American Oil and Gas Reporter - November 2016 - 51

SpecialReport: Oil & Gas Computing

FAZ Optimizes Multiple Attenuation
By Duane Dopkin
HOUSTON-As seismic waves travel
through the earth, they are dissipated
through both absorption (anelastic attenuation) and wave path scattering (elastic
attenuation).
Energy propagating through the earth
also can reverberate and create energy referred to as "multiple energy." This energy
can significantly impair a geoscientist's
ability to interpret and prospect with seismic data. Consequently, despite significant
advances in the science of multiple energy
attenuation, it remains one of the most
challenging areas for the seismic method.
Predictive, or data-driven, as well as
model-driven methods continue to be
modified to handle a complex range of
multiple generating conditions in the presence of irregular water bottoms, shallow
water, salts, volcanics, and high-reflectivity
carbonate and anhydrite sequences.
While all these conditions can generate
challenges for application geophysicists,
it is the interbed multiples, which are
generated from sequences of high-reflectivity formations, that can significantly
compromise the use of seismic data for
reservoir delineation and advanced characterization methods. Under these conditions, methods that attempt to exploit
move-out differences between primaries
and multiples fail.
One of the newer ways to address this
interbed multiple problem, together with
the broader range of multiple generating
conditions, is using full-azimuth depth
imaging and decomposition technology
to attenuate or remove this undesirable
energy from the seismic wave field. In
this model-driven process, primaries can
be distinguished from multiples, based
on their respective energy distributions
in "directivity" (dip-azimuth) space.
The full-azimuth imaging system is
able to map and decompose surfacerecorded seismic data into subsurface,
multidimensional prestack image gathers.
This mapping and decomposition technique is carried out with a special "bottom-up" ray tracing operator using an in
situ reference system referred to as the
local angle domain (LAD).
Five-Dimensional Gathers
Figure 1 illustrates the LAD imaging
method, with the source point shown in

red and the receiver point in green. The
outcome of the ray tracing and mapping
is a five-dimensional image gather described by full-azimuth subsurface directivity (the dip and azimuth of the local
reflecting surface) and by full-azimuth
subsurface reflectivity (the opening angle
and its associated azimuth defined by the
incidence and reflected ray pair).
Figure 2 shows examples of mapping
surface-recorded seismic data to five-dimensional gathers of full-azimuth reflectivity and directivity, and displaying the
results in 3-D or 2-D forms. This multidimensional decomposition provides the
highest levels of flexibility in designing
special imaging and inversion operators
to emphasize or attenuate different subsurface features. Specifically, the technology can be applied to:
* Enhance continuous reflections in
the presence of low signal-to-noise with
operators that emphasize "specular ener-

gy;"
* Recover the low energy associated
with small faults, discontinuities or feature
edges with operators that emphasize "diffraction energy;"
* Map in situ stresses and natural
fractures using full-azimuth reflectivity
data, and full-azimuth amplitude-variation-with-azimuth and velocity-variationwith-azimuth inversions; and
* Differentiate between primary and
multiple data.
Multiple Suppression
Two approaches can be used to attenuate the broad spectrum of multiples that
may be present in the fully recorded seismic wave field. Both methods exploit
the "directionality" of the imaging operator
and associated multidimensional gather
output.
The first approach is based on the internal (imaging) implementation of local

FIGURE 1
LAD Imaging System for Five-Dimensional Mapping of
Surface-Recorded Seismic to Subsurface Image Points

Displacement
azimuth
tance
ment dis
Displace

Offset
azimuth
Of
f
dis set
tan
ce

Incident
ray

Opening azimuth
Reflected
ray
Opening angle
Azimuth
Dip

NOVEMBER 2016 51



Table of Contents for the Digital Edition of American Oil and Gas Reporter - November 2016

