Method of reducing harmonic noise in vibroseis operations
US6603707B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 26, 2002 |
| Grant date | Aug 5, 2003 |
| Priority date | — |
| Expiry date | Feb 26, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V2210/3246
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The invention relates to a vibroseis analysis method in which frequency-sweep signals (10) are emitted into a subsurface, the signals reflected on the substrata of such a subsurface (10, 20) are logged and the logged signals are processed, a method in which the harmonics (20) of the fundamental signal (10) initially emitted are eliminated from the logged signals, by applying the steps consisting in:a) providing a time/frequency plot, showing the respective contributions of the fundamental (10) and of the harmonics (20) in the logged signal,b) providing a time/frequency plot also showing these contributions of the fundamental (10) and of the harmonics (20) in the logged signal, this plot having been stretched in the direction of the frequency axis such that the fundamental (10) of this plot is over the location of a harmonic (20) chosen from the plot;c) adapting the power amplitude of this stretched plot to make this amplitude correspond to that of the said chosen harmonic (20) of the plot;d) subtracting these two plots one from the other such that the said chosen harmonic (20) is eliminated, by subtraction with the fundamental (10) of the stretched plot.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.