EOR by CO2 InjectiGreenhouse gasses emissions are of major worldwide concern nowadays, on top of this list comes CO2 emissions. There is a global orientation that supports any attempt to reduce carbon emissions, so investigations and research have been developed intensely in this area. One of these attempts is the injection of CO2 into an oil reservoir to increase its recovery. CO2 injection is an efficient process for increasing enhanced oil recovery (EOR) in oil reservoirs, which has been around in the oil and gas industry for about 40 years. There are some challenges that may face this technique, like finding an economic CO2 source or producer, achieving the miscibility pressure for better efficiency, oil prices, and others.