Electrical well logging system

Claim 1

ELECTRICAL WELL LOGGING APPARATUS COMPRISING, AN ELECTROMAGNETIC FLUX GENERATOR GROUP INCLUDING AT LEAST ONE GENERATOR COIL DISPOSED WITH RESPECT TO A TOOL BODY IN SPACED APART RELATION TO A RECEIVER COIL GROUP INCLUDING AT LEAST ONE RECEIVER COIL, A LATERAL CURRENT ELECTRODE MEANS DISPOSED ON SAID BODY FOR PASSING A FIRST LATERAL CURRENT FLOW THROUGH EARTH FORMATIONS ABOUT SAID BODY, A NORMAL CURRENT ELECTRODE MEANS DISPOSED ON SAID BODY FOR PASSING A SECOND NORMAL CURRENT FLOW THROUGH SAID FORMATIONS, AT LEAST ONE NORMAL POTENTIAL ELECTRODE DISPOSED IN SPACED APART RELATION TO SAID NORMAL CURRENT MEANS, AT LEAST ONE LATERAL POTENTIAL ELECTRODE DISPOSED IN SPACED APART RELATION TO SAID LATERAL CURRENT MEANS, MATCHING MEANS FOR RECEIVING ALTERNATING CURRENT POWER VOLTAGE INTO SAID BODY THROUGH A CONDUCTOR OF A WELL LOGGING CABLE AND JOINTLY IMPRESSING SIGNALS OF RESPECTIVE FREQUENCIES WITH A SPONTANEOUS POTENTIAL SIGNAL ON SAID CONDUCTOR, A SPONTANEOUS POTENTIAL ELECTRODE DISPOSED ON SAID BODY AND IN CONNECTION WITH SAID MATCHING MEANS, A FIRST VOLTAGE MEANS CONNECTED WITH SAID MATCHING MEANS FOR PRODUCING A DIRECT CURRENT VOLTAGE, A SECOND VOLTAGE MEANS CONNECTED WITH SAID MATCHING MEANS AND SAID FIRST VOLTAGE MEANS FOR PRODUCING A VOLTAGE OF FIRST FREQUENCY, A THIRD VOLTAGE MEANS CONNECTED WITH SAID MATCHING MEANS AND SAID FIRST VOLTAGE MEANS FOR PRODUCING A VOLTAGE OF SECOND FREQUENCY, A MEANS CONNECTED WITH SAID FIRST VOLTAGE MEANS AND SAID GENERATOR GROUP FOR PRODUCING A CONSTANT ALTERNATING CURRENT THROUGH SAID GENERATOR GROUP, A MEANS CONNECTED WITH SAID FIRST VOLTAGE MEANS, SAID SECOND VOLTAGE MEANS, AND SAID LATERAL ELECTRODE MEANS FOR PRODUCING SAID FIRST FORMATION CURRENT FLOW, MEANS CONNECTED TO SAID FIRST VOLTAGE MEANS, SAID THIRD VOLTAGE MEANS, AND SAID NORMAL CURRENT ELECTRODE MEANS FOR PRODUCING SAID SECOND FORMATION CURRENT FLOW, A FIRST RECEIVER MEANS CONNECTED TO SAID RECEIVER GROUP FOR RECEIVING THE COMPOSITE VOLTAGE INDUCED IN SAID RECEIVER GROUP BY THE FLUX DIRECTLY PRODUCED BY SAID GENERATOR GROUP AND THE FLUX SECONDARILY PRODUCED BY EDDY CURRENTS INDUCED BY SAID GENERATOR GROUP FLUX IN SAID FORMATIONS, NULLING MEANS CONNECTED BETWEEN SAID CONSTANT CURRENT MEANS AND SAID RECEIVER MEANS FOR SELECTIVELY NULLING RESPECTIVE COMPONENTS OF SAID COMPOSITE VOLTAGE, MEANS CONNECTED TO SAID RECEIVER MEANS AND SAID FIRST VOLTAGE MEANS FOR CONVERTING A RESULTANT RECEIVED VOLTAGE INTO A DIRECT CURRENT VOLTAGE, MODULATING MEANS CONNECTED TO SAID SECOND VOLTAGE MEANS AND SAID CONVERTER MEANS TO PRODUCE A SUB-CARRIER MODULATING SIGNAL OF SAID FIRST FREQUENCY AND REPRESENTATIVE OF SAID RESULTANT VOLTAGE, A FIRST FREQUENCY MODULATED TRANSMITTER MEANS CONNECTED TO SAID FIRST VOLTAGE MEANS, SAID MODULATION MEANS AND SAID MATCHING SECTION FOR IMPRESSING A FREQUENCY MODULATED FIRST SIGNAL ON SAID CONDUCTOR REPRESENTATIVE OF SAID RESULTANT VOLTAGE, A SECOND RECEIVER MEANS CONNECTED TO SAID NORMAL POTENTIAL ELECTRODE AND A REMOTE POTENTIAL REFERENCE FOR RECEIVING A POTENTIAL PRODUCED ONLY BY SECOND NORMAL CURRENT, A SECOND FREQUENCY MODULATED TRANSMITTER MEANS CONNECTED TO SAID SECOND RECEIVER MEANS, SAID FIRST VOLTAGE MEANS AND SAID MATCHING SECTION FOR IMPRESSING A SECOND FREQUENCY MODULATED SIGNAL ON SAID CONDUCTOR REPRESENTATIVE OF SAID NORMAL POTENTIAL, A THIRD RECEIVER MEANS CONNECTED TO SAID LATERAL POTENTIAL ELECTRODE AND A REMOTE POTENTIAL REFERENCE FOR RECEIVING A POTENTIAL PRODUCED ONLY BY SAID FIRST LATERAL CURRENT, A THIRD FREQUENCY MODULATED TRANSMITTER MEANS CONNECTED TO SAID THIRD RECEIVER MEANS, SAID FIRST VOLTAGE MEANS AND SAID MATCHING SECTION FOR IMPRESSING A THIRD FREQUENCY MODULATED SIGNAL ON SAID CONDUCTOR REPRESENTATIVE OF SAID LATERAL POTENTIAL.