Techno-Economic Assessment and Life Cycle Assessment of CO₂-EOR

CO₂-enhanced oil recovery (EOR) can have less GHG emissions compared to conventional oil production methods. The economy of CO₂-EOR can significantly benefit from the recent rise of carbon prices in carbon markets due to its greenhouse gas (GHG) emission savings. This study conducted a life cycle assessment (LCA) of CO₂-EOR in major hydrocarbon provinces of the world. Estimated net GHG emissions of CO₂-EOR were compared with GHG emissions of average produced oil in the given country. When sourcing CO₂ from coal-fired power plants, Kazakhstan and China have net GHG emissions of CO₂-EOR of 276 and 380 kg CO₂ eq/bbl, respectively, which are lower than the GHG emission factor of average oil produced in each of them. Significantly lower GHG emissions of CO₂-EOR are observed in other hydrocarbon provinces (Iraq, Saudi Arabia, Kuwait, etc.), where CO₂ could be delivered from Natural Gas Combined Cycle (NGCC) power plants. However, the cost of CO₂ capture is higher at NGCC power plants than at coal-fired power plants. Further, we developed a techno-economic assessment (TEA) model of the CO₂-EOR and integrated it with LCA to thoroughly consider carbon credits in its economy. The model was built based upon previous investigations and used statistics from a large industrial data set of CO₂-EOR to produce accurate estimates of the CO₂-EOR economy. The technical model iteratively estimated the balance of three fluids (crude oil, CO₂, and water) in the CO₂-EOR system with a 25 year operational lifespan and obtained actual data for the LCA and TEA models. The model was simulated for the Kazakhstan case with its oil market conditions for a demonstration purpose. TEA results showed that, with the available low-cost CO₂ capture source or high CO₂ cost in carbon trading, CO₂-EOR can compete with current upstream projects in Kazakhstan by simultaneously increasing oil production and reducing GHG emissions.