Shot to shot processing for measuring a characteristic of earth formations from inside a borehole
US4543648A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 29, 1983 |
| Grant date | Sep 24, 1985 |
| Priority date | — |
| Expiry date | Dec 29, 2003 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V1/303
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method and apparatus for measuring an earth formation characteristic from inside a borehole penetrating earth formations is described. A tool carrying a sonic transmitter and an array of receivers is moved along the borehole and waveform signals from the receiver array are generated from repetetive operations of the transmitter. Sub-arrays of particularly related waveform signals relevant to a selected depth interval that is less in length than the aperture of the array are identified. Each sub-array of signals is then converted to a domain of signals composed of values of a coherence as a function of a range of values of a characteristic such as slowness. The converted signals are then combined so as to provide combined coherence values as a function of different values of the characteristic. One or several peaks of the combined coherence values are detected and determine the value of the characteristic for the selected depth interval. Similar processing is continued for other depth intervals. Independent measurements of the characteristic can be made with both receiver section and transmitter section processing and a borehole compensation technique is described. A fast processi…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.