<p>This study explores the effectiveness of CO₂ injection for enhancing methane (CH₄) recovery and its storage characteristics in low permeability gas reservoirs. Conducted under controlled conditions of 90°C and 10 MPa, experiments employed a CO₂ injection rate of 0.4 mL/min to assess displacement efficiency between dry cores and cores saturated with bound water. The results indicate that the presence of bound water significantly delays CO₂ breakthrough by approximately 0.15 PV compared to dry cores, leading to a longer transition zone as CO₂ first dissolves in the bound water before effectively displacing CH₄. In wet cores, initial effective displacement of CO₂ is minimal, resulting in a lag in CH₄ recovery rates. However, the final CH₄ recovery rate in wet cores is slightly higher than that in dry cores due to the ability of bound water to occupy smaller pores, facilitating the displacement process. Additionally, CO₂ storage efficiency is evaluated through retention rates and storage ratios. The presence of bound water enhances CO₂ retention, significantly increasing retention rates during injection. The dissolved CO₂ in formation water accounts for a substantial portion of the pore volume, indicating improved solubility at higher pressures. In conclusion, this research demonstrates that CO₂ injection not only improves CH₄ recovery but also serves as a viable method for geological CO₂ storage in gas reservoirs, with recovery rates ranging from 88.37% to 96.29% and breakthrough times between 0.62 PV and 0.88 PV.</p>