Using homogeneous and heterogeneous models, gas flooding and WAG flooding experiments were carried out to research the effects of injection patterns on gas flooding in different heterogeneity models. The results show that continuous gas displacement and the WAG displacement after water flooding in the homogeneous models can enhanced the oil displacement efficiency by 15.8% and 14.9% respectively, and gas injection patterns do not affect gas flooding enormously. In heterogeneous models, the oil recovery of WAG、continuous gas injection、intermittent gas injection and periodic gas injection are 78%、41.9%、32.2% and 42.3% respectively, and the WAG have the highest oil recovery, which meanings that the gas injection patterns do affect the gas flooding enormously in heterogeneous models. In homogeneous models, water slug is the main medium to displace the residual oil for the WAG after gas flooding, but in the heterogeneous models it is mainly the gas slug that displaces the residual oil for the WAG after gas flooding.