Hydrology and Earth System Sciences Discussions www.hydrol-earth-syst-sci-discuss.net 1812-2108 1812-2116 5 4 2008 10.5194/hessd-5-2409-2008 http://www.hydrol-earth-syst-sci-discuss.net/5/2409/2008/ http://www.hydrol-earth-syst-sci-discuss.net/5/2409/2008/hessd-5-2409-2008.html http://www.hydrol-earth-syst-sci-discuss.net/5/2409/2008/hessd-5-2409-2008.pdf 2409 2423 2008-08-28 Thermal conductivity of unsaturated clay-rocks D. Jougnot A. Revil arevil@mines.edu Colorado School of Mines, Green Center, Department of Geophysics, Golden, CO, USA ANDRA, Chatenay-Malabry, France CNRS-LGIT (UMR 5559), University of Savoie, Equipe Volcan, Le Bourget-du-Lac, France The thermal conductivity of porous materials can be related to the electrical conductivity and therefore electrical resistivity tomography can be used to map the thermal conductivity of porous rocks. In this paper, a relationship is developed to connect the thermal conductivity of unsaturated clay-rocks to the thermal conductivity of the different phases of the porous composite, a textural parameter called the thermal formation factor, and the tortuosity of the water phase. The thermal formation factor is related to the electrical formation factor and to the first Archie's first exponent m. The tortuosity of the water phase is related to the second Archie's exponent n and to the relative saturation of the water phase. A very good agreement is obtained between the new model and thermal conductivity measurements of packs of glass beads and cores of the Callovo-Oxfordian argillite at different saturations of the water phase. Anisotropy of the effective thermal conductivity is mainly due to the anisotropy of the thermal conductivity of the solid phase. ANDRA: Dossier 2005: référentiel du site de Meuse/Haute-Marne, Rep. C.RP.ADS.04.0022, ANDRA, Châtenay-Malabry, France, 2005. Archie, G. E.: The electrical resistivity log as an aid in determining some reservoir characteristics, T. Am. I. Min. Met. Eng., 146, 54–62, 1942. Clauser, C. and Huenges, E.: Thermal conductivity of rocks and minerals, in: Rocks physics and phase relations: a handbook of physical constants, AGU Reference Shelf 3, edited by: Ahrens, T., American Geophysical Union, Washington, DC, USA, 105–126, 1995. Cosenza, P., Guérin, R., and Tabbagh, A.: Relationship between thermal conductivity and water content of soils using numerical modelling, Eur. J. Soil Sci., 54(3), 581–588, 2003. Giraud A., Gruescu, C., Do, D. P., Homand, F., and Kondo, D.: Effective thermal conductivity of transversely isotropic media with arbitrary oriented ellipso\"ıdal inhomogeneities, Int. J. Solids Struct., 44(9), 2627–2647, 2007. Giroux, B. and Chouteau, M.: A hydrogeophysical synthetic model generator, Comput. Geosci., 34(9), 1080–1092, 2008. Gruescu, I. C., Giraud, A., Homand, F., Kondo, D., and Do, D. P.: Effective thermal conductivity of partially saturated rocks, Int. J. Solids Struct., 44, 811–833, doi:10.1016/j.ijsolstr, 2006. Homand, F.: Mesures thermiques sur le site est, Technical Report ANDRA, DRP0ENG 98-009/A, INPL-LAEGO, France, 1998. Kohout, M., Collier, A. P., and \vStepánek, F.: Effective thermal conductivity of wet particle assemblies, Int. J. Heat Mass Tran., 47, 5565–5574, 2004. Kooi, H.: Spatial variability in subsurface warming over the last three decades; insight from repeated borehole temperature measurements in the Netherlands, Earth Planet. Sc. Lett., 270(1–2), 86–94, 2008. Lesmes, D. P. and Friedman, S.: Relationships between the electrical and hydrogeological properties of rocks and soils, in: Hydrogeophysics, edited by: Rubin, Y. and Hubbard, S., Springer, New York, USA, 87–128, 2005. Linde, N., Binley, A., Tryggvason, A., Pedersen, L. B., and Revil, A.: Improved hydrogeophysical characterization using joint inversion of cross-hole electrical resistance and ground penetrating radar traveltime data, Water Resour. Res., 42, W12404, doi:10.1029/2006WR005131, 2006. Revil, A.: Thermal conductivity of unconsolidated sediments with geophysical applications, J. Geophys. Res., 105(B7), 16 749–16 768, 2000. Revil A., Leroy, P., and Titov, K.: Characterization of transport properties of argillaceous sediments. Application to the Callovo-Oxfordian Argillite, J. Geophys. Res., 110, B06202, doi:10.1029/2004JB003442, 2005. Revil A., Linde, N., Cerepi, A., Jougnot, D., Matthäi, S., and Finsterle, S.: Electrokinetic coupling in unsaturated porous media, J. Colloid Interf. Sci., 313, 315–327, doi:10.1016/j.jcis.2007.03.037, 2007. Schwartz, L .M. and Kimminau, S.: Analysis of electrical conduction in the grain consolidated model, Geophysics, 52, 1402–1411, 1987. Woodside, W., and Messmer, J. H.: Thermal conductivity of porous media, I. Unconsolidated sands, J. Appl. Phys., 32, 1688–1699, 1961.