Imaging Multiple Reflections with Reverse- Time Migration Yue Wang University of Utah.

Imaging Multiple Imaging Multiple Reflections with Reverse-Reflections with Reverse-

Time MigrationTime Migration

Yue WangYue Wang

University of UtahUniversity of Utah

OutlineOutline

• BackgroundBackground

• Motivation & ObjectiveMotivation & Objective

• MethodologyMethodology

• Numerical ExamplesNumerical Examples

• ConclusionsConclusions

Forward ProcessForward Process

Distance (km)Distance (km)

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*SourceSource Geophone LineGeophone Line



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obsobs

Reverse Time MigrationReverse Time Migration


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obsobs

Extrapolated WavefieldExtrapolated Wavefieldobsobs

Reversed tracesReversed traces

Reverse-Time MigrationReverse-Time Migration

Extrapolated WavefieldExtrapolated Wavefield

Imaging ConditionImaging Condition

Migration SectionMigration Section

OutlineOutline






Ocean-Bottom SurveyOcean-Bottom Survey


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ProblemProblem


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*Receiver-side MultiplesReceiver-side Multiples

Synthetic Shot GatherSynthetic Shot GatherT

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Receiver side multiplesReceiver side multiples

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0.90.9 3.63.6

Field DataField DataT

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Distance (m)Distance (m)44

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-80-80 19001900


Time MigrationTime MigrationT

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ObjectiveObjective

• Using both primary and multiple Using both primary and multiple reflections for imaging by reverse-reflections for imaging by reverse-time migration.time migration.

OutlineOutline








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VV

Up-goingUp-going

Multi-Component DataMulti-Component Data

pressure + particle velocitypressure + particle velocity( P & V )( P & V )

ocean-bottom surveyocean-bottom survey



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Down-goingDown-going

PPVV

( P & V Scheme )( P & V Scheme )



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( Particle Velocity Only )( Particle Velocity Only )

Key IdeaKey IdeaPrimary + Multiple Primary + Multiple

Correct Positions Correct Positions

P & V Scheme P & V Scheme

Key IdeaKey IdeaPrimary + Multiple Primary + Multiple

Incorrect Positions Incorrect Positions

V-Only Scheme V-Only Scheme



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Up-going WavesUp-going Waves

P & V SchemeP & V Scheme


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PPVV

Correct PositionCorrect Position

Down-going wavesDown-going waves

Particle Velocity Only SchemeParticle Velocity Only Scheme


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VVVV

IncorrectIncorrect



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VV

Down-going wavesDown-going waves( Multiples )( Multiples )



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PPVV

Correct PositionCorrect Position Up-going wavesUp-going waves



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IncorrectIncorrect

OutlineOutline





Salt Dome ModelSalt Dome Model


Salt ModelSalt Model


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Shot GatherShot GatherNormal StressNormal StressVerticalVerticalHorizontalHorizontal

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Distance (km)Distance (km)22

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0.90.9 3.63.6 Distance (km)Distance (km)0.90.9 3.63.6 Distance (km)Distance (km)0.90.9 3.63.6

MultiplesMultiples

Kirchhoff MigrationKirchhoff Migration


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Kirchhoff MigrationKirchhoff Migration


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Primary + Multiple Primary + Multiple

Correct Positions Correct Positions

ConclusionConclusion

P + V RTM P + V RTM

Future Work: Field Data TestFuture Work: Field Data TestT

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AcknowledgementAcknowledgement

We are grateful to the 1999 sponsors We are grateful to the 1999 sponsors of the UTAM consortium for the of the UTAM consortium for the financial supportfinancial support

OutlineOutline





Plane-wave examplePlane-wave example



DistanceDistance

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Up-going wavesUp-going waves


DistanceDistance

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Time (s)Time (s)

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1.21.2



DistanceDistance

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P + V RTMP + V RTM


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PP++VV


Correct PositionCorrect Position


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PP



Imaging Multiple Reflections with Reverse- Time Migration Yue Wang University of Utah.

Documents

survey slide

waves slide

obs slide

survey distance

vv incorrect slide

problem distance

time migration time

kirchhoff migration