Oil remains one of the planet's main energy sources, playing a central role in the global economy, international politics, and the development of many countries. But where are the world's largest oil reserves located? Reserves indicate the amount of oil that can be extracted economically using today's available technology.
What are oil reserves?
Oil reserves are estimates of the volume of crude oil that can be extracted from known reservoirs, considering current technical and economic criteria. The numbers vary according to new geological analyses, price changes, and revisions to production data.
Reservations are classified into three groups.
Confirmed reservations (1P) gather volumes whose extraction is considered certain under current conditions. In probabilistic models, the chance of recovery equal to or greater than the estimate is at least 90%.
Likely reservations (2P) include the proven ones and increase the estimated volume, with a minimum probability of 50%.
Reservations possible (3P) sum proven and probable, with a chance of recovery starting at 10%.
These estimates change over time due to discoveries, revisions of known fields, variations in the price of a barrel, which is equivalent to about 159 liters, and regulatory decisions.
The term "reserves" does not include all the oil that exists underground. Unconventional or unmapped resources are excluded from these calculations until they can be exploited in a viable way.
Which countries have the most oil?
Countries like Saudi Arabia, Iran, Iraq, Kuwait, and the United Arab Emirates concentrate large oil fields, with Saudi Arabia being particularly noteworthy. Outside the Middle East, other regions also possess significant volumes. In South America, Venezuela holds the world's largest proven reserves, mostly in the form of extra-heavy oil. In North America, Canada and the United States have large reserves, many of them unconventional, such as tar sands and shale oil.
Russia is also among the major global holders of reserves. In Africa, countries like Libya, Nigeria, and Angola play a significant role in the international market. In Asia, China, India, and Indonesia have smaller reserves compared to their domestic consumption. In Europe, the North Sea stands out, where the United Kingdom and Norway maintain substantial reserves.
Ranking of the largest oil reserves
| Position | Country | Barrels (in billions) |
|---|---|---|
| 1 | Venezuela | 300,9 |
| 2 | Saudi Arabia | 266,5 |
| 3 | Canada | 169,7 |
| 4 | Iran | 157,8 |
| 5 | Iraque | 150,0 |
| 6 | Russia | 103,2 |
| 7 | Kuwait | 101,5 |
| 8 | Emirados Arabes Unidos | 97,8 |
| 9 | United States | 48,5 |
| 10 | Libia | 48,4 |
| 15 | Brazil | 16,2 |
Source: OPEC – Annual Statistical Bulletin 2024/2025; Oil & Gas Journal; Energy Institute (former BP) – Statistical Review of World Energy; ANP; Visual Capitalist.
Venezuela leads the world ranking, with approximately 303 billion barrels of proven reserves. Next are Saudi Arabia, with approximately 266 billion barrels, Iran, with about 157 billion, and Canada, with 169 billion barrels.
Together, these countries hold more than half of the world's reserves, estimated at between 1,5 and 1,6 trillion barrels.
Which country has the largest oil reserves in the world?
Venezuela leads the world ranking in oil reserves. Most of the volume is concentrated in the Orinoco Belt, an area of approximately 55 km² in the north of the country. The presence of large deposits is linked to the geology of the region, marked by the La Luna Formation, a source rock from the Cretaceous period that extends through Venezuela and areas of Colombia.
This formation is rich in organic matter accumulated over millions of years from algae, plankton, bacteria, and plant material. Subjected to high pressures and temperatures, these sediments gave rise to the oil that now fuels the country's main oil fields. In addition to the Orinoco Basin, Venezuelan reserves are distributed across basins such as Maracaibo, Barinas-Apure, and Falcón. The Maracaibo Basin was the first to be explored and still concentrates a significant portion of production.
Venezuelan oil is mostly extra-heavy, with high viscosity and a high sulfur content. Extraction requires techniques such as steam injection and blending with lighter oils, which increases costs and reduces the market value of the product. Production is controlled by the state-owned PDVSA, which faces operational and financial limitations, as well as the effects of international sanctions, restricting the exploitation of reserves.
