Removing noise from a seismic measurement

Patent metadata

Field	Value
Publication number	US-10353098-B2
Application number	US-201414308889-A
Country	US
Kind code	B2
Filing date	Jun 19, 2014
Priority date	Nov 3, 2009
Publication date	Jul 16, 2019
Grant date	Jul 16, 2019

Abstract

A technique includes spatially filtering a signal that is derived from a seismic acquisition. The filtering is associated with a filter length, and the filtering includes varying the filter length with frequency. The filtering may be used in connection with adaptive noise attenuation, which is applied to decomposed subbands. Furthermore, the filtering may be applied during the reconstruction of the signal from the subbands.

First claim

What is claimed is:

1. A method for conducting a seismic survey using a survey vessel comprising:
acquiring a signal using a seismic streamer attached to the survey vessel, wherein acquiring the signal is performed using a multi-component sensor having particle motion sensing capabilities associated therewith;
decomposing, at the seismic streamer or onboard the survey vessel, the signal derived from a seismic acquisition into subbands in successive stages, the subbands being associated with at least different frequency ranges of the signal;
selectively applying, using a low pass spatial filter, at the seismic streamer or onboard the survey vessel, adaptive noise attenuation in between the successive stages such that the stages decompose noise-attenuated subbands, wherein the low pass spatial filter is configured to adjust a filter length based upon, at least in part, a frequency being filtered; and
reconstructing, at the seismic streamer or onboard the survey vessel, the signal from the subbands resulting from the decomposition.

2. The method of claim 1 , wherein
some of the subbands resulting from the decomposition are associated with lower frequencies than the remaining subbands resulting from the decomposition; and
the act of applying adaptive noise attenuation comprises applying the adaptive noise attenuation to the subbands that are associated with the lower frequencies and not applying adaptive noise attenuation to the remaining subbands.

3. The method of claim 1 , wherein the subbands are further associated with different wavenumber ranges.

4. The method of claim 3 , wherein
some of the subbands resulting from the decomposition are associated with lower wavenumbers than the remaining subbands resulting from the decomposition; and
the act of applying adaptive noise attenuation comprises applying the adaptive noise attenuation to the subbands that are associated with the lower wavenumbers and not applying the adaptive noise attenuation to the remaining subbands.

5. The method of claim 1 , wherein
some of the subbands resulting from the decomposition are within a frequency-wavenumber region associated with a desired seismic signal; and
the act of applying adaptive noise attenuation comprises applying the adaptive noise attenuation to the subbands that are within the frequency-wavenumber region and not applying the adaptive noise attenuation to the first subbands that are outside of the frequency-wavenumber region.

6. The method of claim 1 , wherein the act of decomposing comprises performing discrete wavelet transformations.

7. The method of claim 1 , further comprising:
spatially filtering the noise attenuated subbands; and
for each noise attenuated subband, regulating a length of the filtering based on a frequency associated with the noise attenuated subband.

8. The method of claim 7 , wherein spatially filtering includes adapting the filtering to pass through aliasing components of the noise-attenuated subbands.

9. The method of claim 1 , wherein decomposing the signal is performed prior to selectively applying adaptive noise attenuation and selectively applying adaptive noise attenuation is performed prior to reconstructing the signal.

10. A system for conducting a seismic survey using a survey vessel comprising:
a seismic streamer attached to the survey vessel, the seismic streamer configured to acquire a signal using a multi-component sensor having particle motion sensing capabilities associated therewith;
an interface, at the seismic streamer or onboard the survey vessel, to receive data indicative of a signal derived from a seismic acquisition; and
a processor, at the seismic streamer or onboard the survey vessel, to:
decompose the signal into subbands in successive stages, the subbands being associated with at least different frequency ranges of the signal;
selectively apply, using a low pass spatial filter, adaptive noise attenuation in between the successive stages such that the stages decompose noise-attenuated subbands, wherein the low pass spatial filter is configured to adjust a filter length based upon, at least in part, a frequency being filtered; and
reconstruct the signal from the subbands resulting from the decomposition.

11. The system of claim 10 , wherein the processor is further adapted to selectively spatially filter the subbands between the stages and regulate a length of the filtering based on a frequency associated with the subband being filtered.

12. The system of claim 10 , wherein
some of the subbands resulting from the decomposition are associated with lower wavenumbers than the remaining subbands resulting from the decomposition, and
the processor is further adapted to process the data to apply the adaptive noise attenuation to the subbands that are associated with the lower wavenumbers and not apply the adaptive noise attenuation to the remaining subbands.

13. The system of claim 10 , wherein
some of the subbands resulting from the decomposition are within a frequency-wavenumber region associated with a desired seismic signal; and
the processor is further adapted to apply the adaptive noise attenuation to the subbands that are within the frequency-wavenumber region and not apply the adaptive noise attenuation to the subbands that are outside of the frequency-space region.

14. The system of claim 10 , wherein the processor is further adapted to perform discrete wavelet transformations to decompose the signal.

15. The system of claim 10 , further comprising:
a spread of at least one streamer comprising seismic sensors to acquire data indicative of the signal derived from the seismic acquisition; and
a vessel to tow the spread.

Assignees

• Westerngeco Llc

Inventors

• Martin James Edward
• Özdemir Ahmet Kemal
• Kjellesvig Bent Andreas
• Ozbek Ali

Classifications

• G01V2210/324

  Filtering · CPC title

• G01V1/364 Primary

  Seismic filtering (G01V1/37 takes precedence) · CPC title

• G01V2210/21

  Frequency-domain filtering, e.g. band pass · CPC title

• G01V1/368 Primary

  Inverse filtering · CPC title

• G01V1/3808

  Seismic data acquisition, e.g. survey design · CPC title