PRESTACK TARGET-ORIENTED LEAST SQUARES MIGRATION
This presentation is the property of its rightful owner.
Sponsored Links
1 / 23

PRESTACK TARGET-ORIENTED LEAST SQUARES MIGRATION PowerPoint PPT Presentation


  • 111 Views
  • Uploaded on
  • Presentation posted in: General

PRESTACK TARGET-ORIENTED LEAST SQUARES MIGRATION. Zhiyong Jiang and Min Zhou. Geology and Geophysics Department University of Utah. Outline. Least Squares Migration Prestack Target-Oriented LSM Prestack Numerical Examples Conclusions. Standard Migration. LSM. d=Lm. d=Lm.

Download Presentation

PRESTACK TARGET-ORIENTED LEAST SQUARES MIGRATION

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Prestack target oriented least squares migration

PRESTACK TARGET-ORIENTED LEAST SQUARES MIGRATION

Zhiyong Jiang and Min Zhou

Geology and Geophysics Department

University of Utah


Prestack target oriented least squares migration

Outline

  • Least Squares Migration

  • Prestack Target-Oriented LSM

  • Prestack Numerical Examples

  • Conclusions


Prestack target oriented least squares migration

Standard Migration

LSM

d=Lm

d=Lm

mmig=LTd

mmig=[LTL]-1LTd

m : reflectivity model

mmig: migration image

d : observed data

L : forward operator


Prestack target oriented least squares migration

A Simple Model

Distance (km)

1

0

0

Depth (Km)

1.2

True Reflectivity Model


Prestack target oriented least squares migration

Common Shot Gathers

Distance (km)

Distance (km)

1

1

0

0

0

Time (s)

1

CSG 51

CSG 101


Prestack target oriented least squares migration

Distance (km)

1

0

0

Depth (Km)

1.2

Standard LSM-35

Standard Migration vs. LSM

Distance (km)

1

0

0

Depth (Km)

1.2

Standard Migration


Prestack target oriented least squares migration

Limitation of LSM

Requires 10 or more iterations,where each iteration requires several forward modeling and migration steps

Impractical to implement for current 3-D prestack imaging of large data sets


Prestack target oriented least squares migration

Outline

  • Least Squares Migration

  • Prestack Target-Oriented LSM

  • Prestack Numerical Examples

  • Conclusions


Prestack target oriented least squares migration

Target-Oriented Prestack LSM

Prestack LSM

Data

Model


Prestack target oriented least squares migration

Answer:

Smaller Model Fast Convergence

Why faster convergence &

better resolution?

Simple Model Revisited

Distance (km)

Distance (km)

1

1

0

0

0

Depth (Km)

1.2

Target Oriented LSM-20

Standard LSM-35


Unocal poststack data 2003

UNOCAL POSTSTACK DATA, 2003

Distance (km)

0

14.4

a

0.8

D (Km)

1.5

0.8

b

D (Km)

1.5

(a) Standard Migration (b) TO LSM-5


Unocal poststack data 20031

UNOCAL POSTSTACK DATA, 2003

Distance (km)

0

14.4

a

0.8

D (Km)

1.5

0.8

b

D (Km)

1.5

(a) Standard Migration (b) TO LSM-10


Prestack target oriented least squares migration

Outline

  • Least Squares Migration

  • Prestack Target-Oriented LSM

  • Prestack Numerical Results

  • Conclusions


Prestack target oriented least squares migration

MOBIL MARINE DATA

X (m)

10,356

22,856

0

V (m/s)

3643

Depth (m)

1500

3500

Velocity Model


Prestack target oriented least squares migration

X (m)

X (m)

10,356

22,856

10,356

22,856

500

Depth (m)

2500

Kirchhoff Migration

Standard LSM-6


Prestack target oriented least squares migration

X (m)

10,356

22,856

1000

Depth (m)

Kirchhoff

1800

1000

Standard LSM-6

Depth (m)

1800


Prestack target oriented least squares migration

Trace NO.

Trace NO.

0

120

0

120

0

Time (s)

Field Data CSG 600

Modeled Data CSG 600

6


Prestack target oriented least squares migration

X (m)

10,356

22,856

1000

Depth (m)

Kirchhoff

1800

1000

Target Oriented LSM-3

Depth (m)

1800


Prestack target oriented least squares migration

X (m)

10,356

22,856

1000

Standard LSM-6

Depth (m)

1800

1000

Target Oriented LSM-3

Depth (m)

1800


Prestack target oriented least squares migration

Outline

  • Least Squares Migration

  • Prestack Target-Oriented LSM

  • Prestack Numerical Results

  • Conclusions


Conclusion

LSM is effective in suppressing the migration artifacts, but expensive

Prestack Target-oriented LSM improves the image quality in a few iterations

Prestack Target-oriented LSM greatly reduces CPU time

Conclusion


Future work

Future Work

Eliminate the noise

Implement preconditioning and regularization for LSM

Test the poststack/prestack target-oriented LSM on 3-D data


Prestack target oriented least squares migration

Acknowledgements

We thank Utah Tomography and

Modeling/Migration Consortium

sponsors for their financial support


  • Login