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Geological sequestration of carbon dioxide (CO2) is an effective method to reduce greenhouse gases and an important technology for carbon neutralization. Among all geological sequestration sites, coal reservoirs are potentially effective and practicable. The Xiangzhong Depression of Hunan Province of China is selected as the research area, and the coal seam of Longtan Formation is the target reservoir in this paper. CO2‐enhanced coalbed methane (CO2‐ECBM) and CO2 sequestration capacity are both simulated according to the laboratory experiments on reservoir parameters. During simulation, four production wells and one injection well were designed, and the simulation process can be divided into two stages: CO2‐ECBM and CO2 geological storage. The CO2‐ECBM stage refers to CO2 injection for increasing methane production, and the CO2 geological storage stage aims to predict the CO2 sequestration capacity. After that, sensitivity analyses of sequestration effect are carried out. During the simulation, when maintaining a constant pressure injection of CO2 under the original conditions of 0.01 mD permeability, 9% porosity, and 1.47 MPa reservoir methane pressure, the total storage amount is only 0.14 × 106 m3. However, the storage amount increases significantly to 6.62 × 106 m3 if the permeability increases to 1.5 mD. Orthogonal simulation indicates that permeability has the greatest impact on CO2 sequestration. © 2024 Society of Chemical Industry and John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

AbstractCharacterization of pore structures and flow simulation are essential to spatial migration of coalbed methane. In this paper, coal samples from Xinjing and Xinzhuang coal mines are collected and a comprehensive characterization method by using computed tomography (CT) technique and experiments of mercury intrusion porosimetry (MIP) and scanning electron microscopy (SEM) is proposed. Pore structure parameters are finely characterized and analyzed. Moreover, the flow process for coal samples is visualized and flow characteristics are analyzed. The result shows that pore structures of coal samples are strongly heterogeneous and are dominated by micropores, and filled with kaolinite, calcium monofluorophosphate, pyrite, etc. The flow velocity increases obviously in micropores and narrow throats. The flow is greatly affected by the pore structure. This study is of practical significance for the coalbed methane recoverability evaluation and exploration. [ABSTRACT FROM AUTHOR]