UH Physic Professor & the Director of the Mission Oriented Seismic Research Program Arthur B. Weglein's introduction of the annual report for the year 2013. Arthur B. Weglein, a professor in the Department of Physics & the Department of Earth & Atmospheric science, he holds the Hugh Roy and Lillie distinguished chair in Physic at University of Houston

1. 2013 SEG Annual Meeting
Tuesday, September 24, 2013

2. 2

4. To develop and deliver fundamental new effective
capability that addresses pressing off-shore and
on-shore challenges --- where these plays often
involve complex media with ill-defined subsurface
properties

6.  ISS for:
• 1. Free surface multiple removal
• 2. Internal multiple removal
• 3. Depth imaging
• 4. Non-linear direct AVO
• 5. Q compensation without Q
 All have the same prerequisites:
(1) Reference wave
(2) Deghosting
6

7. Algorithms to satisfy the prerequisite are derived
from Green’s theorem.
ISS and Green’s theorem provide direct methods
that do not require subsurface information.
7

8. Arthur B. Weglein
M-OSRP/UH
Monday, September 23, 2013
Recent Advances and the Road Ahead

9.  (1) Recent progress
 (2) current outstanding challenges
 (3) a proposed road ahead with the potential to
address these challenges

10. In this talk we will:
1) Recognize and exemplify the progress that has
been made and the capability that is currently
available and delivered;

11. In this talk we will:
2) Recognize that current on-shore and complex
off-shore plays increasingly represent
challenges with removing multiples that go
well beyond our entire collective industry’s
capability to effectively respond to/ address;

12. In this talk we will:
3) Propose a three pronged technical strategy with
the potential to address this current gap
between challenge and capability.

13.  Multiples that have experienced at least one downward reflection at the
air-water or air-land surface (free surface) are called free surface multiples.
Multiples that have all of their downward reflections below the free
surface are called internal multiples.
 The order of a free-surface multiple is defined as the number of reflections it has
experienced at the free surface, independent of the number of downward
reflections in its history. In contrast, the order of an internal multiple is defined by
the total number of downward reflections it has experienced – independent of the
location of the downward reflection.

14. Distinct algorithms/methods have been developed that:
 (1) can eliminate free surface multiples of all orders;
 (2) can attenuate internal multiples of all orders.
 Attenuate means it reduces the amplitude but does not
remove (eliminate) the multiples.
— and these algorithms do not require (1) any subsurface
information or (2) selecting a “phantom layer,” where the
generators of the internal multiples are assumed to reside,
and (3) are independent of earth model type.

15. These methods do require (they have
prerequisites) :
(1) the direct wave (reference wave)
needs to be identified to find the
source wavelet and radiation
pattern
(2) Source and receiver deghosting

16.  For the free surface and internal multiple algorithms to
reach their potential/deliver their promise, these
prerequisites need to be satisfied
 Energy minimization adaptive subtraction is often
called upon to recognize/accommodate all differences
between the prediction algorithm and its prerequisites,
and all the other factors (beyond the assumed physics)
that need to be accommodated to eliminate the
multiple.

17. Major issues in the last 20-25 years:
1) Industry trend to deep water, and
2) Exploration plays in ever more complex and ill-
defined circumstances.

18. Carvalho et al. (1992)

19. Araújo et al. (1994)

20. Master Thesis
Andre S. Ferreira
Advisor: Dr. Arthur B. Weglein

21. Free surface multiple attenuation
Multiple prediction
Shot gather
Corresponding multiple
prediction

22. Free surface multiple attenuation
Stack before free surface multiple removal
(A. Ferreira, P. Terenghi)

23. Free surface multiple attenuation
Stack after free surface multiple removal
(A. Ferreira, P. Terenghi)

24. Internal multiple attenuation
The internal multiple high computer cost process

25. Internal multiple attenuation
Multiple prediction
Shot gather
Corresponding multiple
prediction

26. Internal multiple attenuation results
Common offset sections

27. Internal multiple attenuation results
Common offset sections

28. Internal multiple attenuation results
Stacked sections

29. Internal multiple attenuation results
Stacked sections

30. Internal multiple attenuation results (stacked sections)

31. Internal multiple attenuation results (stacked sections)
(A. Ferreira, P. Terenghi)

32. Internal multiple attenuation results (stacked sections)
(A. Ferreira, P. Terenghi)

33. Multiple removal/attenuation is a major problem in seismic
exploration
Free surface multiple removal results
Multiple prediction is excellent
Improved when source wavelet information was provided
Anti-alias filter application is important
Multiples from 3D structures are attenuated but not removed
Adaptive subtraction required
Internal multiple attenuation results
Multiple prediction is excellent
Very high computer cost (both CPU time and memory)
Adaptive subtraction required
(A. Ferreira et al.)

34. ISS methods were able to attenuate both free surface and internal
multiples in a very complex situation
No a priori information about the dataset is necessary
No other tested method was able to attenuate the sequence of
internal multiples below the salt layers
High computer cost (internal multiples)
Adaptive subtraction requirement
(A. Ferreira et al.)

