Where the oil is: 6 huge untapped fields

Alarms about peak oil are still sounding in certain circles, but the world, for now, is still awash in petroleum.

There are many oil reserves around the globe that remain untapped, and explorers continue to discover new fields deep beneath the earth’s surface. Depending on how the controversy surrounding the Arctic National Wildlife Refuge turns out, the U.S. could exploit oil reserves in the area, despite potentially grave environmental consequences. And to the North, Canada’s tar sands are one of the largest oil reserves yet to be produced, holding the majority of the country’s 178 billion barrels of oil resources.

Elsewhere there are even more reserves, but they’re often in places that are either geologically or politically difficult to access. Some of them come with dangerous security risks to drilling.

Indeed, the oil squeeze has everything to do with access, and very little to do with the sheer volume of untapped oil left in the earth.

The U.S. gets about a third of the crude it produces from drilling in the Gulf of Mexico. U.S. offshore territory will keep producing for some time, but there are also major untapped reserves on the Mexican side of the Gulf.

They’re owned by the national oil company Petróleos Mexicanos, or PEMEX. Some of the most promising plays are northeast of Mexico City and off the coast of Campeche and onshore in the Choncotepec region.

But no one besides PEMEX can really access them. Ever since Mexico kicked out foreign oil investors in 1938, the government has controlled all exploration in the country. That’s been lucrative, since traditionally, the Mexican government has taken 60% of PEMEX’s profits. But Mexico’s oil production has slowed from near 3.4 million barrels per day in 2004 to under 2.6 million barrels per day during the beginning of 2010, squeezing those profit margins.

Mexico is starting to change the rules, but slowly. The country started offering incentives for foreign explorers and drillers to extract more oil out of its mature fields. In 2012, Mexico is expected to open up some of its newer plays to foreigners.

But while there’s probably plenty of untapped oil in Mexico, the country’s stringent rules about keeping all of the profits could still deter many of the majors.

Venezuela has a long history of oil production, but it has yet to fully exploit a huge chunk of reserves inland, in a stretch of about 20,000 square miles that follows the Orinoco River, called the Orinoco Basin.

The country estimates a substantial jump in production from the area, claiming that the Orinoco will add another 400,000 barrels per day to its production by 2016.

There’s some debate over whether they’ll make that goal — and even over how much oil Venezuela currently produces. Venezuela claims that its national oil company Petróleos de Venezuela SA produces 2.96 million barrels per day. U.S. estimates are generally lower, around 2.09 million barrels per day.

U.S. relations with Venezuela have been tense. But production in Venezuela is scheduled to ramp up soon. The country has partnered with Italian company Eni and Chinese company Sinopec to develop Orinoco. Turkey is interested in two blocks as well, and multinational giant Chevron has a 34% stake in a block of Orinoco.

Even with all those big players in the pot, Orinoco still holds much more undeveloped opportunity

Brazilian national oil companies have established themselves as global experts in offshore drilling, namely because the country has such a wealth of resources off of its own coast.

East of Rio de Janiero, Brazil’s Santos and Campos Basins contain tremendous oil reserves in something called a pre-salt layer. The oil and other petrochemicals are trapped under about two miles of salt and rock layers, which starts about a mile deep in the Atlantic Ocean.

New studies have shown that there’s probably more oil in these pre-salt plays than anyone guessed. The area could contain up to 123 billion barrels of oil, blowing away the earlier 50 billion barrel estimate from studies conducted by the Brazilian government.

Currently, Brazilian company Petrobras will legally operate all new exploration licenses in the pre-salt area, but the company plans to sell off rights to drill in portions of the region. There could be up to 60 new fields, averaging about 2.2 billion barrels each, studies estimate.