Seismic scattering attenuation and its applications in seismic imaging and waveform inversion

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Seismic scattering attenuation and its
applications in seismic imaging and waveform
inversion

• Yinbin Liu
• Vancouver Canada

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Seismic imaging mathematics Wave localization
physics and geology Oil and gas
reservoir strongly-scattered inhomogeneous
media Low frequency scattering resonance A new
physical concept passive seismic monitoring and
non-volcanic seismic tremor
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Outlines
Introduction Low frequency scattering
resonance Discussions
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Anderson wave localization
Wave in impurity band conduction
Incident pulse
Very few believed localization at the time, and
even fewer saw its importance among those who
failed to fully understand it at first was
certainly its author. It has yet to receiver
adequate mathematical treatment, and one has to
resort to the indignity of numerical simulations
to settle even the simplest questions about
it. -- Philip W. Anderson, Nobel
lecture,
8 December 1977
Random arrangements of electronic or nuclear
spins
Energy space distribution
Common wave phenomenon
mechanical wave, electromagenetic wave, matter
wave energy trap
within low velocity zone
multiple scattering
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Interference and absorption
Shale Sandstone shale
Absorption has very little inference on signal
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Gas reservoir strong local heterogeneity
Macroscope
thin CBM
Rock physics Well log
fractures
microscope
Modified from Einsel,1992
Well log (rock physics)
seismic response
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Seismic imaging resolution
Velocity 3000 m/s Dominant frequency 30
Hz Wavelength 3000 / 30 100 m Reservoir
thickness is usually much less than
wavelength Only strongly-scattered reservoir can
be seen by seismic
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Gas-bearing formation
Strong heterogeneity multiple scattering
Microscopic scale heterogeneity has an important
influence on seismic response
Effective media and Diffusive approximation
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Low frequency earthquake
A high frequency small-amplitude onset
superposing on a low-frequency large-amplitude
background
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Strongly-scattered small-scale heterogeneity
Media gas-oil-bearing or magam geological bodies
-- strong microscopic-scale
heterogeneity Seismic response macroscopic
effect Medium structure microscopic scale
Model coupling effect (mecroscopy) it
is still a challenge project in physics
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Similarity of different wave fields
Ocean wave
Microwave dispersion
Pleshko and Palocz, 1969
Hyper-Airy function
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Fundamental laws
Interference exactly include
multiple scattering
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Two scatterers (m and l)
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Multiple scattering theory
Systematic perturbation theory (T matrix) Twesky
multiple scattering theory Above two theories
are not suitable for studying the high order
multiple scattering in strongly scattered
scale-small heterogeneity Convergence
issue
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Seismic scale effects
M1
M2
M3
M256


512 layers
2 layers
4 layers
6 layers
Ray
Scattering
A quasi-periodic layered model
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Comparison between theory and experiment
10 MHz
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Scale-dependent multiple scattering
ray
Low frequency
coda
enhancement
effective
dispersion
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Multiple scattering
Ray theory large scale
slowing velocity Multiple low frequency
scattering theory resonance
coherent scattering
enhancement Effective medium theory
micro-scale
Inhomogeneous scale
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Physical explanation for dispersion
vD/t
The direct wave rapidly reduces to negligible
values and the multiple reflection wave becomes
the first arrival.
Liu and Schmitt, 2002
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Physical interpretation
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1
2
23 (scattering resonance)
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Coda
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Impact on wave imaging
The frequency of LFSR, which is about one order
of magnitude lower than that of the natural
resonance, provides higher resolution. Multiple
scattering Multiple correlation Multiple
iteration Passive seismic monitoring (geophones
are put in borehole) Non-volcanic seismic tremor
Signal is no beginning and no ending
persisting for days and months
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Thank you for your attention