seismic reflection processing post-stack

19
Basic Seismic Processing Basic Seismic Processing INPUT FILTER CMP Gather NMO STACK MIGRATE DISPLAY GEOM VEL ANAL STATICS MUTE

Upload: adobi

Post on 17-Nov-2015

43 views

Category:

Documents


9 download

DESCRIPTION

Seismic Reflection Processing Post-Stack

TRANSCRIPT

  • Basic Seismic ProcessingINPUTFILTERCMP GatherNMOSTACKMIGRATEDISPLAYSTATICSMUTE

  • More Seismic ProcessingINPUTBP FILTERCMP GatherNMOSTACKMIGRATEDISPLAYGEOMVEL ANALSTATICSDEMUXVIB CORRFK FILTERDECONDMO/MIGRATESAVEDECONFK FILTERMUTEGAIN RCVRCOHERENCYENHANCECOHERENCYENHANCETIMETODEPTHEDIT

  • Stack

  • MigrationactualSeismic section(unmigrated)Migration(move it back)sin() = tan (a), where = true dip, a = apparent dip

  • Migration: Syncline

  • Migration EffectsModels(perfectly migrated)Synthetic Seismic Sections(Unmigrated)

  • DiffractionPoint Reflector(Diffractor)Reflection Response(Diffraction)

  • Diffraction Model of Generic ReflectionMultiple diffractors Dx = finiteMultiple diffractors Dx 0

  • Migration with Velocity DistortionLayer 1Layer 2Layer 3ALL

  • Depth Migration & Stack SmearingZero-0ffset(Single fold)10 Fold Stack

  • Migration Ex: SynclineBeforeAfter Migration?

  • Migration Ex: FaultBefore MigrationAfter Migration

  • Migration ExampleBefore MigrationAfter Migration

  • Migration: MethodologyDiffraction Summation(Diffraction Stack)Wavefront Summation(Kirchoff Stack)unmigratedmigrated

  • Migration MethodologyExploding Reflector(Back Propagation, Wave EquationFinite Difference, FK)

  • Migration Artifacts: Aperture35 traces70 traces150 traces256 traces

  • Migration Artifacts: VelocityTrue VV 5% lowV 10% lowV 20% low

  • Migration and NoiseRandom NoiseRandom Noise+MigrationMigration smilesesp at edges of dataUnmigratedMigrated

  • Migration: VoilaNote: Steep dip migration