CO<sub>2</sub>地质封存中随机裂隙网络走向对盖层密封性影响
摘要
In the process of CO 2 geological storage, in order to explore the influence of fracture network orientations on the twophase transport of CO 2 -salt water in the caprock and evaluate the sealing performance of the caprock, six fracture networks with different orientations (with angles of 0°-180°, 30°-150°, 45°-135°, 60°-120°, 90°-90° and 90°-180°, respectively) were selected for numerical simulation, so as to realize the two-phase flow study of CO 2 displacement of salt water under explicit fracture network.It is found that the fracture network orientations directly change the occurrence of water saturation, thereby affecting the difficulty of CO 2 -salt water displacement.When CO 2 reaches the same penetration depth in the caprock, the displacement time decreased by 12.59 times with the fracture angle (0°-60°), but there is no obvious effect after the inclination angle increased to 60°.With the expansion of the permeability range of the fracture network, the permeability of CO 2 in the caprock increases.Among them, orthogonal fractures (90°-180°) have the largest permeability.Therefore, considering the fracture network direction is of great significance for the caprock sealing evaluation. 基金项目：