Microorganisms And Polymer Researchon Low Permeability Reservoir Evaluation To Enhance Oil Recovery

Poor oil reservoir properties, low permeability, heterogeneity, andother characteristics resulted in the difficult exploitation problems ofⅢ-type oil reservoir in later high water cut stage, this thesis mainlyfocused on the difficult exploitation problems to develop the research onthe adaptability of indigenous microbial flooding combined with thepolymer flooding in Ⅲ-type oil reservoir. Three functional indigenousmicrobial strains which were biosurfactant-producing bacterium,acid-producing bacterium and anaerobic petroleum hydrocarbondegrading bacterium were screened from the Ⅲ-type oil reservoir.Bacteria properties and environmental adaptability of three functionalindigenous microbial strains were evaluated. The biosurfactant-producingbacterium B5、B24could reduce the surface tension of fermentation brothfrom59mN·m-1to30mN·m-1during48h; the anaerobic petroleumhydrocarbon degrading bacterium T′6、T′8could degrade35%of crude oilduring90d. The result of core flooding test showed that indigenousmicrobial flooding combined with the polymer flooding could enhanceoil recovery efficiency of14%.