基于二维裂缝扩展的二氧化碳注入砂岩透镜体封存模拟

为保证砂岩透镜体中超临界二氧化碳封存的安全性，对裂缝萌生、扩展、演化过程进行了研究。建立透镜体地质模型和数值计算模型，分析超临界二氧化碳流体在裂缝中的运移机理；利用ABAQUS数值模拟软件建立流-固耦合模型，进行裂缝扩展模拟。结果表明:在有初始裂缝时，裂缝扩展呈现出长、快、曲的趋势；在无初始裂缝时，裂缝扩展呈现出短、慢、平的趋势；在初始裂缝角度为0°、30°情况下，裂缝的宽度、面积随孔隙水压力的变化较为一致，整体上呈线性递增趋势；在初始裂缝角度为60°情况下，裂缝的扩展主要取决于初始注入点和运移通道的选择。

Simulation of CO2 injection into sandstone lens sealing based on 2D crack expansion

To ensure the safety of supercritical carbon dioxide storage in sandstone lens bodies，the initiation，propagation and evolution of cracks were studiedA lenticular geological model and a numerical calculation model were established to analyze the transport mechanism of supercritical carbon dioxide fluid in fracturesABAQUS numerical simulation software was used to establish a fluid solid coupling model for fracture propagation simulationThe results show that when there are initial cracks，the cracks appear to be long，fast，and curved，and when there are no initial cracks，the cracks appear to be short，slow，and flatIn the case of 0° and 30° initial fracture angle，the change of fracture width and area with pore water pressure is similar，showing a linear increasing trend as a whole；in the case of 60° initial fracture angle，the change of fracture expansion is complex，which mainly depends on the selection of initial injection point and migration channel in injection fractureThe results of the study should be paid attention to in the selection of carbon dioxide storage sites