US4259868A
Expired / Lapsed
US
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Method and apparatus for nondestructive testing of cement
Assignee: Halliburton Co
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Filing: 1979-10-01
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Granted: 1981-04-07
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Expires: 1999-10-01
Abstract
Abstract Methods and apparatus for the nondestructive testing of cement slurry samples as a function of time are disclosed. A sample placed in a temperature and pressure controlled autoclave is coupled to transducer means under computer control. Ultrasonic energy is propagated through the sample and the transit time is measured. A predetermined relationship relating transit time to compressive strength is employed and enables the determination of compressive strength. The measurements are repetitively performed on up to eight samples simultaneously and the time history of the development of compressive strength is recorded.
Inventors
- 👤 Prabhakar P. Rao
- 👤 David L. Sutton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 06:22
CPC Classifications
G; G01; G01N; G01N33/00; G01N33/38; G01N33/383; G01N29/00; G01N29/04; G01N29/07; G01N29/22; G01N29/227; G01N2291/00; G01N2291/02; G01N2291/023; G01N2291/0232; G01N2291/025; G01N2291/0251; G01N2291/028; G01N2291/02872
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
99 words
A system for non-destructively measuring the compressive strength of a cement slurry sample comprising: means for housing a cement slurry sample and for controlling the pressure and temperature of the sample; means for generating an ultrasonic signal coupled to said sample; means for measuring the transit time of said ultrasonic signal through the sample and for generating a measurement signal representative thereof; means, responsive to said measurement signal, for generating according to a predetermined relationship relating transit time to compressive strength, a signal representative of the compressive strength of the sample; and means for recording said compressive strength signal.
Claim 2
Independent Claim
99 words
A system for non-destructively measuring the compressive strength of a cement slurry sample comprising: means for housing a cement slurry sample and for controlling the pressure and temperature of the sample; means for generating an ultrasonic signal coupled to said sample; means for measuring the transit time of said ultrasonic signal through the sample and for generating a measurement signal representative thereof; means, responsive to said measurement signal, for generating according to a predetermined relationship relating transit time to compressive strength, a signal representative of the compressive strength of the sample; and means for recording said compressive strength signal.
Claim 3
Dependent Claim
58 words
The system of claim 1 and further including: control means for controlling said generating means and said measurement means to repetitively perform measurements of transit time and compressive strength; and means for recording said repetitive measurements of compressive strength as a function of time, thereby to provide a time history of the compressive strength of the cement sample.
Claim 4
Dependent Claim
52 words
The system of claim 2 and further including: means for comparing said repetitive measurement signals with an arbitrary comparison signal to determine when said measurement signal reaches the level of said comparison signal as a function of time; and means for recording the time at which said comparison signal level is met.
Claim 5
Dependent Claim
23 words
The system of claim 3 wherein said comparison signal comprises a signal representative of the initial set time of the cement slurry sample.
Claim 6
Dependent Claim
23 words
The system of claim 3 wherein said comparison signal comprises a signal representative of an arbitrary variable strength of the cement slurry sample.
Claim 7
Dependent Claim
49 words
The system of claim 1 wherein said means for measuring the transit time of said ultrasonic signal includes means for establishing a noise level characteristic of the measurement system and means for detecting when an ultrasonic signal transmitted through the sample exceeds said noise level by a predetermined amount.
Claim 8
Dependent Claim
45 words
The system of claim 6 and further including time gating means responsive to previous transit time measurements through a sample for establishing a time gate reception interval related to said previous transit time measurements for accepting the arrival of an ultrasonic signal transiting the sample.
Claim 9
Dependent Claim
24 words
The system of claim 1 wherein said means for generating an ultrasonic signal through the sample comprises piezoelectric transducer means coupled to said sample.
Claim 10
Dependent Claim
21 words
The system of claim 8 wherein said piezoelectric transducer means operated in a frequency range from 100 kilohertz to one megahertz.
