Nanofluid flooding technology can effectively improve unconventional oil recovery,of which microscopic mechanism needs to be further investigation.In this paper,the effects of Reynolds number(Re),type of nanoparticles(NPs),concentration of nanoparticles,lipophilicity/lipophobic and surface microstructure of rock stratums on oil displacement efficiency were analyzed by molecular dynamics(MD)method.The analysis of quantum chemical calculations and weak interactions showed that the intermolecular interactions increased with increasing molecular polarity index(MPI).Crude oil molecules were easily displaced by incoming flow at high MPI values,while crude oil molecules were easily adsorbed by rock stratums at low MPI values.Also,the attractive interactions between the oil droplets and the gold plates were more obvious without additional oil displacement agent.According to the total interactions,the oil displacement efficiency was the higher under the conditions of larger Re,CAAL,higher CAAL concentration,stronger rock stratum lipophobic and smaller rock stratum surface defect.The results of this work will be potentially valuable for improving the oil displacement technology,enhancing the oil displacement efficiency and improving the quality of produced crude oil.
维普
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