Study on coal complex resistivity anisotropy and characteristics of frequency response

In order to realize the high-efficient electrical exploring for the material composition and structure of coal and rock, based on IP effects in frequency domain of rock, by using t he method of complex resistivity, frequency response characteristics of complex resistivity for four coal samples with different metamorphic degree were studied in different directions.The exp erimental results show that complex resistivity of all coal show monotone decrease in vertical direction, trend direction and inclination direction with the increase of frequency. The complex res istivity values are obviously different in low frequency. The coal seam complex resistivity values between trend and inclination performs isotropy and performs anisotropy between horizontal an d vertical directions in high frequency.The reason for all this is related to the polarization time for polarizable dielectric in coal .