Optimizing CO2-Water Injection Ratio in Heterogeneous Reservoirs: Implications for CO2 Geo-Storage

作者：Emad A. Al‐Khdheeawi · 发表于：Energies · 年份：2024 · DOI：10.3390/en17030678 · 被引用次数：11 · 研究领域：CO2 Sequestration and Geologic Interactions、Hydraulic Fracturing and Reservoir Analysis、Enhanced Oil Recovery Techniques

The performance of carbon geo-sequestration is influenced by several parameters, such as the heterogeneity of the reservoir, the characteristics of the caprock, the wettability of the rock, and the salinity of the aquifer brine. Although many characteristics, like the formation geology, are fixed and cannot be altered, it is feasible to choose and manipulate other parameters in order to design an optimized storage programme such as the implementation of CO2 injection techniques, including continuous injection or water alternating CO2, which can significantly increase storage capacity and guarantee secure containment. Although WAG (water-alternating-gas) technology has been widely applied in several industrial sectors such as enhanced oil recovery (EOR) and CO2 geo-sequestration, the impact of the CO2-to-water ratio on the performance of CO2 geo-sequestration in heterogeneous formations has not been investigated. In this study, we have constructed a 3D heterogeneous reservoir model to simulate the injection of water alternating gas in deep reservoirs. We have tested several CO2-water ratios, specifically the 2:1, 1:1, and 1:2 ratios. Additionally, we have estimated the capacity of CO2 trapping, as well as the mobility and migration of CO2. Our findings indicate that injecting a low ratio of CO2 to water (specifically 1:2) resulted in a much better performance compared to situations with no water injection and high CO2-water ratios. The residual and solubility trappings were no...