.5 billion) and Canada (168.1 billion), according to the BP Statistical Review of World Energy 2021, which gives figures for the end of 2020. Iran, Iraq, Russia, Kuwait, the United Arab Emirates, the United States and Libya make up the rest of the top 10. Twenty years ago the list looked very different. Saudi Arabia was clearly first. Canada’s reserves looked small because its oil sands were not yet counted, and Venezuela reported only about 80 billion barrels as late as 2005. Most of these changes came from reclassifying oil that was already known about, because proven reserves mean only the oil that can be recovered profitably at current prices and with current technology.

The top 10 at the end of 2020

Different organisations publish different numbers, which is why rankings disagree. OPEC’s own bulletin leaves out Canada’s oil sands and puts Canada at just 4.3 billion barrels. The US Energy Information Administration gives Iran about 209 billion barrels, compared with BP’s 157.8 billion. BP’s review is used here because it counts every major producer, oil sands included, in the same way.

Some of the figures have hardly changed in years. OPEC’s 2025 bulletin still lists Venezuela at 303.2 billion barrels, Iraq at 145.0 billion and Kuwait at 101.5 billion, almost exactly BP’s end-2020 numbers. This happens partly because more than 70 countries do not subtract each year’s production from their stated reserves. Analysts also point out that OPEC’s quota system has allowed members with bigger reserves to produce more, which gives them a reason to report high figures.

Saudi Arabia’s decades at the top, and the 2011 handover to Venezuela

For most of the modern oil age, Saudi Arabia held the largest proven reserves. OPEC put them at 265 billion barrels in 2009, and a 2017 estimate gave about 268 billion, including 2.5 billion in the neutral zone shared with Kuwait. Most of the oil is in the Eastern Province. Saudi Arabia has kept its field data secret since at least 1982, which led to years of doubt, especially in the 2000s when some experts believed in 2008 that Saudi output had peaked or soon would. In January 2019 the energy minister, Khalid Al-Falih, announced the results of the first independent audit, by the consultancy DeGolyer and MacNaughton. It found proven reserves roughly as large as, or somewhat larger than, the official figure. BP’s 297.5 billion is higher than Saudi Arabia’s own 267.2 billion, as reported to OPEC.

Venezuela’s rise came from one decision about what counts. The Orinoco Belt holds a huge deposit of extra-heavy crude, which is expensive to produce. In October 2007 the government put the country’s proven reserves at 100 billion barrels. By February 2008 the figure was 172 billion, by 2009 about 211 billion, and by the end of 2015 about 301 billion. High oil prices in those years made the heavy Orinoco oil count as economic, and by one estimate reserves rose almost fourfold, from 80 billion to 300 billion barrels, between 2005 and 2014. In early 2011 President Hugo Chávez announced that Venezuela had passed Saudi Arabia.

Having the largest reserves did not keep Venezuela a large producer. As recently as 2006 it was one of the main suppliers to the United States, sending about 1.4 million barrels a day, and it reportedly produced 3.1 million barrels a day in 2010 and exported 2.4 million of them. After the 2014 price crash, the economy fell into hyperinflation and shortages. In October 2020, for the first time in a century, no rigs were searching for oil in Venezuela. EIA data puts its 2025 output at about 968,000 barrels a day. At that rate, its BP-listed reserves would last more than 850 years. Some analysts doubt the headline figure. A researcher at Rice University’s Baker Institute has suggested the real total may be closer to 100–110 billion barrels, and Rystad Energy estimates about 81 billion. Our guide to the natural resources of Venezuela covers the Orinoco Belt in more detail.