What are Brazil's oil reserves?
Today, oil extraction in Brazil takes place in ten states: Alagoas, Amazonas, Bahia, Ceará, Espírito Santo, Maranhão, Rio de Janeiro, Rio Grande do Norte, São Paulo, and Sergipe. This distribution helps explain why the country has become one of the world's largest oil producers in recent years.
Brazilian reserves are organized into oil basins, which typically span two or more states and contain dozens of operating fields. In total, Brazil has hundreds of oil fields, spread across different regions.
In the North, production is concentrated in the Amazon and Solimões basins, where exploration occurs mainly in onshore areas. In the Northeast, the map is broader and includes the Sergipe-Alagoas, Potiguar, Parnaíba, Recôncavo, Camamu-Almada, Barreirinhas, and Tucano Sul basins, responsible for a significant portion of onshore and shallow water production.
However, it is in the Southeast that the country's largest reserves are located. The Espírito Santo, Campos, and especially Santos basins concentrate the most productive fields. It is in the latter that the Pre-Salt is found, an extensive strip below the salt layer at the bottom of the Atlantic Ocean, discovered in 2006 and responsible for more than 75% of the oil currently produced in Brazil.
The Lula, Búzios, and Sapinhoá fields, all in the Santos Basin, are among the most productive in the world and support the growth of national production. According to the National Petroleum Agency (ANP), the country ended 2024 with 16,8 billion barrels in proven reserves, a result of new declarations of commerciality, technical revisions, and continuous investments in exploration.
And how much oil is there in the world?
Even with the advancement of renewable energies and global emission reduction targets, oil remains a central component of the world's energy matrix. The exact amount of oil still available on the planet is difficult to estimate precisely, as new discoveries, geological revisions, and technological advances continue to alter the known figures.
Even with the advancement of renewable energy sources and international pressure for cuts in carbon emissions, oil remains the basis of the global energy system. International estimates indicate that proven reserves on the planet are around 1,6 to 1,7 trillion barrels. This number, however, is far from definitive. It changes frequently, influenced by new discoveries, technical revisions of already known fields, and the evolution of the technology used in exploration and production.
Unlike the idea of a fixed stockpile, oil reserves are an economic and technical concept. A volume is only included in this calculation when it can be extracted safely and profitably under current conditions. When the price per barrel rises or when new techniques reduce costs, areas previously considered unviable are included. The opposite also occurs during periods of market downturn.
In this sense, technology plays a direct role in extending the lifespan of oil. Mature fields, which decades ago would have been abandoned after the natural decline in production, now continue to operate for many years. Enhanced recovery methods allow for the extraction of a larger share of the oil present in the reservoir, increasing the recovery factor without the need for new discoveries. In deep and ultra-deep waters, the development of more precise and robust equipment has expanded the scope of exploration, as occurred in the Brazilian pre-salt layer.
Furthermore, advances in geological modeling, the use of seismic data, and field automation have reduced risks and increased operational efficiency. In practice, this means that known oil lasts longer than previously projected, even with high consumption. This is not about denying the energy transition, but about recognizing that it occurs gradually and unevenly across regions and sectors of the economy.
Alutal's technology in the oil industry
This is where the role of technology provider companies becomes relevant. Total It operates in the development of solutions focused on the control, monitoring, and safety of industrial processes, including the oil and gas sector, serving both onshore and offshore operations. Its equipment is used in critical stages of the supply chain, from exploration to refining, with a focus on operational precision and failure reduction.
The company's portfolio includes sensors and instruments for measuring temperature, pressure, level, flow, vibration, and gas detection, as well as solutions for liquid and gas analytics and custody transfer—critical steps in the oil supply chain. This equipment is used in refineries, platforms, terminals, and processing units for process control, increased operational reliability, and reduced failures.
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