Application of carbon dioxide injection in shale oil reservoirs for increasing oil recovery and carbon dioxide storage

•Oil recovery was impacted significantly by the CO2 injection pressure.•The CO2 phase was found to have a strong impact on oil recovery.•CO2 adsorption in the shale was influenced by thermodynamic conditions.•Increasing the CO2 injection pressure increased the CO2 adsorption.•Cyclic CO2 injection could help increase oil recovery from shale reservoirs. Carbon dioxide (CO2) injection is an enhanced oil recovery method that has the potential to increase oil recovery from unconventional shale reservoirs while also storing a portion of the injected CO2 into the reservoir thus reducing the CO2 environmental impact. This research studies the ability of cyclic CO2 injection to increase oil recovery from shale cores and the impact of different factors on the oil recovery potential. The research then studies the ability to store the injected CO2 in the shale through adsorption and the storage capacity at different reservoir thermodynamic conditions. Oil recovery was impacted significantly by the CO2 injection pressure. The CO2 phase was also found to be a factor related to the CO2 injection pressure and also had a strong impact on oil recovery. Increasing the soaking time of the CO2 increased the oil recovery due to the increase in the interaction time between the CO2 and the crude oil. The storage potential of the CO2 in the shale was influenced significantly by the pressure and temperature. Increasing the CO2 injection pressure increased the CO2 adsorption, while increasing the temperature decreased the adsorption capacity. Based on the experiments conducted, it was found that cyclic CO2 injection could be a means of both increasing oil recovery from shale reservoirs and also for CO2 storage operations to reduce CO2 environmental impact.