Thermal conductivity of hydrate-bearing sediments
Cortes, Douglas D.
Martin, Ana I.
Yun, Tae Sup
Francisca, Franco M.
Santamarina, J. Carlos
Ruppel, Carolyn D.
MetadataShow full item record
A thorough understanding of the thermal conductivity of hydrate-bearing sediments is necessary for evaluating phase transformation processes that would accompany energy production from gas hydrate deposits and for estimating regional heat flow based on the observed depth to the base of the gas hydrate stability zone. The coexistence of multiple phases (gas hydrate, liquid and gas pore fill, and solid sediment grains) and their complex spatial arrangement hinder the a priori prediction of the thermal conductivity of hydrate-bearing sediments. Previous studies have been unable to capture the full parameter space covered by variations in grain size, specific surface, degree of saturation, nature of pore filling material, and effective stress for hydrate-bearing samples. Here we report on systematic measurements of the thermal conductivity of air dry, water- and tetrohydrofuran (THF)-saturated, and THF hydrate–saturated sand and clay samples at vertical effective stress of 0.05 to 1 MPa (corresponding to depths as great as 100 m below seafloor). Results reveal that the bulk thermal conductivity of the samples in every case reflects a complex interplay among particle size, effective stress, porosity, and fluid-versus-hydrate filled pore spaces. The thermal conductivity of THF hydrate–bearing soils increases upon hydrate formation although the thermal conductivities of THF solution and THF hydrate are almost the same. Several mechanisms can contribute to this effect including cryogenic suction during hydrate crystal growth and the ensuing porosity reduction in the surrounding sediment, increased mean effective stress due to hydrate formation under zero lateral strain conditions, and decreased interface thermal impedance as grain-liquid interfaces are transformed into grain-hydrate interfaces.
Author Posting. © American Geophysical Union, 2009. 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 114 (2009): B11103, doi:10.1029/2008JB006235.
Suggested CitationArticle: Cortes, Douglas D., Martin, Ana I., Yun, Tae Sup, Francisca, Franco M., Santamarina, J. Carlos, Ruppel, Carolyn D., "Thermal conductivity of hydrate-bearing sediments", Journal of Geophysical Research 114 (2009): B11103, DOI:10.1029/2008JB006235, https://hdl.handle.net/1912/3534
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 ...
Lee, Myung W.; Waite, William F. (American Geophysical Union, 2008-07-09)Relating pore-space gas hydrate saturation to sonic velocity data is important for remotely estimating gas hydrate concentration in sediment. In the present study, sonic velocities of gas hydrate–bearing sands are modeled ...
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 ...