Well logging pulse transmission system

Abstract

Abstract THE PARTICULAR EMBODIMENTS DESCRIBED HEREIN AS ILLUSTRATIVE TO THE INVENTION DESCRIBE A TECHNIQUE FOR TRANSMITTING PULSES AT THE MAXIMUM PERMISSIBLE RATE OF A TRANSMISSION SYSTEM WITHOUT LOSING ANY PULSES. IN ONE FORM, THE DATA PULSES ARE STORED IN AN UP-DOWN BINARY COUNTER. THE COUNTER IS EXAMINED AT A SPECIFIED MINIMUM TIME INTERVAL TO DETERMINE IF ANY COUNTS ARE PRESENT, AND IF SO, A PULSE IS TRANSMITTED TO THE SURFACE OF THE EARTH AND ONE COUNT IS SUBTRACTED FROM THE COUNTER. SUITABLE MEANS ARE SHOWN FOR INSURING THAT THE COUNTER IS NOT PLACED IN THE COUNT-UP AND COUNT-DOWN MODE AT THE SAME TIME AND TO INSURE THAT THE COUNTER IS NOT RESET OR CYCLED AROUND BY COUNTING A PULSE WHEN IT IS FULL. IN ANOTHER FORM, THE TRANSMISSION RATE IS EFFECTIVELY DOUBLED BY GENERATING A CHANGE IN STATE FOR EACH PULSE OR EVENT TO BE TRANSMITTED. THIS TRANSMISSION SYSTEM CAN BE USED WITH THE PULSE STORAGE TECHNIQUE TO FURTHER IMPROVE THE TRANSMISSION RATE. OTHER EMBODIMENTS SHOW MULTIPLEXING PULSES FROM A PLURALITY OF PULSE SOURCES IN THE TOOL TO THE SURFACE OF THE EARTH. THE ABOVE-MENTIONED COUNTING TECHNIQUES IS SHOWN UTILIZED WITH THESE MULTIPLEXING TECHNIQUES TO INSURE THAT PULSES ARE NOT LOST DURING PERIODS OF HIGH INSTANTANEOUS PULSE RATE FROM ONE OR MORE OF THE PULSE SOURCES. MEANS ARE ALSO SHOWN FOR SYNCHRONIZING THE DECOMMUTATING OPERATION AT THE SURFACE OF THE EARTH WHILE THE COMMUTATING OPERATION DOWNHOLE, INCLUDING DETECTING THE SYNCHRONIZING SIGNALS AND SYNCHRONIZING THE FREQUENCY AND PHASE OF THE DOWNHOLE COMMUTATING CLOCK WITH THE SURFACE DECOMMUTATING CLOCK.

Inventors

• 👤 Robert J Schwartz

Bibliographic Details