The Research Of Nanometer Active Microsphere Oil Displacement Used For Low Permeability Reservoirs

The distribution proportion of low permeability oil reservoirs in our country is rising year by year.Improving the reservoir heterogeneity and enlarging water injection swept volume through reservoir of deep profile control to improve oil recovery.So do the research of the nanometer active microsphere oil displacement agent.Combining with the corresponding emulsifier filtering theory to prepare inverse microemulsion.By screening the composition and proportion of emulsifiers and optimizing the component of inverse microemulsion system to determine the composition of W/O reverse microemulsion.The result is: kerosene,44 wt %;quality of 3:1 ratio of Span80 / Tween80 distribution of emulsifier,17 wt %;the mass fraction of 40% aqueous solution for AM,39 wt %.Then prepare the polyacrylamide nanometer active microspheres through the inverse microemulsion polymerization experiment.Choose ammonium persulfate/sodium bisulfite as initiator and MBA as cross-linking agent.Then optimizing reaction conditions to get the results that the amount of initiator and crosslinking agent are o.15% and 0.05% of total water phase,mixing speed is 400 rpm,the most conducive to polymerization temperature of 40 ?,to be the most conducive to polymerization reaction.By evaluating the properties of nanometer active microspheres to reach the conclusion that the diameter of is around 0.1-20 microns and have good sphericity.Swelling degree concentration first increases,then decreases as the microspheres,expansion ratio is influenced by temperature and salinity.Nanometer active microspheres show good temperature resistance and good stability,with the concentration increased mechanical stability becomes bad.Evaluate the injectivity,plugging performance and oil displacement effect of nanometer active microspheres through the core experiment.The results show: the plugging rate of nanometer active microsphere oil displacement agent for low permeability core is above 95%,and the increase of recovery rate is 14%-16%.The nanometer active microsphere oil displacement agen has the dual role of profile modification and oil displacement.