Acoustic well logging system

Claim 1

A SYSTEM FOR MEASURING THE VELOCITY OF ACOUSTIC ENERGY TRAVERSING SUB-SURFACE EARTH FORMATIONS, SAID SYSTEM COMPRISING: MEANS FOR PROVIDING A.C. ENERGY; AN ELECTRIC PULSE GENERATOR PROVIDING, AND SUPERPOSING ON SAID A.C. ENERGY, FIRST ELECTRIC PULSES AT A FIXED REPETITIVE RATE THAT IS A SUB-MULTIPLE OF THE FREQUENCY OF SAID A.C. ENERGY AND THAT ESTABLISHES BETWEEN EACH OF SAID FIRST PULSES AT LEAST A PREDETERMINED AMOUNT OF SAID A.C. ENERGY OF A GIVEN POLARITY; AN ACOUSTIC WELL LOGGING TOOL INTERCONNECTED REMOTELY OF SAID MEANS AND SAID PULSE GENERATOR TO RECEIVE SAID A.C. ENERGY AND SUPERPOSED FIRST PULSES, SAID TOOL COMPRISING AN ACOUSTIC ENERGY TRANSMITTER ENABLED BY EACH OF SAID FIRST PULSES TO TRANSDUCE SAID AMOUNT OF A.C. ENERGY SIMULTANEOUSLY INTO AN ACOUSTIC ENERGY PULSE AND A SECOND ELECTRIC PULSE, AND A PLURALITY OF ACOUSTIC ENERGY RECEIVERS ENABLED BY SAID SECOND ELECTRIC PULSE TO TRANSDUCE RECEIVED ACOUSTIC ENERGY INTO A RESPECTIVE PLURALITY OF ELECTRICAL SIGNALS DURING A PREDETERMINED FIRST TIME INTERVAL; AND A COMPUTER INTERCONNECTED REMOTELY OF SAID TOOL TO MEASURE THE TIME INERVAL BETWEEN RELATED ONES OF SAID ELECTRICAL SIGNALS.