Hydrate morphology : physical properties of sands with patchy hydrate saturation
Santamarina, J. Carlos
Waite, William F.
Kneafsey, Timothy J.
MetadataShow full item record
KeywordAnalytical model; Gas hydrate; Hydrate pore habit; Hydrate-bearing sediments; Numerical model; Upper and lower bounds
The physical properties of gas hydrate-bearing sediments depend on the volume fraction and spatial distribution of the hydrate phase. The host sediment grain size and the state of effective stress determine the hydrate morphology in sediments; this information can be used to significantly constrain estimates of the physical properties of hydrate-bearing sediments, including the coarse-grained sands subjected to high effective stress that are of interest as potential energy resources. Reported data and physical analyses suggest hydrate-bearing sands contain a heterogeneous, patchy hydrate distribution, whereby zones with 100% pore-space hydrate saturation are embedded in hydrate-free sand. Accounting for patchy rather than homogeneous hydrate distribution yields more tightly constrained estimates of physical properties in hydrate-bearing sands and captures observed physical-property dependencies on hydrate saturation. For example, numerical modeling results of sands with patchy saturation agree with experimental observation, showing a transition in stiffness starting near the series bound at low hydrate saturations but moving toward the parallel bound at high hydrate saturations. The hydrate-patch size itself impacts the physical properties of hydrate-bearing sediments; for example, at constant hydrate saturation, we find that conductivity (electrical, hydraulic and thermal) increases as the number of hydrate-saturated patches increases. This increase reflects the larger number of conductive flow paths that exist in specimens with many small hydrate-saturated patches in comparison to specimens in which a few large hydrate saturated patches can block flow over a significant cross-section of the specimen.
Author Posting. © American Geophysical Union, 2012. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 117 (2012): B11205, doi:10.1029/2012JB009667.
Suggested CitationArticle: Dai, Sheng, Santamarina, J. Carlos, Waite, William F., Kneafsey, Timothy J., "Hydrate morphology : physical properties of sands with patchy hydrate saturation", Journal of Geophysical Research 117 (2012): B11205, DOI:10.1029/2012JB009667, https://hdl.handle.net/1912/5635
Showing items related by title, author, creator and subject.
A 2-D tomographic model of the Juan de Fuca plate from accretion at axial seamount to subduction at the Cascadia margin from an active source ocean bottom seismometer survey Horning, Gregory W.; Canales, J. Pablo; Carbotte, Suzanne M.; Han, Shuoshuo; Carton, Helene; Nedimovic, Mladen R.; van Keken, Peter E. (John Wiley & Sons, 2016-08-14)We report results from a wide-angle controlled source seismic experiment across the Juan de Fuca plate designed to investigate the evolution of the plate from accretion at the Juan de Fuca ridge to subduction at the Cascadia ...
Lee, J. Y.; Santamarina, J. Carlos; Ruppel, Carolyn D. (American Geophysical Union, 2010-03-11)Gas hydrate formation and dissociation in sediments are accompanied by changes in the bulk volume of the sediment and can lead to changes in sediment properties, loss of integrity for boreholes, and possibly regional ...
Santamarina, J. Carlos; Dai, Sheng; Terzariol, Marco; Jang, J.; Waite, William F.; Winters, William J.; Nagao, Jiro; Yoneda, Jun; Konno, Yoshihiro; Fujii, Tetsuya; Suzuki, K. (Elsevier, 2015-03-01)Natural hydrate-bearing sediments from the Nankai Trough, offshore Japan, were studied using the Pressure Core Characterization Tools (PCCTs) to obtain geomechanical, hydrological, electrical, and biological properties ...