US4791797A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Density neutron self-consistent caliper
Assignee: Baroid Technology Inc
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Filing: 1988-02-17
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Granted: 1988-12-20
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Expires: 2008-02-17
Abstract
Abstract Two downhole measurement-while-drilling tools, at least one of which is borehole sensitive, are used to make standard measurements of borehole conditions while drilling. From these measurements, and with some prior knowledge of the lithology, the caliber of the borehole is determined by iteration. The preferred tools are a neutron porosity and a density tool with lithology having been determined by prior seismic survey techniques.
Inventors
- 👤 William C. Paske
- 👤 Paul F. Rodney
- 👤 Ray A. Roeder
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 15:12
CPC Classifications
E; E21; E21B; E21B49/00; E21B47/00; E21B47/08; E21B47/085
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
107 words
A system for determining the caliber of a borehole during drilling operations in an earth formation, comprising: first means adapted to make a first measurement of a first physical characteristic of an interior property of said formation; second means adapted to make a second measurement of a second physical characteristic of an interior property of said formation, said second physical characteristic being different from said first physical characteristic; means for determining the lithology of said formation; and means to compare said first and second measurements and to initiate an interation process based at least in part upon the said determined lithology, to determine a self-consistant borehole caliber.
Claim 2
Independent Claim
107 words
A system for determining the caliber of a borehole during drilling operations in an earth formation, comprising: first means adapted to make a first measurement of a first physical characteristic of an interior property of said formation; second means adapted to make a second measurement of a second physical characteristic of an interior property of said formation, said second physical characteristic being different from said first physical characteristic; means for determining the lithology of said formation; and means to compare said first and second measurements and to initiate an interation process based at least in part upon the said determined lithology, to determine a self-consistant borehole caliber.
Claim 3
Dependent Claim
17 words
A system according to claim 1 wherein said first measurement is porosity and said second measurement density.
Claim 4
Dependent Claim
17 words
A system according to claim 1 wherein one of said first or second means is borehole dependent.
Claim 5
Dependent Claim
21 words
A system according to claim 1 wherein at least one of said first or said second means is a neutron tool.
Claim 6
Dependent Claim
15 words
A system according to claim 1 wherein said first means is a density measuring tool.
Claim 7
Dependent Claim
17 words
A system according to claim 5 wherein said density measuring tool is an active gamma ray tool.
Claim 8
Dependent Claim
15 words
A system according to claim 5 wherein said density measuring tool is an acoustic tool.
Claim 9
Dependent Claim
15 words
A system according to claim 1 wherein said second means is a porosity measuring tool.
Claim 10
Dependent Claim
14 words
A system according to claim 8 wherein said second means is a resistivity tool.
Claim 11
Dependent Claim
16 words
A system according to claim 8 wherein said second means is an electromagnetic wave resistivity tool.
Claim 12
Dependent Claim
29 words
A system according to claim 1 wherein a change in reading of both said first and said second means is indicative of the presence of gas in said borehole.
Claim 13
Dependent Claim
23 words
A system according to claim 1 wherein said first means is a neutron porosity tool and said second means is a density tool.
Claim 14
Dependent Claim
23 words
A system according to claim 1 wherein said first means is a neutron porosity tool and said second means is a resistivity tool.
Claim 15
Dependent Claim
25 words
A system according to claim 1 wherein said first means and said second means have different operating characteristics thereby providing a cross check on readings.
Claim 16
Independent Claim
97 words
A method for determining the caliber of a borehole during drilling operations in an earth formation, comprising the steps of: taking a first measurement of a first interior physical property of a formation through which said borehole is passing; taking a second measurement of a second interior physical property of said formation, said second physical property being different from said first physical property; determining the lithology of said formation; and comparing said first and second measurements, and based at least in part upon the said determined lithology, initiating an iteration process to determine a self-consistent borehole caliber.
Claim 17
Independent Claim
97 words
A method for determining the caliber of a borehole during drilling operations in an earth formation, comprising the steps of: taking a first measurement of a first interior physical property of a formation through which said borehole is passing; taking a second measurement of a second interior physical property of said formation, said second physical property being different from said first physical property; determining the lithology of said formation; and comparing said first and second measurements, and based at least in part upon the said determined lithology, initiating an iteration process to determine a self-consistent borehole caliber.
Claim 18
Dependent Claim
14 words
A method according to claim 15 wherein said first measurement is a density measurement.
Claim 19
Dependent Claim
14 words
A method according to claim 15 wherein said second measurement is a porosity measurement.
Claim 20
Dependent Claim
16 words
A method according to claim 15 wherein said lithology determination is made by a seismic survey.
Claim 21
Dependent Claim
15 words
A method according to claim 15 wherein said lithology determination is made by offset logs.
Claim 22
Dependent Claim
16 words
A method according to claim 15 wherein one of said measurements is made by nuclear means.
Claim 23
Dependent Claim
20 words
A method according to claim 15 wherein at least one of said measurements is made by a borehole dependent tool.
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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) | 1991-12-20 | 1992-06-20 | 1992-12-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-12-20 | 1996-06-20 | 1996-12-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-12-20 | 2000-06-20 | 2000-12-20 | $7700.00 | Window Closed / Lapsed |