CO 2 -enhanced oil recovery and CO 2 capture and storage: An environmental economic trade-off analysis

CO 2 enhanced oil recovery can play a significant role in stimulating carbon capture and storage because of additional oil revenues generated. However, it also leads to additional greenhouse gas emissions. We estimate the global warming potential of different CO 2 capture scenarios with and without enhanced oil recovery. During a 10 year period in which oil and electricity are produced without CO 2 being captured, the global warming potential is 11 MtCO 2 equivalents. We show that if CO 2 is captured and used for 15 years of enhanced oil recovery, the global warming potential decreases to 3.4 MtCO 2 equivalents. This level is 100% higher compared to the scenario in which the captured CO 2 would be stored in an offshore aquifer instead. If the capture of CO 2 is stopped when the oil reservoir is depleted, the global warming potential resulting from 10 years electricity production is 6 MtCO 2 equivalents. However, if CO 2 is stored in the depleted reservoir, the global warming potential is six times lower during that period. Electricity production and oil refining are the main contributors to the global warming potential. The net present value analysis indicates that for CO 2 prices lower than or equal to 15 €/t and oil prices greater than or equal to 115 €/t, it is most profitable to capture CO 2 for enhanced oil recovery only. Because of the low CO 2 price considered, large incomes from oil production are required to stimulate CO 2 capture. The environmental economic trade-off analysis shows that if CO 2 -enhanced oil recovery is followed by CO 2 capture and storage, costs increase, but the net present value remains positive and the global warming potential is reduced. Authorities could use these outcomes to support the development of economic mechanisms for shared investments in CO 2 capture installations and to mandate both oil producer and large CO 2 emitting firms to store CO 2 in depleted oil fields.