Nowadays, the oil and gas industry is considering the trends towards the implementation of nanotechnology in many enhanced techniques of hydrocarbon recovery. This trend is greatly influenced by the distinct and unique specifications and properties of nanoparticles. Nanoparticles can provide an additional ability to oversee the conditions of the hydrocarbon reservoirs, with the aim of increasing productivity and reaching satisfactory recovery percentages. Nanoparticles are considered effective to this extent due to their potential to provide an appropriate environment in order to decrease the interfacial tension and change the wettability of reservoir rocks, in addition to their capability to improve the oil mobility and their ability to advance the uniformity of the sand. This study discusses modeling and optimization of different flooding situations using organic alkaline, ethylenediamine, and nanoparticles, SiO2, at harsh reservoir conditions of high salinity. Organic alkaline solves two main problems facing inorganic alkaline like the precipitation of calcium and magnesium ions and reduction of polymer viscosity. The physical properties of the displacing fluids and crude oil are measured. The flooding runs were tested on linear sand pack unit using various slugs' concentrations. Wettability alterations were also observed by various slugs' concentrations. Design Expert software was used to generate the concentrations used in this study and determine the optimum concentrations. The results showed that the highest oil recovery was achieved by 0.7 wt. % ethylenediamine, and 0.02475wt% Nano silica.