**3. Benefits of lifecycle emissions on CO2 reduction of CO2: EOR projects**

As reported by the International Energy Agency (IEA), the hydrocarbons industry is one of the world's pioneers in the development and deployment of CO2 capture. Currently, most of the CO2 injected in CO2–EOR projects is produced from naturally occurring subsurface CO2 deposits. It is clear that the use of natural sources does not provide any advantage in the emissions degree of the oil produced. In the United States, more than 70% of the CO2 dispensed today for CO2–EOR is from natural sources [8].

Nevertheless, there are some programs that use CO2 captured from man-made sources for EOR—the Century and Petra Nova plants in Texas. These are two bigger installations, which are making the development of these projects more efficient and, thus, more profitable (**Table 1**).

Guaranteeing the integrity of CO2 storage is also essential for confirming the emissions decreases. There are some path operators, which demonstrate the permanency of CO2 storage, admitting sites with appropriate geology that gets CO2, avoiding abandoned oil wells that could create a passage for CO2 to get the surface (or checking that these are obstructed), and inserting observance and field surveillance to notice possible escape [8].

An additional potential advantage of CO2–EOR is that it offers a lower-cost opportunity to position CCUS projects.
