Attenuating seismic interference noise using a dual sensor recording system

• US 20100039891A1
• Filed: 08/14/2008
• Published: 02/18/2010
• Est. Priority Date: 08/14/2008
• Status: Active Grant

• Current Assignee: PGS Geophysical As (PGS ASA)
• Original Assignee: PGS Geophysical As (PGS ASA)
• Inventors: Cambois, Guillaume
• Granted Patent: US 8,811,115 B2
• Time in Patent Office: Days
• US Class Current: 367/24
• CPC Class Codes: G01V 1/36 Effecting static or dynamic corrections on records, e.g. correcting spread; Correlating seismic signals; Eliminating effects of unwanted energy
• CPC Class Codes: G01V 1/38 specially adapted for water-covered areas G01V1/28 takes precedence
• CPC Class Codes: G01V 2210/32 Noise reduction
• CPC Class Codes: G01V 2210/56 De-ghosting; Reverberation compensation

Abstract

A method for attenuating noise in marine seismic signals includes cross ghosting pressure responsive marine seismic signals and contemporaneously acquired motion responsive marine seismic signals. A difference is determined between the cross ghosted signals. The difference is used to attenuate noise in at least one of the pressure responsive signals and the motion responsive signals.

Claims

1. A method for attenuating noise in marine seismic signals, comprising:

cross ghosting pressure responsive marine seismic signals and contemporaneously acquired motion responsive marine seismic signals;

determining a difference between the cross ghosted signals; and

using the difference to attenuate noise in at least one of the pressure responsive signals and the motion responsive signals.

2. The method of claim 1 wherein the cross ghosting comprises transforming the pressure responsive signals and the motion responsive signals into the frequency-wavenumber domain and applying a ghosting operator from the pressure responsive signals to the motion responsive signals and vice versa.

3. The method of claim 2 wherein the respective ghosting operators are related to a travel time of seismic energy between a depth of seismic sensors in a body of water and the surface of the body of water.

4. The method of claim 1 wherein the noise comprises horizontally propagating noise.

5. The method of claim 4 wherein the noise comprises at least one of noise from a vessel and noise from a seismic energy source.

6. The method of claim 5 wherein the seismic energy source noise originates from a same source used to acquire the pressure responsive and motion responsive seismic signals.

7. The method of claim 1 wherein the motion responsive signals are normalized for an angle of incidence of seismic energy.

8. The method of claim 1 wherein noise induced in the motion responsive signals by towing seismic equipment in a body of water is attenuated by synthesizing a selected frequency range portion thereof using the pressure responsive signals.

9. The method of claim 1 wherein the using the difference comprises determining time samples of the difference that exceed a selected threshold, and setting time corresponding samples of the pressure responsive signals equal to zero.

10. A method for seismic surveying, comprising:

towing a seismic energy source and a plurality of pressure responsive seismic sensors and motion responsive seismic sensors in a body of water;

actuating the seismic energy source at selected times;

recording signals detected by the pressure responsive sensors and the motion responsive sensors;

cross ghosting the pressure responsive signals and the motion responsive signals;

determining a difference between the cross ghosted signals; and

using the difference to attenuate noise in at least one of the pressure responsive signals and the motion responsive signals.

11. The method of claim 10 wherein the cross ghosting comprises transforming the pressure responsive signals and the motion responsive signals into the frequency-wavenumber domain and applying a ghosting operator from the pressure responsive signals to the motion responsive signals and vice versa.

12. The method of claim 11 wherein the respective ghosting operators are related to a travel time of seismic energy between a depth of seismic sensors in a body of water and the surface of the body of water.

13. The method of claim 11 wherein the noise comprises horizontally propagating noise.

14. The method of claim 13 wherein the noise comprises at least one of noise from a vessel and noise from a seismic energy source.

15. The method of claim 14 wherein the seismic energy source noise originates from the same source used to acquire the pressure responsive and motion responsive seismic signals.

16. The method of claim 10 wherein the motion responsive signals are normalized for an angle of incidence of seismic energy.

17. The method of claim 10 wherein noise induced in the motion responsive signals by towing seismic equipment in a body of water is attenuated by synthesizing a selected frequency range portion thereof using the pressure responsive signals.

18. The method of claim 10 wherein the using the difference comprises determining time samples of the difference that exceed a selected threshold, and setting time corresponding samples of the pressure responsive signals equal to zero.