关键词: 数字岩心, CT扫描, 细观结构, 损伤, 砂岩

Abstract: Detection of microstructures is important for the study of sandstone damage. In this paper, CT scan tests are conducted on sandstone specimens before and after damage; pore throat analysis and finite element simulations of representative volume elements (RVEs) are conducted using digital rock core technology to quantitatively characterize the microscopic damage to sandstone and explore its mechanism. We count the pore defects of sandstone through 3D reconstruction of the sandstone microstructure from the CT scan images, obtain the effective bearing area, and compare it with elastic modulus, verifying CT images can reflect sandstone damage. The pore throat characteristic parameter of RVEs is significantly affected by damage, where the increases in the throat length and pore coordination number are two major factors contributing to microscopic damage. We interface the CT processing software Avizo with the finite element software Comsol to implement elastic modulus simulations of RVEs, proving digital rock cores can unify macroscopic and microscopic damage to sandstone.

Key words: digital rock core, CT scanning, mesoscopic structure, damage, sandstone