3D OBS->OBS Interferometry
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3D OBS->OBS 3D OBS->OBS Interferometry Interferometry Sherif Hanafy Sherif Hanafy February 2009 February 2009
description
3D OBS->OBS Interferometry. Sherif Hanafy February 2009. Outline. Problem: Missing and sparse traces Theory: Interferometric interpolation and extrapolation Numerical results: SEG/EAGE model Conclusions and future work. Outline. Problem: Missing and sparse traces - PowerPoint PPT Presentation
Transcript of 3D OBS->OBS Interferometry
3D OBS->OBS Interferometry3D OBS->OBS Interferometry
Sherif HanafySherif Hanafy
February 2009February 2009
Outline
• Problem: Missing and sparse traces
• Theory: Interferometric interpolation and extrapolation
• Numerical results: – SEG/EAGE model
• Conclusions and future work
Outline
• Problem: Missing and sparse traces
• Theory: Interferometric interpolation and extrapolation
• Numerical results: – SEG/EAGE model
• Conclusions and future work
Problem
In marine surveys, receiver interval could be large (especially in cross line direction)
Solution: Use interferometric interpolation
Water
Water
Outline
• Problem: Missing and sparse traces
• Theory: Interferometric interpolation and extrapolation
• Numerical results: – SEG/EAGE model
• Conclusions and future work
Theory
G(x|A)Natural Green’s
function
SSP
Sea bed
Reflectors
Ocean Surface
xBA
G(x|B)Model based data
SSP
Sea bed
Ocean Surface
xBA
Virtual source
G(B|A)Interpolated data
SSP
Sea bed
Reflectors
Ocean Surface
xBA
Virtual receiver
SSP
o
S
SSP
o
SSPSSP
BAGdxBxGAxGikABGS
*2* )|( )|( )|( 2 )|(
WorkflowInput Field Data
Water Layer Thickness
Generate GF for Water Multiples
Interpolate/Extrapolate Missing Data
Max. Itr (MF)
Get Virtual CSG
Max Iter Intr/Extr
Final CSGN
Matching Filter
N
YY
Tim
e (s
)T
ime
(s)
00
3.03.0X (km)X (km)00 4.54.5
Sea bed
Ocean Surface
x
Tim
e (s
)T
ime
(s)
00
3.03.0X (km)X (km)00 4.54.5
Tim
e (s
)T
ime
(s)
00
3.03.0X (km)X (km)00 4.54.5
Input Data
Unfiltered Virtual
Filtered Virtual
G(x|B)
G(B|A)
G(x|A)
SSP
o
S
SSP
o
SSPSSP
BAGdxBxGAxGikABGS
*2* )|( )|( )|( 2 )|(
Outline
• Problem: Missing and sparse traces
• Theory: Interferometric interpolation and extrapolation
• Numerical results: – SEG/EAGE model
• Conclusions and future work
SEG/EAGE Velocity Model
Velocity (m/s)1500 4500
Acquisition Parameters
• Input– 8 Streamers
– Crossline offset is 30 m
– Inline offset is 12 m
– 170 receivers/streamer
– Total number of receivers 1360
• Goal– 22 Streamers
– Crossline offset is 10 m
– Inline offset is 4 m
– 508 receivers/streamer
– Total number of receivers 11176
Sparse geometry Dense geometry
Scale
2 km0
21
0
8
Tim
e (s
)
Streamer21
SEG/EAGE Model – Input Data
Scale
2 km0
212’1’
0
8
Tim
e (s
)
Streamer21 2’1’
SEG/EAGE Model – Virtual Data
Scale
2 km0
SEG/EAGE Model – Real Data
0
8
Tim
e (s
)
Streamer41 32
Outline
• Problem: Missing and sparse traces
• Theory: Interferometric interpolation and extrapolation
• Numerical results: – SEG/EAGE model
• Conclusions and future work
Conclusions
• 3D marine SSP data can be interpolated with interferometry.
• Proposed approach is successfully tested on a synthetic model.
• Number of receivers can be increased 8 to 10 times by interferometry.
Future Work
• Extrapolation of the data
• Test on field data, we need field data to complete this part
Acknowledgement
We would like to thank the UTAM 2008 sponsors for their support.
Thank You
