CEMENTITIOUS SEALING MATERIAL: 3D DIGITAL IMAGE BASED CHARACTERIZATION OF PORE SIZE DISTRIBUTION AND MODELING OF TRANSPORT PROPERTIES

摘要

Exhausted oil and gas reservoirs are one of the most potential storage facilities to sequestrate the worlds CO_2. These reservoirs are sealed with cementitious materials, that should have a long time performance. Therefore, this paper emphasizes the characterization of the evolving capillary pore network and transport properties of the cementitious microstructure used to seal the wellbore. The Hymostruc numerical model is employed to simulate the development of an evolving virtual microstructure of cementitious materials. The simulated 3D microstructures were then digitized to form a matrix of cubic voxels. The pore-size distributions of the obtained virtual microstructures were calculated using a combination of three-dimensional digital image processing algorithms: 1) distance transform and 2) medial axis thinning algorithm to obtain a 3D skeleton of the pore structure. Transport properties of the simulated microstructures are analyzed employing a finite difference 3D transport model. The modeling results are compared with available literature results.