Which country has the largest proven oil reserves?

Venezuela has the world's largest proven oil reserves. Recent estimates put its proven crude oil reserves at roughly 303 billion barrels, with most of the resource concentrated in the Orinoco Belt.

The Orinoco Belt contains enormous deposits of extra-heavy crude, a dense form of oil that requires specialized extraction, transportation, and refining. Venezuela's reserve total rose sharply when this heavy oil was classified as economically recoverable under prevailing prices and technology. “Proven reserves” therefore means oil estimated to be recoverable under existing economic and operating conditions, not necessarily oil that can be produced cheaply today.

Venezuela's huge reserve base has not translated into the world's highest production. Years of underinvestment, infrastructure problems, management failures, sanctions, and the technical difficulty of processing extra-heavy crude have kept output far below the country's potential.

Saudi Arabia and Iran are common answers because they are major oil powers with enormous reserves, while Canada has very large oil-sands resources. However, under standard proved-crude-reserve rankings, Venezuela is the accepted answer. Reserve estimates can change as prices, technology, reporting methods, and economic conditions change.