Pulse resolution system

Claim 2

In an earth bore logging system including a pulse source which produces a pulse train for transmission over a distorting medium from a location within the bore, the pulses of said train before transmission being variably spaced so that at least two successive pulses of said train may be so closely spaced that they merge into a single, longer duration pulse during transmission through said medium, apparatus for restoring the two pulses of the pulse train received after transmission to the surface, comprising: means responsive to said received pulse train for generating for each individual received pulse thereof a trigger pulse having a duration proportional to the duration of the respective received pulse, and a reference pulse terminating subsequent to the termination of a trigger pulse generated in response to a received pulse representative of a single pulse before transmission; and signal pulse output means responsive to each related pair of trigger and reference pulses including a. means for producing at an output terminal a first output pulse upon each occurrence of one of the related trigger and reference pulses and b. means for producing a second output pulse at the output terminal upon overlap of the trigger pulse and the trailing edge of the reference pulse.

Claim 3

A system as set forth in claim 1 in which the duration of the reference pulse is greater than the duration of a trigger pulse generated in response to a received pulse representative of a single pulse before transmission.

Claim 4

In an earth bore logging system including a pulse source which produces a pulse train for transmission over a distorting medium from a location within the bore, the pulses of said train before transmission being variably spaced so that at least two successive pulses of said train may be so closely spaced that they merge into a single, longer duration pulse during transmission through said medium, apparatus for restoring the two pulses of the pulse train received after transmission to the surface, comprising: means responsive to said received pulse train for generating for each individual received pulse thereof a trigger pulse having a duration proportional to the duration of the respective received pulse, and a reference pulse terminating subsequent to the termination of a trigger pulse generated in response to a received pulse representative of a single pulse before transmission; signal pulse output means responsive to each related pair of trigger and reference pulses for producing at an output terminal a first output pulse upon each occurrence of one of the related trigger and reference pulses and a second output pulse upon overlap of the trigger pulse and the trailing edge of the reference pulse; and means responsive to the trigger pulses for changing the duration of the reference pulse in accordance with variations in the trigger pulse duration.

Claim 5

In an earth bore logging system including a pulse source which produces a pulse train for transmission over a distorting medium from a location within the bore, the pulses of said train before transmission being variably spaced so that at least two successive pulses of said train may be so closely spaced that they merge into a single, longer duration pulse during transmission through said medium, apparatus for restoring the two pulses of the pulse train received after transmission to the surface, comprising: means responsive to said received pulse train for generating for each individual received pulse thereof a trigger pulse having a duration proportional to the duration of the respective received pulse, and a reference pulse terminating subsequent to the termination of a trigger pulse generated in response to a received pulse representative of a single pulse before transmission; signal pulse output means responsive to each related pair of trigger and reference pulses for producing at an output terminal a first output pulse upon each occurrence of one of the related trigger and reference pulses and a second output pulse upon overlap of the trigger pulse and the trailing edge of the reference pulse; and means responsive to the trigger pulses for changing the duration of the reference pulse in accordance with variations in the trigger pulse duration.

Claim 6

A system in accordance with claim 3 wherein the means for changing the duration of the reference pulse comprises a circuit for producing a control signal whose amplitude is a function of variations in the duration of the trigger pulse, and the reference pulse generating means includes means responsive to the amplitude of the control signal for determining the duration of the reference pulse.

Claim 7

A system in accordance with claim 4, further comprising: means for averaging the amplitudes of the control signals corresponding to successive trigger pulses.

Claim 8

A system in accordance with claim 4, in which the control signal producing means comprises: a current source, a charging circuit in series with the current source, and an input circuit receiving the trigger pulse for limiting the charge attainable by the charging circuit in the absence of the trigger pulse.

Claim 9

In an earth bore logging system including a pulse source which produces a pulse train for transmission over a distorting medium from a location within the bore, the pulses of said train before transmission being variably spaced so that at least two successive pulses of said train may be so closely spaced that they merge into a single, longer duration pulse during transmission through said medium, apparatus for restoring the two pulses of the pulse train received after transmission to the surface, comprising: means responsive to said received pulse train for generating for each individual received pulse thereof a trigger pulse having a duration proportional to the duration of the respective received pulse: means responsive to each of said trigger pulses for producing a reference pulse terminating subsequent to the termination of a trigger pulse generated in response to a received pulse representative of a single pulse before transmission; a first differentiator for differentiating one of the reference and trigger pulses to produce the first output pulse; a second differentiator for differentiating a pulse corresponding to the trailing edge of one of the reference and trigger pulses; and differentiator control means responsive to the other of the last-named reference and trigger pulses to inhibit the passage of the corresponding pulse to the output terminal during the time occupied by the reference pulse.

