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

Brother, can you spare a few billion dollars? Nearly six months after OPEC's eagerly anticipated deal in Algiers cut output and boosted prices, crude has held above its January 2016 low of around $37. Still, the current price per barrel near $50 is well below peaks above $100 last seen in 2014. Many OPEC nations are being deprived of needed oil revenues, and governments are scrambling to adjust to a world of cheap and abundant oil amid stagnant demand. In the face of crude's failure to rebound meaningfully, Bank of America-Merrill Lynch declared this week that crude is facing a "moment of truth," and forecasted international and U.S. crude prices will be capped near $70 this year. Separately, the International Energy Agency expects lower oil demand, even as OPEC and non-OPEC countries recently churned out nearly 97 million barrels per day. With those price ranges being far below the comfort levels of oil-producing economies starved for cash, CNBC recently canvassed experts to see which countries — formerly flush with oil money — could desperately use a reversal of fortunes in oil markets.



Angola

An oil offshore platform owned by Total Fina Elf in the surroundings waters of the Angolan coast. Martin Bureau | AFP | Getty Images

Oil production supports more than 50 percent of Angola's economic output, and accounts for about 70 percent of government revenues, according to data from the CIA's World Factbook. Weak oil prices and the dire economic situation have exacerbated long-running civil and political conflicts in the African nation: Analysts point to double-digit inflation and a shortage of currency. "Declining oil revenues have brought the country's economy to its knees and precipitated the end of the 38-year-long rule of President Jose Eduardo dos Santos," said Maja Bovcon, senior Africa analyst at Verisk Maplecroft, a risk analysis company. "Endemic corruption has emptied public coffers. Cracking down on corruption is as important as a recovery in oil prices for Angola's long-term economic health," she added.



Gabon

An off-shore oil rig, off the coast of Port-Gentil in Gabon. Justin Tallis | AFP | Getty Images

Another cash-strapped oil producer, Gabon, has all but drained its crude reserves amid a slow grind in production. Analysts say the decline in output has been happening for nearly 20 years, and is unlikely to improve in the immediate future despite an economy that grew by more than 3 percent in 2016. "Gabon is the fifth largest oil producer in Sub-Saharan Africa. The country aims to recover through economic diversification, explained Julien Marcilly, chief economist at credit insurer Coface. "It is the second largest producer of wood in Africa, and hopes to become the world's leading producer of manganese, which is used in metal alloys."



Nigeria

A girl walks on a gas pipeline running through Okrika community near Nigeria's oil hub city of Port Harcourt, Nigeria. Akintunde Akinleye | Reuters

Barely a week ago, Nigeria's ailing president Muhammadu Buhari returned after weeks of being missing in action from an economy that contracted for the first time in decades. Mounting political instability, foreign exchange shortages and terrorism have hobbled what used to be torrid growth in Africa's largest economy. "At some point, they will have to float the currency like Egypt did. President Buhari appears to be ill (how bad is anyone's guess), so there may be some policy paralysis," Win Thin, global head of foreign exchange for emerging markets at Brown Brothers Harriman. Calling the current situation "unsustainable," Thin told CNBC that "foreign investors are staying away because it's so hard to repratriate funds out. I don't think the current exchange rate is salvageable — they should float it and let it find it's true level."



Saudi Arabia

Aramco (Saudi national oil company) offshore oil rig 'Marjan 2' in the Persian Gulf. Reza | Getty Images

The wealthy Middle East oil nation is fending off a stiff challenge from resurgent U.S. oil production for the mantle of being the world's largest producer. The Saudis were the driving force behind last year's OPEC production cut deal, which hasn't served them well. Less publicized but no less important is the domestic impact of lower oil on Saudi's domestic policies. Last year, the government unveiled a plan to diversify away from its dependence on crude, with the hope of tripling its non-oil revenue by 2020. The Saudi leadership "know this situation of relying on oil revenue is unsustainable," Bernard Haykel, a Middle East expert at Princeton University, told a panel discussion at Columbia University's Center on Global Energy Policy last month. The push for reform, combined with a production cut, is being driven by the idea that "oil may not be as important in 20 to 30 years, so why not get as much money as you can right now," Haykel added.



Venezuela

Oil pumps are seen in Lake Maracaibo, in Lagunillas, Ciudad Ojeda, in the state of Zulia, Venezuela. Isaac Urrutia | Reuters