Pore‐to‐Darcy Scale Stress Dependent Permeability Upscaling for Hydrate‐Bearing Sediments Using LBM‐DEM Method

Abstract This study presents a novel sequentially coupled lattice Boltzmann method (LBM) and discrete element method (DEM) framework for upscaling stress‐dependent permeability from the pore scale to the Darcy scale in heterogeneous hydrate‐bearing sediments (HBS), incorporating pore structure alterations induced by confining pressure. High‐resolution X‐ray micro‐CT is used to reconstruct digital HBS samples, which are subsequently analyzed using a voxelized multi‐sphere clump model to capture sediment grain morphology. Microscopic deformation of pore structures and pore‐scale stress dependent permeability are simulated using the developed LBM‐DEM sequential coupled model. Darcy‐scale permeability is then obtained through simulations based on the spatial distribution of pore‐scale permeability in the HBS samples. The model predictions show good agreement with experimental results, confirming the robustness of the proposed upscaling method. Comparison with established stress‐sensitive permeability model further demonstrates the applicability of the framework. This study provides new insights into stress‐dependent flow behavior in HBS while preserving the effects of pore‐scale structural heterogeneity.