Effect of Hydrate Spatial Distribution on Dynamic Permeability Evolution Using an Unstructured Hydrate-Bearing Network with Complex Pore Morphology and Anisotropy

Abstract

Hydrate spatial distribution plays an important role in dynamic permeability evolution in the development of hydrate-bearing sediments. In this work, an irregular pore network model with complex pore throat cross sections and anisotropy is first generated. Afterward, the hydrate spatial distribution is classified into four patterns and assigned to the established network in the grain-coating mode from large pores to small ones gradually. After the validation, impacts of the hydrate spatial distribution on the effective pore throat radii distribution are investigated in terms of the hydrate-bearing pore network. Furthermore, dynamic permeability evolution in different hydrate spatial distribution modes is studied in detail. Results show that the hydrate spatial distribution has a significant effect on dynamic permeability evolution by influencing the effective size distribution of pore bodies and throats. This study provides a novel insight into dynamic permeability evolution at different hydrate spatial distributions, laying a solid foundation for the efficient development of hydrate-bearing deposits.