Method and apparatus for azimuthal logging of shear waves in boreholes using optionally rotatable transmitter and receiver assemblies
US7471591B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 21, 2005 |
| Grant date | Dec 30, 2008 |
| Priority date | — |
| Expiry date | Apr 11, 2026 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V1/44
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An acoustic logging system with a borehole tool comprising a transmitter assembly and an axially spaced receiver assembly. The transmitter and receiver assemblies are optionally rotatable with respect to each other, depending upon the embodiment of the logging system. The logging system is designed to measure, among other parameters, the velocity (or slowness) and amplitude of shear wave energy induced by the transmitter assembly within formation penetrated by the borehole. These parameters are extracted from full wave acoustic data responses of receiver elements comprising the receiver assembly, and are measured as a function of azimuth around the borehole. These parameters are subsequently used to determine anisotropic properties of the formation, such as the azimuthal direction of formation fracturing with respect to the well borehole. Optional rotation of the transmitter and receiver assemblies minimizes adverse effects of maintaining calibration and balance of multiple transmitters and receivers.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.