针对苏北盆地断块型圈闭CO₂地质封存过程中的安全性问题，在综合考虑断层封闭性、盖层封闭性以及井筒安全性的基础上，结合理论计算、室内实验等方法，明确了相应的安全性界限。在断层封闭性方面，建立了断层连通概率模型；在盖层封闭性方面，通过实验测试明确临界压力；在井筒安全性方面，建立了老井CO₂注入的标准。在明确断层、盖层及井筒安全边界的基础上，借助数值模拟技术，进行CO₂地质封存模拟并计算封存能力。在模拟的过程中，当断层、盖层或井筒的压力状况达到安全边界时，模型停止模拟计算。通过计算模拟模型中的CO₂封存量，分析封存位置所占孔隙体积等关键参数，建立了一种针对苏北断块型圈闭CO₂地质封存能力的计算方法。采用连续注气和排水注气2种方式，对苏北某断块型圈闭CO₂地质封存能力进行了计算，结果表明：圈闭主控断层的开启压力分别为42.9、44.8 MPa，盖层的突破压力最高达到40.5 MPa，套管的破裂压力为45 MPa，连续注气和排水注气对应的封存系数分别为0.04、0.03 t/m³。在排水注气过程中，由于采水井采出一部分地层水，使得压力上升速度较连续注气更加缓慢，最终CO₂封存量更高。同时，由于排水注气方式下CO₂封存位置所占的孔隙体积出现了明显增加，使得CO₂封存系数反而比连续注气方式更小。

To address the safety concerns associated with the CO₂ geological storage process in fault-block traps of the Subei Basin, safety thresholds were systematically determined by integrating fault sealing capacity, caprock integrity, and wellbore stability through theoretical calculations and laboratory experiments. In terms of fault sealing, a fault connectivity probability model was established. For caprock integrity, the critical breakthrough pressure was determined through experimental testing. Regarding wellbore safety, standards for CO₂ injection into old wells were formulated. Based on the identified safety thresholds of faults, caprocks, and wellbores, numerical simulation techniques were used to simulate CO₂ geological storage and calculate the storage capacity. During the simulation, the model ceased computation when pressure conditions of faults, caprocks, or wellbores reached their safety thresholds. A calculation method for the CO₂ geological storage capacity in fault-block traps in the Subei Basin was established by calculating the CO₂ storage volume in the simulation model and analyzing key parameters such as the pore volume occupancy of storage locations. Two injection strategies, continuous gas injection and water-alternating-gas injection, were employed to calculate the CO₂ geological storage capacity in a specific fault-block trap in the Subei Basin. The results indicated that the opening pressures of the main controlling faults in this trap were 42.9 MPa and 44.8 MPa, respectively. The maximum breakthrough pressure of the caprock reached 40.5 MPa, and the casing failure pressure was 45 MPa. The storage coefficients were 0.04 t/m³ for continuous gas injection and 0.03 t/m³ for water-alternating-gas injection. During water-alternating-gas injection, the pressure increased more slowly than in continuous gas injection due to partial extraction of formation water by production wells, resulting in a higher final CO₂ storage capacity. However, due to a significant increase in the pore volume occupied by CO₂ under the water-alternating-gas injection strategy, the CO₂ storage coefficient was lower than that of continuous gas injection.