Deep penetration well logging system and method

摘要

A well logging system and method of the present invention determines the dielectric constant and/or conductivity of earth formations some of which have fluid invasion. The system and method of the present invention includes the transmission of electromagnetic energy into the earth formation from a first location in a borehole in the formations at a frequency which enables the electromagnetic energy to propagate throughout the surrounding earth formations. Electromagnetic energy is received by receivers at three locations in the borehole which are spaced longitudinally from the location of the transmission of the electromagnetic energy. The receivers provide signals representative of the total electromagnetic fields at those locations. The dielectric constant and/or resistivity of the earth formations are determined in accordance with portions of the signals from the three receivers corresponding to secondary electromagnetic fields at the three receiving locations.