气候变化领域集成服务门户(CCPortal): Microstructure Evolution of Hydrate-Bearing Sands During Thermal Dissociation and Ensued Impacts on the Mechanical and Seepage Characteristics

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DOI	10.1029/2019JB019103
	Microstructure Evolution of Hydrate-Bearing Sands During Thermal Dissociation and Ensued Impacts on the Mechanical and Seepage Characteristics
	Wu P.; Li Y.; Liu W.; Liu Y.; Wang D.; Song Y.
发表日期	2020
ISSN	21699313
卷号	125 期号:5
英文摘要	In this study, a microfocus X-ray computed tomography-based triaxial testing apparatus was used to observe and quantify the microstructure evolution of hydrate-bearing sands during thermal dissociation of hydrate. Three triaxial shear tests with X-ray computed tomography were conducted to study the influence of hydrate dissociation on the mechanical behavior of hydrate-bearing sands. The results show that hydrate covering the sand particle surface dissociates first and then at the menisci between sand particles. The secondary hydrate formation mainly occurs on the menisci between sand particles and the surfaces of the hydrate shells where hydrates already exist. Hydrate dissociation could cause fabric changes in hydrate-bearing sands, resulting in a more isotropic orientation distribution of sand particles. The failure behavior of the hydrate-free sand specimen is similar to that of the specimen after hydrate dissociation, which shows an obvious drum-shaped failure pattern with X-shaped shear bands. However, the hydrate-bearing sand specimen exhibits a shear band with a determined thickness and inclination angle. Hydrate dissociation could cause a significant loss of supporting cementation, resulting in a decline in the stiffness and failure strength. The failure strength of hydrate-free sand specimen is slightly higher than that of the specimen after hydrate dissociation; this may due to that the homogeneous orientation frequency distribution can enhance the stability of the force chain between sand particles. The secondary hydrate formation causes sediment deformation resulting in a decrease in absolute permeability due to pore blockage. ©2020. American Geophysical Union. All Rights Reserved.
语种	英语
来源期刊	Journal of Geophysical Research: Solid Earth
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/187882
作者单位	Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education, Dalian University of Technology, Dalian, China
推荐引用方式 GB/T 7714	Wu P.,Li Y.,Liu W.,et al. Microstructure Evolution of Hydrate-Bearing Sands During Thermal Dissociation and Ensued Impacts on the Mechanical and Seepage Characteristics[J],2020,125(5).
APA	Wu P.,Li Y.,Liu W.,Liu Y.,Wang D.,&Song Y..(2020).Microstructure Evolution of Hydrate-Bearing Sands During Thermal Dissociation and Ensued Impacts on the Mechanical and Seepage Characteristics.Journal of Geophysical Research: Solid Earth,125(5).
MLA	Wu P.,et al."Microstructure Evolution of Hydrate-Bearing Sands During Thermal Dissociation and Ensued Impacts on the Mechanical and Seepage Characteristics".Journal of Geophysical Research: Solid Earth 125.5(2020).