US3773120A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Selective firing indicator and recorder
Assignee: Individual
•
Filing: 1972-08-02
•
Granted: 1973-11-20
•
Expires: 1992-08-02
Abstract
Abstract In a multiple perforating gun wherein each in a series of guns is successively fired, the firing arming the next gun in the series, resistors are provided in series with the gun actuating circuit in such a fashion, and in connection with surface control, readout, and recorder equipment, that the condition of the tool is continuously displayed and indicated, whereby a tally may be kept as to the exact guns fired, and down-the-hole irregularities such as shorts or open circuits may be evidenced.
Inventors
- 👤 S Stroud
- 👤 J Estes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 22:48
CPC Classifications
E; E21; E21B; E21B43/00; E21B43/11; E21B43/116; E21B43/1185; E21B43/11857
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
185 words
In a subsurface multiple perforating gun and surface control and measuring assembly comprising a series of guns in vertical array, and wherein each gun in said series is successively fired by a firing pulse which is passed through a circuit extending throughout the series and switched into only one gun at a time, said firing switching in the next gun in the series, each said gun carrying a diode in its firing circuit, with each successive such diode being connected with alternating polarity, the improvement which comprises the provision of a resistor in said circuit for each said gun except for the first gun, each said resistor serving to conduct said firing pulse to any next adjacent gun which is not yet switched to its firing position, and each said resistor being shorted out when its associated gun is switched into firing position; impedance measuring means operating at a level too low to cause firing of said guns and serving to determine the direct current impedance of said circuit at both positive and negative polarities; indicating means to indicate the results of said impedance measuring.
Claim 2
Dependent Claim
185 words
In a subsurface multiple perforating gun and surface control and measuring assembly comprising a series of guns in vertical array, and wherein each gun in said series is successively fired by a firing pulse which is passed through a circuit extending throughout the series and switched into only one gun at a time, said firing switching in the next gun in the series, each said gun carrying a diode in its firing circuit, with each successive such diode being connected with alternating polarity, the improvement which comprises the provision of a resistor in said circuit for each said gun except for the first gun, each said resistor serving to conduct said firing pulse to any next adjacent gun which is not yet switched to its firing position, and each said resistor being shorted out when its associated gun is switched into firing position; impedance measuring means operating at a level too low to cause firing of said guns and serving to determine the direct current impedance of said circuit at both positive and negative polarities; indicating means to indicate the results of said impedance measuring.
Claim 3
Dependent Claim
17 words
The assembly of claim 1 which comprises recording means to record the results of said impedance measurements.
Claim 4
Dependent Claim
35 words
The assembly of claim 1 including means to carry out said impedance measurements by a continuous series of successive fixed current pulses of both positive and neGative current insufficient to fire any of said guns.
Claim 5
Dependent Claim
42 words
The assembly of claim 3 in which said measuring current pulses consist of a relatively high positive current, followed by a relatively low positive current, followed by a relatively high negative current, followed by a relatively low negative current, repeatedly in succession.
Claim 6
Dependent Claim
58 words
The assembly of claim 4 in which said indicating means is actuated by the voltages generated by said measuring current pulses to indicate the various conditions of said gun as to whether a short circuit exists, an open circuit exists, or whether the next gun in firing condition is actuated by a positive or by a negative pulse.
Claim 7
Dependent Claim
27 words
The assembly of claim 4 in which said measuring current pulses actuate a recorder which registers the impedance thus determined and also the polarity for minimum impedance.
Claim 8
Dependent Claim
24 words
The assembly of claim 4 in which said relatively high currents are about 5 milliamperes and said relatively low currents are about 1 milliampere.
Claim 9
Dependent Claim
16 words
The assembly of claim 7 in which the duration of each pulse is about 33 milliseconds.
Claim 10
Dependent Claim
13 words
The assembly of claim 7 in which said resistors are about 10 ohms.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-11-19 | 1977-05-21 | 1977-11-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-19 | 1981-05-21 | 1981-11-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-19 | 1985-05-21 | 1985-11-20 | $7700.00 | Window Closed / Lapsed |