Parametric study of the physical properties of hydrate-bearing sand, silt, and clay sediments : 1. Electromagnetic properties
Lee, J. Y.
Santamarina, J. Carlos
Ruppel, Carolyn D.
MetadataShow full item record
The marked decrease in bulk electrical conductivity of sediments in the presence of gas hydrates has been used to interpret borehole electrical resistivity logs and, to a lesser extent, the results of controlled source electromagnetic surveys to constrain the spatial distribution and predicted concentration of gas hydrate in natural settings. Until now, an exhaustive laboratory data set that could be used to assess the impact of gas hydrate on the electromagnetic properties of different soils (sand, silt, and clay) at different effective stress and with different saturations of hydrate has been lacking. The laboratory results reported here are obtained using a standard geotechnical cell and the hydrate-formed tetrahydrofuran (THF), a liquid that is fully miscible in water and able to produce closely controlled saturations of hydrate from dissolved phase. Both permittivity and electrical conductivity are good indicators of the volume fraction of free water in the sediment, which is in turn dependent on hydrate saturation. Permittivity in the microwave frequency range is particularly predictive of free water content since it is barely affected by ionic concentration, pore structure, and surface conduction. Electrical conductivity (or resistivity) is less reliable for constraining water content or hydrate saturation: In addition to fluid-filled porosity, other factors, such as the ionic concentration of the pore fluid and possibly other conduction effects (e.g., surface conduction in high specific surface soils having low conductivity pore fluid), also influence electrical conductivity.
Author Posting. © American Geophysical Union, 2010. 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 115 (2010): B11104, doi:10.1029/2009JB006669.
Showing items related by title, author, creator and subject.
Dai, Sheng; Santamarina, J. Carlos; Waite, William F.; Kneafsey, Timothy J. (American Geophysical Union, 2012-11-14)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 ...
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 ...
Waite, William F.; Santamarina, J. Carlos; Cortes, Douglas D.; Dugan, Brandon; Espinoza, D. N.; Germaine, J.; Jang, J.; Jung, J. W.; Kneafsey, Timothy J.; Shin, H.; Soga, K.; Winters, William J.; Yun, T.-S. (American Geophysical Union, 2009-12-31)Methane gas hydrates, crystalline inclusion compounds formed from methane and water, are found in marine continental margin and permafrost sediments worldwide. This article reviews the current understanding of phenomena ...