USING WAVEFORM INVERSION TO DETERMINE PROPERTIES OF A SUBSURFACE MEDIUM

• US 20100142316A1
• Filed: 12/07/2008
• Published: 06/10/2010
• Est. Priority Date: 12/07/2008
• Status: Abandoned Application

• Current Assignee: WesternGeco LLC
• Original Assignee: WesternGeco LLC
• Inventors: Keers, Henk, Childs, Paul
• Application Number:
  US12/329,593
• Publication Number:
  US 20100142316A1
• Time in Patent Office: Days
• US Class Current: 367/15
• CPC Class Codes: G01V 1/282 Application of seismic models, synthetic seismograms
• CPC Class Codes: G01V 1/306 for determining physical properties of the subsurface, e.g. impedance, porosity or attenuation profiles
• CPC Class Codes: G01V 2210/614 Synthetically generated data

Abstract

A technique includes providing seismic data acquired in a seismic survey of a medium. The seismic data includes particle motion data. The technique includes modeling waves propagating through the medium during the survey as a function of at least one property of the medium and the seismic data. The technique includes, based on the modeling, determining the property(ies) of the medium.

Claims

1. A method comprising:

providing seismic data acquired in a seismic survey of a medium, the seismic data including particle motion data;

modeling waves propagating through the medium during the survey as a function of at least one property of the medium and the seismic data; and

based on the modeling, determining said at least one property of the medium.

2. The method of claim 1, wherein the determining comprises:

determining finite changes in the seismic data due to finite changes in the model.

3. The method of claim 1, wherein the seismic data further comprises pressure data.

4. The method of claim 1, wherein the property comprises a propagation velocity.

5. The method of claim 1, wherein the act of inverting comprises inverting in the frequency domain or in the time domain.

6. The method of claim 1, wherein the act of inverting comprises using migration velocity analysis to generate initial values for the model.

7. The method of claim 1, wherein the act of inverting comprises applying a ray theory-based, beam theory-based or finite difference-based numerical inversion.

8. The method of claim 1, further comprising:

towing at least one streamer to acquire the seismic data.

9. A system comprising:

an interface to receive seismic data acquired in a seismic survey of a medium, the seismic data including particle motion data; and

a processor to process the seismic data to model waves propagating through the medium during the survey as a function of at least one property of the medium and the seismic data.

10. The system of claim 9, wherein the seismic data further comprises pressure data.

11. The system of claim 9, wherein the property comprises a propagation velocity.

12. The system of claim 9, wherein the processor is adapted to process the data to invert the model in the frequency domain or in the time domain.

13. The system of claim 9, wherein the processor is adapted to process the seismic data to invert the model based on a ray theory-based, beam theory-based or finite difference-based numerical inversion technique.

14. The system of claim 9, further comprising:

at least one streamer to acquire the seismic data.

15. The system of claim 14, further comprising:

a vessel to tow said at least one streamer.

16. The system of claim 9, further comprising:

at least one sea bed cable to acquire the seismic data.

17. An article comprising a computer readable storage medium to store instructions that when executed by a processor-based system cause the processor-based system to:

receive seismic data acquired in a seismic survey of a medium, the seismic data including particle motion data; and

process the seismic data to model waves propagating through the medium during the survey as a function of at least one property of the medium and the seismic data.

18. The article of claim 17, wherein the seismic data further comprises pressure data.

19. The article of claim 17, wherein the property comprises a propagation velocity.

20. The article of claim 17, comprising instructions that when executed cause the processor-based system to invert the model in the frequency domain or in the time domain.

21. The article of claim 17, comprising instructions that when executed cause the processor-based system to invert the model based on a ray theory-based, beam theory-based or finite difference-based numerical inversion technique.

22. A method comprising:

providing seismic data acquired in a seismic survey of a medium;

modeling a wave propagating through the medium during the survey as a function of at least one property of the medium and the seismic data, including modeling the wave as a function of a Bjorn integral having a phase function; and

based on contours of the phase function, constructing the wave.

23. The method of claim 22, wherein the seismic data comprises pressure data and/or particle motion data.

24. The method of claim 22, wherein the act of constructing is performed in the frequency domain or in the time domain.

25. The method of claim 22, further comprising:

towing at least one streamer to acquire the seismic data.