Acoustical velocity well logging

Claim 1

AN ACOUSTICAL VELOCITY WELL LOGGING SYSTEM COMPRISING AN ELONGATED TOOL ADAPTED TO BE PASSED THROUGH THE BORE OF A WELL, SAID TOOL HAVING FIRST AND SECOND TRANSDUCERS POSITIONED IN FIXED SPACED APART RELATIONSHIP IN SAID TOOL, MEANS FOR TRANSMITTING ACOUSTIC PULSES AT PREDETERMINED TIME INTERVALS THROUGH A SUBSURFACE FORMATION BETWEEN SAID FIRST AND SECOND TRANSDUCERS, SAID FIRST AND SECOND TRANSDUCERS BEING IN ACOUSTIC COMMUNICATION WITH SAID SUBSURFACE FORMATION, MEANS FOR PRODUCING A FIRST ELECTRIC PULSE AT THE OCCURRENCE OF A GIVEN ONE OF SAID ACOUSTIC PULSES AT SAID FIRST TRANSDUCER, MEANS FOR PRODUCING A SECOND ELECTRIC PULSE UPON THE ARRIVAL OF SAID GIVEN ACOUSTIC PULSE AT SAID SECOND TRANSDUCER, MEANS DEFINING A SINGLE CONDUCTOR CABLE SYSTEM, MEANS OPERATIVELY COUPLED AND RESPONSIVE TO SAID MEANS FOR PRODUCING SAID FIRST AND SECOND ELECTRIC PULSES FOR TRANSMITTING SAID FIRST AND SECOND ELECTRIC PULSES THROUGH THE BORE OF THE WELL IN SAID SINGLE CONDUCTOR SYSTEM AND A TIME MEASURING CIRCUIT DISPOSED AT THE EARTH''S SURFACE AND OPERATIVELY COUPLED TO SAID MEANS DEFINING SAID SINGLE CONDUCTOR CABLE SYSTEM FOR MEASURING THE TIME INTERVAL BETWEEN SAID FIRST AND SECOND ELECTRIC PULSES SAID MEANS FOR TRANSMITTING SAID FIRST AND SECOND ELECTRIC PULSES COMPRISING A CABLE PULSING CIRCUIT INCLUDING A THYRATRON HAVING AN OUTPUT CIRCUIT COUPLED TO SAID CABLE FOR APPLYING HIGH-POWER, SHORT-DURATION PULSES TO SAID SINGLE CONDUCTOR SYSTEM AND A PULSE COLLECTING CIRCUIT HAVING A SINGLE OUTPUT COUPLED TO THE INPUT OF SAID THYRATRON DEVICE AND FIRST AND SECOND INPUT CIRCUITS, ONE OF SAID PULSE COLLECTING INPUT CIRCUITS BEING OPERATIVELY COUPLED AND RESPONSIVE TO THE MEANS FOR PRODUCING THE FIRST ELECTRIC PULSE, AND THE SECOND OF SAID PULSE COLLECTING INPUT CIRCUITS BEING OPERATIVELY COUPLED AND RESPONSIVE TO SAID MEANS FOR PRODUCING SAID SECOND ELECTRIC PULSE.