Method and apparatus for inspecting well bore casing
US6188643A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 13, 1994 |
| Grant date | Feb 13, 2001 |
| Priority date | — |
| Expiry date | Oct 13, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V1/50
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An improved technique for determining the thickness of a member, especially pipe such as fluid-filled casing in an earth borehole, includes the following steps: directing a pulse of ultrasonic energy toward the inner surface of the pipe, and receiving and storing, as a function of time, signals representative of ultrasonic energy reflected from the inner surface of the pipe; determining, from the stored signals, the arrival time of the initial echo from the inner surface; determining, from the stored signals, the arrival time and the amplitude of a first candidate initial echo from the outer surface of the pipe; performing a reverse search on the stored signals to determine, from stored signals at times earlier than the arrival time of the first candidate, the arrival time and the amplitude of a second candidate initial echo from the outer surface; comparing amplitudes of the first and second candidates, and selecting, based on the comparison, one of the first and second candidates as the actual outer surface echo; and determining the thickness of the pipe from the arrival time of the actual outer surface echo and the arrival time of the inner surface echo. Using this technique, th…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.