Study On Hydrodynamic Size And Injectivity Of Polymer Solution

The molecular configuration of polymer solution is influenced by many environmental factors,which will be selected by pore throat size inaflow through porous media. If most of the polymer molecule is hindered through the pore throat, it will become very difficult to inject polymer solution into the stratum. So before beginning the polymer flooding in the mine, the selection of the polymer adaptation to the formation conditions is very importantThe main content of this paper includes two aspects, which one is the study of the factors that influence the polymer hydrodynamic size and the other one is the study of the polymer injection capacity limits and injection effect.In this paper, the author reseached the hydrodynamic size of polymers of the meta system research (polymer),thebinary system (polymer+surfactant, polymer+a lkali),and the ternary system (polymer+surfactant+alkali) through the microporous membrane filter device and analyzed the influence of different factors on polymer hydrodynamic size.The author used the constant pressure displacement mode, in cylindrical artificial core of seven kinds of permeability from 29 ×10-3 μm2 to 305×10-3μm2,.There are 5 kinds of polymer concentration from 500mg/L to 2500mg/L and 7 kinds of molecular weight from 700×104 to 3000×104)in the combination experiments of polymer flow.Through the researches above, the author found that many factors such as the molecular weight, concentration, alkali,and surface active agent have distinct effect on polymer hydrodynamic size.Among them, the molecular weight and concentration are the most important factors. On the basis of injection experiments indoors, the author comes up with the reasonable polymer injectivity boundary relying on the actual data and draw and destablishes amatching relation between different types of polymers and core permeability. Combined with the actual situation,the author gave some suggestions about the selection of polymer molecular weight and concentration corresponding to the different permeability.We should choose a molecular weight of 700∑×104～1000×104 and the concentration of 500～1500 mg/L when the permeability is within the scope of in 30～100×10-3μm2,and choose a molecular weight of 1500×104～1900×104 and the concentration of 1000～2000 mg/L when the permeability is within the scope of in 100～200×10-3 μm2,and choose a molecular weight of 1900×104～2300×104 and the concentration of 1500～2000 mg/L when the permeability is within the scope of in 200～300×10-3 μm2.