Statement of Removal

Abstract

ABSTRACTChemical flooding is an attractive approach to improve both microscopic and macroscopic sweep efficiencies due to the synergistic effects of interfacial tension reduction and mobility control improvement. In this study, the effect of two hydrophilic silica nanoparticles with different particle sizes of 7 and 25 nm on the phase behavior of surfactant solution and rheological behavior of polymer solution was investigated. Oil recovery experiments for the formulations with high viscosity and low interfacial tension were also conducted in a quarter five-spot glass micromodel. Phase behavior tests indicated that interfacial tension decreased dramatically (0.002 mN/m) due to the presence of smaller dispersed silica nanoparticles in surfactant solution. Rheological experiments showed that larger silica nanoparticles improve the viscosity of low molecular-weight polymer solution more than 20 cP in a wide range of shear rates. Oil recovery experiments revealed that dispersed silica nanoparticles in both surfactant and polymer solutions can improve heavy oil recovery significantly.