Estimating an earth response

Patent metadata

Field	Value
Publication number	US-10267936-B2
Application number	US-201715446328-A
Country	US
Kind code	B2
Filing date	Mar 1, 2017
Priority date	Apr 19, 2016
Publication date	Apr 23, 2019
Grant date	Apr 23, 2019

Abstract

Estimating an earth response can include deconvolving a multi-dimensional source wavefield from near-continuously recorded seismic data recorded at a receiver position. The deconvolving can include spreading the near-continuously recorded seismic data across a plurality of possible source emission angles. The result of the deconvolution can be the earth response estimate.

First claim

What is claimed is:

1. A method, comprising:
receiving, by a machine, a seismic data set recorded near-continuously by a plurality of receivers, wherein the near-continuously recorded seismic data is indicative of a subterranean formation;
estimating an earth response by deconvolving a near-continuously emitted multi-dimensional source wavefield from the near-continuously recorded seismic data within the seismic data set and recorded at a receiver position, the deconvolving comprising:
spreading the near-continuously recorded seismic data across a plurality of source emission angles,
wherein a result of the deconvolution is the earth response estimate; and

generating a seismic image based on the earth response estimate that is better indicative of the subterranean formation than the received seismic data set.

2. The method of claim 1 , wherein estimating the earth response further comprises:
extracting coherent signals from the earth response estimate; and
wherein the extracted coherent signals comprise an additional earth response estimate.

3. The method of claim 2 , wherein estimating the earth response further comprises:
determining a contribution of the additional earth response estimate to the near-continuously recorded seismic data recorded at the receiver position;
subtracting the contribution from the near-continuously recorded seismic data;
in response to the subtracting, generating a different deconvolution result by deconvolving the multi-dimensional source wavefield from remaining near-continuously recorded seismic data spread across a different plurality of source emission angles;
extracting a different set of coherent signals from the different deconvolution result; and
adding the different set of coherent signals to the additional earth response estimate.

4. The method of claim 3 , further comprising iteratively performing the determining of the contribution of the additional earth response estimate, the subtracting of the contribution from the near-continuously recorded seismic data, the generating of the different deconvolution result, the extracting of the different set of coherent signals, and the adding of the different set of coherent signals to the earth response estimate.

5. The method of claim 3 , wherein the different plurality of source emission angles comprises source emission angles possible subsequent to the subtracting.

6. The method of claim 1 , wherein the plurality of source emission angles comprises possible source emission angles.

7. A system, comprising:
a processing resource;
a memory resource coupled to the processing resource, wherein the memory resource stores instructions executable by the processing resource to:
receive a seismic data set recorded near-continuously by a plurality of receivers, wherein the near-continuously recorded seismic data set is indicative of a subterranean formation;
estimate an earth response by:
deconvolving a near-continuously emitted multi-dimensional source wavefield from the near-continuously recorded seismic data within the seismic data set,
wherein the deconvolution comprises spreading the near-continuously recorded seismic data across a plurality of source emission angles; and
wherein a result of the deconvolution is the earth response estimate;

extract a first set of coherent signals from the earth response estimate,
wherein the extracted coherent signals comprise an additional earth response estimate;

iteratively:
determine a contribution of the additional earth response estimate to the near-continuously recorded seismic data at a receiver position;
subtract the contribution from the near-continuously recorded seismic data;
responsive to the subtraction, generate a different deconvolution result by deconvolving the multi-dimensional source wavefield from remaining near-continuously recorded seismic data spread across the plurality of source emission angles;
extract a second set of coherent signals from the different deconvolution result; and
add the different set of coherent signals to the additional earth response estimate; and

generate a seismic image based on the earth response estimate and the additional earth response estimate that is better indicative of the subterranean formation than the received seismic data set.

8. The system of claim 7 , wherein the plurality of source emission angles comprises all possible source emission angles.

9. The system of claim 7 , wherein the near-continuously recorded seismic data is data previously recorded in the receiver position and comprises a near-continuous receiver trace.

10. The system of claim 7 , further comprising instructions executable to perform the iterations, based on a threshold, until coherent signals are no longer extractable.

11. The system of claim 7 , further comprising instructions executable to deconvolve the near-continuously emitted multi-dimensional source wavefield using a multi-dimensional phase correction and a one-dimensional amplitude correction.

12. The system of claim 7 , further comprising instructions executable to convolve the deconvolved source wavefield with the extracted coherent signals to model a contribution of the extracted coherent signals to a receiver trace associated with a position of at least one of the plurality of receivers and subtract the contribution from the receiver trace to determine a residual receiver trace.

13. A method, comprising:
receiving, by a machine, seismic data recorded near-continuously at a point receiver as a near-continuous receiver trace, wherein the seismic data is indicative of a subterranean formation;
estimating an earth response by extracting source emission data from the near-continuously recorded seismic data, the extracting comprising:
deconvolving a near-continuously emitted multi-dimensional source wavefield from the near-continuously recorded seismic data, the deconvolving comprising:
spreading receiver signals across a plurality of source emission angles;
extracting coherent signals from a result of the deconvolution of the seismic data;
iteratively performing until no coherent signals are extractable:
determining a contribution of the extracted coherent signals to the near-continuous receiver trace by convolving a first source wavefield with the extracted coherent signals;
subtracting the contribution from the near-continuous receiver trace to determine a residual receiver trace;
deconvolving the first source wavefield from the residual receiver trace; and
extracting coherent signals from a result of the deconvolution of the first source wavefield;

estimating an updated earth response by deconvolving a second source wavefield associated with the near-continuously recorded seismic data based on the extractable coherent signals; and
generating a seismic image based on the updated earth response estimate that is better indicative of the subterranean formation than the received seismic data.

14. The method of claim 13 , further comprising adding the residual receiver trace to a signal model, wherein adding the residual receiver trace to the signal model comprises:
spreading the residual receiver trace across a second plurality of source emission angles; and
deconvolving the first source wavefield based on the spreading of the residual receiver trace.

15. The method of claim 13 , further comprising correcting for motion of the point receiver as a function of time based on a distance the point receiver moved relative to a start of the near-continuous recording of the seismic data.

16. The method of claim 13 , wherein extracting coheren

Assignees

• Pgs Geophysical As

Inventors

• Kluver Tilman
• Hegna Stian

Classifications

• G01V1/368 Primary

  Inverse filtering · CPC title

• G01V2210/21

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

• G01V1/48

  Processing data · CPC title

• G01V1/37

  specially adapted for seismic systems using continuous agitation of the ground {, e.g. using pulse compression of frequency swept signals for enhancement of received signals} · CPC title

• G01V2210/1293

  Sea · CPC title