Research On Microbial Enhanced Oil Recovery

Microbial enhanced oil recovery technology had exhibited the advantages of low cost, adaptability, simple manipulation, process safety and environmental friendship. Moreover, the technology can be employed in waterflooding reservoirs to further enhance oil recovery. This paper was primarily a fundamental theory research on microbial enhanced oil recovery (MEOR).In this paper, the metabolic pathways of six main microbial consortia in oil reservoir were studied, including:hydrocarbon oxidizing bacteria (HOB), total growth bacteria (TGB), fermentative bacteria (FMB), nitrate reducing bacteria (NRB), sulphate reducing bacteria (SRB) and methane producing bacteria (MPB). The microorganisms in oil reservoir can form a microbial ecology by nutrient-substrate transfer and exhibit diverse mechanisms on enhancing oil recovery due to their own metabolic activities and metabolites, respectively.The physical, chemical and biological factors of oil reservoir can greatly influence the the growth and metabolic activitivities of the microorganisms. Therefore, a comprehensive assessment of the impacts on microbial enhanced oil recovery by these factors was strongly recommanded prior to MEOR application.Base on the former theoretical and experimental studies, we established four typical MEOR strategies, including:HOB enhanced water-flooding, Anaerobic biogas-generation enhanced water-flooding; Biosurfactant-EPS enhanced water-flooding and Microbial profile modification method. Then the mechanisms of MEOR strategies were characterized and demonstrated according to the theoretical and experimental methods. Moreover, we also put forward the criteria of reservoir and microbial characteristics for MEOR strategies.