We are in the midst of an energy revolution. 

Thanks to new applications of technologies like hydraulic fracturing and horizontal drilling, billions of previously unexploitable barrels of oil are now being pulled out of shale beds across the county. And given the scale of this development, the American tight-energy bonanza has created fortunes for investors. 

It should be no surprise, therefore, that an opportunity this big has attracted the attention of the world's smartest investors. Over the past several quarters, billionaire hedge fund manager George Soros has been steadily increasing his position in several American energy producers. Which names is he buying specifically? Let's take a look. 

America's largest oil discovery since Prudhoe Bay
Pioneer Natural Resources (PXD) is one of the country's largest independent oil and gas companies and has been a Soros favorite for many years. The company has been on the front lines of America's energy boom, boasting a great set of assets in the Texas Eagle Ford and Barnett Shale. 

But what makes Pioneer truly exciting are the company's assets in the West Texas Spraberry Wolfcamp. Early drilling results have been impressive, with new wells posting 24-hour initial production rates between 800 barrels per day and 1,700 bpd. And in some parts of the field, the pay zone is up to 3,500 feet thick -- that's like having six Eagle Fords or eight Bakkens stacked on top of one another.

According to Pioneer's estimates, the Spraberry could contain 50 billion barrels of recoverable crude oil. If accurate, that would make the Wolfcamp the largest oil field ever discovered, seconded in size only to Saudi Arabia's Ghawar.

Is this company sitting on North America's next big shale field?
Noble Energy (NBL) could be sitting on the next great American shale play: the Colorado Niobrara. The field may have piqued Soros' interests. Last quarter the hedge fund manager initiated a new position in the company by purchasing $26.6 million in call options.

If there's one thing we know about Niobrara, it's that it's oil rich. According to estimates by the Colorado Oil and Gas Conservation, the field could contain 3.6 billion barrels of recoverable oil. And per drilling-spacing unit the play has almost 60 million barrels of oil in place -- that's about twice that of the Bakken.

Noble is one of the largest players in the region, with a leasehold on about 640,000 thousand acres. The company is rapidly accelerating its development program in the area. The company's drilling 50% more wells this year than in 2013 and management plans to be putting up 500 wells per year by 2016.

In addition to the Niobrara, Noble also has a great set of offshore assets in the Gulf of Mexico, West Africa, Cyprus, and Israel. The company is looking to double its production in five years as these new projects really start to ramp up. Combined with a discount valuation and an endorsement from Soros, this stock could be a breakout performer in 2014. 

This company is a cash machine
America isn't the only investment opportunity in the energy industry. Soros is also looking north of the border. Last quarter he initiated a new position in Canadian oil sands behemoth Suncor Energy (SU 1.00%).

There are plenty of reasons to be optimistic on the company. Management projects production to grow 15% in 2014. And through steady improvements in operational efficiencies, the company is also cutting the cost it pays to extract every barrel. Gains on both the top and bottom lines provide plenty of drivers for cash flow growth.

Suncor is also committed to rewarding shareholders. Since new CEO Steve Williams took the helm at the company in late 2011, Suncor has more than doubled the size of its dividend and repurchased more than $3.8 billion in stock. Expect that payout to rise in-line with the company's cash flow and earnings in the upcoming years.

Foolish bottom line
It never hurts to peek over the shoulder of the world's greatest investors. The fact that a legendary investor like George Soros is betting heavily on America's energy revolution certainly gives the development a lot of credibly. This is certainly an industry investors should put on their watchlist.