passive seismic imagingstanford exploration project passive seismic imaging brad artman

Passive Seismic ImagingStanford Exploration Project

passive seismic imaging

Brad Artman


• passive imaging

• importance of 3D

• migration

• teleseisms

• breaking waves

• north sea reservoir


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


capitalizing on ambient noise• earthquake arrivals

• ocean waves

• wind vibrations coupled with foundations

• cultural activity– vehicle and boat traffic– drilling noise– nearby seismic acquisition


transmission wavefield

time (s)

dep

th (m

)

position(m) position(m)


ambient noiser1 r2

t

r1 r2


ambient noiser1 r2

t

r1 r1 r1 r2

lag

r1 r2


r1 r2

t

r1 r1 r1 r2

twt

r1 r2ambient noise


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)


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


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)


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 imaging


• migration

• teleseisms

• breaking waves



The Sun as a Laboratory

Acoustic Daylight Imaging via spectral factorization, Rickett SEP-100


2D Experiment

1 Receiver line


Break Point?


Whole Data Volume


8 Consecutive Lines


8 Spaced Lines


• passive imaging


• migration

• teleseisms

• breaking waves



active synthetic

reflection gather active migration


passive synthetic

correlated passive gather passive migration


correlated passive gather passive migration

passive synthetic


• passive imaging


• migration

• teleseisms

• breaking waves



2.5 D

Vapp = V/cos()


earthquake energy


• passive imaging


• migration

• teleseisms

• breaking waves



Artman GeoServices


Enlarged data set


5min Night


10min Day


• passive imaging


• migration

• teleseisms

• breaking waves



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


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


Oyo-Geospace cable


Valhall data


Valhall data

3 days, 2300 4C recievers1.2 Tbytes


Valhall data

trace #

Depth slice near 88m

energy localized around rig

moveout across traces suggests surface noise


Valhall data

Reflector?

mono-freq. boat noise

rig activity


Valhall pipe cut image

4km

12km


Valhall active seismic

4km

12km


thank you

passive seismic imagingstanford exploration project passive seismic imaging brad artman

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