Depth (m) Time (s) Raw Seismograms Four-Layer Sand Channel Model Midpoint (m)

Interferometric Seismic Imaging of the Moho J. Sheng, D. Sheley, J. Pechmann, G. Schuster, R. Nowack

Outline PP Imaging: Alaska Earthquake PS Imaging: Crosswell Data Interferometric Principle: Interferometric Principle: Time Diff. between Arrivals Structure Diff. Interferometric Imaging Applications: Interferometric Imaging Applications:

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 pseudo-shot gathers Kirchhoff Migrate pseudo-shot gathers Ghost Direct has kinematics of primary reflection x M BONUS: Reduced Sensitivity to V(r) Sensitivity to V(r)

Migrate s(x,t) s(x,t) rather than s(x,t) Migrate s(x,t) s(x,t) rather than s(x,t) No need to know source location, wavelet No need to know source location, wavelet Reduced sensitivity to velocity errors Reduced sensitivity to velocity errors Problem: Virtual multiples Problem: Virtual multiples Summary

Outline PP Imaging: Alaska Earthquake PS Imaging: Crosswell Data Interferometric Principle: Interferometric Principle: Time Diff. between Arrivals Structure Diff. Interferometric Imaging Applications: Interferometric Imaging Applications:

0 km 200 km 0 s 1.6 s UTAH 0 50 km

Denali Earthquake 0 km 200 km 0 km 48 km Reflectivity Model 4 km/s 5.9 km/s 6.5 km/s 8.0 km/s

Denali Earthquake 0 km 200 km 0 s 40 s Z-Component Seismograms Time (s)

Denali Earthquake 0 km 200 km 0 km 48 km Z-Comp. Migration Image

Denali Earthquake

0 km 200 km 0 s 1.6 s Utah Stations 0 50 km

Vertical Component Vertical Component(Bandpass) Time (s) 0 km 150 km p pp

Vertical Component Vertical Component(Bandpass+PEF) Time (s) 0 km 150 km

Vertical Component Vertical Component(Bandpass+PEF+FX) Time (s) 0 km 150 km

#1 #40 300s 460 s Z-Componentp pp

1 150 km 0 km 40 km Migration Image 

Vertical Comp. (Synthetic) traces (1 km evenly) Time (sec.)

Xmig (Synthetic) Xmig (Synthetic) Depth (km) Distances (km)

Colima, Mexico UU Strong Motion Network

Colima, Mexico Earthquake Colima, Mexico Earthquake(Vertical) Time (sec.)

Colima, Mexico Earthquake Colima, Mexico Earthquake (Vertical, Bandpass) Time (sec.)

Colima, Mexico Earthquake Colima, Mexico Earthquake (Vertical, Deconed)

Crosscorrelogram Crosscorrelogram Time (sec.)

Xmig (P, P Ghost) Xmig (P, P Ghost) Depth (km) 150 Distances (km)

Outline PP Imaging: Alaska Earthquake PS Imaging: Crosswell Data 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

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)

6 Time (ms) Depth (m) 0 Time Shifted CRG

Conventional PS Offset (m) 50 0Reduced-Time Depth (m)

2. Possible Applications: Horizontal Drill Bit Imaging, CDP Mult. Earth, Mars/Sun Seismology 2 4. Limitations: 4. Limitations: Virtual Multiples Out-of-plane events, Common Inage Gath. 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 PP, PS, PSP,… 3. Opportunities: Interfer. Tomo., Red. error

2. Possible Applications: Horizontal Drill Bit Imaging, CDP Mult. Reservoir Monitoring, Mars/Sun Seismology 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

Thanks to UTAM sponsors and DOE. and DOE. Thanks to Lew Katz and Fred Followill.

