Method and apparatus for logging foam cement in cased boreholes
US7885142B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 2, 2007 |
| Grant date | Feb 8, 2011 |
| Priority date | — |
| Expiry date | Jul 23, 2029 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B47/005
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An acoustic logging system that measures distribution of foam cement and other material in a casing-borehole annulus. The distribution is preferably displayed as map. A borehole tool utilizes at least one acoustic transducer with a known frequency response and mounted on a rotating scanning head that is pointed essentially perpendicular to the borehole wall. The response of the transducer is used to measure an original impedance map of material within the borehole-casing annulus. A fast Fourier transform is used to generate a FFT map from the data comprising the original impedance map. The original impedance map is then combined with the FFT map using logic rules to obtain a final impedance map that is indicative of material within the casing-borehole annulus.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.