Simultaneous Joint Inversion of Surface Wave and Refraction Data

• US 20110134722A1
• Filed: 12/06/2010
• Published: 06/09/2011
• Est. Priority Date: 12/07/2009
• Status: Active Grant

• Current Assignee: WesternGeco LLC
• Original Assignee: Mediwound Ltd.
• Inventors: Strobbia, Claudio, Virgilio, Massimo
• Granted Patent: US 8,861,308 B2
• Time in Patent Office: Days
• US Class Current: 367/75
• CPC Class Codes: G01V 1/282 Application of seismic models, synthetic seismograms
• CPC Class Codes: G01V 1/30 Analysis G01V1/50 takes precedence
• CPC Class Codes: G01V 1/306 for determining physical properties of the subsurface, e.g. impedance, porosity or attenuation profiles

Abstract

A technique includes a method and apparatus for simultaneous joint inversion of surface wave and refraction data to identify near surface geophysical and geological properties.

Claims

1. A computer-implemented method for use in exploring a subsurface geological formation, comprising:

extracting the surface wave and refracted wave properties from a set of seismic data representing the subsurface geological formation; and

simultaneously and jointly inverting the extracted surface wave and refracted wave properties to estimate the visco-elastic shear and compressional parameters in the near surface.

2. The computer-implemented method of claim 1, wherein the extracted surface wave properties include the dispersion of the surface wave modes, their attenuation and frequency response.

3. The computer-implemented method of claim 1, wherein the extracted refracted wave properties include the travel time for each pair of source and detector, the amplitude information, and the wavelet information.

4. The computer-implemented method of claim 1, wherein extracting the surface wave and refracted wave properties includes extracting first break travel times for the source-detector pairs in a survey and the estimation of modal dispersion curves for all locations within the survey area simultaneously.

5. The computer-implemented method of claim 1, wherein extracting the surface wave and refracted wave properties includes:

identifying the respective wave properties to be refracted; and

performing single domain inversions of the extracted wave properties.

6. The computer-implemented method of claim 5, wherein simultaneously and jointly inverting the extracted surface wave and refracted wave properties includes:

parameterizing the simultaneous joint inversion; and

performing the simultaneous joint inversion.

7. The computer-implemented method of claim 1, wherein simultaneously and jointly inverting the extracted surface wave and refracted wave properties includes:

parameterizing the simultaneous joint inversion; and

performing the simultaneous joint inversion.

8. The computer-implemented method of claim 1, wherein extracting the surface wave and refracted wave properties includes:

processing the seismic data in the surface wave domain, including;

selecting a set of shot gathers spanning a large offset range are selected;

classifying the near surface modes in the selected shot gathers;

identifying events in the classified near surface modes; and

extracting the dispersion and attenuation curves for the different surface wave modes present in the data.

processing the seismic data in the refracted wave domain, including;

pre-processing and conditioning the seismic data; and

extracting the first break travel-time, the peak amplitude, and the spectral properties of the wavelet for all source-detector pairs generating the seismic data.

9. The computer-implemented method of claim 8, wherein simultaneously and jointly inverting the extracted surface wave and refracted wave properties includes:

determining the geometries of the simultaneous and joint inversion iterations from the extracted surface wave and refracted wave properties; and

performing a simultaneous joint inversion to extract a near surface model.

10. A program storage medium encoded with instructions that, when executed by a computing device, perform a computer-implemented method for use in exploring a subsurface geological formation, the computer-implemented method comprising:

extracting the surface wave and refracted wave properties from a set of seismic data representing the subsurface geological formation; and

simultaneously and jointly inverting the extracted surface wave and refracted wave properties to estimate the visco-elastic shear and compressional parameters in the near surface.

11. The program storage medium of claim 10, wherein simultaneously and jointly inverting the extracted surface wave and refracted wave properties includes:

parameterizing the simultaneous joint inversion; and

performing the simultaneous joint inversion.

12. The program storage medium of claim 10, wherein extracting the surface wave and refracted wave properties includes:

processing the seismic data in the surface wave domain, including;

selecting a set of shot gathers spanning a large offset range are selected;

classifying the near surface modes in the selected shot gathers;

identifying events in the classified near surface modes; and

extracting the dispersion and attenuation curves for the different surface wave modes present in the data.

processing the seismic data in the refracted wave domain, including;

pre-processing and conditioning the seismic data; and

extracting the first break travel-time, the peak amplitude, and the spectral properties of the wavelet for all source-detector pairs generating the seismic data.

13. A programmed computing apparatus, comprising:

a computing device;

a bus system;

a storage communicating with the computing device over the bus system;

a software component residing on the storage that, when executed by the computing device, performs a method for use in exploring a subsurface geological formation, the method comprising;

extracting the surface wave and refracted wave properties from a set of seismic data representing the subsurface geological formation; and

simultaneously and jointly inverting the extracted surface wave and refracted wave properties to estimate the visco-elastic shear and compressional parameters in the near surface.

14. The programmed computing apparatus of claim 13, wherein simultaneously and jointly inverting the extracted surface wave and refracted wave properties includes:

parameterizing the simultaneous joint inversion; and

performing the simultaneous joint inversion.

15. The programmed computing apparatus of claim 13, wherein extracting the surface wave and refracted wave properties includes:

processing the seismic data in the surface wave domain, including;

selecting a set of shot gathers spanning a large offset range are selected;

classifying the near surface modes in the selected shot gathers;

identifying events in the classified near surface modes; and

extracting the dispersion and attenuation curves for the different surface wave modes present in the data.

processing the seismic data in the refracted wave domain, including;

pre-processing and conditioning the seismic data; and

extracting the first break travel-time, the peak amplitude, and the spectral properties of the wavelet for all source-detector pairs generating the seismic data.

16. The programmed computing apparatus of claim 13, wherein the computing apparatus comprises a computing system.

17. A computer-implemented method for modeling near surface features of a subsurface geological formation, comprising:

processing a set of seismic data independently in a surface wave domain and a refracted wave domain; and

simultaneously and jointly inverting the results of the independent processing in the surface wave domain and the refracted wave domain to obtain a model of the near surface.

18. A computer-implemented method for modeling near surface features of a subsurface geological formation, comprising:

performing a pair of independent, single domain inversions of a seismic data set yielding a pair of independent inverted models;

performing a simultaneous and joint inversion of the independent inverted models to obtain a near surface model.