3D Digital Sedimentary Petrology Models

“Digital sedimentary petrology” models represent the microstructure of clastic rocks in 3D and use forward process models to simulate diagenesis in response to evolving burial conditions. This modeling approach predicts textures and morphologies that can be readily compared with natural samples and laboratory experiments. These models are useful tools for studying diagenetic processes and also are designed to predict rock microstructure in undrilled areas of the subsurface. Digital petrology models are natural counterparts to “digital rock physics” models that use rock microstructure as input when simulating a broad array of fluid transport and geomechanical properties. Linking these models extends digital rock physics models beyond assessment of rock properties based on scans of physical samples to predicting rock properties in undrilled portions of the subsurface. Applications of this coupled modeling approach includes hydrocarbon and geothermal energy exploration and production, CO2 sequestration, hydrogen and compressed air storage, wastewater injection, and groundwater studies. Our work to date on the development of the Cyberstone™ digital sedimentary petrology model involves simulation of sediment deposition, grain rearrangement, mechanical compaction, chemical compaction (pressure solution as well as temperature dependent contact dissolution resulting from chemical corrosion), and growth of various cement types with various morphologies. Although the system was developed for clastic sedimentary rocks, we also have found it to be a useful tool for simulation of the evolution in fluid flow and geomechanical properties of evaporite rubble associated with the collapse of a chamber in a salt dome that is being used for nuclear waste disposal.