Marine Methane Hydrate-Bearing Sediments: A Review of Physical-Mechanical Properties and Exploitation Technologies

Given the advancement of society and the mounting consumption of energy, the reserves of coal, oil, natural gas and other traditional fossil energies are limited and are tending to be exhausted. Although hydropower, wind power, photovoltaic, hydrogen and other new energies have achieved rapid development, their energy supply proportion is still relatively low. At present, the global energy consumption mainly depends on fossil energy. This creates an pressing need to identify a new alternative energy source moving forward. With its enormous resource base, high heating value, and low pollution characteristics, methane hydrate is considered worldwide as one of the most promising substitutes for conventional petroleum among new fossil energy sources. However, occurrence patterns of methane hydrate are diverse, and the processes of hydrate formation and dissociation tend to be highly sensitive to changes in temperature and pressure conditions. Furthermore, the mechanical behavior of methane hydrate-bearing sediments is distinctive. As hydrate saturation changes, so do key properties such as stiffness, dilation, shear strength, and cohesion, resulting in currently the mining of methane hydrate is expensive and difficult. This article will show a brief review and summary of the occurrence patterns, physical and mechanical properties, commonly used mining technologies, as well as research hotspots, thereby offering a reference for future investigations into both the physical and mechanical behavior of methane hydrate and the methods for its extraction.