Nano-composites positively impact subsurface porous media's properties during enhanced oil 8 recovery. In this paper, γ-Al2O3/ZnO/Urea nano-composites were selected to improve 9 simultaneous water alternative associate gas tests (SWAG) based on better results in compared 10 to pure γ-Al2O3 in the static phase. According to the interfacial tension (lowest), contact angle 11 (lowest), Zeta potential (highest absolute value), and viscosity (lowest) tests in the presence of 12 nano-composites, 80 ppm was chosen as the optimum concentration (OP) to perform SWAG 13 experiments. The interfacial tension (mN m-1) and contact angle (degree) values of nano-fluids 14 at concentrations of 20, 40, 60, 80, 100, and 120 ppm were higher than alumina and were 15 (27.50, 130.12), (24.38, 80.32), (21.63, 70.98), (15.63, 40.69) (10.75, 8.50) and (6.80, 46.01) 16 mN m-1, respectively. It was evident that considering effective, efficient parameters before 17 performing the main SWAG test was important, and due to using OP, the recovery factor 18 increased from 55.9 % to 83.1 % at a constant SWAG ratio (1:1) and temperature (40 °C). 19 Furthermore, higher instant oil and lower produced water (PW) were seen as OP during the 20 nano-composites-assisted SWAG test at 80 ppm.
