Technique and System to Cancel Noise from Measurements Obtained from a Multi-Component Streamer

• US 20080219095A1
• Filed: 03/08/2007
• Published: 09/11/2008
• Est. Priority Date: 03/08/2007
• Status: Active Grant

• Current Assignee: WesternGeco LLC
• Original Assignee: WesternGeco LLC
• Inventors: Perciot, Patrick, Ozdemir, Ahmet Kemel
• Granted Patent: US 8,593,907 B2
• Time in Patent Office: Days
• US Class Current: 367/24
• CPC Class Codes: G01V 1/3808 Seismic data acquisition, e.g. survey design

Abstract

A technique includes receiving a pressure measurement and a particle motion measurement from at least towed seismic sensor. The pressure measurement contains signal and noise. The technique includes estimating the signal in the pressure measurement and based at least on the estimated signal in the pressure measurement, estimating a noise in the pressure measurement. Noise in the particle motion measurement is predicted based on at least the estimated noise in the pressure measurement, and the particle motion measurement is processed to remove noise based on at least the predicted noise.

Claims

1. A method comprising:

receiving a pressure measurement and a particle motion measurement obtained from at least one towed seismic sensor, the pressure measurement containing a signal and noise;

estimating the signal in the pressure measurement;

based at least on the estimated signal in the pressure measurement, estimating a noise in the pressure measurement;

predicting a noise in the particle motion measurement based on at least the estimated noise in the pressure measurement; and

processing the particle motion measurement to remove noise based at least on the predicted noise.

2. The method of claim 1, wherein the act of estimating the noise in the pressure measurement comprises subtracting the estimated signal in the pressure measurement from the pressure measurement.

3. The method of claim 1, wherein the act of processing the particle motion measurement produces low noise particle motion data.

4. The method of claim 1, wherein the act of estimating the signal in the pressure measurement comprises using digital group forming to estimate the signal.

5. The method of claim 1, wherein the act of processing the particle motion measurement to remove noise comprises estimating a signal in the particle motion measurement.

6. The method of claim 1, wherein the estimated signal in the particle motion data contains low frequency noise.

7. The method of claim 5, wherein the act of processing the particle motion measurement to remove noise further comprises:

subtracting the predicted noise in the particle motion measurement from the estimated signal in the particle motion measurement.

8. The method of claim 5, wherein the act of estimating the signal in the particle motion measurement comprises using digital group forming.

9. The method of claim 1, wherein the act of predicting the noise in the particle motion measurement comprises:

processing the estimated noise in the pressure measurement with a prediction filter.

10. The method of claim 9, wherein the prediction filter comprises one of the following:

a least mean square filter, a recursive least square filter and an QR-RLS filter.

11. The method of claim 1, wherein the act of processing the particle motion measurement to remove noise comprises removing low frequency noise that cannot be substantially removed by digital group forming.

12. A system comprising:

an interface to receive data indicative of a pressure measurement obtained from at least one sensor in tow and data indicative of a particle motion measurement obtained from at least one sensor in tow; and

a processor to;

estimate a signal in the pressure measurement;

based at least on the estimated signal in the pressure measurement, estimate a noise in the pressure measurement;

predict a noise in the particle motion measurement based on at least the estimated noise in the pressure measurement; and

process the particle motion measurement to remove noise based on at least the predicted noise.

13. The system of claim 12, wherein the processor subtracts the estimated signal in the pressure measurement from the pressure measurement in the generation of the estimate of the noise in the pressure measurement.

14. The system of claim 12, wherein the processor generates low noise particle motion data as a result of the processing of the particle motion data to remove noise.

15. The system of claim 12, wherein the processor uses digital group forming to estimate the signal in the pressure measurement.

16. The system of claim 12, wherein the processor estimates a signal in the particle motion measurement in the processing of the particle motion measurement to remove noise.

17. The system of claim 16, wherein the processor subtracts the predicted noise in the particle motion measurement from the estimated signal in the particle motion measurement to generate low noise particle motion data.

18. The system of claim 16, wherein the processor uses digital group forming to estimate the signal in the particle motion measurement.

19. The system of claim 12, wherein the processor uses a prediction filter to predict the noise in the particle motion measurement.

20. The system of claim 19, wherein the prediction filter comprises one of the following:

a least mean square filter, a recursive least square filter and an QR-RLS filter.

21. The system of claim 12, wherein the processor in the processing of the particle motion measurement to remove noise removes low frequency noise that cannot be substantially removed by digital group forming.

22. The system of claim 12, further comprising:

a streamer,

wherein the processor is disposed in the streamer.

23. The system of claim 12, further comprising:

a towing vessel to tow said at least one sensor.

24. The system of claim 23, wherein the processor is located on the towing vessel.