Integrated test system for interfacial strength and morphology of multi-type hydrate-bearing sediments.

Predicting the strength parameters of multi-type sediments containing hydrates is the basis and precondition for the safe and efficient development of natural gas hydrates. However, studies on the shear mechanical behavior and morphology of multi-type hydrate-bearing sediments (HBS) are still insufficient. Herein, this study presents an integrated test system that can be used to measure the interfacial strength and morphology of multi-type sediments containing hydrates. This device integrates specimen preparation, shear test, morphology observation, and data analysis, which is helpful to comprehensively evaluate interfacial strength, roughness, and morphology. The propagation and development characteristics of microfractures of HBS during shearing can be obtained, which is favorable for identifying the damage and failure modes. Preliminary validation experiments have been conducted on massive pure hydrate, hydrate-sediment interface, and homogenous HBS to verify the applicability of the device for multi-type HBS. The device and corresponding analysis method are expected to support the evaluation of interfacial strength and morphology, thereby promoting a deeper understanding of hydrate-sediment interactions and failure mechanisms of hydrate reservoirs.