An international team that includes University of Calgary scientists has shown how crude oil in oil deposits around the world including in Albertas oil sands are naturally broken down by microbes in the reservoir.
Their discovery published in the prestigious science journal Nature could revolutionize heavy oil and oil sands production by leading to more energy-efficient, environmentally friendly ways to produce this valuable resource.
Understanding how crude oil biodegrades into methane, or natural gas, opens the door to being able to recover the clean-burning methane directly from deeply buried, or in situ, oil sands deposits, says Steve Larter, U of C petroleum geologist in the Department of Geoscience who headed the Calgary contingent of the research team.
The oil sands industry would no longer have to use costly and polluting thermal, or heat-based, processes (such as injecting steam into reservoirs) to loosen the tar-like bitumen so it flows into wells and can be pumped to the surface.
The main thing is youd be recovering a much cleaner fuel, says Larter, Canada Research Chair in Petroleum Geology. Methane is, per energy unit, a much lower carbon dioxide emitter than bitumen. Also, you wouldnt need all the upgrading facilities and piping on the surface.
Biodegradation of crude oil into heavy oil in petroleum reservoirs is a problem worldwide for the petroleum industry. The natural process, caused by bacteria that consume the oil, makes the oil viscous, or thick, and contaminates it with pollutants such as sulphur. This makes recovering and refining heavy oil difficult and costly.
Some studies have suggested that biodegradation could by caused by aerobic bacteria, which use oxygen. But Larter and colleagues from the U of C, University of Newcastle in the U.K., and Norsk Hydro Oil & Energy in Norway, report in Nature that the dominant process is, in fact, fermentation. It is caused by anaerobic bacter
|Contact: Mark Lowey|
University of Calgary