Laboratory Experiment on Inaccessible Pore Volume of Polymer Flooding

The research on inaccessible pore volume is completed on the basis of laboratory experiments. The experiment prepared 4 different kinds of polymers, whose molecular weight are 8 million, 12 million, 16 million and 20 million whose molecular coil size are measured by light blockage counter. Through kerosene mass method we can get pore cumulative distribution of field cores and finally plot the relation between the inaccessible pore volume and molecular coil size of polymer. The size of small pore where primary water was taken as the minimum number polymer coils can be passed. Then the polymer molecular weight with better compatibility with rock pores is optimized. The study shows with the increase of polymer relative molecular mass, pore volume increased linearly. The conclusion can better guide the selection of the polymers in practical production.