Call it unconventional oil, tight oil, shale oil, continuous oil, you name it, but the end result is the same: the bottom of the barrel. Recent technological developments are changing the oil extraction industry dramatically and opening up oil reserves to economically viable extraction. Unequivocally, this new development will have repercussions for the environment and the development of renewable energy and a sustainable energy economy.

Hydraulic fracturing of a shale. Source: Environmental Protection Agency

Unconventional oil sources are created by the same processes as conventional oil—that is, through the combination of organic material, heat, and pressure. The main difference between the two is their ability to move underground. Conventional oil migrates upward due to its buoyancy. This oil moves through pathways in the underground rock in its fluid state and becomes trapped between impermeable layers of rock.

Unconventional oil, meanwhile, is formed in sealed spaces of rock and is not able to move up; it therefore remains in the source rock, trapped in unconnected pores. The development of new technologies such as hydraulic fracturing(or “fracking”), which is used to break up the porous rock in order to connect these micropores, is making the extraction of unconventional oil technologically possible and economically viable.

To put such advances into perspective, the amount of recoverable oil from the Bakken Reserve in the U.S. states of North Dakota and Montana increased 25-fold (an additional 3 to 4.3 billion barrels of oil) from the 1995 estimate, becoming the largest oil accumulation in the lower 48 states and accounting for 7 percent of the total U.S. onshore oil production. Other technically accessible shale oil resources in the United States include the Eagle Ford formation in South Texas and the Avalon and Bone Springs formations in southeast New Mexico and West Texas.

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Bakken, fracking, Fuel Quality Directive, greenhouse gas emissions, hydraulic fracturing, life-cycle analysis, Low Carbon Fuel Standards, shale oil, tight oil, Unconventional oil