1. Autocorrelogram Migration for Field Data Generated by A Horizontal Drill-bit Source Jianhua Yu, Lew Katz Fred Followill and Gerard T. Schuster

2. Outline Motivation and Objective Motivation and Objective Autocorrelogram Migration Autocorrelogram Migration Examples Examples Summary Summary

3. Outline Motivation and Objective Motivation and Objective Autocorrelogram Migration Autocorrelogram Migration Examples Examples Summary Summary

4. IVSPWD Objective Provide Look-ahead Image Below Drill Bit Provide Look-ahead Image Below Drill Bit Reduce Uncertainty in Drilling Reduce Uncertainty in Drilling ?

5. Problems No Source Wavelet No Source Wavelet No Source Initiation Time No Source Initiation Time Not Easy to Get Pilot Signal in Not Easy to Get Pilot Signal in Deviated Well Deviated Well

6. Autocorrelogram Migration No need to know source wavelet No limits to a deviated well No need for initiation time Solution

7. Outline Outline Motivation and Objective Motivation and Objective Autocorrelogram Migration Autocorrelogram Migration Examples Examples Summary Summary

8. Well Drill bit Receiver Primary wave Primary, Ghost and Direct Wave Direct Wave Ghost

9. x g s Primary Autocorrelogram Imaging Condition:

10. x g s

11. g Ghost Autocorrelogram Imaging Condition Ghost Autocorrelogram Imaging Condition: x s g’

12. x g s Ghost Autocorrelogram Imaging Condition Ghost Autocorrelogram Imaging Condition:

13. Autocorrelogram Migration Migrated Image Autocorrelation Function

14. Outline Outline Motivation and Objective Motivation and Objective Autocorrelogram Migration Autocorrelogram Migration Examples Examples Summary Summary

15. Acquisition Survey 0 04.5 -5 East (kft) North (kft) Well Rig 3C Receivers Drill bit 10 Depth (kft) 0

16. Main Acquisition Parameters Drill-bit Depth: 9188 ft Offset Range: 1135-4740 ft Recording Length: 20 s Sample Interval: 2 ms Station Number: 10

17. Main Processing Steps Orienting receivers, trace editing, and static shift Orienting receivers, trace editing, and static shift Frequency panel analysis and noise elimination Frequency panel analysis and noise elimination Velocity analysis and beam steering Velocity analysis and beam steering Amplitude balance and energy normalization Calculating autocorrelograms, vertical stacking Calculating autocorrelograms, vertical stacking Autocorrelogram migration

18. Raw Data Frequency Panel Analysis 1 10 0 7 Time (s) 1 10 0 7 Time (s) < 5 Hz 5-15 Hz

19. 1 10 0 7 Time (s) 1 10 0 7 Time (s) 15-25 Hz 25-40 Hz Raw Data Frequency Panel Analysis

20. Processed CSG 96 Part of CRG 6 1 10 0 7 Time (s) 1 13 0.5 4.5 Time (s)

21. Autocoreelograms Associated With CRG 6 1 10 0 5 Time (s)

22. Primary Image 1 0 4 Time (s) 501 Ghost Image Autocorrlogram Migration Images Traces Traces No reflections

23. Acquisition Survey Map Well Rig 3C Receivers Drill bit 0 0 150030004500 -5000 East (ft) North (ft) C Line AC4

24. 1.0 3.0 2.0 126512351215 Time (s) SP Drilling hole Primary Image with CDP Section

25. 3.0 2.0 1.0 Time (s) SP1255 1235 1215 Ghost Image with CDP Section (Reverse Polarity) Drilling hole

26. Outline Outline Motivation and Objective Motivation and Objective Autocorrelogram Migration Autocorrelogram Migration Examples Examples Summary Summary

27. SUMMARY Autocorrelogram Migration works for deviated well Primary autocorrelogram image correlates well with the surface- CDP section Ghost autocorrelogram migration result is comparable to surface-CDP section but suffers from more noise

28. SUMMARY The upgoing and downgoing wave separation can cause some artifacts in migration image

29. Acknowledgements We greatly appreciate DOE for Financial supportWe greatly appreciate DOE for Financial support We are grateful to Union Pacific Resources for donating this dataWe are grateful to Union Pacific Resources for donating this data I am grateful to the 1999 sponsors of the UTAM consortium for financial supportI am grateful to the 1999 sponsors of the UTAM consortium for financial support