Estimating thermo-osmotic coefficients in clay-rocks: II. In situ experimental approach

Estimating thermo-osmotic coefficients in clay-rocks: I. Theoretical insights

“…Therefore, a dramatic decrease of the thermoosmotic coefficient should be expected at increasing temperatures. The new experimental work presented in the companion paper [30] supports this view. Variations as high as one order of magnitude of the thermo-osmotic conductivity were found for a temperature variation of 9°C.…”

“…3a which shows the available data of k T for clay materials listed in Table 1. However, the values of k T obtained by Zheng and Samper [29] for bentonite and by Trémosa et al [30] in a companion paper for Toarcien argilites at Tournemire, France, suggest that it would be hazardous to suppose a direct Log-linear proportionality between these two parameters. A more reliable relation is shown in Fig.…”

Analytical Expressions for Thermo‐Osmotic Permeability of Clays

“…Natural stands for heterogeneous materials containing a nonclay minerals fraction. Error bars are only available for the in situ data and are associated with the uncertainty on the borehole test chamber compressibility (Tremosa et al, ). The asterisk refers to the fact that the linear regression (dashed line) is based on the available data excepting the in situ values.…”

“…According to equation (1), the thermo-osmotic permeability is k T = kΔH∕T (Pa m 2 K −1 ). Most often, ΔH >0 in clays, and fluid flow occurs in the direction of decreasing temperature, but negative values have also been reported (see, e.g., Tremosa et al, 2010).…”

Semipermeable Membrane Properties and Chemomechanical Coupling in Clay Barriers

“…The present simple analysis, based on a few available data, suggests that the pore size could be a fundamental descriptive variable for the thermoosmotic conductivity. In addition, the diffusive heat transport (Fourier's law of thermal conductivity) may be weakly affected by electrochemical effects since the solid phase accounts for most of the bulk thermal conductivity of the porous media (de Marsily, 1986;Tremosa et al, 2010).…”