Claim 10

In an earth bore logging system including a pulse source which produces a pulse train for transmission over a distorting medium from a location within the bore, the pulses of said train before transmission being variably spaced so that at least two successive pulses of said train may be so closely spaced that they merge into a single, longer duration pulse during transmission through said medium, apparatus for restoring the two pulses of the pulse train received after transmission to the surface, comprising: means responsive to said received pulse train for generating for each individual received pulse thereof a trigger pulse having a duration proportional to the duration of the respective received pulse: means responsive to each of said trigger pulses for producing a reference pulse terminating subsequent to the termination of a trigger pulse generated in response to a received pulse representative of a single pulse before transmission; a first differentiator for differentiating one of the reference and trigger pulses to produce the first output pulse; a second differentiator for differentiating a pulse corresponding to the trailing edge of one of the reference and trigger pulses; and differentiator control means responsive to the other of the last-named reference and trigger pulses to inhibit the passage of the corresponding pulse to the output terminal during the time occupied by the reference pulse.

Claim 11

A system as defined in claim 7, in which: the first differentiator operates on the edge of the reference pulse, the second differentiator operates on a pulse corresponding to the trailing edge of the trigger pulse, and the differentiator control means is responsive to the reference pulse.

Claim 12

A system as recited in claim 8, in which: the first differentiator differentiates the trailing edge of the reference pulse.

Claim 13

In an earth bore logging system including a pulse source which produces a pulse train for transmission over a distorting medium from a location within the bore, the pulses of said train before transmission being variably spaced so that at least two successive pulses of said train may be so closely spaced that they merge into a single, longer duration pulse during transmission through said medium, apparatus for restoring the two pulses of the pulse train received after transmission to the surface, comprising: means responsive to said received pulse train for generating for each individual Received pulse thereof a trigger pulse having a duration proportional to the duration of the respective received pulse, and a reference pulse terminating subsequent to the termination of a trigger pulse generated in response to a received pulse representative of a single pulse before transmission; signal pulse output means responsive to each pair of related trigger and reference pulses for producing at an output terminal a first output pulse upon each occurrence of one of the related trigger and reference pulses and a second output pulse when the duration of the trigger pulse exceeds the duration of the reference pulse; and means for controlling the occurrence of the first and second output pulses so that the time separation therebetween is related to the time separation between the two successive pulses of the pulse train.

Claim 14

In an earth bore logging system including a pulse source which produces a pulse train for transmission over a distorting medium from a location within the bore, the pulses of said train before transmission being variably spaced so that at least two successive pulses of said train may be so closely spaced that they merge into a single, longer duration pulse during transmission through said medium, apparatus for restoring the two pulses of the pulse train received after transmission to the surface, comprising: means responsive to said received pulse train for generating for each individual Received pulse thereof a trigger pulse having a duration proportional to the duration of the respective received pulse, and a reference pulse terminating subsequent to the termination of a trigger pulse generated in response to a received pulse representative of a single pulse before transmission; signal pulse output means responsive to each pair of related trigger and reference pulses for producing at an output terminal a first output pulse upon each occurrence of one of the related trigger and reference pulses and a second output pulse when the duration of the trigger pulse exceeds the duration of the reference pulse; and means for controlling the occurrence of the first and second output pulses so that the time separation therebetween is related to the time separation between the two successive pulses of the pulse train.

