Integrated Assessment of CO2-Enhanced Oil Recovery and Storage Capacity

Abstract

Abstract CO2 enhanced oil recovery (EOR) has been used as a commercial process for enhancing oil recovery since the 1970s, whereas limited field applications of CO2 storage were undertaken only recently. In practice, considerable reservoir engineering design effort was made to reduce the total amount of CO2 required to recover each barrel of oil in a CO2 EOR project. For CO2 storage, however, the objective is to increase the amount of CO2 left behind at the end of the injection process; therefore, the approach to the design question changes. Consequently, optimization of CO2 EOR and CO2 storage processes differs significantly from the current CO2 injection practices. In this paper, techniques were developed to systematically assess CO2 EOR and storage capacity in a hydrocarbon reservoir selected for a demonstration project. More specifically, oil recovery was assessed and determined under miscible conditions, while CO2 storage capacity was determined by using an estimation model improved in this study. In addition, economic analysis was conducted, assuming that CO2 was captured from a chemical plant and transported 120 km to the oilfield. It is found that the geological framework is suitable for CO2 storage in the selected reservoir and that, due to a favourable CO2 miscible displacement mechanism, high oil recovery and storage capacity can be achieved, which leads the demonstration project to be economically profitable if prices of crude oil and CO2 remain above certain values.