Viscous-Elastic Polymer Can Increase Microscale Displacement Efficiency in Cores

摘要: When flooding with viscous Polymers, due to the increase in viscosity and decrease permeability (for polymers that absorb on rock surface), mobility ratio compared water becomes more favorable. Therefore volumetric sweep efficiency increases recovery of reservoir a macro scale also. Most people think polymer does not at micro scale. But numerous results this work contradict conclusion. From cores lab, effect viscous-elastic different types residual oil after was studied. The are: 1) film surface; 2) dead ends; 3) pores throats retained by capillary forces; 4) un-swept heterogeneous portions core. It could be seen all micro-scale were reduced polymers. Due elastic nature polymer, velocity distribution are quite from Newtonian Fluids also exert very strong pulling oil. study pointed out relationship between Capillary Number Recovery for apply fluids properties. In study, it related properties fluids. Different had Some practically no elasticity. Therefore, when selecting flooding, its must considered. difference incremental can than 6 % OOIP (original place), which is substantial, make flood successful (both technically economically) or not. above conclusions confirmed pressure coring data field large (PAM) Daqing Oil Field, obtaining an 13% OOIP. This magnitude explained just efficiency. explain why some floods not; should considered and, able future floods. rheology porous media much Much needs done field. Many conclusion obtained studies need re-assessed used visco-elastic