Claim 15

In an earth bore logging system including a pulse source which produces a pulse train for transmission over a distorting medium from a location within the bore, the pulses of said train before transmission being variably spaced so that at least two successive pulses of said train may be so closely spaced that they merge into a single, longer duration pulse during transmission through said medium, apparatus for restoring the two pulses of the pulse train received after transmission to the surface, comprising: means responsive to said received pulse train for generating for each individual received pulse thereof a trigger pulse having a duration proportional to the duration of the respective received pulse; means responsive to each of said trigger pulses for producing a reference pulse terminating subsequent to the termination of a trigger pulse generated in response to a received pulse representative of a single pulse before transmission; signal pulse output means responsive to each related pair of trigger and reference pulses for producing at an output terminal a first output pulse upon each occurrence of one of the related trigger and reference pulses and a second output pulse upon overlap of the trigger pulse and the trailing edge of the reference pulse; and amplifying means connected between the distorting medium and the trigger pulse generating means and having a transfer characteristic effective to produce successive individual received pulses of substantially constant amplitude at the output thereof.

Claim 16

In an earth bore logging system including a pulse source which produces a pulse train for transmission over a distorting medium from a location within the bore, the pulses of said train before transmission being variably spaced so that at least two successive pulses of said train may be so closely spaced that they merge into a single, longer duration pulse during transmission through said medium, apparatus for restoring the two pulses of the pulse train received after transmission to the surface, comprising: means responsive to said received pulse train for generating for each individual received pulse thereof a trigger pulse having a duration proportional to the duration of the respective received pulse; means responsive to each of said trigger pulses for producing a reference pulse terminating subsequent to the termination of a trigger pulse generated in response to a received pulse representative of a single pulse before transmission; signal pulse output means responsive to each related pair of trigger and reference pulses for producing at an output terminal a first output pulse upon each occurrence of one of the related trigger and reference pulses and a second output pulse upon overlap of the trigger pulse and the trailing edge of the reference pulse; and amplifying means connected between the distorting medium and the trigger pulse generating means and having a transfer characteristic effective to produce successive individual received pulses of substantially constant amplitude at the output thereof.

Claim 17

In an earth bore logging system including a pulse source which produces a pulse train for transmission over a distorting medium from a location within the bore, the pulses of said train before transmission being variably spaced so that at least two successive pulses of said train may be so closely spaced that they merge into a single, longer duration pulse during transmission through said medium, apparatus for restoring the two pulses of the pulse train received after transmission to the surface, comprising: means responsive to said received pulse train for generating for each individual received pulse thereof a trigger pulse having a duration proportional to the duration of the respective received pulse; means responsive to each of said trigger pulses for producing a reference pulse terminating subsequent to the termination of a trigger pulse generated in response to a received pulse representative of a single pulse before transmission; signal pulse output means responsive to each related pair of trigger and reference pulses for producing at an output terminal a first output pulse upon each occurrence of one of the related trigger and reference pulses and a second output pulse upon overlap of the trigger pulse and the trailing edge of the reference pulse; and means connected between the distorting medium and the trigger pulse generating means and having a transfer characteristic effective to produce successive individual received pulses representative of a single pulse before transmission, each individual received pulse having the same pulse width at a predetermined amplitude thereof.

Claim 18

In an earth bore logging system including a pulse source which produces a pulse train for transmission over a distorting medium from a location within the bore, the pulses of said train before transmission being variably spaced so that at least two successive pulses of said train may be so closely spaced that they merge into a single, longer duration pulse during transmission through said medium, apparatus for restoring the two pulses of the pulse train received after transmission to the surface, comprising: means responsive to said received pulse train for generating for each individual received pulse thereof a trigger pulse having a duration proportional to the duration of the respective received pulse; means responsive to each of said trigger pulses for producing a reference pulse terminating subsequent to the termination of a trigger pulse generated in response to a received pulse representative of a single pulse before transmission; signal pulse output means responsive to each related pair of trigger and reference pulses for producing at an output terminal a first output pulse upon each occurrence of one of the related trigger and reference pulses and a second output pulse upon overlap of the trigger pulse and the trailing edge of the reference pulse; and means connected between the distorting medium and the trigger pulse generating means and having a transfer characteristic effective to produce successive individual received pulses representative of a single pulse before transmission, each individual received pulse having the same pulse width at a predetermined amplitude thereof.

