Depth (m) Time (s) Raw Seismograms Four-Layer Sand Channel Model Midpoint (m)
Interferometric Seismic Imaging Gerard T. Schuster
Outline Passive data for IVSP while Drilling Imaging of Free Surface CDP Multiples Imaging of Hydo-Frac Location Transmission PS Migration Interferometric Principle: Interferometric Principle: Time Diff. between Arrivals Structure Diff. Interferometric Imaging Applications: Interferometric Imaging Applications:
Claerbout, Katz, 70’s xx Earthquake 1900’s xx Utah+LLNL 1997 Migrate Claerbout, Rickett 1999 xyxyxyxy xyxyxyxyMigrate Arbitrary Unknown Src V(z) V(x,y,z) W(t) Location W(t) Location NOYESYESYES NO YESYESYES YES/NO YESNO? NOYESYES YESNO YES YES YES SELECTIVE HISTORY PASSIVE IMAGING Validity
Interference Pattern Optical Lens LASER t
Interference Pattern Optical Lens ss t LASER Lens Deformation Time Differences
Outline Passive data for IVSP while Drilling Interferometric Principle: Interferometric Principle: Time Diff. between Arrivals Structure Diff. Interferometric Imaging Applications: Interferometric Imaging Applications:
Seismic Ghost Reflection Direct Ghost ? Find R(x,z) but not know source location
Direct Ghost 12Directx Directx Master Seismic Ghost Reflection Seismic Interferogram: Correlate Traces t }M m(x) = (g, t + t ) gx g MxMxMxMxgx M Kirchhoff Migrate psuedo-shot gathers Kirchhoff Migrate psuedo-shot gathers Ghost Direct has kinematics of primary reflection x M
Depth (m) Time (s) Raw Seismograms Four-Layer Sand Channel Model Midpoint (m)
Depth (m) Time (s) Raw Seismograms Migration Image: 1-s Stack Midpoint (m)
Midpoint (m) Depth (m) Raw Seismograms Time (s) Migration Image: 50 1-s Stacks
Geological Model 0 Depth (m) 3 40 X (m) V1 V2 V4 V3 V5 V6
Velocity Model (J. Yu) Depth(km) X(km) X(km) Interval VelocityRMS Velocity
Shot Gather Time (s) CSG Time (s) Traces Autocorrelogram
X (km) Without ghost Ghost Autocorrelogram Depth Migration Depth (km) X (km) With primary+ghost
Acquisition Survey East (kft) North (kft) Well Rig 3C Receivers Drill bit 10 Depth (kft) 0
1 Trace # Time (s) 5-40 Hz 1 Trace # 10 Raw CGR 96 Proc. CGR 96
Acquisition Survey Map Well Rig 3C Receivers Drill bit East (ft) North (ft) C Line AC4
Time (s) SP Ghost Autocorrelogram Image( Corr. window=8 s) Drill hole
Outline Passive data for IVSP while Drilling Imaging of Free Surface CDP Multiples Interferometric Principle: Interferometric Principle: Time Diff. between Arrivals Structure Diff. Interferometric Imaging Applications: Interferometric Imaging Applications:
Primary Ghost 12 Free-Surface Multiple
Primary Ghost 12 x PrimaryxPrimary Seismic Interferogram: Correlate Traces Caution: Ghostx Primary = R 3 t } m(x) = (g, t + t ) gx g MxMxMxMxgx M Kirchhoff Migrate psuedo-shot gathers Kirchhoff Migrate psuedo-shot gathers Ghost Primary has kinematics of primary ref. x
Nine-Layered Model (J. Sheng) Depth (km) 2.4 Model Crosscorrelogram image Distance (km) Distance (km) artifacts Kirchhoff Image
Nine-Layered Model Kirchhoff Image Product Image =Kirch*correl Depth (km) 2.4 Distance (km) Distance (km) artifacts
SEG/EAGE Salt Model Depth (km) Distance (km)
Crosscorrelogram Image Crosscorrelogram Image Depth (km) Distance (km)
Kirchhoff Image Depth (km) Distance (km)
Product Image Depth (km) Distance (km)
Outline Passive data for IVSP while Drilling Imaging of Free Surface CDP Multiples Imaging of Hydo-Frac Location Interferometric Principle: Interferometric Principle: Time Diff. between Arrivals Structure Diff. Interferometric Imaging Applications: Interferometric Imaging Applications:
Hydro-Fracturing=Unknown Source ? P P P P x12?
