MEASUREMENT OF CORE ELECTRICAL PARAMETERS AT UHF AND MICROWAVE FREQUENCIES.

The Electromagnetic Propagation Tool (EPT) has demonstrated that the electrical conductivity and dielectric permittivity of rocks at microwave frequencies are different than at low frequencies. These differences are helpful in determining the properties of the rocks and the fluids they contain and thus contribute to improved formation evaluation. Electrical parameters of rocks are found to be generally complex. A technique has been developed for measuring the complex dielectric permittivity, conductivity and magnetic permeability over a range of frequencies in the UHF and microwave frequency bands (100 MHz to 2. 0 GHz). The sample core constitutes the dielectric of a coaxial transmission line sample holder. Using a Hewlett Packard S-parameter setup, two-port S-parameter measurements are made. The complex constituent parameters ( epsilon prime , epsilon double prime , sigma , mu ) of the core samples are then computed from the S-parameters.