Matching Relation between HPAM Polymer DQ3500 and Pores of Reservoir Rock

The matching relation between HPAM (partially hydrolyzed polyacrylamide) polymer DQ3500 and the pores of reservoir rock was investigated using nuclepore film filtration, core flooding, and dynamic light scattering (DLS). The results indicated that when the polymer DQ3500 solution passed through nuclepore films with different pore diameters, the figure of the filtration curves, the solution viscosity and concentration before and after filtration, and the size variation of polymer molecular clews differed. Sharp changes in the shape of the solution filtration curve, concentration and viscosity of the solution and size of the polymer molecular clews occurred at a nuclepore film pore diameter of 0.6-0.7 μm, where retention of the polymer molecules began to occur. Pores less than 0.7 μm could be readily blocked by the polymer molecules, while pores larger than that showed good matching with the polymer DQ3500 without blocking. For tests with conglomerate core, cores with a gas permeability of 136×10-3 μm2 were readily blocked by the polymer molecules, while cores with a gas permeability of not less than 316×10-3 μm2 were blocking-free. It may be concluded from this study that the polymer DQ3500 has good matching only with large nuclepore film pores and large reservoir rock pores.