Study on oil displacement mechanism of compound bacteria for enhancing recovery

To improve the production of Songfangtun Oilfield,the author selects three facultative anaerobic microbial strains with hydrocarbon as carbon source from Block Fang-6 of the oilfield and conducts research on the interactions between the microbial strains and crude oil,the impact microbial metabolite on crude oil properties,and the capability of the microbe in enhancing oil recovery.Research shows that the three microbial strains have approximate optimum growth temperature strains and all of them are capable of releasing biosurfactant,acid,and gas.What’s more,they can take hydrocarbon as carbon source,grow up under reservoir temperature,and make anaerobiosis.The compound bacteria composed of the three strains can degrade the saturated hydrocarbon and nonhydrocarbon in crude oil.Core test shows that the compound bacteria can greatly enhance oil recovery,improve the physical property of crude oil in porous media,and therefore decrease the viscosity,oil/water interfacial tension,pH and wax content of crude oil obviously.Test results indicate that this type of microbe can improve physical property of crude oil and has great capacity of oil displacement.