Contents
American Oil and Gas Reporter - November 2016 - 1
American Oil and Gas Reporter - November 2016 - 2
American Oil and Gas Reporter - November 2016 - Contents
American Oil and Gas Reporter - November 2016 - 4
American Oil and Gas Reporter - November 2016 - 5
American Oil and Gas Reporter - November 2016 - 6
American Oil and Gas Reporter - November 2016 - 7
American Oil and Gas Reporter - November 2016 - 8
American Oil and Gas Reporter - November 2016 - 9
American Oil and Gas Reporter - November 2016 - 10
American Oil and Gas Reporter - November 2016 - 11
American Oil and Gas Reporter - November 2016 - 12
American Oil and Gas Reporter - November 2016 - 13
American Oil and Gas Reporter - November 2016 - 14
American Oil and Gas Reporter - November 2016 - 15
American Oil and Gas Reporter - November 2016 - 16
American Oil and Gas Reporter - November 2016 - 17
American Oil and Gas Reporter - November 2016 - 18
American Oil and Gas Reporter - November 2016 - 19
American Oil and Gas Reporter - November 2016 - 20
American Oil and Gas Reporter - November 2016 - 21
American Oil and Gas Reporter - November 2016 - 22
American Oil and Gas Reporter - November 2016 - 23
American Oil and Gas Reporter - November 2016 - 24
American Oil and Gas Reporter - November 2016 - 25
American Oil and Gas Reporter - November 2016 - 26
American Oil and Gas Reporter - November 2016 - 27
American Oil and Gas Reporter - November 2016 - 28
American Oil and Gas Reporter - November 2016 - 29
American Oil and Gas Reporter - November 2016 - 30
American Oil and Gas Reporter - November 2016 - 31
American Oil and Gas Reporter - November 2016 - 32
American Oil and Gas Reporter - November 2016 - 33
American Oil and Gas Reporter - November 2016 - 34
American Oil and Gas Reporter - November 2016 - 35
American Oil and Gas Reporter - November 2016 - 36
American Oil and Gas Reporter - November 2016 - 37
American Oil and Gas Reporter - November 2016 - 38
American Oil and Gas Reporter - November 2016 - 39
American Oil and Gas Reporter - November 2016 - 40
American Oil and Gas Reporter - November 2016 - 41
American Oil and Gas Reporter - November 2016 - 42
American Oil and Gas Reporter - November 2016 - 43
American Oil and Gas Reporter - November 2016 - 44
American Oil and Gas Reporter - November 2016 - 45
American Oil and Gas Reporter - November 2016 - 46
American Oil and Gas Reporter - November 2016 - 47
American Oil and Gas Reporter - November 2016 - 48
American Oil and Gas Reporter - November 2016 - 49
American Oil and Gas Reporter - November 2016 - 50
American Oil and Gas Reporter - November 2016 - 51
American Oil and Gas Reporter - November 2016 - 52
American Oil and Gas Reporter - November 2016 - 53
American Oil and Gas Reporter - November 2016 - 54
American Oil and Gas Reporter - November 2016 - 55
American Oil and Gas Reporter - November 2016 - 56
American Oil and Gas Reporter - November 2016 - 57
American Oil and Gas Reporter - November 2016 - 58
American Oil and Gas Reporter - November 2016 - 59
American Oil and Gas Reporter - November 2016 - 60
American Oil and Gas Reporter - November 2016 - 61
American Oil and Gas Reporter - November 2016 - 62
American Oil and Gas Reporter - November 2016 - 63
American Oil and Gas Reporter - November 2016 - 64
American Oil and Gas Reporter - November 2016 - 65
American Oil and Gas Reporter - November 2016 - 66
American Oil and Gas Reporter - November 2016 - 67
American Oil and Gas Reporter - November 2016 - 68
American Oil and Gas Reporter - November 2016 - 69
American Oil and Gas Reporter - November 2016 - 70
American Oil and Gas Reporter - November 2016 - 71
American Oil and Gas Reporter - November 2016 - 72
American Oil and Gas Reporter - November 2016 - 73
American Oil and Gas Reporter - November 2016 - 74
