Applications of the Discrete Element Method for Gas Hydrate-Bearing Sediments: Recent Advances and Perspectives

The understanding of the mechanical properties of hydrate-bearing sediments (HBSs) is fundamental to the safe and efficient exploitation of natural gas hydrates. HBSs are granular materials composed of detrital mineral particles and hydrates. The inherent heterogeneity, discontinuity, and anisotropy cannot be effectively treated by continuum-based numerical methods. The discrete element method (DEM) has been widely used for modeling geomaterials, such as soils and rocks. Recently, it has been increasingly applied to study the mechanical properties of HBSs at the particle level. This paper presents a comprehensive review of recent advances in studies of simulating hydrate-bearing sediment models using the DEM, including complex hydratebearing models and their applications. The contact models and micromechanical parameters used in the DEM models are summarized, and the various applications, including laboratory tests, submarine landslides, and hydraulic fracturing, are discussed. In addition, the advantages and challenges for future studies are discussed. This review is beneficial to help researchers thoroughly understand the state-of-the-art DEM modeling of HBSs.