Performance Evaluation Of Emulsion Polymers And Study Of Oil Displacement Effect

Suizhong 36-1 oil field reservoir temperature is an average of 65~°C,formation water salinity of 9374.1 mg/L,an average of 75 m Pa·s crude oil viscosity,strong heterogeneity,a water drive recovery factor is only 18%?20%,due to long-term water erosion,injected water formed invalid water cycle.Aiming at the development contradiction of formation heterogeneity in suizhong 36-1 oilfield,this paper studied the flooding performance of emulsion polymer.The static properties of three W/O emulsion polymers were compared and evaluated through the laboratory static experiments and the target reservoir conditions.The viscosity characteristics of emulsion polymer and polymer under different temperature,concentration,salinity and aging time were investigated.The rheological and viscoelastic properties of emulsion polymer and polymer were compared by rheological kinetics experiments.The effect of emulsion polymer in porous media was evaluated by core fluidity and oil displacement experiments.The results show that emulsion polymer is a pseudoplastic non-newtonian fluid with better viscoelasticity than polymer.In the fluidity experiment,the longer the aging time of emulsion polymer,the smaller the core permeability,and the larger the resistance coefficient and residual resistance coefficient.In the single core flooding experiment,the emulsion polymer under the same viscosity condition increased the recovery degree by4.1%and reduced the water content by 6.4%compared with the polymer.In the experiment of dual-pipe parallel core flooding with different permeability levels,the emulsion polymer has good applicability.With the increase of permeability level difference,the profile control effect becomes more obvious.In the oil displacement experiment of dual-pipe parallel cores with the same permeability grade difference,when the emulsion polymer of equal volume 0.5pv was injected into the slug,the slug combination of 0.35pv emulsion polymer and 0.15pv polymer had a better effect of precipitation and oil increase.