Digital rock mechanics: A discrete way of approaching failure

Rock mechanics modeling based on 3D μCT-generated images at pore and grain scale can be used to compute mechanical behavior. The discrete particle modeling approach provides a tool to simulate complex behavior, such as rock failure, based on relatively simple laws describing the relevant inter- and intragranular contact mechanics. In this paper, challenges in building models, calibrating the required model parameters, and analyzing the results of simulations, are described. The numerical results are compared with controlled laboratory experiments on three different sandstones. Strength at different confining pressures and the transition between dilatant and contractant behavior appears well described by the model, as does stress dependence of ultrasonic P- and S-wave velocities. Accounting properly for sub-grid features and upscaling to core scale and beyond remain challenges primarily limited by computational efficiency.