Patent US3916685A successfully refreshed from Google Patents.
US3916685A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Well logging system and method using an armored coaxial cable and compensation circuit
Assignee: Individual
•
Filing: 1971-10-27
•
Granted: 1975-11-04
•
Expires: 1991-10-27
Abstract
Abstract A well logging system comprising a transmitter in a borehole having a sensor such as a radiation detector, a condition relating to the earth''s formation traversed by the borehole and providing data pulses corresponding in number and peak amplitude to the sensed condition. The transmitter also includes a reference pulse source and means for combining the reference pulses and the data pulses. The combined pulses are conducted to a receiver at the surface by an inner conductor of an armored coaxial cable. The shield of the armored coaxial cable is insulated from the inner conductor and from an outer cable armor which surrounds it. The shield provides a return path for the combined pulses thereby reducing the skin effect encountered when using the outer armor as a return path. High voltage for energizing the sensor is also conducted to the sensor by the inner conductor of the armored coaxial cable from a direct current power supply on the surface. Low voltage is conducted by the shield of the armored coaxial cable from the power supply to the sensor, to the reference pulse source and to the combining means while the outer armor of the armored coaxial cable provides a common ground connection between the transmitter, the power supply and the receiver. The receiver includes a compensating circuit which monitors the reference pulses and adjusts the data pulses in accordance with the monitored reference pulses to compensate for deterioration of the data pulses during their transmission. The receiver also includes recording means which provides a record of the sensed nature of the earth formation in accordance with the compensated data pulses. The invention is of particular utility as embodied in a nuclear logging system.
Inventors
- 👤 Hans J Paap
- 👤 Jr Robert W Pitts
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 21:29
CPC Classifications
G; G01; G01V; G01V5/00; G01V5/04; G01V5/045; E; E21; E21B; E21B47/00; E21B47/12
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
200 words
A well logging system for providing an output corresponding to a condition sensed in a borehole, comprising a logging instrument including means for providing a signal representative of said condition sensed in the borehole and means for providing a reference signal; a transmission system comprising an armored coaxial cable connected between said logging instrument and surface electronics adjacent the borehole, said cable comprising an inner coaxial conductor, an outer coaxial conductor separated from said inner conductor by a coaxial first insulator, and an outer armor of conductive material separated from said outer conductor by a coaxial second insulator, said logging instrument further includes means for applying said condition signal and said reference signal to one end of said transmission system; said surface electronics comprising receiving means coupled to the other end of said transmission system for receiving said signals over armored coaxial cable from the signal applying means, compensating means connected to the receiving means for adjusting said signals from the receiving means to compensate for deterioration of said signals to provide compensated signals and means connected to the compensating means for providing the output corresponding to said sensed condition in accordance with the compensated signals from the compensating means.
Claim 2
Dependent Claim
200 words
A well logging system for providing an output corresponding to a condition sensed in a borehole, comprising a logging instrument including means for providing a signal representative of said condition sensed in the borehole and means for providing a reference signal; a transmission system comprising an armored coaxial cable connected between said logging instrument and surface electronics adjacent the borehole, said cable comprising an inner coaxial conductor, an outer coaxial conductor separated from said inner conductor by a coaxial first insulator, and an outer armor of conductive material separated from said outer conductor by a coaxial second insulator, said logging instrument further includes means for applying said condition signal and said reference signal to one end of said transmission system; said surface electronics comprising receiving means coupled to the other end of said transmission system for receiving said signals over armored coaxial cable from the signal applying means, compensating means connected to the receiving means for adjusting said signals from the receiving means to compensate for deterioration of said signals to provide compensated signals and means connected to the compensating means for providing the output corresponding to said sensed condition in accordance with the compensated signals from the compensating means.
Claim 3
Dependent Claim
34 words
A system as described in claim 1 in which the applying means applies the condition signal and the reference signal across the inner coaxial conductor, the outer coaxial conductor, and the coaxial first insulator.
Claim 4
Dependent Claim
79 words
A system as described in claim 2 in which the logging instrument requires direct current operating voltages, and the surface electronics further comprises a direct current voltage source connected to the armored coaxial cable, and providing a direct current voltage of one amplitude, with respect to ground, to the inner coaxial conductor of the armored coaxial cable, and a direct current voltage of another amplitude, with respect to ground, to the outer coaxial conductor of the armored coaxial cable.
Claim 5
Dependent Claim
27 words
A system as describeD in claim 1 in which the applying means includes a low noise discriminator to prevent noise from being transmitted by the transmission system.
Claim 6
Dependent Claim
215 words
A system as described in claim 4 in which the condition signal has pulses corresponding in number and peak amplitude to the sensed condition and the reference signal has reference pulses of a predetermined amplitude; and the low noise discriminator includes amplifying means connected to the condition signal means and to the reference signal means for providing an output comprising amplified condition and reference pulses, means connected to the amplifying means for delaying the output from the amplifying means, means connected to the amplifying means and receiving a reference voltage corresponding to a predetermined noise level for comparing the output from the amplifying means with the reference voltage and providing a control pulse when the output from the amplifying means is greater than reference voltage and no control pulse when the output from the amplifying means is not greater than the reference voltage, and switching means connected to the delay means, to the comparing means and to the transmission system for passing the delayed output from the delay means to the transmission system in response to a control pulse from the comparing means and for blocking the delayed output from the delay means during the absence of a control pulse so as to effectively pass the amplified condition and reference pulses to the transmission system.
Claim 7
Dependent Claim
120 words
A system as described in claim 1 further comprising a tape recording system which includes means connected to the output means for converting the output corresponding to said condition to digital signals, at least two memory sections, means for recording digital signals on a magnetic tape, switching means connecting the converting means to the memory sections for alternately storing the digital signals from the converting means in one memory section and then the other memory section, and control means connected to the memory sections and to the tape recording means for controlling each memory section to transfer its digital signal content to the tape recording means while the other memory section is storing the digital signals from the converting means.