American Oil and Gas Reporter - November 2016 - 75
American Oil and Gas Reporter - November 2016 - 76
American Oil and Gas Reporter - November 2016 - 77
American Oil and Gas Reporter - November 2016 - 78
American Oil and Gas Reporter - November 2016 - 79
American Oil and Gas Reporter - November 2016 - 80
American Oil and Gas Reporter - November 2016 - 81
American Oil and Gas Reporter - November 2016 - 82
American Oil and Gas Reporter - November 2016 - 83
American Oil and Gas Reporter - November 2016 - 84
American Oil and Gas Reporter - November 2016 - 85
American Oil and Gas Reporter - November 2016 - 86
American Oil and Gas Reporter - November 2016 - 87
American Oil and Gas Reporter - November 2016 - 88
American Oil and Gas Reporter - November 2016 - 89
American Oil and Gas Reporter - November 2016 - 90
American Oil and Gas Reporter - November 2016 - 91
American Oil and Gas Reporter - November 2016 - 92
American Oil and Gas Reporter - November 2016 - 93
American Oil and Gas Reporter - November 2016 - 94
American Oil and Gas Reporter - November 2016 - 95
American Oil and Gas Reporter - November 2016 - 96
American Oil and Gas Reporter - November 2016 - 97
American Oil and Gas Reporter - November 2016 - 98
American Oil and Gas Reporter - November 2016 - 99
American Oil and Gas Reporter - November 2016 - 100
American Oil and Gas Reporter - November 2016 - 101
American Oil and Gas Reporter - November 2016 - 102
American Oil and Gas Reporter - November 2016 - 103
American Oil and Gas Reporter - November 2016 - 104
American Oil and Gas Reporter - November 2016 - 105
American Oil and Gas Reporter - November 2016 - 106
American Oil and Gas Reporter - November 2016 - 107
American Oil and Gas Reporter - November 2016 - 108
American Oil and Gas Reporter - November 2016 - 109
American Oil and Gas Reporter - November 2016 - 110
American Oil and Gas Reporter - November 2016 - 111
American Oil and Gas Reporter - November 2016 - 112
American Oil and Gas Reporter - November 2016 - 113
American Oil and Gas Reporter - November 2016 - 114
American Oil and Gas Reporter - November 2016 - 115
American Oil and Gas Reporter - November 2016 - 116
https://www.nxtbook.com/nxtbooks/aogr/202105
https://www.nxtbook.com/nxtbooks/aogr/202104
https://www.nxtbook.com/nxtbooks/aogr/202103
https://www.nxtbook.com/nxtbooks/aogr/202102
https://www.nxtbook.com/nxtbooks/aogr/202101
https://www.nxtbook.com/nxtbooks/aogr/202012
https://www.nxtbook.com/nxtbooks/aogr/202011
https://www.nxtbook.com/nxtbooks/aogr/202010
https://www.nxtbook.com/nxtbooks/aogr/202009
https://www.nxtbook.com/nxtbooks/aogr/202008
https://www.nxtbook.com/nxtbooks/aogr/202007
https://www.nxtbook.com/nxtbooks/aogr/202006
https://www.nxtbook.com/nxtbooks/aogr/202005
https://www.nxtbook.com/nxtbooks/aogr/202004
https://www.nxtbook.com/nxtbooks/aogr/202003
https://www.nxtbook.com/nxtbooks/aogr/202002
https://www.nxtbook.com/nxtbooks/aogr/202001
https://www.nxtbook.com/nxtbooks/aogr/201912
https://www.nxtbook.com/nxtbooks/aogr/201911
https://www.nxtbook.com/nxtbooks/aogr/201910
https://www.nxtbook.com/nxtbooks/aogr/201909
https://www.nxtbook.com/nxtbooks/aogr/201908
https://www.nxtbook.com/nxtbooks/aogr/201907
https://www.nxtbook.com/nxtbooks/aogr/201906
https://www.nxtbook.com/nxtbooks/aogr/201905
https://www.nxtbook.com/nxtbooks/aogr/201904
https://www.nxtbook.com/nxtbooks/aogr/201903
https://www.nxtbook.com/nxtbooks/aogr/201902
https://www.nxtbook.com/nxtbooks/aogr/201901
https://www.nxtbook.com/nxtbooks/aogr/201812
https://www.nxtbook.com/nxtbooks/aogr/201811
https://www.nxtbook.com/nxtbooks/aogr/201810
https://www.nxtbook.com/nxtbooks/aogr/pbios_201810
https://www.nxtbook.com/nxtbooks/aogr/201809
https://www.nxtbook.com/nxtbooks/aogr/201808
https://www.nxtbook.com/nxtbooks/aogr/201807