P S P P MasterP*P P*P x12 Hydro-Fracturing=Unknown Source t } m(x) = (g, t - t ) gx g MxMxMxMxgx M Kirchhoff Migrate psuedo-shot gathers Kirchhoff Migrate psuedo-shot gathers Difference between Paths
m 70 Ringy 30 Hz Seismograms Time (s) m Kirchhoff Migration Image Correlogram Migration Image Midpoint (m)
Migration Image: 1-s Stack Migration Image: 40-s Stack m 70 Raw Seismograms Time (s) m 0 Migration Image: 40-s Stack Migration Image: 1-s Stack
Outline Passive data for IVSP while Drilling Imaging of Free Surface CDP Multiples Imaging of Hydo-Frac Location Transmission PS Migration Interferometric Principle: Interferometric Principle: Time Diff. between Arrivals Structure Diff. Interferometric Imaging Applications: Interferometric Imaging Applications:
Seismic P and PS Transmission S P P S ? Find R(x,z)
S P P S MasterS*S P*S Seismic P and PS Transmission P and PS Transmission Interferograms P and PS Transmission Interferograms x12 t } m(x) = (g, t - t ) gx g MxMxMxMx M Kirchhoff Migrate psuedo-shot gathers Kirchhoff Migrate psuedo-shot gathers Difference between Paths
Crosswell Model (D. Sheley) Depth (m) Offset (m) V p /V s = 1.5 Well Separation = 100 m = 100 m Source = 1500 Hz ds = 2 m dg = 2 m 5000 m/s 5500 m/s
Synthetic Data Depth (m) Time (ms) Original Data Depth (m) Time (ms) Shifted Muted Data SPPS PPS S SP
Conventional PS Transmission Migration Depth (m) Offset (m) True Velocity + 10 % Velocity Offset (m) 0100
Depth (m) Offset (m) True Velocity Reduced-Time PS Migration + 10 % Velocity Offset (m) 0100
Depth (m) Offset (m) Conventional PS Comparison +10% Velocity Interferometric PS Offset (m) 0100
km/sec Kidd Creek Crosswell Well Receiver Well Source Depth (m) Offset (m)
Time Delay = 3 ms ?Time Delay = 3 ms ? Well LocationWell Location Velocity ModelVelocity Model Data Problems
6 Time (ms) Depth (m) 0 Time Shifted CRG
Conventional PS Offset (m) Depth (m)
Conventional PS Offset (m) 50 0Reduced-Time Depth (m)
2 3. Limitations: 3. Limitations: Virtual Multiples Reflectivity Imaging > Source Imaging N Traces N Correlograms Coherent Noise Summary m(x) = (g, t + t ) g gx MxMxMxMx M 1. New Passive Seismic Imaging Capability: Valid for V(x,y,z) Arbitrary Sources Src & R Images Poststack & Prestack 2. Possible Applications: Horizontal Drill Bit Imaging, CDP Mult. Reservoir Monitoring, Mars/Sun Seismology Earthquake Rec.-Function/Ghost Imaging
1. Reduce Coherent Noise and Virtual Multiples Current & Future Work 2. Earthquake Rec. Funct. & Ghost Imaging 3. Reservoir Monitoring with CDP Data 4. Passive Data Experiment
Reduced-Time Migration Shift Traces by R1 Traveltime R1 Traveltime R1 R2 Mitigate Src-Rec Statics m(x)= d(x, t + t - t ) sxgxred.
Acknowledgements Thanks for support of UTAM sponsors. Thank J. Rickett and J. Claerbout for fruitful discussions. fruitful discussions.
