What countries lose when oil prices drop

Oil workers conduct a drill in a petroleum well in Lagunillas at the east coast of Lake Maracaibo near Maracaibo City in Venezuela.
Jorge Silva | Reuters
Oil workers conduct a drill in a petroleum well in Lagunillas at the east coast of Lake Maracaibo near Maracaibo City in Venezuela.

The world's oil producing countries just got a little poorer Tuesday, as crude prices fell more than than 3 percent to three-year lows.

As the price of oil extends a free fall that began this summer, countries around the world that rely on oil revenues are bracing for an imminent economic and budget hit.

The drop is widening budget gaps in the Gulf states like Saudi Arabia, the United Arab Emirates, Qatar, Oman and Bahrain that rely heavily on oil to pay government services.

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The price plunge comes as a slowing global economy cuts into the demand for oil. At the same time, expanded production—including rising output from North America—has left the world awash in oil.

Lower prices could eventually crimp some production from higher-cost producers, including recent finds that have spurred a U.S. oil shale boom. Some analysts say output could slow if crude stays below $80 a barrel.

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In the meantime, countries that have been spending cash generated by $100-a-barrel oil face the much tighter budgets.

An IMF report last month said the hardest hit will include small oil exporters like Oman, which faces a budget gap of 1.8 percent of gross domestic product in 2016. Bahrain could see its budget deficit swell top 5.7 percent by next year, the IMF said.

Bigger producers are also at risk. Oil giant Saudi Arabia faces a budget shortfall of 1.3 percent of GDP in 2017 and currency controls that have led to shortages of many consumer goods, its first since crude exports dried up in 2009 following the global financial crisis.

With oil and gas production accounting for some 70 percent of Russia's government spending, Moscow also faces a big shortfall—after budgeting based on $100-a-barrel oil for 2015. Russia's economic growth was already slowing before the plunge in oil prices. Trade sanctions imposed by the U.S. and Europe—in response to the invasion of the Ukraine—will further crimp growth and government spending.

The impact of budget gaps among big producers like Saudi Arabia and Russia, though, will be softened somewhat by large reserves built up during boom years. But a protracted era of cheap oil would force them to undertake serious belt-tightening.

Top oil analyst: Crude could fall to $60
Top oil analyst: Crude could fall to $60   

Other major oil producers—including Iran and Venezuela—haven't built up a cushion to ride out the oil price plunge. Iran is counting on oil at $136 a barrel to pay for generous government spending, including big subsidies to lower the cost of consumer goods.

Among major producers, Venezuela is the worst prepared for lower oil prices, with dwindling reserves and a budget deficit of 17 percent of GDPeven before oil prices began tumbling. Anti-government protests earlier this year were sparked by rampant inflationwith consumer prices rising as much as 50 percent a yearand currency controls that have led to shortages of many consumer goods.

Read MoreVenezuela, with world's largest reserves, imports oil

But Venezuelan President Nicolas Maduro has vowed to maintain the generous government spending and social programs paid for with oil profits.

"The price of oil will hit its floor, and it will rise again," Maduro said at a news conference last month. "Venezuela will continue with its social plans ... Venezuela will move forward."