Spiral winding ring type rock core resistivity measuring device and method

Abstract

The invention discloses a spiral winding ring type rock core resistivity measurement device and method, and relates to the technical field of rock core resistivity measurement, and the specific steps are as follows: enabling a rock core not to be loaded, wherein two electrodes are opposite; applying an alternating voltage with a fixed amplitude and a fixed frequency to the transmitting spiral winding ring, and measuring an induced voltage of the receiving spiral winding ring; calculating a loop background resistance value by using the alternating voltage and the induced voltage; loading a rock core between the two electrodes, applying a second alternating voltage with a fixed amplitude and a fixed frequency to the transmitting spiral winding ring, and measuring a second induced voltage of the receiving spiral winding ring; calculating a loop resistance value when the rock core is loaded by using the second alternating voltage and the second induced voltage; and calculating the resistivity of the rock core by subtracting the loop resistance value from the loop background resistance value and utilizing the size parameter of the rock core. In the invention, the measurement system and the core current path are mutually independent, the error introduced by the additional impedance is small, stable and controllable, and the measurement result is accurate.

Description

technical field [0001] The invention relates to the technical field of core resistivity measurement, in particular to a spiral-wound core resistivity measurement device and method. Background technique [0002] In oil and gas resource reservoir evaluation, in order to understand the relationship between reservoir resistivity characteristics and reservoir parameters, it is necessary to conduct a large number of petrophysical experiments to measure the resistivity of rocks. Rock resistivity measurement under variable saturation conditions is the most basic rock resistivity experiment. During the experiment, the liquid in the core needs to be displaced to change the properties of the core pore structure. [0003] The traditional rock resistivity measurement is mainly based on the electrode method and the coil method. The principle of electrode method measurement is voltammetry measurement. By measuring the voltage and current applied to both ends of the core, the resistance of...

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Problems solved by technology

Moreover, due to non-direct contact with the core, the measurement results reflect the local resistivity information of the core. In the two-phase displacement experiment, due to the heterogeneity of oil-water distribution, the measurement results cannot reflect accurate core information. In addition, The coil method also has a disadvantage: the coil needs to be placed inside the core sample, and the sample needs to be destroyed

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