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Effective thermal conductivity (ETC) of five dry rocks (sandstone, limestone, amphibolite, granulite, and pyroxenegranulite) have been measured over a temperature range from (273 to 423) K and at pressures up to 350 MPa with a steady-state parallel-plate apparatus. It is an absolute, steady-state measurement device with an operational temperature range of (273 to 1273) K and hydrostatic pressures up to 1500 MPa. The estimated uncertainty of the method is 2 %. The porosity of the samples (sandstone, limestone, amphibolite, granulite, and pyroxene-granulite) was 5 %, 5 %, 1.0 %, 1.0 %, and 1.2 %, respectively. A sharp increase of ETC was found for rocks at low pressures between (0.1 and 100) MPa along various isotherms between (273 and 423) K. At high pressures (P > 100 MPa), a weak linear dependence of the ETC with pressure was observed. The measured values of ETC of rocks were used to test and confirm of applicability of the various theoretical and semiempirical models. The effect of structure (size, shape, and distribution of the pores), porosity, and mineralogical composition on temperature and pressure dependences of the ETC of various rocks types is discussed.

The effective thermal conductivity (ETC) of fluid-saturated porous mica ceramics with open pores was measured over a temperature range from 275 to 423 K and at pressures up to 400 MPa using a steady-state parallel-plate apparatus. It is an absolute, steady-state measurement device with an operational temperature range of 273-1273 K and a pressure range up to 1500 MPa. We used argon and water as pore saturants. The estimated accuracy of the method is (2%. The porosity of the samples was 2%, 14%, and 26%. The effect of pressure, temperature, and porosity on the ETC behavior of the fluid (Ar and H 2 O)-saturated porous mica ceramic was studied. A sharp increase of the ETC was found for porous mica ceramic with gas (Ar) saturated at low pressures (between 0.1 and 100 MPa) along the various isotherms, while for the same sample saturated with water, the pressure dependence of the ETC displayed very weakly. The measured values of the ETC for a fluid-saturated porous mica ceramic were compared with the values predicted by various theoretical and semiempirical models. The effect of the size, shape, and distribution of the pores on the ETC of porous mica ceramic was discussed.

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