US4780858A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Borehole televiewer mudcake monitor
Assignee: Shell USA Inc
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Filing: 1986-12-29
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Granted: 1988-10-25
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Expires: 2006-12-29
Abstract
Abstract In connection with a borehole televiewer system (10), the delta time (51) between low threshold (54) crossing (T 1 ) and signal peak arrival (T 2 ) provides a measure of mudcake (43) thickness.
Inventors
- 👤 Edward A. Clerke
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 10:05
CPC Classifications
G; G01; G01B; G01B17/00; G01B17/02; G01B17/025; E; E21; E21B; E21B47/00; E21B47/08; E21B47/085; G01V; G01V1/00; G01V1/40; G01V1/44; G01V1/48; G01V1/50
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
136 words
A method for determining the thickness of mudcake on the wall of a borehole, comprising: directing acoustic energy, from a borehole televiewer within the borehole, toward the mudcake; detecting the precursor reflection of the acoustic energy from the mudcake at the borehole/mudcake interface by detecting the time T 1 when the reflected precursor acoustic energy level rises above a predetermined threshold level greater than the background noise level and less than the later signal peak of the reflected acoustic energy; detecting the time T 2 of the reflection of the acoustic energy from the borehole wall at the mudcake/borehole wall interface by detecting the later signal peak arrival of the reflected acoustic energy; and determining the thickness of the mudcake from the difference T 2 -T 1 in the detected mudcake and borehole wall reflection times.
Claim 2
Independent Claim
136 words
A method for determining the thickness of mudcake on the wall of a borehole, comprising: directing acoustic energy, from a borehole televiewer within the borehole, toward the mudcake; detecting the precursor reflection of the acoustic energy from the mudcake at the borehole/mudcake interface by detecting the time T 1 when the reflected precursor acoustic energy level rises above a predetermined threshold level greater than the background noise level and less than the later signal peak of the reflected acoustic energy; detecting the time T 2 of the reflection of the acoustic energy from the borehole wall at the mudcake/borehole wall interface by detecting the later signal peak arrival of the reflected acoustic energy; and determining the thickness of the mudcake from the difference T 2 -T 1 in the detected mudcake and borehole wall reflection times.
Claim 3
Independent Claim
153 words
A method of using a borehole televiewer for determining the thickness of mudcake on the wall of a borehole, comprising: directing a pulse of acoustic energy, from a borehole televiewer within the borehole, substantially radially outwardly toward the mudcake; detecting the precursor reflection of the acoustic energy pulse back to the borehole televiewer from the mudcake at the borehole/mudcake interface by detecting when the reflected precursor acoustic energy level rises above a predetermined threshold level greater than the background noise level and less than the later peak level of the reflected acoustic energy; detecting reflection of the acoustic energy pulse back to the borehole televiewer from the borehole wall at the mudcake/borehole wall interface by detecting when the reflected acoustic energy level later reaches a peak; and determining the thickness of the mudcake from the difference in the time between said detecting of the borehole/mudcake interface reflection and the mudcake/borehole wall interface reflection.
Claim 4
Independent Claim
153 words
A method of using a borehole televiewer for determining the thickness of mudcake on the wall of a borehole, comprising: directing a pulse of acoustic energy, from a borehole televiewer within the borehole, substantially radially outwardly toward the mudcake; detecting the precursor reflection of the acoustic energy pulse back to the borehole televiewer from the mudcake at the borehole/mudcake interface by detecting when the reflected precursor acoustic energy level rises above a predetermined threshold level greater than the background noise level and less than the later peak level of the reflected acoustic energy; detecting reflection of the acoustic energy pulse back to the borehole televiewer from the borehole wall at the mudcake/borehole wall interface by detecting when the reflected acoustic energy level later reaches a peak; and determining the thickness of the mudcake from the difference in the time between said detecting of the borehole/mudcake interface reflection and the mudcake/borehole wall interface reflection.
Claim 5
Dependent Claim
151 words
A borehole televiewer adapted for determining the thickness of mudcake on the wall of a borehole, comprising: means on said borehole televiewer for directing acoustic energy from within the borehole toward the mudcake; means on said borehole televiewer for detecting the precursor reflection of the acoustic energy from the mudcake at the borehole/mudcake interface by detecting the time T 1 when the reflected precursor acoustic energy level rises above a predetermined threshold level greater than the background noise level and less than the later signal peak of the reflected acoustic energy; means for detecting the time T 2 of the reflection of the acoustic energy from the borehole wall at the mudcake/borehole wall interface by detecting the late signal peak arrival of the reflected acoustic energy; and means for determining the thickness of the mudcake from the difference T 2 -T 1 in the detected mudcake and borehole wall reflection times.
Claim 6
Dependent Claim
151 words
A borehole televiewer adapted for determining the thickness of mudcake on the wall of a borehole, comprising: means on said borehole televiewer for directing acoustic energy from within the borehole toward the mudcake; means on said borehole televiewer for detecting the precursor reflection of the acoustic energy from the mudcake at the borehole/mudcake interface by detecting the time T 1 when the reflected precursor acoustic energy level rises above a predetermined threshold level greater than the background noise level and less than the later signal peak of the reflected acoustic energy; means for detecting the time T 2 of the reflection of the acoustic energy from the borehole wall at the mudcake/borehole wall interface by detecting the late signal peak arrival of the reflected acoustic energy; and means for determining the thickness of the mudcake from the difference T 2 -T 1 in the detected mudcake and borehole wall reflection times.
Claim 7
Dependent Claim
169 words
A borehole televiewer adapted for determining the thickness of mudcake on the wall of a borehole, comprising: transducer means on said borehole televiewer for directing a pulse of acoustic energy, from within the borehole, substantially radially outwardly toward the mudcake; transducer means on said borehole televiewer for detecting the precursor reflection of the acoustic energy pulse back to the borehole televiewer from the mudcake at the borehole/mudcake interface by detecting when the reflected precursor acoustic energy level rises above a predetermined threshold level greater than the background noise level and less than the later peak level of the reflected acoustic energy; transducer means on said borehole televiewer for detecting reflection of the acoustic energy pulse back to the borehole televiewer from the borehole wall at the mudcake/borehole wall interface by detecting when the reflected acoustic energy level later reaches a peak; and means associated with said borehole televiewer for determining the thickness of the mudcake from the difference in the time between the detected mudcake and borehole wall reflections.
Claim 8
Dependent Claim
169 words
A borehole televiewer adapted for determining the thickness of mudcake on the wall of a borehole, comprising: transducer means on said borehole televiewer for directing a pulse of acoustic energy, from within the borehole, substantially radially outwardly toward the mudcake; transducer means on said borehole televiewer for detecting the precursor reflection of the acoustic energy pulse back to the borehole televiewer from the mudcake at the borehole/mudcake interface by detecting when the reflected precursor acoustic energy level rises above a predetermined threshold level greater than the background noise level and less than the later peak level of the reflected acoustic energy; transducer means on said borehole televiewer for detecting reflection of the acoustic energy pulse back to the borehole televiewer from the borehole wall at the mudcake/borehole wall interface by detecting when the reflected acoustic energy level later reaches a peak; and means associated with said borehole televiewer for determining the thickness of the mudcake from the difference in the time between the detected mudcake and borehole wall reflections.
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) | 1991-10-25 | 1992-04-25 | 1992-10-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-10-25 | 1996-04-25 | 1996-10-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-10-25 | 2000-04-25 | 2000-10-25 | $7700.00 | Window Closed / Lapsed |