Abstract: By columnar core model,the microscopic displacement characteristics of emulsion was studied.Experimental results of emulsion flooding in different permeability cores show that how well emulsion improve displacement efficiency is related to the permeability,and emulsion particle size range is closer to pore diameter range,the higher the displacement efficiency.Droplets in emulsion play a great role in enhancing displacement efficiency,while the contribution of emulsifiers in enhancing displacement efficiency is relatively small.For intermediate permeability cores,the displacement efficiency of polymer solution and emulsion with the same viscosity is similar.

Key words: emulsion, displacement efficiency, permeability, polymer, emulsifier