A Fully Coupled Thermomechanical Analysis of Methane Hydrate Bearing Sediments Based on Bond-Based Peridynamics Theory

The extraction of methane gas from methane hydrate bearing sediments (MHBS) in deep subsea and permafrost regions involves a multi-physics field coupling process. In numerous studies, this has been used to simulate and predict engineering problems such as formation compaction, sand production, and wellbore failures caused by improper production. There are many physical phenomena that have non-local effects. Those models do not consider non-local effects when analyzing heat convection between layers, local deformation caused by compaction, and stress relaxation caused by damage to the bonded structure. Thus, this study is a preliminary attempt to introduce peridynamics into MHBS research. peridynamics is increasingly used because of its superior capacity to simulate dynamic fracture propagation and branching. This has significant application potential in the field of MHBS (i.e. saturated/partially saturated geomaterials) development and application. This study presents a fully coupled bond-based peridynamic (PD) model for MHBS. The formulation includes coupling of both thermal and mechanical fields. The model is fully coupled in the sense that the formulation includes coupling of both thermal and mechanical fields, and the governing equations describing the evolution of deformation, damage, and temperature are in the form of coupled partial differential equations (PDEs). A C++ program is used to verify the model. By contrasting the computed results with test data and other simulation results, the performance of the newly generated code was evaluated. The comparison of the numerical simulation results and the measured results demonstrated how the model can essentially reflect the physical field evolution characteristics in the coupling process of MHBS.