Dia Consultants Company, Japan

For scientific deep drilling projects such as the integrated ocean drilling program (IODP), core-based laboratory measurements of electrical resistivity and seismic velocity are important to estimate the physical properties of rocks under in-situ conditions and to examine relations between the physical properties and the conditions, because the data of physical properties and the relations are indispensable for the interpretations of survey results of geophysical explorations on a wide area and logging data in boreholes. The resistivity of four sandstones, three tuffs and two granites, the velocities of Inada granite and Tako sandstone were measured under various measurement conditions such as volumetric water content (saturation degree of pore water), pore water resistivity, confining pressure, differential stress, high-temperature etc. The results showed that the effects of these conditions on the physical properties were distinct and cannot be neglected. In addition, we emphasize that measurement conditions must be taken into consideration for the correct estimation of physical properties of rocks under in-situ conditions.