Study On Oil Reservoir Microbial Strains Screening And Their Characteristics

Microbial Enhanced Oil recovery (MEOR) is a kind of enhanced oil recovery method that take advantage of the growth, reproduction and metabolism and other activities of the Microbial to take complex physical, chemical and biological reaction on solid and liquid in oil reservoir. Dingbian oil reservoir belongs to low permeability reservoirs with low porosity and low oil recovery. MEOR Provides a technological means to take a further exploitation to it.In this paper16strains of microorganisms isolated and cultivated from Dingbian oilfild wastewater and activated sludge of refinery. The four strains of microorganisms named D-1、 D-2、D-3and D-4were been identified through metabolize characteristics. The reservoir adaptability and other characteristics just like change the oil content, reduce oil-water interfacial tension,reduce pH, reduce wax content, reduce solidifying point, reduce viscosity, emulsify oil, change carbon distribution of the oil had been analyzed.The result show:four strains of microorganisms could have a better growth in the environment which temperature from45℃～55℃, pH from weak acid to alkalescence and Nacl content less than5%. When culture on45℃for5days, the fermentation liquor of D-3and D-4could low down the oil-water interfacial tension for39.1%and45.39%. Four strains could produced more organisms acid at35℃which the temperature is lower than the most appropriate temperature. They could reduce wax content, reduce solidifying point, reduce viscosity effectively when the temperature from45℃～55℃,the time from2-15d. four strains reduce solidifying point better on the oil which has the lower solidifying point,D-3and D-4reduce viscosity better on the oil which has the higher viscosity. when culture on45℃for30days to oil Ⅰ,getting an wax removal rate of49.47%、41.28%、49.58%and46.19%, reduce solidifying point for7℃,5.4℃,8.0℃and7.7℃, reduce viscosity for45.96%、38.97%、50.37%and49.26%. The emulsifying ability four strains is D-3>D-4>D-1>D-2. four strains could degrade the various components of oil. D-3and D-4could degrade saturated hydrocarbon, gum and asphaltine effectively, when culture on45℃for30days to oil Ⅰ reduce hydrocarbon for63.41%and39.34%, reduce gum for57.68%and46.45%, reduce asphaltine for34.85%and26.19%. The lightweight components of the carbon distribution of the oil Ⅰ which had treat by the strains is increased。...