This is the main process thats occurring all over the Earth, in any oil reservoir where youve got biodegradation, Larter says.
Using a combination of microbiological studies, laboratory experiments and oilfield case studies, the 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 its possible. We can do it in the laboratory. The question is: can we do it in a reservoir"
Doing so would revolutionize the heavy oil/oil sands industry, which now manages to recover only about 17 per cent of a resource that consists of six trillion barrels worldwide. 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 biodegradation also provides an immediate tool for predicting where the less-biodegraded oil is located in reservoirs, enabling companies to increase recovery by targeting higher-quality oil. It gives us a better understanding of why the fluid properties are varying within the reservoir, Larter says. That will help us with thermal recovery processes such as SAGD (steam-assisted gravity drainage).
The research team also discovered an intermediate step in the biodegradation process. It 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
|Contact: Mark Lowey|
University of Calgary