LAUSR

Abstract To decrease the unwanted water and increase oil, the influences of factors such as matching coefficient (the ratio of particle size to pore throat size), particle elasticity, seepage velocity, and particle concentration on migration and plugging of polymer microspheres (PMs) in porous media were studied. Then, particular emphasis was placed on the development of empirical correlations of resistance coefficient and blocking rate versus the factors mentioned above, which was less studied in the profile control of PMs. The results indicated that the plugging capability of PMs was notably enhanced after the matching coefficient and particle elasticity were increased to 1.2 and 10 K Pa, respectively. The resistance coefficient and blocking rate increased while reducing seepage velocity and raising particle concentration, especially the seepage velocity from 1.3 to 0.8 m/d and the particle concentration from 0.1 to 0.3 wt%. To control water production in mature waterflooded oil reservoirs with high-permeable layers, the matching coefficient, particle elasticity, and particle concentration were supposed to be at least 1.2, 10 K Pa, and 0.2 wt%, respectively, and seepage velocity should be no higher than 0.8 m/d. The obtained empirical correlations were expected to predict the profile control performance and optimize the size, elasticity, seepage velocity, and concentration of PMs.