The use of renewable energy sources appears to be a panacea for combating the adverse environmental issues caused due to the unconstrained burning of fossil fuels. In particular, the unconventional extraction of geothermal energy from Abandoned Oil and Gas Wells AOGWs serves as a twofold way to deal with the leaking issues (of methane and oil) and increase the longevity of the near-depleted oil and gas wells. The porous sedimentary oil reservoirs PSORs, where AOGWs reside, due to their high dual porosity and permeability and a caprock at the top serve as the befitting storage unit of CO2 for the carbon capture and storage CCS. At the same time, the extraction of geothermal energy from the PSOR can further be conveniently used to utilize the CO2 as a working fluid, thereby serving as a means for the carbon capture, utilization, and storage (CCUS), and thus achieving the NET ZERO. This niche area, involving the use of CO2 to extract geo-thermal energy, will require a complete understanding of the interaction between the porous media (characterized by pore structure, saturation, and mineralogy) and the reservoir conditions with the varying temperature and pressure of the CO2 working fluid. Hence, this paper brings forward the amalgamation of the following main aspects: (1) the various environmental issues that are mitigated by the repurposing of AOGWs, (2) the possible use of CO2 as a working fluid for CCUS, (3) the changes that occur in porous media due to the interaction of gases with varying properties (pH, temperature, pressure, concentration).