ESCI 444Exploration Geophysics II Reflection Seismic Data Processing

1
ESCI 444-Exploration Geophysics IIReflection
Seismic Data Processing
Spring, 2007

• Steve H. Danbom, Ph.D., P.G.
• Adjunct Professor
• Office - Room 206A
• Office Hours By Appointment

Lecture Week 4 Seismic equipment and field
procedures
2
(T.M. Boyd at CSM)
3
(T.M. Boyd at CSM)
4
(T.M. Boyd at CSM)
5
(T.M. Boyd at CSM)
6
(T.M. Boyd at CSM)
7
(T.M. Boyd at CSM)
8
Small shear-wave source for near-surface site
investigations.
9
Vibrator had competitionthis is CGGs Marthor
hammer
10
Early version of assisted weight drop seismic
source.
11
Weight-drop seismic source being used in the
desert where drilling is difficult for explosives
and Vibroseis can be ineffective.
12
The most common, buried point source explosive
for seismic.
13
Marthor wasnt the only competitionheres
another CGG idea
14
P-wave Vibroseis vibrator buggy.
15
P-wave Vibroseis vibrators forming a source array.
16
Series of seismic Vibroseis vibrators executing a
source array.
17
P-wave vibrator with baseplate down and executing
sweep.
18
Conoco shear-wave vibrator mounted on a Crane
carrier
19
Vibrator worked well in clay soils not a friend
of OK bridges
20
Close-up of the baseplate of a S-wave Vibroseis
vibrator.
21
Divots left in the ground from the S-wave
vibrator.
22
Schematic showing the forcing functions of the
P-wave and S-wave Vibroseis seismic sources.
23
Comparing and contrasting two important applied
mathematical relationships that will be used
throughout the course.
24
(No Transcript)
25
For cross-correlation, if the diagonals of the
product matrix that is formed by the two
vectors, are summed down to the right, the
resulting vector is the cross-correlation of the
two input vectors.
f2(0)
f2(0)
f2(0)
f2(0)
26
For convolution, if the diagonals of the product
matrix that is formed by the two vectors, are
summed down to the left, the resulting vector is
the convolution of the two input vectors.
27
For the Vibroseis seismic source,
cross-correlation and auto- correlation (two
vectors are identical) are crucial to its working.
28
Vibroseis schematic from the designed input
sweep, through the received signals, to the final
correlated trace.
29
(No Transcript)
30
(No Transcript)
31
(No Transcript)
32
Engineering drawing of the Bolt air gun developed
by the Chalminski brothers of Norwalk, CT.
33
Engineering drawing of the Bolt air gun developed
by the Chalminski brothers of Norwalk, CT.
34
Photograph of the Bolt air gun developed by the
Chalminski brothers of Norwalk, CT.
35
(T.M. Boyd at CSM)
36
(T.M. Boyd at CSM)
37
Vertical (Z-component) geophone that is part of
an array.
38
Picture comparing conventional vertical geophone
(left) with two-component geophone for PP and PS
acquisition.
39
Schematic showing the operation of the geophone
40
Geophone response to vibrations
41
Geophone response to vibrations cont.
42
Geophone response to vibrations cont.
43
Geophone response curve showing various levels of
damping.
44
What I mean when I say bandwidth is definition 2.
45
(T.M. Boyd at CSM)
46
(T.M. Boyd at CSM)
47
As we laugh at this old slide, which was a
caricature when it was first created, the
similarities to today are still there.
48
Recording truck circa 1978they look about the
same today.
49
Schematic of marine streamer with hydrophones
50
(No Transcript)
51
(No Transcript)
52
(T.M. Boyd at CSM)
53
(T.M. Boyd at CSM)
54
(T.M. Boyd at CSM)
55
(T.M. Boyd at CSM)
56
(T.M. Boyd at CSM)
57
(T.M. Boyd at CSM)
58
(T.M. Boyd at CSM)
59
(T.M. Boyd at CSM)
60
(T.M. Boyd at CSM)
61
Polarity standards set by the Society of
Exploration Geophysicists