Scientists develop process by which microbes break down crude oil into gas

December 13th, 2007 - 1:10 pm ICT by admin  

Washington, Dec 13 (ANI): Researchers have developed a process by which crude oil in oil deposits around the world is naturally broken down by microbes into gas.

Steve Larter, petroleum geologist in the Department of Geoscience, University of Calgary, headed the research team that developed this method.

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.

Now, using a combination of microbiological studies, laboratory experiments and oilfield case studies, the research team demonstrated the anaerobic degradation of hydrocarbons to

produce methane. The findings offer the potential of ‘feeding’ the microbes and rapidly accelerating the breaking down of the oil into methane.

“Instead of 10 million years, we want to do it 10 years,” Larter says. “We think it’s possible. We can do it in the laboratory, he added.

According to researchers, this process can revolutionize heavy oil and oil sands production by leading to more energy-efficient, environment friendly ways to produce this valuable resource. Oil sands companies would be able to recover only the clean-burning natural gas, leaving the hard-to-handle bitumen and contaminants deep underground.

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, said Steve Larter.

Using this process, the oil sands industry would benefit greatly as it 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 you’d be recovering a much cleaner fuel,” said Larter. “Methane is, per energy unit, a much lower carbon dioxide emitter than bitumen. Also, you wouldn’t need all the upgrading facilities and piping on the surface,” he added.

The research team also discovered an intermediate step in the biodegradation process, which involves a separate family of microbes that produce carbon dioxide and hydrogen from partly degraded oil, prior to it being turned into methane.

This paves the way for using the microbes to capture this CO2 as methane, which could then be recycled as fuel in a closed-loop energy system. This would keep the CO2, a greenhouse gas blamed for global warming and climate change, out of the atmosphere.

The petroleum industry already has expressed interest in trying to accelerate biodegradation in a reservoir. “It is likely there will be field tests by 2009,” said Larter. (ANI)


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