About This Item
- Full TextFull Text(subscription required)
- Pay-Per-View PurchasePay-Per-View
Purchase Options Explain
Share This Item
AAPG Bulletin, V.
Compression behavior of hydrate-bearing sediments
Yi Fang, 1Peter B. Flemings,2 John T. Germaine,3 Hugh Daigle,4 Stephen C. Phillips,5 and Josh O’Connell6
1Institute for Geophysics, Jackson School of Geosciences, The University of Texas at Austin, Austin, Texas; present address: Department of Geology and Geological Engineering, South Dakota School of Mines and Technology; [email protected]
2Institute for Geophysics and Department of Geological Sciences, Jackson School of Geosciences, The University of Texas at Austin, Austin, Texas; [email protected]
3Department of Civil and Environmental Engineering, Tufts University, Medford, Massachusetts; [email protected]
4Hildebrand Department of Petroleum and Geosystems Engineering, The University of Texas at Austin, Austin, Texas; [email protected]
5Institute for Geophysics, Jackson School of Geosciences, The University of Texas at Austin, Austin, Texas; present address: US Geological Survey, Woods Hole, Massachusetts, [email protected]
6Institute for Geophysics, Jackson School of Geosciences, The University of Texas at Austin, Austin, Texas; [email protected]
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.
Pay-Per-View Purchase Options
The article is available through a document delivery service. Explain these Purchase Options.
|Protected Document: $10|
|Internal PDF Document: $14|
|Open PDF Document: $24|
Members of AAPG receive access to the full AAPG Bulletin Archives as part of their membership. For more information, contact the AAPG Membership Department at [email protected].