Turning tar sands into natural gas with bacteria
By Dennis T. Avery
Scientists said recently in the journal Nature they can radically speed up the underground bacterial fermentation that turns Canada's tar-like Athabasca sands into natural gas at far less cost and with far less environmental pollution. This is huge global news because the world has about six trillion barrels of such heavy oil, more than 20 times the proven oil reserves in Saudi Arabia. They're focused in Canada's Athabasca, in Venezuela's Orinoco tar belt, and in the oil shale of the U.S. Rocky Mountains. All may be economically recoverable with bacterial refining.
Dr. Steve Larter of the University of Calgary says understanding how anaerobic bacteria ferment heavy oil into clean-burning methane underground opens the door to recovering the gas from deeply buried oil sands. "The main thing is you'd be recovering a much cleaner fuel," he says. "Methane is, per energy unit, a much lower carbon dioxide emitter than bitumen."
A separate family of microbes that produces CO2 and hydrogen from partly-degraded oil offers a way to capture the CO2 from the tar sands as methane, for burning in a closed-loop system would keep the CO2 out of the atmosphere.
Larter's research team combined microbiological studies, lab experiments and oilfield case studies to demonstrate the anaerobic degradation of oil into methane. The findings offer the potential of "feeding" the microbes and rapidly accelerating the gas production process. Says Larter, "Instead of 10 million years, we want to do it in 10 years. We think it's possible. We can do it in the laboratory. The question is can we do it in a reservoir? "
No longer would huge diesel shovels have to dig up three tons of sand for each ton of heavy oil recovered. Nor would refiners inject expensive steam to liquefy the heavy oil so it can flow to the surface. With bacterial refining, the tar, and the contaminating sulfur, can be left deep underground—along with most of the sand.
The oil-eating bacteria have been used for some years to clean up contaminated soils and lagoons near oil refiners. Lab results have been encouraging, and the team expects to do field tests as early as 2009.
At almost the same moment, a Penn State professor said drilling newly-feasible horizontal gas wells across the Marcellus black shale in northern Appalachia could earn the U.S. a trillion dollars worth of additional clean-burning energy. The rock deposits run from southern New York westward through Pennsylvania into West Virginia and Ohio.
Dr. Terry Engelder says the vertical fractures in the Marcellus shale can't effectively be tapped with vertical wells. A horizontal well costs three times as much, but can collect gas from dozens of the fractures. He says the horizontal wells could bring in 50 trillion cubic feet of gas, the equivalent of a Super Giant gas field.
Eco-activists have been telling us we must renounce fossil fuels because "they're nearly gone anyway." However, the U.S. has centuries worth of coal that could be burned in "clean" high-tech systems. Bacterial refining and Dr. Engelder's horizontal drilling provides other examples of high-tech energy. Cambridge Energy Research Associates
Dennis T. Avery is a senior fellow for the Hudson Institute in Washington, DC and is the Director for the Center for Global Food Issues. (www.cgfi.org) He was formerly a senior analyst for the Department of State. He is the co-author of Unstoppable Global Warming Every 1500 Hundred years. Readers may write him at PO Box 202, Churchville, VA 2442 or email to firstname.lastname@example.org.
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