The growing demand for fossil fuels as the dominant energy resource requires the search for new technologies for the production of hydrocarbons. Among these technologies, low salinity water flooding and nanofluid flooding of oil reservoirs have recently been extensively investigated to enhance oil recovery and more efficiently displace trapped residual oil. It was found that the use of these reagents leads to the wettability alteration of the pore walls of the rock, an interfacial tension reduction, a decrease in oil viscosity, and an increase in the disjoining pressure. This paper presents the results of studying the displacement of residual oil on homogeneous quartz sandstone using the nanofluids, obtained by peptizing the sediments in a mixture of seawater with sodium carbonate, without and with the addition of PEG8000. When using the developed nanofluids, an increase in oil production by 15–20% was achieved in comparison with seawater. A new approach for the mechanism of action of nanoparticles on the formation, leading to an increase in oil production, is proposed.