The Role of Oil Shale in the Future of Hydrocarbon Production

Jeremy Boak, Yuval Bartov, and Dag Nummedal
Colorado Energy Research Institute, Colorado School of Mines, Golden, CO

Global oil shale resources comprise >2.8 trillion barrels (>2X as much oil as has been produced from conventional fields since 1859). High oil prices and increased emphasis on domestic energy development have brought unconventional hydrocarbon resources to the forefront in industrial exploration and public debate. The largest known oil shale resources in the world occur in Eocene lake sediments in western Colorado and adjacent Utah and Wyoming. Colorado oil shale resources are thick (~300 m) and very rich, with areal energy density up to 1.3 million barrels per acre, compared to Wyoming coal (500,000 bbls/acre) and Canadian oil sands (100,000 bbls/acre) and commonly thinner, less energy dense conventional oil reservoirs. Carroll (2007) suggested resources in China equal to those in Colorado at the 27^th Oil Shale Symposium. Other lake basins that preserved organic material well and were buried only to shallow depths, have potential for similarly rich oil shale.

Current production of shale oil is limited to surface processing of mined resources. New technology for production and impact mitigation suggest the time may have arrived for shale oil development, but production >1,000,000 BOPD lies well in the future. Private companies propose testing in-situ (subsurface) conversion of kerogen into light oil using downhole electrical heaters (Shell), conductively propped rock fracture networks (ExxonMobil), injection of CO₂ (Chevron) or closed loop fluid heating (EGL Resources). It is clear that surface mining and large-scale water use to produce shale oil have an uncertain future in the U. S. Oil shale production may release >100,000,000 tons annually of CO₂ apart from the burning of the resultant fuel. The future for commercial oil shale will depend on development of CO₂ capture and sequestration technology to ensure zero emissions from the production sites.

AAPG Search and Discovery Article #90078©2008 AAPG Annual Convention, San Antonio, Texas