Title: Geological Model
1Geological Model
X(km)
0
4
0
Depth(km)
3
2001 Year
2Migration Result Using Crosscorrelation Imaging
X (km)
1.6
2.1
0
Too Simple?
Widen illumination?
Time (s)
If there are static errors in well?
2.2
3Enhancing Illumination Coverage of VSP by
Crosscorrelation Migration
Jianhua Yu
University of Utah
4Contents
Motivation
Crosscorrelation Migration
SEG/EAGE Model
2-D RVSP Exxon Data
Conclusions
5Contents
Motivation
Crosscorrelation Migration
SEG/EAGE Model
2-D RVSP Exxon Data
Conclusions
6What Affects VSP Imaging Quality?
7Why uses Crosscorrelation Migration?
8Why uses Crosscorrelation Migration?
9Why uses Crosscorrelation Migration?
10Why uses Crosscorrelation Migration?
11Objectives
Investigate the crosscorrelation migration method
on
12Contents
Motivation
Crosscorrelation Migration
SEG/EAGE Model
2-D RVSP Exxon Data
Conclusions
13Well
Receiver
Source
VSP
14Ghost Reflection Imaging Condition
g
s
x
15After Crosscorrelation of Two Traces at Locations
g g
g
s
x
16After Crosscorrelation of Two Traces at Locations
g g
g
s
x
17After Crosscorrelation of Two Traces at Locations
g g
g
s
x
18Why not sensitive to static errors in the well?
19Crosscorrelogram Migration
20Benefits from Crosscorrelation Migration
21Contents
Motivation
Crosscorrelation Migration
SEG/EAGE Model
2-D RVSP Exxon Data
Conclusions
220
Depth (km)
SEG/EAGE Model
2
0
3
X (km)
23Well
0
1 km
Depth (km)
2
0
3
X (km)
24Depth (km)
0.2
0.9
0
CSG 160
Time (s)
3
25Depth (km)
0.2
0.9
0
Ghosts (CSG 160)
Time (s)
3
26Depth (km)
0.2
0.9
0
Primary (CSG 160)
Time (s)
3
27X (km)
0
2.4
0
Time (s)
CRG 60
3
28Kirchhoff Migration (45 degree)
0.5
Depth (km)
2.0
0.5
2.5
X (km)
29Crosscorrelation Migration (45 degree)
0.5
Depth (km)
2.0
0.5
2.5
X (km)
30Crosscorrelation Migration (15 degree)
0.5
Depth (km)
2.0
0.5
2.5
X (km)
31Kirchh Mig (45)
0.5
Depth (km)
2.0
0.5
2.5
X (km)
320
Well Depth (m)
900
50
Raw Data
Static errors (ms)
-50
Static Errors at Well
33Kirchhoff Migration
Static Error 0
0.5
Depth (km)
2.0
0.5
34Crosscorrelation Migration
Static Error 0
0.5
Depth (km)
2.0
0.5
35Contents
Motivation
Crosscorrelation Imaging Condition
SEG/EAGE Model
2-D RVSP Exxon Data
Conclusions
36Depth (ft)
30
900
0
Exxon Raw Data(CRG15)
Time (s)
0.3
37Depth (ft)
30
900
0
Ghosts (Exxon)
Time (s)
0.3
38Depth (ft)
30
900
0
Primary(Exxon)
Time (s)
0.3
39Exxon CSG 25
Trace No.
5
24
0.5
Raw data (muted)
Time (s)
1.4
40X (ft)
0
400
200
Xcorr. mig
Depth (ft)
1300
41X (ft)
0
400
200
Standard mig
Depth (ft)
1300
42X (ft)
X (ft)
0
400
0
400
200
Standard mig
Cross. mig
Depth (ft)
1300
43Exxon Data
Well data
Xcorr. Migration
0
Depth (ft)
1100
44Exxon Data
Well data
Standard Migration
0
Depth (ft)
1100
45Exxon Data
Standard
0
Depth (ft)
1100
46Contents
Motivation
Crosscorrelation Migration
SEG/EAGE Model
2-D RVSP Exxon Data
Conclusions
47Conclusions
Increase illumination coverage in the deeper part
of VSP image
48Conclusions
Loss of some lateral resolution?
49Acknowledgments
2003 UTAM sponsors
Exxon for 2-D field data