1. Processing and Binning Overview
From chapter 14 “Elements of 3D Seismology” by Chris Liner

2. Outline
Justification for Processing
Processing Flow
Bins

3. Justification
Field data representation of the data is distant from a distance-depth representation of data.

5. Categories of Processing
Adjustments to wavelets, or short-pulse adjustments e.g.,
frequency filtering
phase shifts (rotation)
vibroseis correlation
Traveltime Corrections (fig. 14.1) :
Statics
Normal Moveout
Dip Moveout
Migration

6. Categories of Processing
Amplitude Corrections
Geometric spreading
Automatic Gain Control
Noise Reduction
Vertical stack
Muting
CMP stack
filtering (f, f-k, tau-p (or radon)
multiple suppression

7. An example of analysis for near-surface seismic structure
Xia et al., 2004

8. Seismic data “Multiple universes for seismic data”
Shotpoint gathers (distance versus time)
CMP gathers (distance versus time)
Tau-p (horizontal slowness versus intercept time)
f-k (frequency versus wavenumber)

9. Distance between shot and the receiver (m)
Two-way traveltime (s)

10. Distance between shot and the receiver (m)
Velocity (m/s)
Distance between shot and the receiver (m)
Two-way traveltime (s) T0
dT/dx = 1/V (s/m)
T2 = T02 + x2/ V2

11. Distance between shot and the receiver (m)
Velocity (m/s)
Distance between shot and the receiver (m)
Two-way traveltime (s) T0
dT/dx = 1/V (s/m)
T2 = T02 + x2/ V2

12. x V
dT/dx = 1/V (s/m)
1/V = 0 ( s/m)
1/V = p (ray parameter)

13. Distance between shot and the receiver (m)
Velocity (m/s)
Distance between shot and the receiver (m)
Two-way traveltime (s) T0
dT/dx = 1/V (s/m)
T2 = T02 + x2/ V2

14. V angle x dT/dx = 1/Vh (s/m) 1/Vh = 1/[V/ sin(angle) ] ( s/m)
1/Vh = p (ray parameter)

15. Distance between shot and the receiver (m)
Velocity (m/s)
Distance between shot and the receiver (m)
Two-way traveltime (s) T0
dT/dx = 1/V (s/m)
T2 = T02 + x2/ V2

16. x
angle V
1/Vh = 1/[V/sin(angle) ]( s/m)
1/Vh = p (ray parameter)

17. Two-way traveltime (s) tau (intercept time) s
p (s/m)
x (m)
Two-way traveltime (s)
tau (intercept time) s
p=0 T0
Add amplitude

18. Two-way traveltime (s) tau (intercept time) s
p (s/m)
x (m)
Two-way traveltime (s)
tau (intercept time) s
p=0 T0
Add amplitude

19. Two-way traveltime (s) k (wavenumber - 1/m)
f (1/s)
x (m)
Two-way traveltime (s)
k (wavenumber - 1/m)
p=0
1000 m/s
V=f/k (m/s)
1/10 m
100 Hz

20. Two-way traveltime (s) k (wavenumber - 1/m)
f (1/s)
x (m)
Two-way traveltime (s)
k (wavenumber - 1/m)
p=0
1000 m/s
V=f/k (m/s)
1/10 m
100 Hz

21. Two-way traveltime (s) k (wavenumber - 1/m)
f (1/s)
x (m)
Two-way traveltime (s)
k (wavenumber - 1/m)
Vh=1000 (m/s)
Vh=inf (m/s)
Vh=1000 (m/s)
Vh=inf (m/s)

22. Sz Sx
P-wave
& Sv -wave

23. Vh ~= 90% shear wave velocity
“skin depth” = 1/2 longest wavelength

24. Dispersion t1 t2 t0 t1 t2
Dispersion

25. Xia et al., 2004

26. Two-way traveltime (s) k (wavenumber - 1/m)
f (1/s)
x (m)
Two-way traveltime (s)
k (wavenumber - 1/m)
p=0
1000 m/s
V=f/k (m/s)
100 Hz

27. Outline Bins Calculated common midpoints “CMP bin center”
Length and width of bin <= spatial aliasing dimensions

28. Rule of Thumb: 12.5m by 12.5 m for > 2000 m
To prevent aliasing:
max dimension = V/4fmax
For GOM:
V = V x depth
Rule of Thumb: 12.5m by 12.5 m for > 2000 m
IDEAL BIN SIZE: 5m by 5m for seafloor and deeper

29. The “best” bin:
SMALL
ALL OFFSETS
ALL AZIMUTHS
LARGE FOLD

30. Outline
Justification for Processing
Processing Flow
Bins