Simple seismic processing workflow

1. Simple Seismic processing
workflow
By: Ali Ismael AlBaklishy
Senior Student, Geophysics Department,
School of sciences, Cairo University

2. Content
 Introduction.
• Data Initialization.
• Amplitude Processing.
• Noise Attenuation.
• Deconvolution.
• Multiple Attenuation.
• Velocity Analysis and NMO.
• Migration.
• Stack.
• Data Makeup.
 Processing Workflow:
 References.
 Q&A.

3. Content
• Data Initialization.
• Amplitude Processing.
• Noise Attenuation.
• Deconvolution.
• Multiple Attenuation.
• Velocity Analysis and NMO.
• Migration.
• Stack.
• Data Makeup.
 Processing Workflow:
 References.
 Q&A.

4. Introduction
Seismic Prospecting
Seismic
Interpretation
Seismic
acquisition
Seismic
Processing
Seismic
Interpretation

5. Content
 Introduction.
• Data Initialization.
• Amplitude Processing.
• Noise Attenuation.
• Deconvolution.
• Multiple Attenuation.
• Velocity Analysis and NMO.
• Migration.
• Stack.
• Data Makeup.
 Processing Workflow:
 References.
 Q&A.

6. Content
 Introduction.
• Data Initialization.
• Amplitude Processing.
• Noise Attenuation.
• Deconvolution.
• Multiple Attenuation.
• Velocity Analysis and NMO.
• Migration.
• Stack.
• Data Makeup.
 References.
 Q&A.

7.  DataReformat(Transcription)
Field data format
SEG Y
SEG D
Internal format of
the co.
Ex.: DIO (Omega)
Data Initialization

8.  Geometry update
Objective :
• Insert the X,Y,Z coordinates for each
shot and geophone group by merge the
Navigation/SPS file with the data file .
Data Initialization

9.  Trace Editing
Objective :
1- Remove bad traces.
2- Remove bad shots.
3-Remove Duplicated traces.
4- Polarity Revers.
Data Initialization

10. Trace Editing
before
after
Data Initialization

11. Content
 Introduction.
• Data Initialization.
• Amplitude Processing.
• Noise Attenuation.
• Deconvolution.
• Multiple Attenuation.
• Velocity Analysis and NMO.
• Migration.
• Stack.
• Data Makeup.
 References.
 Q&A.

12.  AmplitudeRecovery AndGain
• Energy is attenuated due to the spherical divergence
effect.
Amplitude Processing

13. Before after
• Before And After Amplitude Recovery
Amplitude Processing

14. Content
 Introduction.
• Data Initialization.
• Amplitude Processing.
• Noise Attenuation.
• Deconvolution.
• Multiple Attenuation.
• Velocity Analysis and NMO.
• Migration.
• Stack.
• Data Makeup.
 References.
 Q&A.

15. 1- Ground Roll Attenuation.
Before
Noise Attenuation

16. • Ground Roll Attenuation
After
Noise Attenuation

17. 2- Swell Noise Attenuation.
Before After
Noise Attenuation

18. 3- Liner Noise Attenuation
By using FK filter & Radon (tau p)
Noise Attenuation

19. • Tau p Radon transform
Noise Attenuation

20. Content
 Introduction.
• Data Initialization.
• Amplitude Processing.
• Noise Attenuation.
• Deconvolution.
• Multiple Attenuation.
• Velocity Analysis and NMO.
• Migration.
• Stack.
• Data Makeup.
 References.
 Q&A.

21. Deconvolution
Objective:
To get rid of the energy wavelet so that get the earth’s
Reflectivity.

22. • Deterministic Deconv. (de-signature Deconv.)
(known Wavelet)
Deconvolution
• Statistical Deconv. (Gap Deconv).
(Unknown Wavelet)

23. Before
Deconvolution

24. After
Deconvolution

25. Content
 Introduction.
• Data Initialization.
• Amplitude Processing.
• Noise Attenuation.
• Deconvolution.
• Multiple Attenuation.
• Velocity Analysis and NMO.
• Migration.
• Stack.
• Data Makeup.
 References.
 Q&A.

