Resonance-based inversion of acoustic impedance of annulus behind casing
US10345465B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 27, 2016 |
| Grant date | Jul 9, 2019 |
| Priority date | — |
| Expiry date | May 19, 2037 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V2210/677
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Techniques involve obtaining acoustic data (including waves reflected from the casing, the annular fill material, the formation, and/or interfaces between any of the mud, the casing, and the annular fill material) from an acoustic logging tool. Techniques include normalizing the acoustic wave to result in a normalized wave having a comparable spectral shape with a reference wave, and comparing the normalized wave with the reference wave. The reference wave may be generated or modeled or produced from a look-up table or database, and may be estimated based on initial estimates of wellbore parameters. Based on the comparison of the normalized wave with the reference wave, a best-fit reference wave substantially matching the normalized wave may be identified. The best-fit reference wave may correspond with a thickness of the casing, an acoustic impedance of the annular fill material, and an acoustic impedance of mud.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.