Resistivity and dielectric constant determination of earth formations - uses electromagnetic wave logging system to transmit, and receive at different spacings at 30 megahertz

摘要

The system operating at radio frequencies in the range of 10 MHZ to 60 MHZ is provided for simultaneously determining the resistivity and dielectric constant of earth formations in the vicinity of a well bore. A transmitter coil and two longitudinally spaced receiver coils are provided in the system. Circuit for measuring the unnormalized amplitude ratio and the relative phase shift of electromagnetic waves at the spaced receiver coils are provided. A relationship is given whereby the formation dielectric constant and resistivity may be obtained from the amplitude ratio and relative phase shift measurements.