You been holding out on us, Dog?
What the public has not really noticed to a large extent is that our domestic oil industry has figured out a way to extract reserves from shale formations in the past decade, or so.
Shales used to be avoided, drilled through and completions attempted primarily in sandstones and limestones.
The reason was clear. Shales are mud turned into stone, and while there is plenty of organic matter in them that turned into oil or gas, the formation is too closely packed ("tight") to allow the flow of the hydrocarbons from the rock into the wellbore.
Shales make great seals over the top of deeper formations which trap oil and gas and prevent it from escaping to the surface of the earth, where it naturally wants to go.
Today, with horizontal drilling, the industry can make a huge long wellbore in these shales, and then with innovative fracturing and chemical treatments of the formation, actually coax the shales into releasing the oil and/or gas into the well.
It's huge. It's not just the Bakken shales. Perhaps the hottest play right now in Texas is the Barnett Shale, which is being exploited the same way.
The great thing about these formations is that you don't have to worry about finding a localized dome or anticline which has trapped the hydrocarbons. The shale itself has trapped it because of its lack of porosity. It's hard to drill a dry hole because these shales are like a blanket covering a span of hundreds of miles.
It's not cheap to drill these horizontal wells. They cost far more than their vertical equivalents. But with a 90% chance of success or more, and the price of crude being what it is, the oil industry is going to drill the heck out of these things. They're doing it right now.