A Rapid Reconstruction Method of 3D Digital Rock with Strong Pore Connectivity

As a technique capable of replacing laboratory experiments, a large number of digital rock simulations have been widely used for the characterization of reservoir petrophysical parameters. For conditions with less coring data, rapid reconstruction of three-dimensional (3D) digital rocks using two-dimensional (2D) pore structure images is an important prerequisite for the accurate calculation of petrophysical parameters. However, the conventional digital rock rapid reconstruction method with poor pore connectivity leads to the erroneous evaluation of key reservoir rock parameters (e.g., permeability and resistivity ). In this study, we used the sequential indicator simulation method as the base data and combined the erosion operation and expansion operation in mathematical morphology to realize the rapid construction of 3D digital rock models with strong pore connectivity . The accuracy of the digital rock model reconstructed by the new method was verified by comparing with the permeability and electrical properties obtained by the CT-based method, sequential indicator simulation method, multi-point statistical method, process-based method, and deep leaning method. This study overcomes the shortcomings of the sequential indicator simulation digital rock reconstruction method in terms of small pore radius and poor pore connectivity, improves the permeability of constructing 3D digital rocks, and lays the foundation for accurate and rapid analysis of petrophysical properties.