Eor Bacteria Compatibility Study Of Fermentation Performance

Microbial Enhanced Oil Recovery was a comprehensive EOR technique, which wide application, good economical returns, simple process, no pollution. The main mechanism is the use of microbes and their metabolites acting on the crude oil, thereby reduce oil viscosity and interfacial tension between oil and water in order to improve the flow of crude oil in the reservoir, finally improve the efficiency of oil displacement.In this experiment, first, strains which are presered of the laboratory and collectded Daqing Oilfield waste water samples and soil samples are screened. 10 strains of high yield of Single metabolite are obtained, do viscosity reduction of crude oil emulsion test for 10 strains. Selected 6 strains which have good effect in MEOR detection growth of strains under different temperatures, acidities, salinities.Selected no antagonistic strains to do fermentation compatibility test, obtain environmental adaptability and the viscosity reduction of crude oil capacity both good compatible of strains 2-2,S2-1,YG1-2,crude oil viscosity reduction rate of 76.80%,Temperature 35-50℃, pH 5-9, salinity range of 0.3% -3% of the strains to maintain the concentration of OD₆₀₀ > 2.0 mixed strains production of organic acid is 2.907 g / L,Lipopeptide yield 803.6mg / L.After the strain morphological, physiological and biochemical characteristics test and identification of 16SrDNA,Three strains were: 2-2 (Bacillus subtilis), S2-1 (Bacillus thuringiensis), YG1-2 (Bacillus cereus). Fermentation conditions optimized by orthogonal test, Compatibility of strains of crude oil viscosity reduction rate 83.46%, than before optimization increased 8.67%.The results show that compatibility of mixed strains on the temperature resistance, salt resistance, acid resistance and viscosity reduction of crude oil are better than single strain, have advantages of compatibility.