METHOD AND DEVICE FOR MEASURING RESISTIVITY ANISOTROPY OF ROCK SAMPLES HAVING LITAGES

摘要

P - Method and device for measuring the resistivity anisotropy of rocks having different conductivity bedding, such as laminations.- - The method involves placing the sample saturated with a first fluid in a device of petrophysical measurements for submitting it to drainage operations by injection under pressure of a second fluid. Electrode pairs (E, E ') are pressed against its peripheral wall for applying an electric current and for detecting differences in potential occurring between different application points in response to the application of electric current. . During these operations, at least one injection pressure bearing of the second fluid is established and precise measurements are made continuously of the variations of the complex electrical impedance of the sample at several frequencies during a phase of displacement of the saturating fluid. In a first step, measurements of the impedance presented by the sample are made in a position where the bedding is oriented substantially transversely to the electric field (EF) created by the application of the electric current and in a second step, it is realized the same measurements in another position where the beds are oriented substantially in the direction of the electric field. The anisotropy of resistivity is then determined.- Applications for example to petrophysical measurements on porous rock samples. / P