Patent US3701902A successfully refreshed from Google Patents.
US3701902A
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Dual detector compensated density wall logging system
Assignee: Western Atlas International Inc
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Filing: 1971-06-09
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Granted: 1972-10-31
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Expires: 1991-06-09
Abstract
Abstract A density well logging compensation system wherein the outputs of the two detectors, which are spaced different distances from a gamma ray source, are applied to temperature compensated logarithmic amplifiers the outputs of which are compared to derive a correction signal which is employed to correct the output of one of the detectors to give true formation density. In connection with the spine and ribs plot of such a system, provision is made for adjusting both the spine angle and the rib angle so that the compensation system may be employed with density logging tools of different geometries and physical dimensions. Furthermore, provision is made for compensating for curvature of the rib with increasing mudcake thickness. Facilities are also provided for holding the source end of the logging instrument against the borehole wall to minimize errors in the compensated output of the system.
Inventors
- 👤 Hermann W Janssen
- 👤 James F Mooring
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 05:03
CPC Classifications
G; G01; G01V; G01V5/00; G01V5/04; G01V5/08; G01V5/12; G01V5/125
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
130 words
In apparatus for automatically computing a true formation characteristic from first and second input signals representing in a non-linear manner the apparent formation characteristic at two different spacings from a common source, the combination of, means for converting said input signals into signals which are linear with respect to the desired formation characteristic to be recorded, means for comparing said converted signals to produce a correction signal representative of the difference therebetween, means for adjusting the amplitude of one of said converted signals so that said converted signals are equal and said correction signal is zero at a predetermined value of said formation characteristic, and means for adding said correction signal to one of said converted signals to produce a signal representing the true value of said desired formation characteristic.
Claim 2
Dependent Claim
130 words
In apparatus for automatically computing a true formation characteristic from first and second input signals representing in a non-linear manner the apparent formation characteristic at two different spacings from a common source, the combination of, means for converting said input signals into signals which are linear with respect to the desired formation characteristic to be recorded, means for comparing said converted signals to produce a correction signal representative of the difference therebetween, means for adjusting the amplitude of one of said converted signals so that said converted signals are equal and said correction signal is zero at a predetermined value of said formation characteristic, and means for adding said correction signal to one of said converted signals to produce a signal representing the true value of said desired formation characteristic.
Claim 3
Dependent Claim
134 words
In apparatus for automatically computing a true formation characteristic from first and second input signals representing in a non-linear manner the apparent formation characteristic at two different spacings from a common source, the combination of, temperature compensated logarithmic amplifier means for converting said input signals into signals which are linear with respect to the desired formation characteristic to be recorded, means for comparing said converted signals to produce a correction signal representative of the difference therebetween, means for adjusting the amplitude of one of said converted signals so that said converted signals are equal and said correction signal is zero at a predetermined value of said formation characteristic, and means for adding said correction signal to one of said converted signals to produce a signal representing the true value of said desired formation characteristic.
Claim 4
Dependent Claim
134 words
In apparatus for automatically computing a true formation characteristic from first and second input signals representing in a non-linear manner the apparent formation characteristic at two different spacings from a common source, the combination of, temperature compensated logarithmic amplifier means for converting said input signals into signals which are linear with respect to the desired formation characteristic to be recorded, means for comparing said converted signals to produce a correction signal representative of the difference therebetween, means for adjusting the amplitude of one of said converted signals so that said converted signals are equal and said correction signal is zero at a predetermined value of said formation characteristic, and means for adding said correction signal to one of said converted signals to produce a signal representing the true value of said desired formation characteristic.
References Cited (Backward Citations)
US3321625A
Cited
US3508439A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-10-31 | 1976-05-01 | 1976-10-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-31 | 1980-05-01 | 1980-10-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-31 | 1984-05-01 | 1984-10-31 | $7700.00 | Window Closed / Lapsed |