(147g) How Much Oil and CO2? at What Cost? Bounding the Quantities of Produced Oil and Stored CO2 from CO2 EOR in Conventional Oil Fields in the United States

Carbon dioxide (CO₂) enhanced oil recovery (EOR) is a technology that uses supercritical CO₂ as a solvent to extract additional oil from a conventional oil field after oil production from primary production and secondary water flooding are no longer economical. If captured CO₂ is used in CO₂ EOR, then the CO₂ that remains in the subsurface after CO₂ EOR operations conclude is stored CO₂. There are many conventional oil fields in the United States where CO₂ EOR could be applied. The National Energy Technology Laboratory (NETL), which is part of the Office of Fossil Energy (FE) within the United States (US) Department of Energy (USDOE), has developed two models for rapidly evaluating potential oil production and CO₂ storage resulting from application of CO₂ EOR. The FE/NETL CO₂ Prophet Model is a streamline/stream tube reservoir simulator that models oil production and CO₂ storage resulting from application of CO₂ EOR. The output from the FE/NETL CO₂ Prophet Model is used as input to the FE/NETL Onshore CO₂ EOR Cost Model which is a cash flow model that estimates the profitability of the oil, water and CO₂ flows by computing all of the associated revenues, capital costs, operating costs, royalties, taxes (including federal income taxes), financing costs and, ultimately, the net present value of earnings after taxes. This model also calculates the break-even oil price that provides investors with their minimum desired return on investment for the oil field. The Energy Information Agency (EIA), which is part of USDOE, maintains a dataset of geologic and oil properties for many of the conventional oil fields in the lower 48 states in the US. After screening the oil fields in this dataset for suitability for CO₂ EOR, we exercise the models to find that approximately 40 billion barrels of oil are technically recoverable from these oil fields. At an oil price of $75/barrel, 16 billion barrels of oil are economically recoverable with roughly 9 billion tonnes of CO₂ stored. However, there is significant uncertainty associated with many of the variables used in the analysis. In this paper, ten oil fields from different regions of the US are selected and subjected to a sensitivity analysis where geologic properties and economic variables are systematically varied to illustrate how changes in these variables affect the break-even price of oil. Based on this analysis, selected variables are adjusted and applied to the entire oil field dataset to illustrate how uncertainty in these variables affects the calculated volume of oil produced and mass of CO₂ stored using CO₂ EOR at different market prices for oil.