35. “Their (ISS internal multiple algorithm) performance was
demonstrated with complex synthetic and challenging land
field datasets with encouraging results, where other
internal multiple suppression methods were unable to
demonstrate similar effectiveness.”
- Yi Luo, Panos G. Kelamis, Qiang Fu, Shoudong Huo, and
Ghada Sindi, Saudi Aramco; Shih-Ying Hsu and Arthur B.
Weglein, U. of Houston, “The inverse scattering series
approach toward the elimination of land internal multiples.”
Aug 2011, TLE

36.  The industry trend to more complex and
difficult on-shore and offshore plays

37.  These plays can often have proximal or
interfering primary and multiple events, and
multiples of different orders interfering
 That raises the bar on multiple removal
effectiveness: to predict the amplitude and
phase of all orders of free surface and internal
multiples

38.  That challenge has returned multiple
elimination to center stage within M-OSRP
 In principle, the ISS has subseries that can
eliminate (amplitude and phase predict) all free
surface and internal multiples—locate that
capability, directly and without subsurface
information. The ISS is the only method with
that promise and potential.

39.  All ISS subseries share a common set of
prerequisites
 Reference wave removal
 Deghosting
 Source signature and radiation pattern identified
and utilized (accommodated) in the algorithms
 Green’s theorem provides methods to achieve these
prerequisites that are consistent with the ISS methods
they are meant to serve – in fact those prerequisites are
steps taken in all derivations of ISS task specific
subseries.

40.  Develop a new adaptive criteria (and
algorithms that seek to satisfy that criteria) that
derive from and align with ISS algorithms

41.  Three pronged strategy
 Improve satisfaction of prerequisites (in particular
develop methods for on-shore)
 Stronger algorithms (eliminate internal multiples of
all orders)
 Consistent adaptive criteria and subsequent
prediction methods
 For off-shore and on-shore applications

42. 1. Provide methods from the Inverse Scattering Series (ISS) that
predict the phase and amplitude of all orders of free surface and
internal multiples at all offsets
2. Provide the prerequisites, e.g., the removal of the reference
wavefield, the wavelet, and deghosted data required by ISS
methods
3. Develop a replacement to the energy minimization criteria behind
adaptive subtraction methods with a property that always is
satisfied by (aligns with) the free surface and internal multiple
algorithms

43. 44
FS
WB
9m
7m
Source
300m
One reflecting horizons; source depth, 7m;
receiver depth, 9m; receiver interval, 3m;
1601 traces.
Pre-requisite
With and without ghost

44. 0.5
1.0
1.5
2.0
Time(s)
500 1000 1500
Trace Number
0.5
1.0
1.5
2.0
Time(s)
500 1000 1500
Trace Number
0.5
1.0
1.5
2.0
Time(s)
500 1000 1500
Trace Number
Input data with
ghosts
Data after free-surface
multiple removal
Free-surface multiple
prediction
Free Surface Multiple Elimination Results Without Ghosts Removed
(Jinlong Yang, Jim Mayhan 2013)

45. 0.5
1.0
1.5
2.0
Time(s)
500 1000 1500
Trace Number
0.5
1.0
1.5
2.0
Time(s)
500 1000 1500
Trace Number
0.5
1.0
1.5
2.0
Time(s)
500 1000 1500
Trace Number
Input data without
ghosts
(Jinlong Yang, Jim Mayhan 2013)
Free-surface multiple
prediction
Data after free-surface
multiple removal
Free Surface Multiple Elimination Results With Ghosts Removed

46. Reflection
CoefficientDepth (m)
375
535 .45
.50
910 .80
Synthetic model, constant velocity, invisible primary
Downward reflection point (DRP)
47
Dragoset 2000

47. Synthetic shot
48

48. Synthetic shot after ghost and FS multiple removal
49

54. Identify the limitations in the lowest order ISS
internal multiple attenuator
1) Attenuate
2) Spurious events
Extend that algorithm to remove those limitations.

55. 500m
1700m
2700m
5700m
Model
V=1500m/s ρ=1.0g/cm3
V=1700m/s ρ=1.8g/cm3
V=1700m/s ρ=1.0g/cm3
V=3500m/s ρ=4.0g/cm3
V=5000m/s ρ=4.0g/cm3
Yanglei Zou 2013
From attenuate to eliminate

56. 57
IM213 and IM312
IM323
P3
IM212
P3 IM212 IM213 IM312 IM323
1
2
3
Attenuation algorithm for internal multiples from ISS
Yanglei Zou 2013

57. 58
IM213 and IM312
IM323
P3
IM212
P3 IM212 IM213 IM312 IM323
1
2
3
Elimination algorithm for internal multiples from ISS
Yanglei Zou 2013

