Biodegradation
Biodegradation is the process that produces heavy oil and bitumen by the microbial degradation of conventional crude oils in reservoirs over geological timescales.
- Biodegradation is anaerobic in the subsurface and involves predominantly methanogenic biodegradation of oils in reservoirs.
- Oil hydrocarbons react with water to produce methane via intermediate hydrogen and carbon dioxide, as well as a residuum of heavy oil or bitumen.
- Process is mediated by a consortium of syntrophic bacteria and methanogenic archaea
- Biodegradation operates over geological timescales in oil-water transition zones, and
- Rates are controlled by thermal history of the reservoir and with a pasteurization temperature of 80?C.
