Indonesia Conference Directory

The electrical complex impedance is very important physical parameter to determine the fluid and matrix condition of the rock sample. One mechanism in the samples that influences this complex, frequency – dependent behavior of resistivity is the disseminated metal ores which can block the pores and subsequently trigger the mechanism for storage/delay. Pore water ions build up on either side of the grain, results in the effect of a capacitor. This paper presents a simple experimental set up to measure the complex resistivity of rock samples. The main mechanism is generation of high voltage sinusoidal signal. This is implemented as collector voltage of a transistor. The high voltage sinusoidal signal then is applied on either side of the rock sample. At two distances of the sample we measure the resulting voltage using the oscilloscope. The observed delay can be considered as the measured phase, whereas the amplitude of the observed voltage is considered as the voltage. We determine the absolute impedance as the voltage divided by the current. Using this simple method we measured the complex impedances of 14 rock samples obtained from Halmahera Island. From the results of measurement, we tried to infer and to model the disseminated metal ores of the samples.