Академическое издательство «Гео»

Thermal conductivity, porous gas hydrates, dispersed species, self-preservation effect, ice



KRIOSFERA ZEMLI, 2013, Vol. XVII, № 1, p. 69-79

Experimental study of the thermal conductivity of frozen hydrate-saturated sediments at atmospheric pressure

E.M. Chuvilin, B.A. Bukhanov

Lomonosov Moscow State University, Department of Geology,
119991, Moscow, Leninskie Gory, 1, Russia; chuvilin@geol.msu.ru

This paper presents the results of experimental investigations of the thermal conductivity of artificial hydrate bearing sediment samples in the frozen state under nonequilibrium conditions. Pore hydrates in these samples have been maintained for a long time due to the manifestation of the self-preservation effect of gas hydrates at temperatures below zero. It is possible to estimate the hydrate saturation of frozen samples, to describe their structure and to carry out the identification of a number of physical characteristics (water content, density, porosity and thermal conductivity). At the same time the authors have carried out the comparative analysis of the data for the frozen hydrate-saturated samples and frozen control samples that did not contain porous methane hydrate. The experiments have demonstrated that the thermal conductivity of frozen gas hydrate samples are lower than the frozen control samples. The magnitude of the differences depends on the composition and structure of sediments and this structural feature can be tens of percent or more. With increasing hydrate saturation of samples and decreasing dispersion, these differences in values of the thermal conductivity increase. Due to self-preservation of porous gas hydrates, the thermal conductivity of frozen hydrate-saturated samples enhances in time. The obtained results demonstrate the possibility of the future use of the thermal conductivity parameter for selecting hydrate horizons in permafrost, including those in metastable state.

Thermal conductivity, porous gas hydrates, dispersed species, self-preservation effect, ice
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