Enhanced gas recovery and storability in a high CO2 content gas reservoir

Benefits of CO2 injection into a gas-condensate reservoir were examined based on a real-field data. The observed natural gas reservoir has high content of CO2, therefore it is desirable to inject the produced CO2 back to the reservoir in order to reduce the emissions at the natural gas processing plant and possibly increase hydrocarbon production. Simulation was made as to compare hydrocarbons production with and without CO2 injection. Since the CO2 source is the reservoir itself, CO2 injection is limited by the produced gas quantities. Investments in low risk projects on already producing natural gas fields can be feasible compared to investments in completely new and high-risk/high-gain projects, as the highest storability, and additional recovery of hydrocarbon part of the gas is achieved near the end of production. As in late production periods the process can be carbon-negative, i.e., more CO2 is injected than produced, such an enhanced gas recovery scheme can be considered as an advantageous preliminary step before converting the reservoir to CO2 storage facility.