Interference Pattern Phase Difference Phase of Rays with Common Path Cancels We only “see” Phase Difference
Outline Interferometric Principle: Phase Differences Interferometric Principle: Phase Differences Synthetic Data Results Synthetic Data Results Passive Seismic Data: Ghost Reflection Imaging Passive Seismic Data: Ghost Reflection Imaging CDP Multiple Data: Ghost Reflection Imaging CDP Multiple Data: Ghost Reflection Imaging Synthetic Data Results Synthetic Data Results Source Imaging & Transmission PS Imaging Source Imaging & Transmission PS Imaging Summary Summary
Outline Interferometric Principle: Phase Differences Interferometric Principle: Phase Differences Synthetic Data Results Synthetic Data Results Passive Seismic Data: Ghost Reflection Imaging Passive Seismic Data: Ghost Reflection Imaging
Outline Interferometric Principle: Phase Differences Interferometric Principle: Phase Differences Synthetic Data Results Synthetic Data Results Passive Seismic Data: Ghost Reflection Imaging Passive Seismic Data: Ghost Reflection Imaging CDP Multiple Data: Ghost Reflection Imaging CDP Multiple Data: Ghost Reflection Imaging
Outline Interferometric Principle: Phase Differences Interferometric Principle: Phase Differences Synthetic Data Results Synthetic Data Results Passive Seismic Data: Ghost Reflection Imaging Passive Seismic Data: Ghost Reflection Imaging CDP Multiple Data: Ghost Reflection Imaging CDP Multiple Data: Ghost Reflection Imaging Synthetic Data Results Synthetic Data Results
Outline Interferometric Principle: Phase Differences Interferometric Principle: Phase Differences Synthetic Data Results Synthetic Data Results Passive Seismic Data: Ghost Reflection Imaging Passive Seismic Data: Ghost Reflection Imaging CDP Multiple Data: Ghost Reflection Imaging CDP Multiple Data: Ghost Reflection Imaging Synthetic Data Results Synthetic Data Results Source Imaging & Transmission PS Imaging Source Imaging & Transmission PS Imaging
Outline Interferometric Principle: Phase Differences Interferometric Principle: Phase Differences F.S. CDP Multiples IVSPWD ? ? ? ? F.S. CDP Multiple Migration F.S. CDP Multiple Migration
Outline Interferometric Principle: Phase Differences Interferometric Principle: Phase Differences F.S. CDP Multiples ? IVSPWD ? Hydro-Frac ? ? ? ? ? Locating Hydro-Fractures in EOR Locating Hydro-Fractures in EOR
? Outline Interferometric Principle: Phase Differences Interferometric Principle: Phase Differences F.S. CDP Multiples ? IVSPWD ? Hydro-Frac ? PS Transmission Migration Migration PS ? ? ? ? ? PS Transmission Migration PS Transmission Migration
? Outline Interferometric Principle: Phase Differences Interferometric Principle: Phase Differences Passive Seismic Data: Ghost Reflection Imaging Passive Seismic Data: Ghost Reflection ImagingIVSPWD ? ?
Outline Interferometric Principle: Phase Differences Interferometric Principle: Phase Differences F.S. CDP Multiples ? IVSPWD ? Hydro-Frac ? ? ? ? ? Locating Hydro-Fractures in EOR Locating Hydro-Fractures in EOR
Outline Interferometric Principle: Phase Differences Interferometric Principle: Phase Differences F.S. CDP Multiples IVSPWD ? ? ? ? ? Locating Hydro-Fractures in EOR Locating Hydro-Fractures in EOR
Outline Interferometric Principle: Phase Differences Interferometric Principle: Phase Differences F.S. CDP Multiples ? IVSPWD ? Hydro-Frac ? ? ? ? ? PS Transmission Migration PS Transmission Migration
Outline Interferometric Principle: Phase Differences Interferometric Principle: Phase Differences F.S. CDP Multiples ? IVSPWD ? Hydro-Frac ? PS Transmission Migration MigrationPS ? ? ? ? ? ? PS Transmission Migration PS Transmission Migration
Crosscorrelogram R*G Migration 1. Construct M pseudo-shot gathers (g, t ) M m(x) = (g, t + t ) gx g MxMxMxMxgx M 2. Migrate psuedo-shot gathers by sum M, g M shifted time shifted time R G R*R R*G
Outline Interferometric Principle: Phase Differences Interferometric Principle: Phase DifferencesIVSPWD ? ? ? F.S. CDP Multiple Migration F.S. CDP Multiple Migration
Outline Interferometric Principle: Phase Differences Interferometric Principle: Phase Differences Passive Seismic Data: Ghost Reflection Imaging Passive Seismic Data: Ghost Reflection Imaging F.S. CDP Multiples IVSPWD ? ? ? ? ? F.S. CDP Multiple Migration F.S. CDP Multiple Migration
Direct Ghost Specular Ray Ray Master DG
Ghost Direct D*D D*G
Midpoint (m) Depth (m) Raw Seismograms Time (s) 4-Layer Model
Midpoint (m) Depth (m) Raw Seismograms Time (s) R G 4-Layer Model
Midpoint (m) Depth (m) Raw Seismograms Time (s) Correlogram Migration Image Others Imaged Incorrectly Ghosts Imaged Correctly
Crosscorrelogram R*G Migration 1. Construct N pseudo-shot gathers (g, t ) N m(x) = (g, t + t ) gx g NxNxNxNxgx N 2. Migrate psuedo-shot gathers by sum N, g N shifted time shifted time MP
Crosscorrelogram R*G Migration 1. Construct N pseudo-shot gathers (g, t ) N m(x) = (g, t + t ) gx g NxNxNxNxgx N 2. Migrate psuedo-shot gathers by sum N, g N shifted time shifted time MP