River taxis wait for customers at the dock in the town of Bartica, Guyana on June 6, 2016. Bartica is a town at the confluence of two major rivers and is the launching point for people who work in the jungle regions, mining gold and diamonds.

The International Monetary Fund (IMF) believes one of South America's smallest countries is likely to see a dramatic upswing in economic growth next year.

Guyana, a country of about 780,000 which shares a border with Brazil, Suriname and Venezuela in the northeast of South America, will see economic growth of 86% in 2020, according to the IMF. That's up from 4.4% in 2019.

Such an explosive expansion of annualized real GDP (gross domestic product) would likely see Guyana register the fastest economic growth in the world next year. To be sure, Guyana's projected economic expansion would be 40 times that of what is expected from the U.S. — the world's largest economy.

"The reason the IMF is projecting that is because Guyana has the highest amount of oil for each individual person of any country in the world," Natalia Davies Hidalgo, a freelance Latin American analyst, told CNBC via telephone on Monday.

In comparison to OPEC kingpin Saudi Arabia, which has approximately 1,900 barrels of offshore reserves per person, Guyana has 3,900 barrels, Hidalgo said.

"And it could have more, as production hasn't even started yet and new discoveries are still being made."