Method and system for generating a beam of acoustic energy from a borehole, and applications thereof
US8116167B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 12, 2008 |
| Grant date | Feb 14, 2012 |
| Priority date | — |
| Expiry date | Mar 31, 2029 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V1/46
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A compact array of transducers is employed as a downhole instrument for acoustic investigation of the surrounding rock formation. The array is operable to generate simultaneously a first acoustic beam signal at a first frequency and a second acoustic beam signal at a second frequency different than the first frequency. These two signals can be oriented through an azimuthal rotation of the array and an inclination rotation using control of the relative phases of the signals from the transmitter elements or electromechanical linkage. Due to the non-linearity of the formation, the first and the second acoustic beam signal mix into the rock formation where they combine into a collimated third signal that propagates in the formation along the same direction than the first and second signals and has a frequency equal to the difference of the first and the second acoustic signals. The third signal is received either within the same borehole, after reflection, or another borehole, after transmission, and analyzed to determine information about rock formation. Recording of the third signal generated along several azimuthal and inclination directions also provides 3D images of the formation,…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.