Microbiology of petroleum reservoirs

Abstract

Subsurface oil reservoirs are complex ecosystems comprising physiological diverse indigenous microbial communities. Those populations have been the subject of intense investigation in recent years. Their study and characterization is of great relevance to understanding the activities and roles of indigenous microorganisms in oil reservoirs, as well as the genesis and transformations of petroleum hydrocarbons. Furthermore, their study can contribute to predict or avoid detrimental effects caused by deleterious microorganisms as well as to promote the development of new and innovative technologies to enhance oil productivity and recovery efficiency from poorly performing and depleted oil fields. As microorganisms inhabiting oil reservoirs are adapted to extreme environmental conditions, they usually harbor enzymes or metabolic functions that might be of great interest for scientific and industrial applications. The current knowledge of the microbial ecology of oil fields, however, is still largely insufficient and further studies are required. This review provides a microbiological perspective of oil reservoirs, focused on the application of microorganisms to increase oil recovery from mature reservoirs as an alternative to the traditional chemical-enhanced oil-recovery methods.