Alberta’s oil sands and Canada’s 2003 jump

Canada rose even more suddenly. Its conventional reserves, spread across Alberta, Saskatchewan and offshore Newfoundland, are small by world standards. Then, in 2003, the bitumen of Alberta’s oil sands was judged economic to produce, and Canada’s proven reserves jumped almost overnight. The province’s regulator, the Energy Resources Conservation Board, counted about 174 billion barrels of oil sands as proven. This was controversial, because bitumen does not flow to a well: it has to be mined or heated and then upgraded before refineries can use it. By the start of 2015 Canada’s reserves stood at 172 billion barrels, with more than 95% of them in the oil sands. By January 2024 the total stood at 163 billion barrels, fourth in the world on some counts, behind Venezuela, Saudi Arabia and Iran. By 2015, according to Natural Resources Canada, Venezuela held 18% of the world’s proven oil reserves, Saudi Arabia 16.1% and Canada 10.3%. Before 2003, Canada would not have been in that top three.

Production followed. Shell Canada’s Albian Sands mine opened in 2003, and by 2007 oil sands supplied 64% of Alberta’s 1.86 million barrels a day. Canada now produces about 5 million barrels a day, according to EIA figures for 2025. Because OPEC does not count oil sands, rankings that use only OPEC data leave Canada out of the top 10, which is why some lists online do not include it.

Iran and Iraq: revisions, wars and unaudited figures

Iran’s total has been revised upwards several times. Its reserves were about 99 billion barrels at the start of 2001. A study by the National Iranian Oil Company in 2002 added about 31.7 billion barrels of recoverable oil, partly by raising the assumed recovery factor of its fields from 29% to 36%. Its official figure then rose to 138.4 billion at the end of 2006, about 150 billion by 2013 and about 208.6 billion in current OPEC and EIA data. Iran has been producing oil since 1908, and by the end of 2007 it had already extracted about 61 billion barrels.

Iraq’s figure has stayed almost the same, largely because of decades of war and unrest. The US Geological Survey estimated its proven reserves at 78 billion barrels in 1995, and the US Department of Energy at 112 billion in 2003. Official statistics have not been properly revised since 2001, and they rely on 2-D seismic surveys that are decades old. Today’s 145 billion barrels could therefore be an underestimate. Production fell from about 2.6 million barrels a day before the 2003 invasion to 2.0 million in 2006, then recovered to about 4.4 million a day in 2025. Kuwait, the UAE and Libya, the other OPEC members in the top 10, have kept similar figures for years. Kuwait’s 101.5 billion barrels are centred on the Burgan field, the second-largest oil field in the world. The UAE shows how much sources can differ: BP counts 97.8 billion barrels, but OPEC and the EIA both put it at 113 billion. Libya, in tenth place with 48.4 billion, holds the largest reserves in Africa, ahead of Nigeria’s 36.9 billion. More on the group is in our list of OPEC countries.

The shale era: why the United States produces most but holds far less

The biggest shift of the last 15 years has been in production, not reserves. The US reached a production peak in November 1970. By 2007 it relied heavily on imports: net imports of oil and oil products had risen from 3.16 million barrels a day in 1970 to 12.04 million. Then shale drilling changed things. In 2012 US output rose by 800,000 barrels a day, the largest one-year increase since drilling began in 1859. In 2018 the United States became the world’s largest crude oil producer, and it has stayed there. EIA data for 2025 shows about 13.6 million barrels a day.

Its proven reserves, however, are modest: 68.8 billion barrels by BP’s count, and 44.4 billion barrels of crude in 2021 on a narrower, crude-only count. The US produces much faster than it adds reserves, so dividing BP’s reserves by 2025 output gives it only about 14 years of production in reserve, compared with about 30 for Russia and 85 for Saudi Arabia.

Russia published no official reserve estimate until July 2013, when its Natural Resources Ministry released one for the first time. Estimates still range from 80 billion barrels (OPEC) to 107.8 billion (BP), most of it in Western Siberia. The geologist Farman Salmanov found the region’s great fields in Tyumen Oblast in 1961, they have been pumped since the 1970s, and they still supply about two-thirds of Russia’s oil.

So the answer depends on the question. Venezuela and Saudi Arabia hold the most oil in the ground, Canada rose to third on its oil sands, and the United States went from importing heavily to producing more than anyone else, as our ranking of the countries that produce the most oil shows year by year.