26. MultipleAttenuation
• Water Bottom Multiples Attenuation
BeforeAfter

27. • Surface Multiples Attenuation
MultipleAttenuation
BeforeAfter

28. • Interbed Multiples Attenuation
• Short period and residual Multiples
Attenuation
By using Deconvolution
MultipleAttenuation

29. Content
 Introduction.
• Data Initialization.
• Amplitude Processing.
• Noise Attenuation.
• Deconvolution.
• Multiple Attenuation.
• Velocity Analysis and NMO.
• Migration.
• Stack.
• Data Makeup.
 References.
 Q&A.

30. VelocityAnalysisAndNMO
Objective :
1- Determine NMO Velocity.
2- Determine stack velocity.
3- Determine Migration velocity.

31. VelocityAnalysisAndNMO
MVFS

32. • In case of wrong Velocity
VelocityAnalysisAndNMO

33. • Stretch Muting
VelocityAnalysisAndNMO

34. Content
 Introduction.
• Data Initialization.
• Amplitude Processing.
• Noise Attenuation.
• Deconvolution.
• Multiple Attenuation.
• Velocity Analysis and NMO.
• Migration.
• Stack.
• Data Makeup.
 References.
 Q&A.

35. Migration
Objective:
Is to reposition the data from its apparent reflection
point (due to Non Horizontal Reflectors) to its true
reflection point.

36. • Migration classification According to its position in the
workflow
Post stack
Migration
Pre-Stack
Migration
• Take long time.
• High cost.
• No data losses.
• Less time.
• Low cost.
• Loss in data.
Migration

37. • Pre-stack and post stack
Migration
Migration

38. • Migration classification According to its types:
Time
Migration
Depth
Migration
• Time and space
Domain.
• Don’t takes ray
bending & lateral
velocity change into
account.
• Take shorter time.
• Depth Domain.
• takes ray bending
& lateral velocity
change into
account.
• require greater
computer time.
Migration

39. 1- Time Migration
• Time migration is the repositioning of reflected seismic data to their
true reflection points in space and time.
Ex: Kirchhoff Migration
Migration

40. 2- Depth Migration.
• In depth migration, data are migrated in depth domain
and the input data for the process is unmigrated seismic
data in time domain. The output is migrated data in the
depth domain.
• take into account the bending of ray paths by
refraction within a complex geology.
Migration

41. • Time Migration and depth Migration
Migration

42. • Migration Examples
Migration

43. • Migration Examples
Migration

44. Content
 Introduction.
• Data Initialization.
• Amplitude Processing.
• Noise Attenuation.
• Deconvolution.
• Multiple Attenuation.
• Velocity Analysis and NMO.
• Migration.
• Stack.
• Data Makeup.
 References.
 Q&A.

45. Stacking

46. Stacking

47. Content
 Introduction.
• Data Initialization.
• Amplitude Processing.
• Noise Attenuation.
• Deconvolution.
• Multiple Attenuation.
• Velocity Analysis and NMO.
• Migration.
• Stack.
• Data Makeup.
 References.
 Q&A.

48.  Data Makeup
• Data Filtering
• Amplitude Scaling

49. Stacking

50. Stacking

51. Content
 Introduction.
• Data Initialization.
• Amplitude Processing.
• Noise Attenuation.
• Deconvolution.
• Multiple Attenuation.
• Velocity Analysis and NMO.
• Migration.
• Stack.
• Data Makeup.
 Processing Workflow:
 Q&A.

52. References:
• Exploration Geophysics, Mamdouh R. Gadallah · Ray
Fisher,2009.
• Seismic data Processing, OZ Yilmaz.
• Seismic Data Analysis And Techniques in Hydrocarbon
Exploration, ENWENODE ONAJITE, 2014
• Seismic Reflections: Marine Processing - Part 5 | Direct
Arrivals, Refractions, and Linear Noise
• Seismic Reflections: Marine Processing - Part 4 | Swell Noise
Removal

53. Q&A