1. BP AIT 2004 2D velocity benchmark
Copyright s BP America Inc. - No release, transfer, license, sell, trade or otherwise disclosure permitted outside of Queen’s U.
BP AIT D velocity benchmark
Frederic Billette – AIT Houston
Title slide
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The second line (in smaller type style) is for the date of the presentation – depending on your presentation, you may also need to include Location and/or Presenter’s name/s and Job title if needed – as a such a second line may be used for these purposes.
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2. Legal issues
Data release agreement dated February 3rd, 2004 and confidentiality
agreement dated September17th, 2004 specify that:
You can:
use the dataset internally for any purpose.
Publish / show results using this dataset.
Show these slides internally.
Publish / show your result compared to the exact model after specific permission to be obtained from BP
You can not:
Release, distribute or sell the dataset.
Show, release, distribute or sell any material extracted form this presentation to a third party (exception specified above).

3. Agenda Model, data, challenges, … Queen’s U. contribution
Velocity model comparison
PSDM image comparison
Feedback & ranking

4. Timeline 2003 2004 Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Data
generation
Data offered to
the industry
Exact model revealed
Results collected
Results
distributed to
the network
Model
generation
Results
analyzed QC
Feedback
provided
Feedback to
contractors

5. Model Generation Velocity
67km wide, 12km deep, build on a 6.25m x 6.25m grid
Density

6. Challenges 1/3 Salt 1 - Shot migration no SRME complex overhangs
rugose top salt
sediment
inclusion
overpressure
zones
Complex/broken
reflectivity

7. Challenges 2/3 Salt 2 - Shot migration no SRME multiples shallow HV
anomaly
channels
steep
dips
poorly imaged
flanks

8. Challenges 3/3 Extra salt - Shot migration with SRME shallow gas
mud volcano
shallow LV anomalies
HV anomalies on
structure flanks

9. Data generation
2D Finite difference acoustic modeling (variable velocity & density).
Free-surface multiples are present.
Data shot split-spread (streamer data provided), every surface point recording data. Shot every 50m, receiver every 12.5m. 6ms sampling.
Frequency peak is 27Hz and data can be whitened up to 54Hz.
The wavelength is causal and has not been 0 phased (see typical trace below), time delay can be estimated considering the zero offset traces.

10. Data transfer Tape or ftp download available.
Document with experiment details provided.
15km of offset..
Model to be returned by June 9, 2004 when the exact model was revealed.

11. Data recipients Total: 25 1 oil company 13 seismic contractors
7 universities
3 research institutes
1 software company
Total: 25

12. Presented results publicly at the EAGE
0 oil company
5 seismic contractors: CGG, Veritas, GXT, Paradigm, and Data Modeling Inc. (Calgary)
2 universities: KACST (Riyadh) and Queen’s (Kingston)
2 research institutes: SINTEF (Trondheim) and OPERA (France).
0 software company.
Total: 9

13. Participating to BP benchmark
0 oil company
8 seismic contractors: CGG, Veritas, WesternGeco, PGS, GXT, Fairfield, Paradigm, Data Modeling Inc. (Calgary)
2 universities: DIG (Paris), Queen’s (Kingston)
2 research institutes: SINTEF (Trondheim) and OPERA (Pau)
0 software company.
Total: 12

14. Queen’s University contributors
Small team work in an university lab
Professor:
Gerhard Pratt
Student:
Drew Brenders

15. Queen’s U. processing flow
Reduced the dataset:
Hz, 1/8 shots and 1/8 receivers, 2km – 15km offset
Initial smooth model using first-arrival travel time tomography
Automatic velocity update without migration using waveform tomography
No salt interpretation, all automatic
Did not request feedback

16. Part1: velocity models Display information
All images are vertically exaggerated 3 times
DX=25m ; Dz=6.25m
Images are 67km wide and 12 km deep
Velocity scale goes from 1429m/s to 4790m/s
(min & max in the exact model)

17. Exact model

18. Exact model: velocity contours

19. Queen’s University Colour usage
A custom slide colour scheme has been applied

20. A
Colour usage
A custom slide colour scheme has been applied

21. B
Colour usage
A custom slide colour scheme has been applied

22. C Note: C did not deliver the right part of the model on time.
Colour usage
A custom slide colour scheme has been applied
Note: C did not deliver the right part of the model on time.

23. C
Colour usage
A custom slide colour scheme has been applied
Note: C delivered the right part of the model on September 1st, 2004.

24. D
Colour usage
A custom slide colour scheme has been applied

25. E Note: E estimated the model extra-salt only Colour usage
A custom slide colour scheme has been applied
Note: E estimated the model extra-salt only

26. F Note: left and right part have been updated independently.
Colour usage
A custom slide colour scheme has been applied
Note: left and right part have been updated independently.

27. H
Colour usage
A custom slide colour scheme has been applied

28. I
Colour usage
A custom slide colour scheme has been applied

29. J Note: J estimated the sediment velocities only Colour usage
A custom slide colour scheme has been applied
Note: J estimated the sediment velocities only

30. K
Colour usage
A custom slide colour scheme has been applied

31. L
Note: L estimated the model extra-salt only

32. Part2: migrations Display information
All images are vertically exaggerated 3 times
DX=25m ; Dz=6.25m
Images are 67km wide and 12 km deep
Model have been expanded or reduced if necessary
2D SRME has been applied
No other pre or post-processing applied
2D wave-equation migration (downwards propagation only)
For display purposes, low frequency outputs are presented
Exact water layer has been inserted.

33. Exact density model

34. Exact model

35. Exact model

36. Queen’s University

37. A

38. B

39. C
Note: C delivered the right part of the model on September 1st, 2004.

40. D

41. E
Note: E estimated the model extra-salt only

42. F
Note: left and right part have been updated independently.

43. H

44. I

45. J
Note: J estimated the sediment velocities only

46. K

47. L
Note: E estimated the model extra-salt only

48. + Queen’s University: strengths
Good long & short wavelength updates in the shallow section.
Impressive resolution for some shallow anomalies.
Good image of the top salt without interpretation.
Good delineation of the overhangs without interpretation.
See glimpses of the base salt.

49. - Queen’s University : weaknesses
Deep part of the model not estimated.
Variable velocity in salt.
Too high frequency. Regularization/smoothing issues?
Imaging issues with several targets, even shallow.

50. Ranking Process
Ranking along 2 axes: 1) salt & sub-salt ; 2) extra salt sediment update.
Ranking is an average after ~12 peer review.
Only results provided on time were considered.
Ranking is based on this test only.

51. Ranking
Quality of salt and sub-salt model building D H B F J I C
Accuracy of extra-salt sediment update A K E L

52. Ranking
Quality of salt and sub-salt model building
Tier 3
Tier 2
Tier 1 D H B
Tier 1 F J I C
Accuracy of extra-salt sediment update A
Tier 2 K E L
Tier 3

53. Questions?