Experimental Measurements and Theoretical Prediction of the Thermal Conductivity of Two- and Three-Phase Water/Olivine Systems

The thermal conductivity of olivine, dry and mixed with water, up to saturation, has been measured with a thermal probe, using the step heating method. The olivine is composed of solid particles with dimensions in the range from 0.8 to 1 mm. Dry olivine has been measured in the range of temperatures between –17° to +50°C. Olivine mixed with water has been measured at +50°C. The cubic cell model has been used to make predictions to compare with the measured data. Comparisons of the experimental thermal conductivities and the predicted values of dry and water-mixed olivine show good agreement. The cubic cell model can be used to evaluate the porosity of olivine and the thermal conductivity of the solid particles, from the values measured at dryness and saturation, with reasonably good agreement. In this way, it is not necessary to measure the mineral composition of the particles of the porous media. Also, the porosity of the medium is predicted with reasonable agreement, which takes into account the phenomenon of the porosity increase near the probe, since the diameter of the probe is smaller than that of the solid particles.