In order to improve the effect of CO2 injection in low-permeability gas reservoir for enhanced oil recovery and buried technology, taking a sample well as an example, the experiment of CO2 injection for gas displacement was carried out. In the study, numerical simulation method was used to optimize the gas drive scheme, water drive scheme, total CO2 injection volume, injection timing, well soak system, the effect of diffusion on CO2 drive and adsorption conditions, so as to enhance CO2 injection for enhanced oil recovery in low-permeability gas reservoir. The simulation results show that CO2 rich industrial waste gas injection can improve the recovery of shale gas to a certain extent, and the gas injection volume has an impact on the recovery of shale gas and the relative adsorption capacity of waste gas. Although the recovery of shale gas has been improved to a certain extent, the ratio of adsorbed gas to total injected gas will be reduced. Therefore, the optimal injection volume is determined to be 80000 m3/day, and 0.440PV is determined as the optimal time for reinjection. The maximum recovery of shale gas can be achieved by soaking the well in January at 1.408PV for different soaking time and duration. Under different diffusion coefficients, gas reservoir production and CO2 storage have certain effects, and adsorption has little effect on CO2 injection EOR. However, with adsorption, the EOR effect of CO2 injection is 0.7% higher than that without adsorption. In terms of sequestration, CO2 breakthrough time is later when considering adsorption, indicating that more CO2 is left in the formation, which increases the stability of CO2 sequestration. The simulation results show that adsorption increases the CO2 sequestration by 17.8%, about 0.7·106t, indicating that adsorption is conducive to CO2 sequestration.
