Investigating the mechanical behaviors of hydrate-bearing marine sediments can provide the basis for predicting the risks of silty reservoirs due to large-scale hydrate production, which are located in the South China Sea and contain huge hydrate reserves. To this end, hydrate-bearing marine sediments were remolded by the hydrate cores drilled from the South China Sea using the excess water method, and a series of triaxial tests with or without depressurization were conducted on these materials. The initial study shows that the hydrate obviously strengthens the strength and modulus of marine sediments, while the cement strength of the hydrate may depend on its cementing morphology content. No collapse occurs on this material during the depressurization even when the axial load reaches 90% peak strength of hydrate-bearing marine sediments, while serious deformations are observed and dominated mainly by the effective stress. The initial hydrate saturation plays a vital role in the deformation proportion of marine sediments induced by dissociation, while the stress also shows a certain impact during hydrate production. These results support the basic theory for hydrate production of silty reservoirs.

中文翻译：

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减压过程中南海含甲烷水合物海洋沉积物的强度和变形行为

研究含水合物海洋沉积物的力学行为可以为预测因大规模水合物生产而导致的粉质储层风险提供依据，这些储层位于南海，水合物储量巨大。为此，利用从南海钻出的水合物岩心，采用富水法改造含水合物海相沉积物，并对这些材料进行了一系列减压或不减压的三轴试验。初步研究表明，水合物明显增强了海相沉积物的强度和模量，而水合物的胶结强度可能取决于其胶结形态含量。即使轴向载荷达到含水合物海洋沉积物的 90% 峰值强度，该材料在降压过程中也不会发生坍塌，而观察到的严重变形主要由有效应力主导。初始水合物饱和度对海相沉积物解离引起的变形比例起着至关重要的作用，而应力在水合物生产过程中也表现出一定的影响。这些结果支持粉砂质储层水合物生产的基本理论。