Professor Ian Head explains. The majority of the world’s petroleum deposits are made up of heavy crude oil, which is highly viscous and cannot easily flow to production wells under normal reservoir conditions, making it difficult and costly to extract and refine.

It is generally considered to be a less valuable resource than light oil, which flows freely at room temperature, and produces a higher percentage of gasoline and diesel fuel when converted into products by an oil refinery.

Heavy oil is formed by the biodegradation of crude oil in petroleum reservoirs, but until recently, little was understood about the process. The breakthrough in our research came when we established that in-reservoir biodegradation is actually an anaerobic process driven by water-hydrocarbon reactions at an oil-water contact zone, rather than one driven by oxygen delivered in meteoric waters, as was previously believed.

New approach to finding oil wells

Our findings have overturned decades of conventional wisdom in the oil industry, and have had significant practical implications for oil production, including a whole new approach to the placement of oil wells.

As a result, oil companies are more readily able to identify and target areas of lower viscosity in biodegraded oil fields, leading to improved production from heavy oil reservoirs.

Commercial success

The impact of this research on the oil industry and related companies has been far-reaching. Using fundamental insights, models and software tools that the research generated, companies can now more accurately identify areas of greatest potential in biodegraded oil fields.

Our research led to the launch of a spin out company, Gushor Inc, by our collaborators in the University of Calgary. Gushor was recently acquired by Schlumberger, which provides services to the heavy oil sector.

Recovering energy

We are currently exploring ways to harness the microbial processes that led to heavy oil formation over geological timescales. Even the most advanced extraction processes can leave as much as 60% of oil trapped in reservoirs. By manipulating these natural processes, we hope to be able to recover the energy from this left over heavy oil and residual oil by converting it to methane gas.

Methane is more readily recovered and has the added advantage that electricity generation from methane produces about one third less CO2 per kWh than oil itself. This could be an important route to lower – though clearly not zero – emission fossil energy.

Such strategies will be important bridges from our current fossil fuel based energy economy to a future when sustainable energy generation from a range of sources becomes a reality.