Compression behavior of hydrate-bearing sediments

AAPG Bulletin
By: , and 



This work experimentally explores porosity, compressibility, and the ratio of horizontal to vertical effective stress (K0) in hydrate-bearing sandy silts from Green Canyon Block 955 in the deep-water Gulf of Mexico. The samples have an in situ porosity of 0.38 to 0.40 and a hydrate saturation of more than 80%. The hydrate-bearing sediments are stiffer than the equivalent hydrate-free sediments; the K0 stress ratio is greater for hydrate-bearing sediments relative to the equivalent hydrate-free sediments. The porosity decreases by 0.01 to 0.02 when the hydrate is dissociated at the in situ effective stress. We interpret that the hydrate in the sediment pores is a viscoelastic material that behaves like a fluid over experimental time scales, yet it cannot escape the sediment skeleton. During compression, the hydrate bears a significant fraction of the applied vertical load and transfers this load laterally, resulting in the apparent increased stiffness and a larger apparent K0 stress ratio. When dissociation occurs, the load carried by the hydrate is transferred to the sediment skeleton, resulting in further compaction and a decrease in the lateral stress. The viewpoint that the hydrate is a trapped viscous phase provides a mechanism for how stiffness and stress ratio (K0) are greater when hydrate is present in the porous media. This study provides insight into the initial stress state of hydrate-bearing reservoirs and the geomechanical evolution of these reservoirs during production.

Study Area

Publication type Article
Publication Subtype Journal Article
Title Compression behavior of hydrate-bearing sediments
Series title AAPG Bulletin
DOI 10.1306/01132221002
Volume 106
Issue 5
Year Published 2022
Language English
Publisher American Association of Petroleum Geologists
Contributing office(s) Woods Hole Coastal and Marine Science Center
Description 26 p.
First page 1101
Last page 1126
Country United States
State Louisiana
Other Geospatial Green Canyon Block 955, Green Knoll, Gulf of Mexico
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