Claim 11
Dependent Claim
16 words
The system of claim 9 wherein said piezoelectric transducer means operates at approximately 400 kilohertz frequency.
Claim 12
Dependent Claim
32 words
The system of claim 8 and further including a piezoelectric transducer means coupled to the sample on a side opposite said signal generating means, for receiving the ultrasonic signal transiting the sample.
Claim 13
Dependent Claim
27 words
The system of claim 8 wherein said piezoelectric transducer means further comprises a transceiving transducer means for both transmitting and receiving ultrasonic signals coupled to the sample.
Claim 14
Dependent Claim
24 words
The system of claim 12 and further including ultrasonic signal reflecting means coupled to the sample on a side opposite said transceiving transducer means.
Claim 15
Independent Claim
82 words
A method for non-destructively measuring the compressive strength of a cement slurry sample, comprising the steps of: maintaining a cement slurry sample at controlled temperature and pressure; transmitting an ultrasonic signal through the sample; detecting said ultrasonic signal subsequent to its transiting the sample and measuring the time required for said signal to transit the sample; determining, according to a predetermined relationship relating transit time to compressive strength, the compressive strength of the sample; and recording the compressive strength of the sample.
Claim 16
Independent Claim
82 words
A method for non-destructively measuring the compressive strength of a cement slurry sample, comprising the steps of: maintaining a cement slurry sample at controlled temperature and pressure; transmitting an ultrasonic signal through the sample; detecting said ultrasonic signal subsequent to its transiting the sample and measuring the time required for said signal to transit the sample; determining, according to a predetermined relationship relating transit time to compressive strength, the compressive strength of the sample; and recording the compressive strength of the sample.
Claim 17
Dependent Claim
37 words
The method of claim 14 wherein the steps are performed repetitively and the compressive strength of the sample is recorded as a function of time, thereby providing a time history of the compressive strength of the sample.
Claim 18
Dependent Claim
58 words
The method of claim 15 and further including the steps of: at each repetition of measurement of compressive strength of the sample, comparing the compressive strength with an arbitrary strength level and determining the time when the compressive strength reaches said arbitrary strength level; and recording the time at which the compressive strength reaches said arbitrary strength level.
Claim 19
Dependent Claim
21 words
The method of claim 16 wherein said arbitrary strength level represents the value of the initial set time of the sample.
Claim 20
Dependent Claim
20 words
The method of claim 16 wherein said arbitrary strength level represents an arbitrary variable strength of the cement slurry sample.
Claim 21
Dependent Claim
39 words
The method of claim 14 wherein the step of detecting said ultrasonic signal and measuring its transit time includes establishing a noise level characteristic of the measurement system and detecting when said ultrasonic signal exceed said noise level characteristic.
Claim 22
Dependent Claim
40 words
The method of claim 19 and further including the step of establishing a time region, based on previous measurements of the transit time of an ultrasonic signal across the sample, in which to detect the arrival of said ultrasonic signal.
Claim 23
Dependent Claim
22 words
The method of claim 14 wherein said transmitting and detecting steps are performed with separate piezoelectric transducer elements coupled to the sample.
Claim 24
Dependent Claim
26 words
The method of claim 14 wherein said transmitting and detecting steps are performed with a single piezoelectric transceiver transducer coupled to one side of the sample.
Claim 25
Dependent Claim
18 words
The method of claim 22 wherein a reflecting element is coupled to an opposite side of the sample.
Claim 26
Dependent Claim
23 words
The method of claim 14 wherein said steps are performed using an ultrasonic frequency in the range from 100 kilohertz to one megahertz.
Claim 27
Dependent Claim
17 words
The method of claim 14 wherein said steps are performed at a frequency of approximately 400 kilohertz.
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) | 1984-04-06 | 1984-10-06 | 1985-04-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-04-06 | 1988-10-06 | 1989-04-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-04-06 | 1992-10-06 | 1993-04-07 | $7700.00 | Window Closed / Lapsed |