3D reconstruction of pore throat connectivity in Shale: An SAXS-MICP integrated framework

Abstract

Digital rock technology enables simulation of reservoir dynamic response under coupled multi-physical fields, providing scientific basis for optimization of development schemes through virtual experiments. However, traditional CT technology shows significant limitations in processing low-porosity samples (<5 %), with insufficient ability to accurately identify nano-scale throats, resulting in unrealistic isolated pore networks in reconstruction. Meanwhile, challenges remain in balancing resolution and field of view, as well as experimental cost and efficiency. To address these issues, this study innovatively introduces Small-Angle X-ray Scattering technology, leveraging its advantages of wide testing range, excellent sample representativeness, and ability to characterize closed pores. The research employs fast Gaussian random field method for 3D reconstruction, combines Delaunay triangulation and minimum spanning tree algorithms for network structure optimization, and integrates throat parameters obtained from mercury intrusion capillary pressure data. Finally, a low-porosity porous media model with realistic connectivity characteristics was successfully constructed, laying a solid foundation for detailed reservoir characterization and fluid transport mechanism research.