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

Abstract

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.