58.  Q compensation without Q
 With K. Innanen (U. Calgary) and J. E. Lira
(Petrobras)

61. Make prediction algorithm stronger without subsurface information
• Addressing spurious prediction
z0 = 0 m
z1 = 300 m
z2 = 720 m
z3 = 2200 m
ρ = 1.0 g/cm3 ; v = 1500 m/s
ρ = 1.6 g/cm3 ; v = 2500 m/s
ρ = 1.8 g/cm3 ; v = 1700 m/s
ρ = 3.0 g/cm3 ; v = 5000 m/s
ρ = 1.5 g/cm3 ; v = 2040 m/s
z4 = 2300 m
Water Bottom
Top Salt
Base Salt
Target
Test model

62. Make prediction algorithm strong without subsurface information
• Addressing spurious prediction
Synthetic data

63. Make prediction algorithm strong without subsurface information
• Addressing spurious prediction (without higher-order term)
Synthetic data and leading-order prediction results

64. Make prediction algorithm strong without subsurface information
• Addressing spurious prediction (with the higher-order term)
Synthetic data and leading-order and higher-order
prediction results

65. • Well log data (before blocking) (data courtesy of KOC)
Velocity
Density

66. • Well log data (after blocking) (data courtesy of KOC)
Velocity
Density

67. Comparison among reference internal multiple (blue), leading-order prediction
without (red) and with (green) higher-order term [data courtesy of KOC]

68. • KOC Exploration/Geosolution for permission to
use their well log data in studies on the ISS method;
• KOC and WG/SLB management for permission to
cite the results of the study;
• M-OSRP student Chao Ma for carrying out the
study, during internship at WG/SLB in Houston.
Acknowledgements

72. • c0=1500 (correct)
• P0
0 0( , , ) ( ) ( , , )s sP r r A G r r  
73

73. • c0=1490 (wrong)
• P0
0 0( , , ) ( ) ( , , )s sP r r A G r r  
74

74. • c0=1450 (wrong)
• P0
0 0( , , ) ( ) ( , , )s sP r r A G r r  
75

75. Wavelet estimation
using different reference velocities
76
15001450 1490
Angle invariance →

88.  Monday, September 23, 4:25 PM.
 Arthur B. Weglein on “Multiple attenuation: Recent advances and the
road ahead (2013).”
 SS 2: Recent Advances and the Road Ahead session.
 Tuesday, September 24, 2:10 PM.
 Lin Tang on “Using Green‘s theorem to satisfy data requirements of
multiple removal methods: The impact of acquisition design.”
 Co-Author: James D. Mayhan, Jinlong Yang and Arthur B.
Weglein.
 SPNA P1: Deghosting and Ground-Roll Removal. Location: 7C.

89.  Wednesday, September 25, 2013 at 9:40 AM.
 Hong Liang on "General theory for accommodating primaries and multiples in
internal multiple algorithm: Analysis and numerical tests."
 Co-Author: Chao Ma and Arthur B. Weglein.
 SPMUL P1: Methods for Multiples session. Location: 11B.
 Wednesday, September 25, 2013 at 10:00 AM.
 Jinlong Yang on "Accommodating the source (and receiver) array in free-
surface multiple elimination algorithm: Impact on interfering or proximal
primaries and multiples."
 Co-Author: James D. Mayhan, Lin Tang and Arthur B. Weglein.
 SPMUL P1: Methods for Multiples session. Location: 11C.

90.  Wednesday, September 25, 2013 at 1:30 PM.
 Wilberth Herrera on “Eliminating first-order internal multiples with downward reflection at the
shallowest interface: Theory and initial examples.”
 Co-Author: Arthur B. Weglein.
 SPMUL E-P1: Methods for Multiples session, at E-Poster Station: 4, Room 342 A.
 Wednesday, September 25, 2013 at 1:50 PM.
 Yanglei Zou on "A new method to eliminate first-order internal multiples for a normal incidence
plane wave on a 1D earth."
 Co-Author: Arthur B. Weglein.
 SPMUL E-P1: Methods for Multiples session, at E-Poster Station: 4, Room 342 A.

91.  Wednesday, September 25, 2013 at 3:30 PM.
 Hichem Ayadi on “Time saving method based on angular quantities applied to an
internal multiple attenuation algorithm: Fundamental concept, development, and
numerical analysis.”
 Co-Author: Arthur B. Weglein.
 SPMUL E-P1: Methods for Multiples session, at E-Poster Station: 4, Room 342 A.
 SEG post convention Workshop on Internal Multiples.
 Thursday September 26, 2013. 1:30-5 pm.
 Arthur B. Weglein “A three pronged strategy to address the current pressing
internal multiple challenges for off-shore and on-shore plays.”
 W-7: Tools and Methods for Internal Multiple Elimination: Recent Advances and
Practicality.

92. Recent Advances and the Road Ahead (2013)
Summary
• As with seismic imaging and inversion – today
there is much to celebrate; much fundamental
work yet to be done.
• We have demonstrated recent progress and
propose a three pronged strategy for the road
ahead.
• For on-shore internal multiple elimination that
strategy will require new ideas, concepts, and
capability.

93. Develop and deliver the three pronged strategy for
complex marine (off-shore) multiple elimination
while the theory and methods for on-shore
prerequisites are developed and evaluated.

94. All projects are showing reasonable/good
progress and delivery.

95. 96