Transcript No Slide Title

POIC-Radon Filtering of the
Near-offset Multiples
Min Zhou
Geology and Geophysics Department
University of Utah
Outline
•
•
•
•
POIC Review
Radon + POIC
SMAART Data
Conclusions
Standard Migration Image Condition
Smear Event at
obs along Ellipse

Primary
S
Multiple
S
R
Depth
R
Multiple artifacts
X
X

Migration
+ POIC
Imaging
Cond
Smear
Event
at obs
along Ellipse
if
obs =
pred.


Multiple
Primary
Depth
S
R
S
R
pred.
pred.
X
X
POIC Review
Why POIC:
• POIC effectively removes some
surface related multiples
• POIC is as fast as Kirchhoff
• POIC accounts for diffractions
with non-zero apices
POIC Review
R
Time
Depth
S
POIC Review
Problem:
POIC performs better when
near-offset data are not used
Zoom views
KM Image
POIC Image
Depth (km)
1
3
7
Distance (km)
30 7
Distance (km)
30
Original Data: CMP 8703
Time (s)
1
7
-2.0
0.0
Offset (km)
2.0
Multiples by POIC: CMP 8703
Time (s)
1
7
-2.0
0.0
Offset (km)
2.0
How to Fill the
Near-offset Gaps?
• Picking
• Prediction
• Interpolation
Radon transform
Outline
•
•
•
•
POIC Reviews
Radon +POIC
SMAART Data
Conclusions
Radon + POIC: Simple Test
0
Predicted
Multiples
Multiples
Time (s)
Primaries
Data
+
0.3
-2
0
Offset (km)
2
-2
0
Offset (km)
2
 -p Domain
0
Predicted
Fitted
Multiples
Multiples
Fitted
Data
Primaries
Time (s)
-
0.3
-0.05
0
p (us/m2)
0.15
-0.05
0
p (us/m2)
0.15
Radon + POIC: Simple Test
0
Errors
Time (s)
Fitted Primaries
0.3
-2
0
Offset (km)
2
-2
0
Offset (km)
2
POIC+Radon
• Radon filter can separate
multiples and primaries in near
offsets
• Primaries/multiples should be
separated with each other in the
 - p domain
Outline
•
•
•
•
POIC Reviews
Radon +POIC
SMAART Data
Conclusions
SMAART Data: CMP8703
Data
1
Predicted Multiples by POIC
1st 2nd water bottom
Time (s)
1st subsalt sediments
1st – 3rd salt top
8
-2.5
Offset (km)
2.5
-2.5
Offset (km)
2.5
SMAART Data: CMP8703
Fitted Multiples by Radon
Time (s)
0
PredictedPrimaries
Multiples by POIC
9
-2.5
Offset (km)
2.5
-2.5
Offset (km)
2.5
Depth Images with Near-offset Data
KM Image
Depth (km)
1
POIC+Radon
POIC Image
Image
8
7
Distance (km)
25
7
Distance (km)
25
Depth Images with Near-offset Data
KM Image
POIC+Radon
POIC Image
Image
Depth (km)
1
2.8
10
Distance (km)
23
10
Distance (km)
23
Depth Images with Near-offset Data
KM Image
POIC+Radon
POIC Image
Image
Depth (km)
3.5
6.5
10
Distance (km)
24
10
Distance (km)
24
Depth Images with All Data
POIC Far-offset Data
POIC+Radon
POIC+Radon
near
All offsets
Data
Depth (km)
0
+
8
7
Distance (km)
25
7
Distance (km)
25
Depth Images with All Data
POIC+Radon
All Data
KM Image
Depth (km)
0
8
7
Distance (km)
25
Outline
•
•
•
•
POIC Reviews
Radon +POIC
SMAART Data
Conclusions
Conclusions
• POIC-Radon filter can predict
some multiples in near offset
• POIC image with near-offset
data has higher resolution
• Low resolution in  - p domain
Future Work
• Resolution in  - p domain
High resolution Radon
• Performance of POIC
Datum - subsalt structures
Gaussian-beam - conflicting
events
• 3-D
Acknowledgments
We thank SMAART JV. to provide
the 2-D synthetic dataset
We thank UTAM sponsors for their
financial support
POIC Images
All Data
Depth (km)
Far-offset
KM image
Data
Distance (km)
Distance (km)
Distance (km)
Depth (km)
Distance (km)
KM Image
Depth (km)
0
6
7
Distance (km)
30
POIC Image (far offset > 4050 ft)
Depth (km)
0
6
7
Distance (km)
30
Zoom views
Depth (km)
KM Image
1
3
Depth (km)
POIC Image
1
3
7
Distance (km)
30