Microbe-enhanced heavy oil recovery technology
Some thoughts and references on MEOR.
In recent years, Microbe-Enhanced Oil Recovery Technology (MEOR) has entered a new development period and has had limited success in some countries. The two primary microbes used in MEOR are brevibacillus brevis and bacillus cereus. Some oil reservoirs naturally contain a lot of bacteria - in other cases bacteria can be injected into the reservoir. Nutrients such as molasses, ammonium nitrate, nitrogen, oxygen, and phosphorus are put into the reservoir. These feed the bacteria, which in turn grow, producing gases that increase reservoir pressure and degrade the heavy oil which acts to increase recovery by reducing oil viscosity.
An example of naturally occurring bacteria was highlighted in the recent article: http://www.dailyindia.com/show/142053.php/New-bacteria-discovered-in-tar-pits
According to the article, researchers from the University of California-Riverside reported a new species of bacteria that have the ability to survive and grow in heavy oil and natural asphalt and might have future application for heavy oil MEOR.
I also found the paper SPE 63229-MS, Reservoir Engineering Analysis of Microbial Enhanced Oil Recovery, to be a good reference on MEOR if you want to explore the topic in more depth.
While the research on MEOR mechanisms is still not adequate and the success rate is still not high enough to increase heavy oil recovery on a large scale, at today’s oil prices this is promising technology and warrants further research.
Kambiz.
