We're in the midst on an American energy revolution. Booming production from the North Dakota Bakken and the Texas Eagle Ford have put the nation on a path toward energy independence...while lining the pockets of savvy investors in the process. However, sitting under West Texas is another shale play that could be larger than the Eagle Ford and the Bakken combined. 

This could be America's biggest oil discovery...
According to early estimates provided by Pioneer Natural Resources (PXD -0.13%), the Spraberry Wolfcamp shale play near Midland, Texas could be the largest oil field in the country and the second largest oil find in the world. The company estimates that the play contains 50 billion barrels of recoverable oil. Only the infamous Ghawar oil field of Saudi Arabia is larger. 

Source: Pioneer Natural Resources' Investor Presentation

What makes the Wolfcamp so exciting is what's called in the industry vernacular as 'stacked pay potential.' The geology in the region features several hydrocarbon-rich formations stacked one on top of the other. Think of it like a layered cake, which includes the Spraberry Shale (7,700 feet beneath the surface), the upper Wolfcamp (9,100 feet beneath the surface), the lower Wolfcamp (9,400 feet beneath the surface), and the Cline Shale (10,000 feet beneath the surface). 

These stacked plays are great for operators has it allows them to target several formations with a single vertical well. In some places the hydrocarbon producing zone is a much as 3,000 to 4,000 feet thick. That compares to a 300 foot pay zone for your typical Eagle Ford well. 

But it's not just Pioneer that's excited. In recent months, other Wolfcamp operators have posted impressive results. Last quarter Devon Energy (DVN 0.98%), which owns about 250,000 acres in the Wolfcamp, brought 19 wells on-line with initial 30-day production rates as high as 1,000 BOE/d. The company is betting big on the Permian with plans to spend $1.5 billion to develop its acreage including 300 new wells. 

Energen (EGN)is one of the smaller players in the play. In August, the stock shot up 20% after reporting impressive drilling results in the Permian Basin. Energen reported that its first operated Wolfcamp well in the Midland Basin posted an initial production of 861 BOE/d. Based on the result of this well, it appears that multiple benches of the Wolfcamp shale will have commercial potential.

Shale developments in the Spraberry Wolfcamp could also be a big boost for more conventional operators. Occidental Petroleum (OXY 0.82%) is one of the largest landholders in the region. However, unlike Pioneer and Devon, Occidental has been slower to jump on the shale bandwagon. Just under two thirds of the company's Permian production is related to enhanced oil recovery-pumping carbon dioxide into legacy oil wells to boost production. But given that Occidental holds key acreage in an area bursting at the seams with unconventional shale production, the Wolfcamp could be a hidden catalyst for the stock. 

...but don't pop the cork yet
Of course as prudent investors, we should evaluate industry claims with a certain degree of skepticism. How did Pioneer come up with that 50 billion recoverable barrel estimate? Typically oil companies take production data from existing wells and extrapolate it over the entire field. But much of the Wolfcamp hasn't been de-risked beyond a handful of core acreage, and shale production can vary wildly throughout an entire field. 

However, data from rival operators is starting to support Pioneer's initial estimate. Indeed, as exploration of the play is completed, those early reserve estimates may even be revised higher. If the Spraberry Wolfcamp can even live up to even a fraction of the hype, this could still be a very big development. 

Foolish bottom line
Will the Spraberry/Wolfcamp become America's next great shale play? It certainly has the potential. Investors should keep a close eye on the drilling results from operators as they roll in.