Ultrasonic measurement apparatus
USRE34975E · kind E · reissue
Assignee
Inventors
Key dates
| Filing date | May 11, 1994 |
| Grant date | Jun 20, 1995 |
| Priority date | — |
| Expiry date | May 11, 2014 |
Classification
- Technology area (CPC —)General
Abstract
Pulse echo apparatus and methods are disclosed for measuring characteristics of a borehole while it is being drilled. A component of a bottomhole assembly, preferably a drilling collar, is provided with one or more ultra-sonic transceivers. A pulse echo sensor of the transceiver is preferably placed in a stabilizer fin of the collar, but may also be placed in the wall of the collar, preferably close to a stabilizing fin. Electronic processing and control circuitry for the pulse-echo sensor is provided in an electronic module placed within such collar. Such pulse echo apparatus, which preferably includes two diametrically opposed transceivers, generates signals from which standoff from a borehole wall may be determined. A method and apparatus are provided for measuring standoff and borehole diameter in the presence of drilling cuttings entrained in the drilling fluid. In a preferred embodiment, such signals are assessed by the electronic processing and control circuity to determine if gas has entered borehole. Three methods and apparatus are provided for such gas entry determination. The first relies on measurement of sonic impedance of the drilling fluid by assessing the amplitude …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.