Resistance coefficient & residual resistance factor of polymer solutions with different molecular weight and mass concentration were studied based on water flooding

polymer flooding and subsequent waterflooding tests.This paper also researched the pore structure characteristics of the cores after the polymer flooding by conventional mercury porosimetry

and analyzed the influences of polymer flooding with polymer solution of different molecular weight and mass concentration on pore structure of cores.The results show that the resistance coefficient and the residual resistance factor increase and the amplitude of permeability decline enlarges along with the increasing molecular weight and mass concentration of polymer solution.Capillary pressure curves were successively arranged from bottom left to top right

pore volume reduces at big pore throat but enlarge at smaller pore throat.The average pore radius & mean values

skewness

structure coefficient and uniformity coefficient show a decreasing trend.The above results have great significances for the research of post-polymer flooding EOR methods.