Claim 8
Independent Claim
222 words
A system for providing an output corresponding to a condition sensed in a borehole, comprising a logging instrument adapted to be passed in a borehole, said instrument including means for providing pulses representative of said condition sensed in the borehole, means for providing reference pulses of a predetermined amplitude; a transmission system comprising an armored coaxial cable connected between said logging instrument and surface electronics adjacent to the borehole, said cable comprising an inner coaxial conductor, an outer coaxial conductor separated from said inner conductor by a coaxial first insulator and an outer armor of conductive material separated from said outer conductor by a coaxial second insulator, said logging instrument further includes means for applying said condition pulses and said reference pulses to one end of said transmission system, said surface electronics comprising receiving means coupled to the other end of said transmission system for receiving said pulses over said armored coaxial cable from the pulse applying means, compensating means connected to the receiving means for adjusting said pulses from the receiving means to compensate for deterioration of said pulses in accordance with the change in the amplitudes of said reference pulses to provide compensated pulses, and means connected to the compensating means for roviding the output corresponding to said sensed condition in accordance with the compensated pulses from the compensating means.
Claim 9
Independent Claim
222 words
A system for providing an output corresponding to a condition sensed in a borehole, comprising a logging instrument adapted to be passed in a borehole, said instrument including means for providing pulses representative of said condition sensed in the borehole, means for providing reference pulses of a predetermined amplitude; a transmission system comprising an armored coaxial cable connected between said logging instrument and surface electronics adjacent to the borehole, said cable comprising an inner coaxial conductor, an outer coaxial conductor separated from said inner conductor by a coaxial first insulator and an outer armor of conductive material separated from said outer conductor by a coaxial second insulator, said logging instrument further includes means for applying said condition pulses and said reference pulses to one end of said transmission system, said surface electronics comprising receiving means coupled to the other end of said transmission system for receiving said pulses over said armored coaxial cable from the pulse applying means, compensating means connected to the receiving means for adjusting said pulses from the receiving means to compensate for deterioration of said pulses in accordance with the change in the amplitudes of said reference pulses to provide compensated pulses, and means connected to the compensating means for roviding the output corresponding to said sensed condition in accordance with the compensated pulses from the compensating means.
Claim 10
Dependent Claim
99 words
A system as described in claim 7 in which the compensating means includes adjusting means connected to the receiving means and to the output means for changing the amplitudes of the pulses from the receiving means in accordance with a control voltage tO provide the compensated pulses, means for providing a direct current reference voltage, and comparing means connected to the adjusting means and receiving said direct current reference voltage for comparing the reference pulses in the compensated pulses with the last mentioned direct current voltage to the adjusting means as said control voltage in accordance with the comparison.
Claim 11
Dependent Claim
228 words
A nuclear well logging system for providing an output corresponding to a condition sensed in a borehole, comprising a logging instrument adapted to be passed through a borehole, said instrument including detecting means responsive to penetration radiation in the borehole for providing data pulses corresponding in number and peak amplitude to the detected penetration radiation, and means for providing reference pulses; a transmission system comprising an armored coaxial cable connected between said logging instrument and surface electronics adjacent the borehole, said cable comprising an inner coaxial conductor, and outer coaxial conductor separated from said inner conductor by a coaxial first insulator, and an outer armor of conductive material separated from said outer conductor by a coaxial second insulator, said logging instrument further includes means for applying said data pulses and said reference pulses to one end of said transmission system; and said surface electronics comprising receiving means coupled to the other end of said transmission system for receiving said data pulses and said reference pulses over the armored coaxial cable from the pulse applying means, compensating means connected to the receiving means for adjusting said received pulses from the receiving means to compensate for deterioration of said pulses to provide compensated pulses, and means connected to the compensating means for providing the output corresponding to said sensed condition in accordance with the compensated pulses from the compensating means.
Claim 12
Dependent Claim
228 words
A nuclear well logging system for providing an output corresponding to a condition sensed in a borehole, comprising a logging instrument adapted to be passed through a borehole, said instrument including detecting means responsive to penetration radiation in the borehole for providing data pulses corresponding in number and peak amplitude to the detected penetration radiation, and means for providing reference pulses; a transmission system comprising an armored coaxial cable connected between said logging instrument and surface electronics adjacent the borehole, said cable comprising an inner coaxial conductor, and outer coaxial conductor separated from said inner conductor by a coaxial first insulator, and an outer armor of conductive material separated from said outer conductor by a coaxial second insulator, said logging instrument further includes means for applying said data pulses and said reference pulses to one end of said transmission system; and said surface electronics comprising receiving means coupled to the other end of said transmission system for receiving said data pulses and said reference pulses over the armored coaxial cable from the pulse applying means, compensating means connected to the receiving means for adjusting said received pulses from the receiving means to compensate for deterioration of said pulses to provide compensated pulses, and means connected to the compensating means for providing the output corresponding to said sensed condition in accordance with the compensated pulses from the compensating means.
Claim 13
Dependent Claim
15 words
A system as described in claim 9 wherein the penetration radiation is neutron-induced gamma radiation.
Claim 14
Dependent Claim
15 words
A system as described in claim 10 wherein the penetration radiation is natural gamma radiation.
References Cited (Backward Citations)
US2350371A
Cited
US2848710A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-11-03 | 1979-05-05 | 1979-11-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-03 | 1983-05-05 | 1983-11-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-03 | 1987-05-05 | 1987-11-04 | $7700.00 | Window Closed / Lapsed |