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)

Time (s) X (km) X (km) With only primaryJoint auto. migration Time Migration Results (39 CSGs) Source

Crosscorrelogram Image Crosscorrelogram Image Depth (km) Distance (km)

Kirchhoff Image Depth (km) Distance (km)

Product Image Depth (km) Distance (km)

Overview of Univ. Utah Tomography and Modeling/Migration (UTAM) M. Budenseik, T. Crosby, M. Budenseik, T. Crosby, C. Cheng, R. He, G. Schuster, J. Sheng, J. Yu and M. Zhou

UTAM Goals Develop Innovative Tomography, Develop Innovative Tomography, Migration & Modeling Software Migration & Modeling Software Tomography: First successful visco/elastic acoustic waveform inversion of xwell data acoustic waveform inversion of xwell data Migration: Originators migration decon, wavepath migration, least squares migration wavepath migration, least squares migration filtering, seismic interferometry, POIC filtering, seismic interferometry, POIC Modeling: Numerical Recipes Book

Source Geophone Bit Position? Problems in RVSPWD Pilot signal? Wavelet ?

Problems with Drill-bit and RVSP Data No source wavelet No source initiation time Not easy to get pilot signal in deviated well Not easy to get pilot signal in deviated well and horizontal well

Static shift errors may exist Difficulty for separating primary and ghost waves from deviated or horizontal well Problems with Drill-bit and RVSP Data

Solution Cross- or Auto-correlogram Migration Why do we use autocorrelation of seismic data rather than the seismogram ???

Strengths of Autocorrelogram Migration No need to know initial time No limits to deviated well Reduce Static errors influence No need to know source wavelet

Weakness of Correlogram Migration Virtual Multiples & Loss of Resolution

Well Drill bit Receiver Primary Direct Wave Ghost What is Joint Migration

Final migration image Ghost migration Primary migration Seismic Data

Horizontal Well Model 0 Depth (m) 3 40 X (m) V1 V2 V4 V3 V5 V6

Shot Gather Time (s) CSG Time (s) Traces Autocorrelogram

Depth (km) X (km) X (km) Standard migration Joint migration Standard Migration with Joint Migration (3 CSGs) Source

East (kft) North (kft) Well Rig 10 Depth (kft) ft Offset= ft Recording Length: 20 s Sample Interval: 2 ms Main Acquisition Parameters

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

Main Processing Steps Trace editing and static shift Trace editing and static shift Frequency panel analysis and noise elimination Frequency panel analysis and noise elimination Velocity analysis Velocity analysis Amplitude balance and energy normalization Autocorrelograms, vertical stacking utocorelograms Joint migrating autocorelograms

Acquisition Survey Map Well Rig 3C Receivers Drill bit East (ft) North (ft) C Line AC4

Time (s) SP Drill hole Joint Migration ( insert) and CDP Section

Time (s) SP Primary Migration ( insert) and CDP Section Drill hole

Time (s) SP Drilling hole Joint Migration ( insert) and CDP Section JOINT

Time (s) SP Primary Migration ( insert) and CDP Section Drilling hole Primary

SUMMARY Need separating primary and multiple? NO Work for deviated or horizontal well ? YES Reduce the influence of static errors ? YES Need pilot signal ? NO Need source wavelet and initial time ? NO Suppress coherent noise ? YES Amplitude fidelity ? NO Virtual Multiple ? YES

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

SEG/EAGE Salt Model Depth (m) Distance (m) 320 shots 176 traces per shot

Kirchhoff Image Depth (m) Distance (m)

XcorM Depth (m) Distance (m)

Depth (m) Distance (m) KMXcorM

Kirchhoff Image Depth (m) Distance (m)

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:

Xmig (Bandpass) Xmig (Bandpass) Depth (km) X (km)

Xmig (Bandpass+PEF+FX) Xmig (Bandpass+PEF+FX) Depth (km) 150 Distances (km)

Denali Earthquake

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

Time Delay = 3 ms ?Time Delay = 3 ms ? Well LocationWell Location Velocity ModelVelocity Model Data Problems

Conventional PS Offset (m) Depth (m)