Claim 19

In an earth bore logging system including a pulse source which produces a pulse train for transmission over a distorting medium from a location within the bore, the pulses of said train before transmission being variably spaced so that at least two successive pulses of said train may be so closely spaced that they merge into a single, longer duration pulse during transmission through said medium, apparatus for restoring the two pulses of the pulse train received after transmission to the surface, comprising: means responsive to said received pulse train for generating for each individual received pulse thereof a trigger pulse having a duration proportional to the duration of the respective received pulse; means responsive to each of said trigger pulses for producing a reference pulse terminating subsequent to the termination of a trigger pulse generated in response to a received pulse representative of a single pulse before transmission; signal pulse output means responsive to each related pair of trigger and reference pulses for producing at an output terminal a first output pulse upon each occurrence of one of the related trigger and reference pulses and a second output pulse upon overlap of the trigger pulse and the trailing edge of the reference pulse; and pulse-extending means responsive to the pulses of the pulse train before transmission to produce corresponding pulses for transmission, each of the corresponding pulses having a predetermined time duration greater than the duration of individual pulse train pulses and less than the normal expected time period between successive pulse train pulses.

Claim 20

In an earth bore logging system including a pulse source which produces a pulse train for transmission over a distorting medium from a location within the bore, the pulses of said train before transmission being variably spaced so that at least two successive pulses of said train may be so closely spaced that they merge into a single, longer duration pulse during transmission through said medium, apparatus for restoring the two pulses of the pulse train received after transmission to the surface, comprising: means responsive to said received pulse train for generating for each individual received pulse thereof a trigger pulse having a duration proportional to the duration of the respective received pulse; means responsive to each of said trigger pulses for producing a reference pulse terminating subsequent to the termination of a trigger pulse generated in response to a received pulse representative of a single pulse before transmission; signal pulse output means responsive to each related pair of trigger and reference pulses for producing at an output terminal a first output pulse upon each occurrence of one of the related trigger and reference pulses and a second output pulse upon overlap of the trigger pulse and the trailing edge of the reference pulse; and pulse-extending means responsive to the pulses of the pulse train before transmission to produce corresponding pulses for transmission, each of the corresponding pulses having a predetermined time duration greater than the duration of individual pulse train pulses and less than the normal expected time period between successive pulse train pulses.

Claim 21

A system as defined in claim 13, in which: the trigger pulses are approximately equal in width to the width of the corresponding pulses produced by the pulse-extending means.

Claim 22

A system as defined in claim 13, in which: the corresponding pulses each have a duration equal to the predetermined time duration plus the time period between successive individual pulse train pulses occurring within the predetermined time duration.

Claim 23

A system according to claim 13, in which the pulse-extending means comprises: monostable multivibrator means for generating an output pulse in response to an input pulse and including a chargeable element upon which the charge is determinative of the output pulse width; a source of charging current; and switch means coupled between the charging current source and the chargeable element and operable to connect the chargeable element in circuit with the current source for a time sufficient to charge the element to a predetermined value upon each occurrence of an input pulse.

Claim 24

In an earth bore logging system including a pulse source which produces a pulse train containing variably spaced pulses for transmission over a distorting medium from a location within the bore, at least two successive pulses of the pulse train being so closely spaced that they merge into a single pulse of longer duration during transmission through the medium, apparatus for detecting the occurrence of the two closely spaced pulses from the pulse train received after transmission through the medium to the earth''s surface, comprising: means responsive to the received pulse train for generating for each individual received pulse thereof a trigger pulse having a duration proportional to the duration of the respective received pulse; means responsive to the initiation of the trigger pulse for generating a reference pulse having a duration greater than a predetermined average duration of trigger pulses generated in response to successive received pulses representative of single pulses of the pulse train before transmission; output means responsive to the trigger and reference pulses for providing to an output terminal a first output pulse for each occurrence of the trigger pulse and a second output pulse upon the termination of one of the trigger and reference pulses; and gating means responsive to the othEr of the trigger and reference pulses for inhibiting the passage of the second output pulse to the output terminal except upon time overlap of the trigger pulse and the termination of the reference pulse.

