Experimental research on polymer carrying elastic micro-spheres flooding in high permeability reservoirs

Two problems were faced when polymer flooding technology was used in complex fault-block high permeability reservoir at the stage of later water-flooding for EOR. Firstly, polymer will go along with water flooded layers with high permeability too soon; secondly, the effect of polymer flooding will decrease in ultra-high water cut stage. This paper conducted the new method of polymer carrying elastic microspheres in high porosity high permeability reservoirs, so as to increase percolation resistance, enlarge sweep volume further and enhance oil displacement efficiency. Experimental research on the physicochemical index of heat resistance, salt tolerance and thermal stability in the reservoir condition have done, which found that microspheres kept primary shape at 65 degree during 60 days; the RF and RRF of polymer carrying elastic microspheres were 1.5 and 1.2 respectively; 1500 mg/L polymer solution flooding improve oil recovery 13.5 percent compared with water flooding; 1000 mg/L polymer combined with 500 mg/L microspheres improve oil recovery 17.3 percent compared with water flooding, and the value of were only 4.8 percent and 3.8 percent respectively compared with 1000 mg/L polymer and 1500 mg/L polymer flooding individuals.