The Difference Between Oil Shale and Oil-Bearing Shale
People are often confused about the overall extent of U.S. oil reserves. Some claim that the U.S. has hundreds of billions or even trillions of barrels of oil waiting to be produced if bureaucrats will simply stop blocking development. In fact, in a recent debate between Republican candidates contending for Gabrielle Giffords’ recently vacated House seat, one candidate declared “We have more oil in this country than in Saudi Arabia.” So, I thought it might be a good idea to elaborate a bit on U.S. oil resources.
Oil production has been increasing in the U.S. for the past few years, primarily driven by expanding production from the Bakken Shale Formation in North Dakota and the Eagle Ford Shale in Texas. The oil that is being produced from these shale formations is sometimes improperly referred to as shale oil. But when some people speak of hundreds of billions or trillions of barrels of U.S. oil, they are most likely talking about the oil shale in the Green River Formation in Colorado, Utah, and Wyoming. Since the shale in North Dakota and Texas is producing oil, some have assumed that the Green River Formation and its roughly 2 trillion barrels of oil resources will be developed next because they think it is a similar type of resource. But it is not.
Although the oil in the Bakken and Eagle Ford is being extracted from shale formations, the term shale oil has been used for over 100 years to describe a very different resource. This has led some to confusion over the differences between current production in North Dakota and potential production in Colorado. The oil in the Bakken and Eagle Ford formations actually exists as oil, but the shale does not allow the oil to flow very well. This oil is properly called “tight oil”, and advances in hydraulic fracturing (fracking) technology have allowed some of this oil to be economically produced. (For more details, I discuss resources, reserves, fracking, shale gas, and oil shale in some detail in my new book Power Plays: Energy Options in the Age of Peak Oil).