US4809237A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for monitoring the goodness of the cement bond to a borehole casing
Assignee: Western Atlas International Inc
•
Filing: 1987-10-01
•
Granted: 1989-02-28
•
Expires: 2007-10-01
Abstract
Abstract A method for monitoring the relative goodness of a cement bond to a borehole casing by observing the relative change in amplitude of a converted-compressional wave as a function of depth in the borehole.
Inventors
- 👤 Charles B. Vogel
- 👤 Mike Davis
- 👤 James O. Guy
- 👤 John R. E. Smith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 03:54
CPC Classifications
G; G01; G01V; G01V1/00; G01V1/28; G01V1/284; G01V1/286; E; E21; E21B; E21B47/00; E21B47/005; G01V1/40; G01V1/44; G01V1/46
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
132 words
A method for monitoring the goodness of a cement bond to a borehole casing, comprising the steps of: suspending an acoustic logging tool in a cased borehole, the casing being characterized by a transverse-wave propagation velocity of V m , said logging tool including an acoustic transmitter element and an acoustic receiver element that is spaced apart from said transmitter element, said transmitter and receiver elements being characterized by two orthogonal dimensions, one of which is of a preselected length L; insonifying said casing at normal incidence thereto with acoustic radiation from said transmitter element in the spectral region of a frequency component, f, given by f=V.sub.m /2L, and detecting the converted-compresional waves emanating from said casing along the normal thereto at a point along the casing opposite to said receiver element.
Claim 2
Independent Claim
132 words
A method for monitoring the goodness of a cement bond to a borehole casing, comprising the steps of: suspending an acoustic logging tool in a cased borehole, the casing being characterized by a transverse-wave propagation velocity of V m , said logging tool including an acoustic transmitter element and an acoustic receiver element that is spaced apart from said transmitter element, said transmitter and receiver elements being characterized by two orthogonal dimensions, one of which is of a preselected length L; insonifying said casing at normal incidence thereto with acoustic radiation from said transmitter element in the spectral region of a frequency component, f, given by f=V.sub.m /2L, and detecting the converted-compresional waves emanating from said casing along the normal thereto at a point along the casing opposite to said receiver element.
Claim 3
Dependent Claim
36 words
The method as defined by claim 1, further comprising: filtering the detected converted-compressional waves, thereby to discriminate against primary compressional waves and to enhance received signals in the acoustic spectral region of said frequency component, f.
Claim 4
Dependent Claim
45 words
The method as defined by claim 2, further comprising: comparing the relative amplitudes of the detected filtered, converted-compressional waves as a function of the depth of the logging tool in said borehole, thereby to determine the relative goodness of said cement bond along the casing.
Claim 5
Dependent Claim
40 words
The method as defined by claim 2, further comprising: comparing the relative amplitude of the detected, filtered converted-compressional waves as a function of the azimuth around the borehole casing, thereby to determine the relative goodness of the cement bond therearound.
Claim 6
Dependent Claim
26 words
The method as defined by claim 3, further comprising: spacing-apart said transmitter element from said receiver element by a preselected multiple, M, of said length L.
Claim 7
Dependent Claim
30 words
The method as defined by claim 5, comprising: selecting said length, L, to be commensurate with the physical size of said logging tool and the diameter of the borehole casing.
References Cited (Backward Citations)
US3265151A
Cited
US3276533A
Cited
US3358788A
Cited
US3333238A
Cited
US3376950A
Cited
US3330375A
Cited
US3340953A
Cited
US4131875A
Cited
US4255798A
Cited
US4516228A
Cited
US4685092A
Cited
US4733380A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-02-28 | 1992-08-29 | 1993-02-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-02-28 | 1996-08-29 | 1997-02-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-02-28 | 2000-08-29 | 2001-02-28 | $7700.00 | Window Closed / Lapsed |