Patent ID: 6975120
Filing Date: 2005-12-13
Classification: G01V

Abstract:
1. An apparatus for measuring the electrical properties of subsurface geologic formations and media within the interstices of the geologic formation comprising the following: a. means for moving the apparatus though the axial length of an uncased borehole; b. an electromagnetic antenna having a first side and a second side and comprising material that is electrically conductive and magnetically permeable; c. a magnetic flux transmitter proximate to the first side of the electromagnetic antenna for engaging the antenna with magnetic flux sufficient to reduce the magnetic permeability of at least a portion of the antenna; d. a second magnetic flux transmitter proximate to an area of the antenna material having reduced magnetic permeability capable of inducing eddy currents in the antenna that emit an electromagnetic wave from the second side of the antenna; and e. at least one electromagnetic wave receiver located near the first side of the antenna to detect any return oscillating magnetic flux engaging with the second side of the antenna.