Optimizing the development plan for oil production and CO2 storage in target oil reservoir

Abstract

Carbon dioxide enhanced oil recovery (CO₂-EOR) technology is used for oil production and CO₂ storage in reservoirs. Methods are being constantly developed to optimize oil recovery and CO₂ storage during the CO₂ displacement process, especially for low-permeability reservoirs under varying geological conditions. In this study, long-core experiments and trans-scale numerical simulations are employed to examine the characteristics of oil production and CO₂ storage. Optimal production parameters for the target reservoir are also proposed. The results indicate that maintaining the pressure at 1.04 to 1.10 times the minimum miscible pressure (MMP) and increasing the injection rate can enhance oil production in the early stage of reservoir development. In contrast, reducing the injection rate at the later stages prevents CO₂ channeling, thus improving oil recovery and CO₂ storage efficiency. A solution-doubling factor is introduced to modify the calculation method for CO₂ storage, increasing its accuracy to approximately 90 %. Before CO₂ breakthrough, prioritizing oil production is recommended to maximize the economic benefits of this process. In the middle stage of CO₂ displacement, decreasing the injection rate optimizes the coordination between oil displacement and CO₂ storage. Further, in the late stage, reduced pressure and injection rates are required as the focus shifts to CO₂ storage.