critical wavepath refraction migration
DESCRIPTION
Critical Wavepath Refraction Migration. Maike Buddensiek, University of Utah, Feb. 2003. Outline. Introduction - Why are we doing this? Basic concept of CRRM method Results of synthetic data Conclusions and further research. Introduction. - PowerPoint PPT PresentationTRANSCRIPT
Critical Wavepath Critical Wavepath Refraction MigrationRefraction Migration
Maike Buddensiek,Maike Buddensiek,
University of Utah, Feb. 2003University of Utah, Feb. 2003
OutlineOutline
• Introduction - Why are we doing this? Introduction - Why are we doing this?
• Basic concept of CRRM methodBasic concept of CRRM method
• Results of synthetic dataResults of synthetic data
• Conclusions and further researchConclusions and further research
IntroductionIntroduction
• Refraction data contain hidden Refraction data contain hidden information of reflection traveltimes.information of reflection traveltimes.
• After resorting the data, they are After resorting the data, they are kinematical equivalent to critical kinematical equivalent to critical reflections.reflections.
• Those critical refractions can be Those critical refractions can be migrated just like reflections.migrated just like reflections.
• Less artifacts Less artifacts
• Velocity of refracting layer not necessaryVelocity of refracting layer not necessary
• Any refractor geometry can be migratedAny refractor geometry can be migrated
BasicBasic ConceptConcept
A X M Y B
TAYTAY + TBX - TAB TAY + TBX TAY + TBX - TAB
v1
v2
Basic ConceptBasicBasic ConceptConcept
A X M Y B
TAYTAY + TBX - TAB TAY + TBX TAY + TBX - TAB
v1
v2
Basic ConceptBasicBasic ConceptConcept
A X M Y B
TAYTAY + TBX - TAB TAY + TBX TAY + TBX - TAB
v1
v2
Basic ConceptBasicBasic ConceptConcept
A X M Y B
TAYTAY + TBX - TAB TAY + TBX TAY + TBX - TAB = TXY
v1
v2
TAY + TBX - TAB
BasicBasic ConceptConcept
A X M Y B
TXYdata : kinematics of reflection
v1
v2 O
Critical Distance
TAY + TBX - TAB = TXY
Migration by RaytracingMigration by Raytracing
A X M Y B
v1
v2
TXO + TOY = TXOYtheory
O
Incidence Angles for RaytracingIncidence Angles for Raytracing
A X M Y B
v1
v2
Migration by RaytracingMigration by Raytracing
A X M Y B
TXOYtheory TXY
data
v1
v2 O
Migration by RaytracingMigration by Raytracing
v1
v2 O
Critical Distance
A X M Y B
TXOYtheory = TXY
data
CRRM MethodCRRM Method• 1. Select A, B, X, Y and then trace rays1. Select A, B, X, Y and then trace rays
• 2. Determine T2. Determine TXOYXOYtheorytheory
• 3. Determine T3. Determine TXYXYdatadata
• 4. If T4. If TXYXYdatadata = T = TXOYXOY
theorytheory – Smear refraction energy at O. Smear refraction energy at O. – Otherwise no energy is smeared.Otherwise no energy is smeared.
v1
v2 O
A X M Y B
Dipping Layer Model 1Dipping Layer Model 1
600
300
Dipping Layer Model 2Dipping Layer Model 2
600
300
Low Frequency UndulationLow Frequency Undulation
600
300
High Frequency UndulationHigh Frequency Undulation
600
300
Fault ModelFault Model
600
300
ResultsResults
• Very accurate mapping of the refractorsVery accurate mapping of the refractors
• No artifactsNo artifacts
• The refracting velocity is not knownThe refracting velocity is not known
• Problemaict zones just result in Problemaict zones just result in unmapped tracesunmapped traces
ConclusionConclusion
• The CRRM method has the potential to The CRRM method has the potential to migrate refraction data more precisely migrate refraction data more precisely than traditional methods.than traditional methods.
• CRRM does not produce artifacts like CRRM does not produce artifacts like traditional methods do.traditional methods do.
• Future Work: Make suggested changes Future Work: Make suggested changes and then apply to field data.and then apply to field data.