Chapter 10 Biodegradation of Chemicals Used in Enhanced Oil Recovery

Publisher Summary This chapter discusses the biodegradation of chemicals used in enhanced oil recovery. In the chemical flooding category, the important processes are polymer flooding, surfactant flooding, and alkaline flooding. In the case of chemical flooding, the compounds used are subject to varying degrees of biodegradation and biodeterioration, changes that involve the activities of microbes. Various enhanced oil recovery (EOR) chemicals in each of these classes are discussed. In regard to specific compounds, most of the alcohols used as cosurfactants are biodegradable, but the degree of biodegradability may vary considerably. Tertiary butyl alcohol is much less biodegradable than primary butyl alcohol (1-butanol), as indicated by the abundance of bacteria in soils able to use these compounds as sole carbon sources. Isobutyl alcohol is very readily degraded, whereas 2-butanol, with a secondary OH group, is much less readily degraded than either 1-butanol or 2-methyl-1-propanol (isobutyl alcohol). Nevertheless, 2-butanol can be degraded. A Geotrichurn species is isolated that grew well on 2-butanol as a sole carbon-energy source.