Polymer flooding is a well-established technique for enhancing oil recovery from reservoirs. In this study, we investigate the performance of two different polymers, Xanthan Gum, and HPAM for secondary oil recovery in the sand pack. The effects of polymer concentration and high salinity on oil recovery are studied. The polymers are characterized using various measurements and tests, including viscosity, shear rate, and interfacial tension. The sand pack flooding experiments are conducted under various conditions, including varying polymer slugs, and nano-silica (silicon dioxide SiO2) concentration. The results are analyzed to determine the optimal conditions for polymer flooding for enhanced oil recovery. The Xanthan Gum's highest oil recovery was at 1250 PPM (69.1% oil recovery) and the HPAM's highest oil recovery was at 1625 PPM (69% oil recovery) and when combined with SiO2 with a concentration of 0.02475 wt% which for Xanthan gum at 1250 PPM gave 74.875% oil recovery and for HPAM at 1625 ppm gave 72.768% oil recovery. Xanthan gum had more resistance to viscosity reduction under high salinity conditions which was not the case with HPAM and thus the xanthan gum had higher oil recovery at lower polymer concentrations.