Post on 20-Oct-2015
Basic Seismic ProcessingBasic Seismic ProcessingINPUT
FILTER
CMP Gather
NMO
STACK
MIGRATE
DISPLAY
GEOM
VEL ANAL
STATICS
MUTE
More Seismic ProcessingMore Seismic Processing
INPUT
BP FILTER CMP Gather
NMO
STACK
MIGRATE
DISPLAY
GEOM
VEL ANAL
STATICSDEMUX
VIB CORR
FK FILTER
DECONDMO/
MIGRATE
SAVE
DECON
FK FILTER
MUTE
GAIN RCVR
COHERENCYENHANCE
COHERENCYENHANCE
TIMETO
DEPTH
EDIT
Pre-ProcessingPre-Processing
IN
OUT
DEMULTIPLEXING
VIBROSEIS CORRELATION
Pt
Corr St
Raw St
Pt Raw StX =
Issues: Demultiplex skew
Issues: DeSpike B4 Corr Filtered Pilot
Raw S-tPt *=
Yilmaz, 2001
Vibroseis CorrelationVibroseis Correlation
Yilmaz, 2001
Gain RecoveryGain Recovery
Options:
•Automatic Gain Control (AGC)• Gain info lost•Spherical Divergence (Need Vt)•Exponential Gain Correction•Programmed Gain Control (PGC)•Trace to Trace Gain Balance •Amplitude Statics
Yilmaz, 2001
Gain RecoveryGain Recovery
Original
with Spherical Gain Correction
Yilmaz, 2001
Gain Recovery: AGCGain Recovery: AGC= window length
AGC shadow
Yilmaz, 2001
EditingEditing
Band Pass FilterBand Pass Filter
st
t
s’t
t
Input Output
Sf
f f f
S’fRf
rt
Filter
X =
* =
Time domain
Frequency domain
Bandwidth/Filter LengthBandwidth/Filter Length
Filter length
Bandwidth = f2/f1
50/2535/5
Filter ShapeFilter Shape
Band Pass Filter: ResolutionBand Pass Filter: Resolution
Increasing frequency
Increasing Bandw
idth
model model
Bandpass Filter TestBandpass Filter Test
TVF = Time Varying Filter
FK (2D) FilteringFK (2D) Filtering
t
f
x
k
FK FilteringFK Filtering
Spatial AliasingSpatial Aliasing
FK FilteringFK Filtering
FK FilteringFK Filtering
FK Spectra
before
after
B4
After
Convolutional ModelConvolutional Model
* W t=
DeconvolutionDeconvolution
conv
decon
Poor decon
DeconvolutionDeconvolution
DeconvolutionDeconvolution
Before Decon After Decon