Claim 25

In an earth bore logging system including a pulse source which produces a pulse train containing variably spaced pulses for transmission over a distorting medium from a location within the bore, at least two successive pulses of the pulse train being so closely spaced that they merge into a single pulse of longer duration during transmission through the medium, apparatus for detecting the occurrence of the two closely spaced pulses from the pulse train received after transmission through the medium to the earth''s surface, comprising: means responsive to the received pulse train for generating for each individual received pulse thereof a trigger pulse having a duration proportional to the duration of the respective received pulse; means responsive to the initiation of the trigger pulse for generating a reference pulse having a duration greater than a predetermined average duration of trigger pulses generated in response to successive received pulses representative of single pulses of the pulse train before transmission; output means responsive to the trigger and reference pulses for providing to an output terminal a first output pulse for each occurrence of the trigger pulse and a second output pulse upon the termination of one of the trigger and reference pulses; and gating means responsive to the othEr of the trigger and reference pulses for inhibiting the passage of the second output pulse to the output terminal except upon time overlap of the trigger pulse and the termination of the reference pulse.

Claim 26

Apparatus for generating an output pulse having a normal predetermined duration that is controllably extendible in accordance with the time period between successive input pulses comprising: monostable multivibrator means for generating an output pulse in response to an input pulse and including a normally conducting active element and a normally nonconducting active element, each such element having a control electrode, and a chargeable element upon which the charge is determinative of the output pulse width; means for providing a current limited discharge path for the chargeable element to deplete a given applied charge thereon in a given time period; a source of charging current, switch means operable to connect the chargeable element in circuit with the current source for a time sufficient to charge the element to a predetermined value and unidirectionally change the potential at one terminal thereof upon each occurrence of an input pulse; and means for coupling said potential change to the control electrode of one of the active elements to change the state of conduction thereof for a duration determined by the time period of discharge.

Claim 27

Apparatus for generating an output pulse having a normal predetermined duration that is controllably extendible in accordance with the time period between successive input pulses comprising: monostable multivibrator means for generating an output pulse in response to an input pulse and including a normally conducting active element and a normally nonconducting active element, each such element having a control electrode, and a chargeable element upon which the charge is determinative of the output pulse width; means for providing a current limited discharge path for the chargeable element to deplete a given applied charge thereon in a given time period; a source of charging current, switch means operable to connect the chargeable element in circuit with the current source for a time sufficient to charge the element to a predetermined value and unidirectionally change the potential at one terminal thereof upon each occurrence of an input pulse; and means for coupling said potential change to the control electrode of one of the active elements to change the state of conduction thereof for a duration determined by the time period of discharge.

Claim 28

Apparatus in accordance with claim 18 in which: the active elements comprise a pair of interconnected transistor means having control and output electrodes, each transistor having a normal state of conduction opposite to the conduction state of the other transistor; and the switch means is connected to the one terminal of the chargeable element.

Claim 29

Apparatus as defined in claim 19, in which: the switch means is a third transistor having base, emitter and collector electrodes, the emitter and collector electrodes being serially connected to the current source and the capacitor, and the base being connected to receive the input pulse so as to render the third transistor momentarily conductive upon the occurrence of the input pulse.

Claim 30

Apparatus as defined in claim 20, further comprising: regenerative feedback means coupled to one of the emitter and base electrodes of the third transistor and responsive to the output pulse to maintain the third transistor conductive for a time sufficient to charge the capacitor to a maximum predetermined charge.

Claim 31

In an earth bore logging system including a pulse source which produces a pulse train for transmission over a distorting medium from a location within the bore, the pulses of said train before transmission being variably spaced so that at least two successive pulses of said train may be so closely spaced that they merge into a single, longer duration pulse during transmission through said medium, apparatus for restoring the two pulses of the pulse train received after transmission to the surface, comprising: means responsive to said received pulses for generating for each received pulse a trigger pulse having a duration representative of the duration which the respective received pulses exceed a given threshold level and a reference pulse having an adjustable duration which is greater than the trigger pulse duration for a single pulse; means responsive to the trigger and reference pulses for generating one pulse if the trigger pulse duration is less than the reference pulse duration and at least two pulses if the trigger pulse duration is greater than the reference pulse duration; means responsive to the trigger pulse for generating a control signal having a characteristic that is a function of the difference between the durations of said related trigger and reference pulses; and means responsive to said control signal for adjusting said reference pulse duration to reduce variations in said control signal characteristic.