https://www.nxtbook.com/nxtbooks/aogr/201806
https://www.nxtbook.com/nxtbooks/aogr/201805
https://www.nxtbook.com/nxtbooks/aogr/201804
https://www.nxtbook.com/nxtbooks/aogr/201803
https://www.nxtbook.com/nxtbooks/aogr/201802
https://www.nxtbook.com/nxtbooks/aogr/201801
https://www.nxtbook.com/nxtbooks/aogr/201712
https://www.nxtbook.com/nxtbooks/aogr/201711
https://www.nxtbook.com/nxtbooks/aogr/201710
https://www.nxtbook.com/nxtbooks/aogr/201709
https://www.nxtbook.com/nxtbooks/aogr/201708
https://www.nxtbook.com/nxtbooks/aogr/201707
https://www.nxtbook.com/nxtbooks/aogr/201706
https://www.nxtbook.com/nxtbooks/aogr/201705
https://www.nxtbook.com/nxtbooks/aogr/201704
https://www.nxtbook.com/nxtbooks/aogr/201703
https://www.nxtbook.com/nxtbooks/aogr/201702
https://www.nxtbook.com/nxtbooks/aogr/201701
https://www.nxtbook.com/nxtbooks/aogr/201612
https://www.nxtbook.com/nxtbooks/aogr/201611
https://www.nxtbook.com/nxtbooks/aogr/201610
https://www.nxtbook.com/nxtbooks/aogr/pbios2016_programguide
https://www.nxtbook.com/nxtbooks/aogr/201609
https://www.nxtbook.com/nxtbooks/aogr/201608
https://www.nxtbook.com/nxtbooks/aogr/201607
https://www.nxtbook.com/nxtbooks/aogr/201606
https://www.nxtbook.com/nxtbooks/aogr/201605
https://www.nxtbook.com/nxtbooks/aogr/201604
https://www.nxtbook.com/nxtbooks/aogr/201603
https://www.nxtbook.com/nxtbooks/aogr/201602
https://www.nxtbook.com/nxtbooks/aogr/201601
https://www.nxtbook.com/nxtbooks/aogr/201512
https://www.nxtbook.com/nxtbooks/aogr/201511
https://www.nxtbook.com/nxtbooks/aogr/201510
https://www.nxtbook.com/nxtbooks/aogr/201509
https://www.nxtbook.com/nxtbooks/aogr/201508
https://www.nxtbook.com/nxtbooks/aogr/201507
https://www.nxtbook.com/nxtbooks/aogr/201506
https://www.nxtbook.com/nxtbooks/aogr/201505
https://www.nxtbook.com/nxtbooks/aogr/201504
https://www.nxtbook.com/nxtbooks/aogr/201503
https://www.nxtbook.com/nxtbooks/aogr/201502
https://www.nxtbook.com/nxtbooks/aogr/201501
https://www.nxtbook.com/nxtbooks/aogr/201412
https://www.nxtbook.com/nxtbooks/aogr/201411
https://www.nxtbook.com/nxtbooks/aogr/201410
https://www.nxtbook.com/nxtbooks/aogr/201409
https://www.nxtbook.com/nxtbooks/aogr/pbios2014_programguide
https://www.nxtbook.com/nxtbooks/aogr/201408
https://www.nxtbook.com/nxtbooks/aogr/201407
https://www.nxtbook.com/nxtbooks/aogr/201406
https://www.nxtbook.com/nxtbooks/aogr/201405
https://www.nxtbook.com/nxtbooks/aogr/201404
https://www.nxtbook.com/nxtbooks/aogr/201403
https://www.nxtbook.com/nxtbooks/aogr/201402
https://www.nxtbook.com/nxtbooks/aogr/201401
https://www.nxtbook.com/nxtbooks/aogr/201312
https://www.nxtbook.com/nxtbooks/aogr/201311
https://www.nxtbook.com/nxtbooks/aogr/201310
https://www.nxtbook.com/nxtbooks/aogr/201309
https://www.nxtbook.com/nxtbooks/aogr/201308
https://www.nxtbook.com/nxtbooks/aogr/201307
https://www.nxtbook.com/nxtbooks/aogr/201306
https://www.nxtbook.com/nxtbooks/aogr/201305
https://www.nxtbook.com/nxtbooks/aogr/201304
https://www.nxtbook.com/nxtbooks/aogr/201303
https://www.nxtbook.com/nxtbooks/aogr/201302
https://www.nxtbook.com/nxtbooks/aogr/201301
https://www.nxtbook.com/nxtbooks/aogr/201212
https://www.nxtbook.com/nxtbooks/aogr/201211
https://www.nxtbook.com/nxtbooks/aogr/201210
https://www.nxtbook.com/nxtbooks/aogr/201209
https://www.nxtbook.com/nxtbooks/aogr/2012_pbios
https://www.nxtbook.com/nxtbooks/aogr/201208
https://www.nxtbook.com/nxtbooks/aogr/201207
https://www.nxtbook.com/nxtbooks/aogr/201206
https://www.nxtbook.com/nxtbooks/aogr/201205
https://www.nxtbook.com/nxtbooks/aogr/201204
https://www.nxtbook.com/nxtbooks/aogr/201203
https://www.nxtbook.com/nxtbooks/aogr/201202
https://www.nxtbook.com/nxtbooks/aogr/201201
https://www.nxtbook.com/nxtbooks/demo/aogr_clone
https://www.nxtbook.com/nxtbooks/aogr/201112
https://www.nxtbookmedia.com