Large Scale Tertiary CO₂ EOR in Mature Water Flooded Norwegian Oil Fields

A technical-economical model for a large-scale infrastructure combining CO₂ EOR and aquifer storage has been used to construct a scenario including 23 Norwegian Continental Shelf oil fields that have been identified as potential candidates for CO₂ flooding. In the injection scenario, 70 million tonnes of CO₂ is injected annually over 40 years. A limited sensitivity analysis has been performed. The EOR potential for continuous CO₂ injection is estimated to be between 276 and 351 million Sm3. This corresponds to 5.9 and 7.6% of the oil originally in place depending on the oil price (low/high: 40/120 USD/bbl), the cost of CO₂ that the oil producers must pay for all stored CO₂ (low/high: 0/50 USD/tonne) and well costs (low/high 25/42 million USD/well). In addition to transportation costs through the main pipeline (8 USD/tonne) specific costs for aquifer deposition also applies (8 USD/tonne). CO₂ mass balance calculations show that more CO₂ is stored in the oil reservoirs during tertiary flooding compared to the CO₂ formed by combustion of the produced oil. The CO₂ footprint becomes even more negative when the CO₂ stored in aquifers is included in the calculations.