Claim 32

In an earth bore logging system including a pulse source which produces a pulse train for transmission over a distorting medium from a location within the bore, the pulses of said train before transmission being variably spaced so that at least two successive pulses of said train may be so closely spaced that they merge into a single, longer duration pulse during transmission through said medium, apparatus for restoring the two pulses of the pulse train received after transmission to the surface, comprising: means responsive to said received pulses for generating for each received pulse a trigger pulse having a duration representative of the duration which the respective received pulses exceed a given threshold level and a reference pulse having an adjustable duration which is greater than the trigger pulse duration for a single pulse; means responsive to the trigger and reference pulses for generating one pulse if the trigger pulse duration is less than the reference pulse duration and at least two pulses if the trigger pulse duration is greater than the reference pulse duration; means responsive to the trigger pulse for generating a control signal having a characteristic that is a function of the difference between the durations of said related trigger and reference pulses; and means responsive to said control signal for adjusting said reference pulse duration to reduce variations in said control signal characteristic.

Claim 33

A system according to claim 22, in which: the control signal generaTing means includes means for comparing the durations of the trigger and reference pulses.

Claim 34

A system according to claim 23, in which: the comparing means produces an overlap pulse of which the duration represents the difference in the durations of related trigger and reference pulses.

Claim 35

A system according to claim 24, in which the control signal responsive means comprises: means responsive to the overlap pulse for generating a pulse adjustment signal having an incremental amplitude variation for each occurrence of one of the related trigger and reference pulses; means responsive to the overlap pulse for modifying the amplitude variation of the adjustment signal according to the duration of the overlap pulse; and means for applying said adjustment signal having the modified amplitude variation to the means generating the reference pulse to vary the duration of the reference pulse.

Claim 36

A system as defined in claim 24, in which the control signal responsive means comprises: a circuit operative to be charged upon the application of current thereto; a current source; means responsive to the occurrence of one of the related trigger and reference pulses for generating a pulse of fixed duration; means responsive to one of the reference and fixed duration pulses for connecting the current source to the charging circuit to place a charge thereon; means responsive to the other of the reference and fixed duration pulses for discharging the charging circuit; and means for applying a signal representative of the charge on the charging circuit to the reference pulse generating means to vary the duration of the reference pulse.

Claim 37

A system as defined in claim 26, in which: current source connecting means is operative to apply the current source to charge the charging circuit at a fixed rate; and the discharging means includes a circuit providing a current discharge path for the charging circuit.

Claim 38

A system as set forth in claim 27, in which: the charging circuit and current discharge path have respective time constants associated therewith that are unequal.

Claim 39

A system as defined in claim 22, further comprising: means responsive to the rate of occurrence of the pulses in the signal pulse train for disabling the control signal responsive means during periods when said rate of occurrence varies from a preselected desired range.

Claim 40

In an earth bore logging system of the type including pulse resolver apparatus for restoring two transmitted signal pulses that may be so closely spaced that they merge into a single pulse of longer duration during transmission to the pulse resolver apparatus: means responsive to the signal pulses for generating a trigger pulse having a duration representative of the duration of each signal pulse received at the pulse resolver apparatus and a reference pulse of variable duration greater than the duration of a trigger pulse representing a received unmerged signal pulse; means jointly responsive to the trigger and reference pulses for producing a first pulse if the reference pulse duration exceeds the trigger pulse duration and at least two pulses if the reference pulse duration is less than the trigger pulse duration; means responsive to the trigger pulse duration for controlling the duration of the reference pulse; and means responsive to the rate of occurrence of the signal pulses for selectively disabling the last-named means when said rate varies from a preselected range.

Claim 41

In an earth bore logging system of the type including pulse resolver apparatus for restoring two transmitted signal pulses that may be so closely spaced that they merge into a single pulse of longer duration during transmission to the pulse resolver apparatus: means responsive to the signal pulses for generating a trigger pulse having a duration representative of the duration of each signal pulse received at the pulse resolver apparatus and a reference pulse of variable duration greater than the duration of a trigger pulse representing a received unmerged signal pulse; means jointly responsive to the trigger and reference pulses for producing a first pulse if the reference pulse duration exceeds the trigger pulse duration and at least two pulses if the reference pulse duration is less than the trigger pulse duration; means responsive to the trigger pulse duration for controlling the duration of the reference pulse; and means responsive to the rate of occurrence of the signal pulses for selectively disabling the last-named means when said rate varies from a preselected range.