In a desertlike stretch of scrub grass and red buttes, oil companies are punching holes in the ground in search of what might be one of the biggest recent discoveries in the Americas: enough gas and oil to make a country known for beef and the tango an important energy player.

The environment is challenging, with resources trapped deep in shale rock. But technological breakthroughs coupled with a feverish quest for the next major find are unlocking the door to oil and natural gas riches here and in several other countries in the Americas not traditionally known as energy producers.

That is quickly changing the dynamics of energy geopolitics in a way that had been unforeseen just a few years ago.

From Canada to Colombia to Brazil, oil and gas production in the Western Hemisphere is booming, with the United States emerging less dependent on supplies from an unstable Middle East. Central to the new energy equation is the United States itself, which has ramped up production and is now churning out 1.7 million more barrels of oil and liquid fuel per day than in 2005.

“There are new players and drivers in the world,” said Ruben Etcheverry, chief executive of Gas and Oil of Neuquen, a state-owned energy firm that is positioning itself to develop oil and gas fields here in Patagonia. “There is a new geopolitical shift, and those countries that never provided oil and gas can now do so. For the United States, there is a glimmer of the possibility of self-sufficiency.”

Oil produced in Persian Gulf countries — notably Saudi Arabia, Iran, the United Arab Emirates, Kuwait and Iraq — will remain vital to the world’s energy picture. But what was once a seemingly unalterable truth — that American oil production would steadily fall while the United States remained heavily reliant on Middle Eastern supplies — is being turned on its head.

Since 2006, exports to the United States have fallen from all but one major member of the Organization of the Petroleum Exporting Countries, the net decline adding up to nearly 1.8 million barrels a day. Canada, Brazil and Colombia have increased exports to the United States by 700,000 barrels daily in that time and now provide nearly 3.4 million barrels a day.

Six Persian Gulf suppliers provide just 22 percent of all U.S. imports, the nonpartisan U.S. Energy Information Administration said this month. The United States’ neighbors in the Western Hemisphere, meanwhile, provide more than half — a figure that has held steady for years because, as production has fallen in the oil powers of Venezuela and Mexico, it has gone up elsewhere.

Production has risen strikingly fast in places such as the tar sands of Alberta, Canada, and the “tight” rock formations of North Dakota and Texas — basins with resources so hard to refine or reach that they were not considered economically viable until recently. Oil is gushing in once-dangerous regions of Colombia and far off the coast of Brazil, under thick salt beds thousands of feet below the surface.

A host of new discoveries or rosy prospects for large deposits also has energy companies drilling in the Chukchi Sea inside the Arctic Circle, deep in the Amazon, along a potentially huge field off South America’s northeast shoulder, and in the roiling waters around the Falkland Islands.

“A range of big possibilities for oil are opening up,” said Juan Carlos Montiel, as he directed a team from the state-controlled company YPF to drill while a whipping wind brought an autumn chill to the potentially lucrative fields here outside Añelo. “With the exploration that is being carried out, I think we will really increase the production of gas and oil.”

Because oil is a widely traded commodity, analysts say the upsurge in production in the Americas does not mean the United States will be immune to price shocks. If Iran were to close off the Strait of Hormuz, stopping tanker traffic from Middle East suppliers, a price shock wave would be felt worldwide.

But the new dynamics for the United States — an increasingly intertwined energy relationship with Canada and more reliance on Brazil — mean U.S. energy supplies are more assured than before, even if oil from an important Persian Gulf supplier is temporarily halted.

The fracking ‘revolution’

Perhaps the biggest development in the worldwide realignment is how the United States went from importing 60 percent of its liquid fuels in 2005 to 45 percent last year. The economic downturn in the United States, improvements in automobile efficiency and an increasing reliance on biofuels all played a role.

But a major driver has been the use of hydraulic fracturing. By blasting water, chemicals and tiny artificial beads at high pressure into tight rock formations to make them porous, workers have increased oil production in North Dakota from a few thousand barrels a day a decade ago to nearly half a million barrels today.

Conservative estimates are that oil and natural gas produced through “fracking,” as the process is better known, could amount to 3 million barrels a day by 2020.

“We have a revolution here,” said Larry Goldstein, director of the Energy Policy Research Foundation in New York. “In 47 years in this business, I’ve never seen anything like this. This is the equivalent of a Category 5 hurricane.”

All of this has happened as exports from Mexico and Venezuela have fallen in recent years, a trend analysts attribute to mismanagement and lack of investment at the state-owned oil industries in those countries. Even so, there is a possibility that new governments in Mexico and Venezuela — Mexico elects a new president July 1, and Venezuelan President Hugo Chavez has cancer — could open the energy industry to the private investment and expertise needed to boost production, analysts say.

“There’s a lot of upside potential in Latin America that will boost the oil supply over the medium term,” said RoseAnne Franco, who analyzes exploration and production prospects in the region for the energy consultant Wood Mackenzie. “So it’s very positive.”

Political elements

Much of the exploration, though, will not be easy, cheap or, as in Argentina’s case, free of political pitfalls. Price controls on natural gas and import restrictions have made doing business in Argentina hard for energy companies. And last month, President Cristina Fernandez de Kirchner’s populist government stunned oil markets by expropriating YPF, the biggest energy company here, from Spain’s Repsol.

But the prize for energy companies is potentially huge. Repsol estimated this year that a cross section of the vast Dead Cow formation here in Neuquen province could hold nearly 23 billion barrels of gas and oil. That followed a U.S. Energy Information Administration report that said Argentina possibly has the third-largest shale gas resources after China and the United States.

“All the top-of-the-line companies are here,” said Guillermo Coco, energy minister of Neuquen province, including ExxonMobil, Chevron and Royal Dutch Shell. Although only about 200 wells have been drilled, Coco said companies here talk of drilling 10,000 or more in the next 15 years.

Wells on the horizon

On a recent day here in a dusty spot called Loma La Lata, German Perez oversaw a team of 30 technicians from the Houston-based oil- services giant Schlumberger as they prepared to frack a well.

The operation was huge: Trucks lined up with revving generators. Giant containers brimmed with water. Hoses used for firing chemicals into wells littered the ground. Cranes hoisted huge bags of artificial sand into mixers. Then, 1,200-horsepower pumps blasted water, chemicals and sand nearly 9,000 feet into the earth. “This is a hard rock, so we create countless cracks and fissures, for the gas and oil to flow,” Perez said.

Staring at the stark landscape, broken up here and there by oil rigs, Perez said he thought many companies would one day arrive in search of oil and gas. “The projections are pretty good,” he said. “In our case, we have been here a year and a half and we have tripled the equipment we have. And we think we will double that in another year.”