Research On Profile Control And Plugging Properties Of New Expansive Resin And Rubber Microspheres

Polymer microspheres technique achieved good profile control and oil displacementeffect after applied in a nμmber of oil fields. However, there are some limitations whenapplied in middle and high permeability zone. The new resin and rubber microspheres in thisthesis are expected to broaden the range of applications. Research on synthesis andperformance evaluation made a nμmber of meaningful research results:1. Butyl acrylate is first introduced as branching monomer to synthesize new quadricpolymer and high-elastic resin microspheres. The size of microspheres always in range of afew to several hundred microns controlled by the adjustment of the synthesis parameters.Microscope and scanning electron microscopy images show that the microspheres are nearlyspherical; Rheological studies show that the new resin microspheres have certain apparentviscosity and elasticity in the different temperatures, indicating that the microspheres haveboth the "profile control" and "drive" function.2. The water-swellable rubber microspheres whose inner core is rubber and outer layergraft polyurethane are first synthesized. The microspheres size can be classified from severaltens to several hundred microns by granulation. Optical microscope and scanning electronmicroscopy images show that the microspheres are granular, not ordinary spherical;Rheological studies of rubber microspheres show that they have higher apparent viscosity andelasticity than resin microspheres in different temperatures. The rubber microspheres alsohave both the "profile control" and "drive" function.3. Research of the resin microspheres shows that they can disperse in water easilywithout suspension and have good indoor injection. The microspheres have effectiveexpansion when temperature is lower than90℃and salinity is lower than20000mg/L. Themaximμm expansion ratio is5. When the temperature rises, expansion speed of microspheresincreases and expansion multiples remain basically unchanged. When salinity rises, expansionvelocity and the largest expansion multiples of the microspheres will reduce; Pluggingexperimental studies show that microspheres have a good migration performance and theplugging rate can reach more than85%; Displacement experiments show that the resinmicrosphere can enhance oil recovery after water flooding. 4. Research of rubber microspheres shows that they have large initial particle size. Themicrospheres have worse dispersion and injection than resin microspheres, so they need to besuspended before injection; Rubber microspheres can effectively expand when temperature islower than90℃and salinity is lower than20000mg/L. Maximμm expansion ratio of rubbermicrospheres is about3, smaller than the resin microspheres. When the temperature rises,expansion speed of microspheres increases and expansion multiples remain unchanged. Whensalinity rises, expansion velocity and the largest expansion multiples of the microspheres willreduce; Indoor plugging experiments show that rubber microspheres have a good migrationperformance and the plugging rate can reach as high as93%; Displacement experiments showthat the rubber microsphere can enhance oil recovery after water flooding effectively.The new resin microspheres and rubber microspheres can effectively improve reservoirheterogeneity and have a better effect for middle-high heterogeneity reservoir. This study hasgreat significance to improve the microsphere technology series.