US4629986A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Nuclear magnetic loggins
Assignee: BTG International Ltd
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Filing: 1984-05-24
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Granted: 1986-12-16
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Expires: 2004-05-24
Abstract
Abstract An elongated probe suitable for lowering down a borehole for nuclear magnetic logging has a pair of similar cylindrical magnets 1 and 2 separated by a gap in which a solenoid 3 is symmetrically disposed. The solenoid has a core 4 of high permeability ferrimagnetic material and has a length preferably equal to half the length of the gap. The magnets 1 and 2 and solenoid 3 with its core 4 are contained within a hollow cylindrical casing 5 of non-magnetic material.
Inventors
- 👤 Hugh Clow
- 👤 William S. Percival
- 👤 Peter E. Walters
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 15:17
CPC Classifications
G; G01; G01N; G01N24/00; G01N24/08; G01N24/081; G01V; G01V3/00; G01V3/18; G01V3/32
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
81 words
A probe for use in nuclear magnetic logging, the probe being of elongated form suitable for lowering down a borehole with its longitudinal axis extending vertically, and incorporating a pair of similar cylindrical permanent magnets disposed with their axes substantially coincident with said longitudinal axis and separated by a gap extending between like poles of the two magnets, a solenoid disposed about the centre of said gap coaxial with the magnets, and a core of magnetic material disposed within the solenoid.
Claim 2
Dependent Claim
81 words
A probe for use in nuclear magnetic logging, the probe being of elongated form suitable for lowering down a borehole with its longitudinal axis extending vertically, and incorporating a pair of similar cylindrical permanent magnets disposed with their axes substantially coincident with said longitudinal axis and separated by a gap extending between like poles of the two magnets, a solenoid disposed about the centre of said gap coaxial with the magnets, and a core of magnetic material disposed within the solenoid.
Claim 3
Dependent Claim
17 words
The probe as claimed in claim 1 in which the solenoid is disposed symmetrically in said gap.
Claim 4
Dependent Claim
27 words
The probe as claimed in claim 1 in which the length of the solenoid is approximately equal to half the length of the gap between the magnets.
Claim 5
Dependent Claim
18 words
The probe as claimed in claim 1 in which the core is of a high permeability ferrimagnetic material.
Claim 6
Dependent Claim
19 words
The probe as claimed in claim 1 in which the magnets are fabricated from material incorporating a cobalt/samarium alloy.
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) | 1989-12-15 | 1990-06-16 | 1990-12-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-12-15 | 1994-06-16 | 1994-12-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-12-15 | 1998-06-16 | 1998-12-16 | $7700.00 | Window Closed / Lapsed |