Enhanced Oil Recovery using CO2 directly captured from air

To mitigate against the negative impacts of climate change, the amount of anthropogenic CO2 emission in the atmosphere should be minimized. Today, a significant volume of CO2 is utilized in enhanced oil recovery (EOR) projects. CO2 capture consumes considerable energy, which is partly compensated by the energy obtained from the produced hydrocarbons. The objective of this work is to determine exergy efficiency and carbon intensity in CO2 and foam EOR projects based on exergy analysis. The analysis is done for different EOR options, which CO2 captured directly from air. The system considers fraction of exergy investments and greenhouse gas emission in material and work streams of projects. The results show that separation of CO2 from flue gas process consumes the highest exergy investment in CO2 EOR project, in consequence, reinjection of produced gas to reservoir without separation is much preferable scenario. Compared to the CO2 injection without mobility control, injection of foam application has higher exergy demand due to surfactant injection process. However, this is compensated with the exergy obtained from the produced oil. It is shown that gained exergy is larger than invested exergy, therefore, foam project is presented with higher system efficiency. Furthermore, with the injection of surfactant and propagation of foam in reservoir, CO2 intensity of oil production is considerably reduced. The study also provides new data about probable CO2 utilization and storage ranges in the reservoir during EOR projects.