US3670567A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Measuring borehole temperatures employing diode junction means
Assignee: WORTH WELL SURVEYS Inc
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Filing: 1969-09-08
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Granted: 1972-06-20
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Expires: 1989-09-08
Abstract
Abstract Method and apparatus for measuring temperatures and temperature anomalies along the longitudinal axis of a borehole penetrating subterranean formations characterized by employing a constant current flowing through a diode junction means and measuring the variations in voltage across the junction as an indication of the temperature. The diode junction means is linear up to temperatures of about 350* F and linear enough to be usable to temperatures as high as 400* F. Signals are generated that are related by the voltage drop across the diode junction means to the temperature and transmitted to the surface where they are converted to an analog indication of temperature. The analog indication of temperature is differentiated to emphasize temperature anomalies. Specific structure of the diode junction means and a temperature compensated constant current regulator is also disclosed.
Inventors
- 👤 Beauford F Stout
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 19:43
CPC Classifications
E; E21; E21B; E21B47/00; E21B47/06; E21B47/07
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
160 words
A method of measuring temperature in a borehole penetrating subterranean formations comprising: a. flowing a constant current through a forward biased diode junction means having a substantially linearly varying voltage drop at a constant current within the temperature range of 60*350* F; b. moving said diode junction means to a plurality of depths in said borehole and generating and transmitting to the surface signals that are a function of the voltage drop across said diode junction means at said constant current; and c. at the surface converting said signals to a second analog signal that is a function of the temperature at the respective depth in the borehole and differentiating said second analog signal to produce an indication of change in the temperature gradient along said borehole, and recording with respect to said depth in said borehole said second analog signal affording indicia of absolute temperature and the differential of said second analog signal indicating a change in temperature gradient.
Claim 2
Independent Claim
160 words
A method of measuring temperature in a borehole penetrating subterranean formations comprising: a. flowing a constant current through a forward biased diode junction means having a substantially linearly varying voltage drop at a constant current within the temperature range of 60*350* F; b. moving said diode junction means to a plurality of depths in said borehole and generating and transmitting to the surface signals that are a function of the voltage drop across said diode junction means at said constant current; and c. at the surface converting said signals to a second analog signal that is a function of the temperature at the respective depth in the borehole and differentiating said second analog signal to produce an indication of change in the temperature gradient along said borehole, and recording with respect to said depth in said borehole said second analog signal affording indicia of absolute temperature and the differential of said second analog signal indicating a change in temperature gradient.
Claim 3
Dependent Claim
28 words
The method of claim 1 wherein said diode junction means comprise a plurality of diode junctions employed in series to increase sensitivity of the temperature sensor thereby effected.
Claim 4
Dependent Claim
315 words
In apparatus for measuring temperature and change in temperature in a borehole penetrating subterranean formations by employing above-ground equipment; a downhole tool suspended on a cable within said borehole for movement along the longitudinal axis of said borehole; and depth measuring means for determining the depth of said tool in said borehole, the improvement comprising: a. diode junction means for measuring temperature, said diode junction means being disposed in said downhole tool and having a substantially linearly varying voltage drop at a constant current within the temperature range of 60*-350* F; b. a constant current regulator means and a power supply means for maintaining a constant current flowing through said diode junction means, said constant current regulator means and said power supply means being serially connected in the forward biased direction with said diode junction means; c. signal generating means for generating signals that are a function of the voltage present at the juncture of said diode junction means and said constant current regulator means, said signal generating means being connected with said diode junction means; d. transmitter means for transmitting said signals to the above-ground equipment, said transmitter means being connected with said signal generating means and with the conductor means in said cable for effecting an electrically continuous path; e. converting means for effecting an analog indication of said temperature in response to said signals, said converting means being disposed in said above-ground equipment and connected with said transmitter means; f. differentiator means for differentiating said analog indication of temperature to effect an indication of temperature anomalies along the longitudinal axis of said borehole, said differentiator means being connected with said converting means; and g. recorder means for recording with respect to depth said analog indication of temperature and said indication of temperature anomAlies, said recorder means being connected with said depth measuring means, with said converting means and with said differentiator means.
Claim 5
Dependent Claim
315 words
In apparatus for measuring temperature and change in temperature in a borehole penetrating subterranean formations by employing above-ground equipment; a downhole tool suspended on a cable within said borehole for movement along the longitudinal axis of said borehole; and depth measuring means for determining the depth of said tool in said borehole, the improvement comprising: a. diode junction means for measuring temperature, said diode junction means being disposed in said downhole tool and having a substantially linearly varying voltage drop at a constant current within the temperature range of 60*-350* F; b. a constant current regulator means and a power supply means for maintaining a constant current flowing through said diode junction means, said constant current regulator means and said power supply means being serially connected in the forward biased direction with said diode junction means; c. signal generating means for generating signals that are a function of the voltage present at the juncture of said diode junction means and said constant current regulator means, said signal generating means being connected with said diode junction means; d. transmitter means for transmitting said signals to the above-ground equipment, said transmitter means being connected with said signal generating means and with the conductor means in said cable for effecting an electrically continuous path; e. converting means for effecting an analog indication of said temperature in response to said signals, said converting means being disposed in said above-ground equipment and connected with said transmitter means; f. differentiator means for differentiating said analog indication of temperature to effect an indication of temperature anomalies along the longitudinal axis of said borehole, said differentiator means being connected with said converting means; and g. recorder means for recording with respect to depth said analog indication of temperature and said indication of temperature anomAlies, said recorder means being connected with said depth measuring means, with said converting means and with said differentiator means.
Claim 6
Dependent Claim
28 words
The apparatus of claim 3 wherein said diode junction means comprise a plurality of diode junctions employed in series to increase sensitivity of the temperature sensor thereby effected.
Claim 7
Dependent Claim
57 words
The apparatus of claim 3 wherein an amplifier means is serially connected with said diode junction means and with said signal generating means for generating and supplying to said signal generating means an output signal that is a function of the voltage present at said juncture of said diode junction means and said constant current regulator means.
Claim 8
Dependent Claim
28 words
The apparatus of claim 5 wherein said diode junction means comprise a plurality of diode junctions employed in series to increase sensitivity of the temperature sensor thereby effected.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-06-20 | 1975-12-20 | 1976-06-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-20 | 1979-12-20 | 1980-06-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-20 | 1983-12-20 | 1984-06-20 | $7700.00 | Window Closed / Lapsed |