Even as attempts are made to develop alternative sources of energy, the importance of oil is unquestionable. It is a revenue generator for countries lucky enough to have oil reserves and produce more than their domestic consumption. On the other hand, it is a drain for those economies that are heavily dependent on imports. The world pays close attention to big changes in the oil markets triggered by events like unrest in oil-producing regions, new oil field discoveries and advances in extraction technology.

Total oil production averaged more than 97 million barrels per day (b/d) in 2016, according to the Energy Information Administration (EIA). The top five oil-producing countries were responsible for nearly half of the world's production. Below is a look at the leading countries based on total oil production in 2016, according to EIA data. Total oil production includes production of crude oil, lease condensate, unfinished oils, refined products obtained from the processing of crude oil, and natural gas plant liquids. It is expressed in barrels per day.

United States

The United States is the top oil-producing country in the world, with an average of 14.86 million b/d, which accounts for 15.3% of the world's production. This is down from 15.12 million b/d in 2015, but it was enough to land the United States in the No. 1 spot, which it has held for the past four years running. The United States overtook Russia in 2012 for the No. 2 spot, and it surpassed former leader Saudi Arabia in 2013 to become the world's top oil producer. Much of the increased U.S. production is attributable to fracking in the shale formations in Texas and North Dakota. The United States has been a net exporter - i.e., exports exceeded imports -of oil since early 2011.

Saudi Arabia

The Kingdom of Saudi Arabia is also the kingdom of oil production, contributing 12.39 million b/d, or 12.7% of the world's total production. This is up from 12.07 million b/d in 2015. Saudi Arabia is the only member of the Organization of the Petroleum Exporting Countries (OPEC) to make this list. Although the government is attempting to diversify the country's economy, it remains heavily dependent on oil. According to The World Factbook, the petroleum sector accounts for roughly 42% of the country's gross domestic product (GDP), 87% of the budget revenues and 90% of export earnings. The major oil fields in Saudi Arabia are Ghawar, Safaniya, Khurais, Manifa, Shaybah, Qatif, Khursaniyah, Zuluf and Abqaiq.

Russia

While Russia has fallen in the ranks, it remains one of the top oil producers in the world, with an average of 11.24 million b/d in 2016. This accounts for 11.6% of total world production and is up from 11.03 b/d in 2015. The main regions of oil production in Russia are Western Siberia, Volga-Ural, Krasnoyarsk, Sakhalin, Komi Republic, Arkhangelsk, Irkutsk and Yakutiya. Most of the production originates from the Priobskoye and Samotlor fields in Western Siberia. The oil industry in Russia was privatized after the fall of the Soviet Union, but after a few years, the companies were reverted to state control. The prominent companies engaged in oil production in Russia are Rosneft - which took over another leading producer, TNK-BP, in 2013 - Lukoil, Surgutneftegaz, Gazprom Neft and Tatneft.

China

China produced an average of 4.87 million b/d of oil in 2016, which accounts for 5% of the world's production. This is down from 5.15 million b/d in 2015. China is a net importer of oil, as the country consumed an average of 12.38 million b/d in 2016. According to the latest EIA data, about 80% of Chinese production capacity is onshore with the remaining 20% coming from shallow offshore reserves. The northeast and north central region of the country are responsible for the majority of domestic production. These regions have mature fields like Daqing, which have been exploited since the 1960s. The production from mature fields has peaked, and companies are investing in enhanced oil recovery (EOR) techniques, such as polymer and stream flooding and water injection, to offset some of the production declines. China is also working on new offshore options.

Canada

Canada holds the fifth spot among the world's leading oil producers with average production of 4.59 million b/d in 2016, accounting for 4.7% of global production and up from 4.51 million b/d in 2015. According to the EIA International Energy Outlook 2017, Canada's production could grow by 1.26 million b/d by 2040. This increase is expected to come primarily from oil sands production, which is one of the costliest ways to extract crude. However, technological advancements are helping bring down costs. Currently, Canada's main sources of oil production are the oil sands of Alberta, the Western Canada Sedimentary Basin and Atlantic offshore fields. The oil sector in Canada is privatized with many foreign and domestic companies operating in the country.

Want to learn how to invest?

Get a free 10 week email series that will teach you how to start investing.

Delivered twice a week, straight to your inbox.