Acoustic apparatus and method for detecting borehole wall discontinuities such as vertical fractures
US4885723A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 18, 1981 |
| Grant date | Dec 5, 1989 |
| Priority date | — |
| Expiry date | Dec 18, 2001 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S367/911
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Apparatus and methods are described for detecting fractures in a wall of a borehole penetrating an earth formation. An acoustic transducer produces pulses of acoustic energy at beam forming frequencies with the direction of the beam being so oriented as to preferentially excite transverse waves in the wall of the borehole. Discontinuities such as fractures cause a reflection of the transverse waves and these in turn are detected so that a positive identification of fractures is obtained. Fractures having various inclination angles are detected by employing apparatus and methods for scanning the acoustic beam while maintaining its orientation which preferentially enhances transverse waves. In this manner the transverse waves may be directed perpendicular to the fractures to enhance detectable reflections. A transducer employing an array of individually excitable acoustic elements is described with associated controls.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.