The utilization of gas enhanced oil recovery to extract oil from unconventional reservoirs has become a widely discussed topic, as it has proven to be effective in significantly boosting oil recovery rates. Among various enhanced oil recovery methods, Gas Enhanced Oil Recovery (GEOR) is a frequently implemented approach. However, a significant challenge encountered during the process of injecting Carbon Dioxide (CO2) or Nitrogen (N2) to displace oil is the occurrence of asphaltene precipitation and deposition, which can impede production. This work is an experimental study to examine the effects of cyclic (huff-n-puff) CO2 or N2 processes on oil recovery performance and asphaltene deposition using Eagle Ford shale cores. The minimum miscibility pressure (MMP) was first determined for CO2 and N2, and then different injection pressures (miscible and immiscible) were chosen to carry out CO2 and N2 huff-n-puff tests. Miscible and immiscible pressures were selected to implement the huff-n-puff test for CO2 and N2. Pore size distribution was analyzed to highlight the impact of asphaltene particles on pore plugging.