Abstract: Gravity Assisted Gas Drive (GAGD) is a gas injection recovery method that can significantly improve oil recovery, but the micro gravity assisted gas drive mechanism for glutenite reservoirs with strong heterogeneity characteristics is still unclear. This article is based on the phase field method of tracking the dynamic changes of the two-phase interface, establishes a 2D seepage model of sand and gravel, conducts numerical simulation research on supercritical CO₂ oil two-phase flow, compares and analyzes the saturation changes under gravity, heterogeneity, and wetting effects, and establishes an empirical formula for predicting the recovery rate of glutenite GAGD considering heterogeneity. The results indicate that the presence of gravity can improve the stability of the oil and gas interface, but unstable pressure fluctuations may occur when passing through different sizes of pore throats, and leading edge displacement may occur in smaller pore throats. The heterogeneity of glutenite can exacerbate the phenomenon of GAGD fingering, and reducing the injection rate is beneficial for increasing the coverage range. The increase of oil wet gravel will help crude oil overcome capillary forces and participate in flow, allowing more residual oil in narrow pores to be discharged. Based on the correlation between gravity number, Bond number, viscosity ratio, heterogeneity coefficient, and GAGD recovery rate, a new dimensionless number NG suitable for predicting the pore scale GAGD recovery rate of glutenite reservoirs was constructed, providing theoretical guidance and technical support for the development of larger scale glutenite reservoirs and CO₂ geological storage research.