US3766388A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Radioactive tracer method and apparatus for boreholes
Assignee: GEN NUCLEAR Inc
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Filing: 1971-06-04
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Granted: 1973-10-16
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Expires: 1991-06-04
Abstract
Abstract Improved well-logging apparatus is provided which employs a long-lived radioactive material for tracing the flow path of fluid traveling in a subterranean borehole. The radioactive source is a porous capsule containing a long-lived parent isotope in a granule form incapable of permeating the wall of the capsule, but producing non-granulated daughter product having a short half-life. A flush of solvent is passed through the capsule and into the borehole to dissolve away the daughter product and to redeposit it in the borehole. Hence, the long-lived parent isotope is kept from contaminating the borehole, and only the short-lived daughter product is used which disappears in a relatively short interval.
Inventors
- 👤 J Greaney
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 23:31
CPC Classifications
G; G01; G01V; G01V5/00; G01V5/04; G01V5/08
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
91 words
A system for tracing fluid flow in a subterranean borehole or the like, comprising an elongate housing means adapted to be passed through said borehole, a first radiation detector disposed in one end of said housing, a second radiation detector disposed in the other end of said housing, and isotope separation means within said housing including a longlived isotope and means for deriving a relatively short-lived radioactive isotope from said relatively long-lived istope and for introducing only said derived short-lived isotope into said borehole at a location generally between said detectors.
Claim 2
Independent Claim
91 words
A system for tracing fluid flow in a subterranean borehole or the like, comprising an elongate housing means adapted to be passed through said borehole, a first radiation detector disposed in one end of said housing, a second radiation detector disposed in the other end of said housing, and isotope separation means within said housing including a longlived isotope and means for deriving a relatively short-lived radioactive isotope from said relatively long-lived istope and for introducing only said derived short-lived isotope into said borehole at a location generally between said detectors.
Claim 3
Dependent Claim
23 words
The system described in claim 1, wherein said isotope separation means is further adapted to isolate said long-lived radioactive material from said borehole.
Claim 4
Dependent Claim
29 words
The system described in claim 2, wherein said isotope separation means is further adapted to derive a predetermined quantity of said short-lived radioactive material from said long-lived radioactive material.
Claim 5
Dependent Claim
37 words
The system described in claim 3, wherein said long-lived radioactive material, is a quantity of an unstable isotope encapsulated by said isotope separation means and wherein said unstable isotope decays to produce a short-lived radioactive daughter product.
Claim 6
Dependent Claim
68 words
The system described in claim 4, wherein said isotope separation means comprises a quantity of non-radioactive granulated material capable of entering into ion exchange with said isotope but not with said daughter product, a capsule means enclosing said granulated material and having a porous wall portion permeable by said daughter product, and rinsing means for discharging a flow of solvent through said capsule means and into said borehole.
Claim 7
Dependent Claim
32 words
The system described in claim 5, further comprising signalling means interconnected with said detectors for generating and transmitting information to the surface of the earth relative to fluid movement in said borehole.
Claim 8
Dependent Claim
28 words
The system described in claim 6, further comprising actuating means interconnected to energize said rinsing means to discharge a predetermined quantity of said solvent through said capsule means.
Claim 9
Dependent Claim
22 words
The system described in claim 7, wherein said unstable isotope is substantially composed of cesium-137, and wherein said solvent is hydrochloric acid.
Claim 10
Independent Claim
93 words
A method of tracing fluid flow in a subterranean borehole, comprising establishing in said borehole a quantity of radioactive tracer material composed of an unstable isotope having a relatively long life and decaying to form a quantity of an unstable daughter product having a substantially short half-life, isolating said quantity of said isotope from fluids in and from earth materials surrounding said borehole, separating said quantity of said daughter product from said isolated quantity of said isotope having a long half-life, and releasing said separated quantity of said daughter product into said borehole.
Claim 11
Independent Claim
93 words
A method of tracing fluid flow in a subterranean borehole, comprising establishing in said borehole a quantity of radioactive tracer material composed of an unstable isotope having a relatively long life and decaying to form a quantity of an unstable daughter product having a substantially short half-life, isolating said quantity of said isotope from fluids in and from earth materials surrounding said borehole, separating said quantity of said daughter product from said isolated quantity of said isotope having a long half-life, and releasing said separated quantity of said daughter product into said borehole.
Claim 12
Dependent Claim
106 words
The method described in claim 9, including the steps of disposing said quantity of unstable isotope in isolation in said borehole for a first time period sufficient to permit a maximum amount of said daughter product to accumulate in combination therewith, separating said accumulated amount of daughter product from said quantity of isotope and releasing said separated daughter product into said borehole, and after a second time period at least as long as twice the half-life of said daughter product and not greater than three times said halF-life thereof separating from said isotope and releasing into said borehole any daughter product accumulated with said isolated isotope.
References Cited (Backward Citations)
US27272A
Cited
US2835699A
Cited
US3123708A
Cited
US2385378A
Cited
US2617941A
Cited
US3010023A
Cited
US3369121A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-10-15 | 1977-04-16 | 1977-10-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-15 | 1981-04-16 | 1981-10-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-15 | 1985-04-16 | 1985-10-16 | $7700.00 | Window Closed / Lapsed |