Secondary field dielectric constant and/or resistivity well logging system and method

摘要

Apparatus for determining the dielectric constant and/or resistivity of earth formations traversed by a borehole includes a transmitter which transmits electromagnetic energy into the earth formation from a first location in the borehole at a frequency which enables the electromagnetic energy to propagate throughout the surrounding earth formations. Receivers receive electromagnetic energy at two locations in the borehole which are spaced longitudinally from the transmitter provide signals representative of the total electromagnetic fields at the receiver locations. Circuitry determines the dielectric constant and/or resistivity of the formations in accordance with a secondary field ratio and a phase difference derived from the signals provided by the receivers.