Accurate velocity model estimation and imaging in the presence of localized attenuation (Q) anomalies

Patent metadata

Field	Value
Publication number	US-11340366-B2
Application number	US-201916571950-A
Country	US
Kind code	B2
Filing date	Sep 16, 2019
Priority date	Oct 17, 2018
Publication date	May 24, 2022
Grant date	May 24, 2022

Abstract

Iterative methods for inversion of seismic data to update a physical property model are disclosed. Such methods may comprise iteratively updating the model until a first predetermined resolution is achieved, using full wavefield inversion of the seismic data up to a first frequency threshold and assuming the seismic data is free of attenuation effects; extracting geobodies from the updated model; obtaining a Q model using the geobodies; and updating the physical property model using an inversion process, wherein the Q model is incorporated into the inversion process. These steps may be repeated until a second predetermined resolution of the physical property model is achieved, wherein the first frequency threshold is progressively increased in each repetition. The Q model may be updated with seismic data at all available frequencies to obtain a full-band Q model; and the physical property model may be updated using full-band migration and the full-band Q model.

First claim

What is claimed is:

1. An iterative method for inversion of seismic data to update a physical property model of subsurface velocity or other physical property comprising:
(a) iteratively updating the physical property model until a first predetermined resolution of the physical property model is achieved, wherein the updating is performed using full wavefield inversion of the seismic data up to a first frequency threshold and assuming the seismic data is free of attenuation effects;
(b) extracting geobodies from the updated physical property model;
(c) obtaining a Q model using the geobodies; and
(d) updating the physical property model using an inversion process, wherein the Q model is incorporated into the inversion process; and
(e) repeating steps (a)-(d) until a second predetermined resolution of the physical property model is achieved, wherein the first frequency threshold in step (a) is progressively increased in each repetition.

2. The iterative method of claim 1 , further comprising:
(f) updating the Q model with seismic data at all available frequencies to obtain a full-band Q model; and
(g) updating the physical property model to obtain a final physical property model, wherein the updating is performed using full-band migration and the full-band Q model.

3. The iterative method of claim 2 , further comprising generating, with the computer, an image of a subsurface using the final model, after step (g).

4. The iterative method of claim 2 , further comprising managing hydrocarbons using the final model, after step (g).

5. The iterative method of claim 1 , wherein the full wavefield inversion used in step (a) is acoustic full wavefield inversion.

6. The iterative method of claim 1 , wherein the first predetermined resolution is sufficient to identify geobodies based on the updated physical property model.

7. The iterative method of claim 1 , wherein the first frequency threshold is initially 6 Hz.

8. The iterative method of claim 1 , wherein the extracting in step (b) comprises identifying regions in the physical property model exhibiting physical property values indicative of attenuation effects.

9. The iterative method of claim 1 , wherein obtaining a Q model comprises using a Q-estimation process to generate the Q model based on the geobodies.

10. The iterative method of claim 9 , wherein the Q-estimation process is Q tomography.

11. The iterative method of claim 1 , wherein the inversion process in step (d) is ray-based tomography.

12. The iterative method of claim 1 , wherein the second predetermined resolution is higher than the first predetermined resolution.

13. The iterative method of claim 1 , wherein the second predetermined resolution is between 10 and 15 Hz.

14. The iterative method of claim 1 , wherein the inversion process in step (d) is viscoacoustic full wavefield inversion.

15. The iterative method of claim 14 , further comprising:
(e) updating the physical property model using ray-based tomography and the Q model.

16. The iterative method of claim 15 , further comprising:
(f) repeating steps (b)-(e) until a second predetermined resolution of the physical property model is achieved, wherein the viscoacoustic full wavefield inversion in step (d) is performed up to a second frequency threshold that is progressively increased in each repetition.

17. The iterative method of claim 16 , further comprising:
(g) updating the Q model with seismic data at all available frequencies to obtain a full-band Q model; and
(h) updating the physical property model to obtain a final physical property model, wherein the updating is performed using full-band migration and the full-band Q model.

18. The iterative method of claim 16 , wherein the second frequency threshold is higher than the first frequency threshold.

19. The iterative method of claim 18 , wherein the second frequency threshold is progressively increased up to 15 Hz.

20. The iterative method of claim 1 , further comprising:
updating the Q model after step (c) with seismic data at all available frequencies to obtain a preliminary full-band Q model; and
using the preliminary full-band Q model to obtain an image of the subsurface using amplitude-only Q migration.

21. An iterative method for inversion of seismic data to update a physical property model of subsurface velocity or other physical property comprising:
(a) iteratively updating the physical property model until a first predetermined resolution of the physical property model is achieved, wherein the updating is performed using full wavefield inversion of the seismic data up to a first frequency threshold and assuming the seismic data is free of attenuation effects;
(b) extracting geobodies from the updated physical property model;
(c) obtaining a Q model using the geobodies; and
(d) updating the physical property model using an inversion process, wherein the Q model is incorporated into the inversion process,_wherein the inversion process in step (d) is viscoacoustic full wavefield inversion;
(e) updating the physical property model using ray-based tomography and the Q model; and
(f) repeating steps (b)-(e) until a second predetermined resolution of the physical property model is achieved, wherein the viscoacoustic full wavefield inversion in step (d) is performed up to a second frequency threshold that is progressively increased in each repetition.

22. The iterative method of claim 21 , further comprising:
(g) updating the Q model with seismic data at all available frequencies to obtain a full-band Q model; and
(h) updating the physical property model to obtain a final physical property model, wherein the updating is performed using full-band migration and the full-band Q model.

23. The iterative method of claim 21 , wherein the second frequency threshold is higher than the first frequency threshold.

24. The iterative method of claim 23 , wherein the second frequency threshold is progressively increased up to 15 Hz.

25. An iterative method for inversion of seismic data to update a physical property model of subsurface velocity or other physical property comprising:
(a) iteratively updating the physical property model until a first predetermined resolution of the physical property model is achieved, wherein the updating is performed using full wavefield inversion of the seismic data up to a first frequency threshold and assuming the seismic data is free of attenuation effects;
(b) extracting geobodies from the updated physical property model;
(c) obtaining a Q model using the geobodies; and
(d) updating the physical property model using an inversion process, wherein the Q model is incorporated into the inversion process;
wherein the method further comprises:
updating the Q model after step (c) with seismic data at all available frequencies to obtain a preliminary full-band Q model; and
using the preliminary full-band Q model to obtain an image of the subsurface using amplitude-only Q migration.

Assignees

• Baumstein Anatoly I
• Ayeni Gboyega
• Marcinkovich Carey M
• Park Jaewoo
• Tan Sirui
• Traynin Peter
• Exxonmobil Upstream Res Co

Inventors

• Baumstein Anatoly I
• Ayeni Gboyega
• Marcinkovich Carey M
• Park Jaewoo
• Tan Sirui
• Traynin Peter

Classifications

• G01V2210/66

  Subsurface modeling · CPC title

• G01V2210/51

  Migration · CPC title

• G01V1/303

  for determining velocity profiles or travel times · CPC title

• G01V1/301

  for determining seismic cross-sections or geostructures · CPC title

• G01V1/282 Primary

  Application of seismic models, synthetic seismograms · CPC title