Study On Selection, Optimization And Evaluation Methods Of Activation System For Indigenous Microorganisms

The selection and optimization of activation system is one of the pivotal technology for activation of stratal microflora recovery (ASMR). The activation system will influence on the effect of application in oil field and development foreground of ASMR.In this paper, a systematic selection and optimization method was established by combining the single factor experiment with orthogonal experiment on the basis of systematic analysis of indigenous microorganisms ecosystem. Meanwhile, an optimum activation system was obtained to active indigenous microorganism in injection water of station Kong 6. The shape of bacterium, properties of the culture medium, properties of oil and the capacity of producing gas were evaluated by means of flask cultivation experiment. The activation effect in porous media, the effect of enhanced oil recovery (EOR), the drive effect after supplying air and the effect of flooding time after time were evaluated by means of laboratory physical simulation experiment. The activation of indigenous microorganisms and startup of residual oil in porous media were oberserved visually by means of micro-imitated glass model. Furthermore, some systematic conclusions were also acquired.The results show that activation speed of indegenous microorganisms could be accelerated after adding some saccharide to the activation system as carbon source, and the sulfate reducing bacterium can be controlled by the addition of some nitrate. In the process of activating indigenous microorganism, the interfacial tension of the culture medium and viscosity of oil can be reduced, the hydrocarbon composition of oil can be changed, and also the viscosity of the culture medium can be increased, as well as the material such as acid and gas will be produced. The supply of air could promote the activation of indigenous microorganism and strengthen the effect of EOR. Within certain driving times, the activation of indigenous will become easier by the increasing of driving time. ASMR could enhance oil recovery by emulsifying the oil, generating some insoluble materials and bio-gas, and so on.