Post on 02-Jan-2016
Passive Seismic ImagingStanford Exploration Project
passive seismic imaging
Brad Artman
Passive Seismic ImagingStanford Exploration Project
• passive imaging
• importance of 3D
• migration
• teleseisms
• breaking waves
• north sea reservoir
Passive Seismic ImagingStanford Exploration Project
passive imaging• not event location
• structural imaging– reflection seismology: subsurface investigation
from the time-delayed reflections of sound off of geologic variations.
– passive imaging: with no application of controlled experimental sources, a relationship between a recorded transmission wavefield and reflection wavefields is required.
• requires: stationary seismometers, lots of disk space
Passive Seismic ImagingStanford Exploration Project
capitalizing on ambient noise• earthquake arrivals
• ocean waves
• wind vibrations coupled with foundations
• cultural activity– vehicle and boat traffic– drilling noise– nearby seismic acquisition
Passive Seismic ImagingStanford Exploration Project
transmission wavefield
time (s)
dep
th (m
)
position(m) position(m)
Passive Seismic ImagingStanford Exploration Project
ambient noiser1 r2
t
r1 r2
Passive Seismic ImagingStanford Exploration Project
ambient noiser1 r2
t
r1 r2
Passive Seismic ImagingStanford Exploration Project
ambient noiser1 r2
t
r1 r2
Passive Seismic ImagingStanford Exploration Project
ambient noiser1 r2
t
r1 r1 r1 r2
lag
r1 r2
Passive Seismic ImagingStanford Exploration Project
r1 r2
t
r1 r1 r1 r2
twt
r1 r2ambient noise
Passive Seismic ImagingStanford Exploration Project
r1 r2
t
r1 r1 r1 r2
twt
r1 r2ambient noise
Passive Seismic ImagingStanford Exploration Project
backscattered PPr1 r2
t
r1 r1 r1 r2
twt
r1 r2
Passive Seismic ImagingStanford Exploration Project0 1200600
position(m)
20 2
5 3
0tim
e(s)
5 1
0
0 200100
lag
(s)0
0.1
0.3
400300offset(m)
Passive Seismic ImagingStanford Exploration Project0 1200600
position(m)
20 2
5 3
0tim
e(s)
5 1
0
0-100 200100
lag
(s)0
0.1
0.3
offset(m)300
Passive Seismic ImagingStanford Exploration Project0 1200600
position(m)
20 2
5 3
0tim
e(s)
5 1
0
0-100-200
200100
lag
(s)0
0.1
0.3
offset(m)
Passive Seismic ImagingStanford Exploration Project0 1200600
position(m)
20 2
5 3
0tim
e(s)
5 1
0
0-100-200
100
lag
(s)0
0.1
0.3
offset(m)-
300
n long traces n short traces2
Passive Seismic ImagingStanford Exploration Project
• passive imaging
• importance of 3D
• migration
• teleseisms
• breaking waves
• north sea reservoir
Passive Seismic ImagingStanford Exploration Project
The Sun as a Laboratory
Acoustic Daylight Imaging via spectral factorization, Rickett SEP-100
Passive Seismic ImagingStanford Exploration Project
2D Experiment
1 Receiver line
Passive Seismic ImagingStanford Exploration Project
Break Point?
Passive Seismic ImagingStanford Exploration Project
Whole Data Volume
Passive Seismic ImagingStanford Exploration Project
8 Consecutive Lines
Passive Seismic ImagingStanford Exploration Project
8 Spaced Lines
Passive Seismic ImagingStanford Exploration Project
• passive imaging
• importance of 3D
• migration
• teleseisms
• breaking waves
• north sea reservoir
Passive Seismic ImagingStanford Exploration Project
active synthetic
reflection gather active migration
Passive Seismic ImagingStanford Exploration Project
passive synthetic
correlated passive gather passive migration
Passive Seismic ImagingStanford Exploration Project
correlated passive gather passive migration
passive synthetic
Passive Seismic ImagingStanford Exploration Project
• passive imaging
• importance of 3D
• migration
• teleseisms
• breaking waves
• north sea reservoir
Passive Seismic ImagingStanford Exploration Project
2.5 D
Vapp = V/cos()
Passive Seismic ImagingStanford Exploration Project
earthquake energy
Passive Seismic ImagingStanford Exploration Project
• passive imaging
• importance of 3D
• migration
• teleseisms
• breaking waves
• north sea reservoir
Passive Seismic ImagingStanford Exploration Project
Artman GeoServices
Passive Seismic ImagingStanford Exploration Project
Enlarged data set
Passive Seismic ImagingStanford Exploration Project
5min Night
Passive Seismic ImagingStanford Exploration Project
5min Night
Passive Seismic ImagingStanford Exploration Project
10min Day
Passive Seismic ImagingStanford Exploration Project
• passive imaging
• importance of 3D
• migration
• teleseisms
• breaking waves
• north sea reservoir
Passive Seismic ImagingStanford Exploration Project
Valhall
VALHALL
STAVANGER
0 100 km
UNITEDKINGDOM
NOR WAY
GERMANY
DENMARK
UNITEDKINGDOM
GERMANY
DENMARK
NORWAY
0 100 km
HOD
• one of the North sea giant fields• partners Amerada Hess, Shell and Total• reservoir highly porous chalk• first production 1982• field life 2028
Passive Seismic ImagingStanford Exploration Project
Valhall Life of Field Seismic
• Permanent field wide seismic array installed at Valhall during 2003 – 120 km seismic cables– 2414 groups of 4C sensors– Covers 45sq km
Passive Seismic ImagingStanford Exploration Project
Oyo-Geospace cable
Passive Seismic ImagingStanford Exploration Project
Valhall data
Passive Seismic ImagingStanford Exploration Project
Valhall data
3 days, 2300 4C recievers1.2 Tbytes
Passive Seismic ImagingStanford Exploration Project
Valhall data
trace #
Depth slice near 88m
energy localized around rig
moveout across traces suggests surface noise
Passive Seismic ImagingStanford Exploration Project
Valhall data
Reflector?
mono-freq. boat noise
rig activity
Passive Seismic ImagingStanford Exploration Project
Valhall pipe cut image
4km
12km
Passive Seismic ImagingStanford Exploration Project
Valhall active seismic
4km
12km
Passive Seismic ImagingStanford Exploration Project
thank you