Gas injection is one of the established methods in enhanced oil recovery. Nevertheless, poor sweep efficiency and viscous instabilities result in early gas breakthrough. Lowering injected gas mobility through foaming is a potential solution to solve the forenamed challenges. Although foaming of the injected gas has been proposed in various stages of oil production, comparatively few studies are carried out about foam injection modeling in the presence of oil. In this study, we aimed to numerically investigate the immiscible foam propagation in a thick, heterogeneous, water-flooded sandstone reservoir with a primary goal to control the surge of the produced gas–oil ratio (GOR) and also the possible incremental oil production by foam. To this end, the implicit-texture local-equilibrium foam model was used to address that how a stable foam front could affect fluid saturation and their mobility in the presence of waterflood residual oil. We treated the reservoir model by considering a pair of horizontal injection/production well through the upper and lower parts of the reservoir to mimic the foam-assisted gravity drainage scheme. Foam generation was considered through alternating (SAG) and simultaneous injection of gas and surfactant solution, and its performance was compared with continuous gas injection and water alternating gas injection. Results showed that gas-phase mobility was reduced in the presence of foam, leading to delaying of gas breakthrough and thereby improvement of gas sweep efficiency. The latter caused a significant reduction in produced gas–oil ratio, enhanced the control of the front movement, and resulted in better oil sweeping. In comparison to the SAG method, occurrence of fingering phenomena in foam co-injection was less likely. In addition, foam front in co-injection method exhibited relatively slower movement compared to the SAG method. Also, with ignoring the prescribed pressure constraint in injection well, the stability and uniformity of the generated foam front decreased, leading to more occurrences of fingering and thus reduction in oil recovery.