1. Migration In a Nutshell Migration In a Nutshell Migration In a Nutshell D.S. Macpherson

2. - The problem with stacking A. The nature of the seismic image Migrating the seismic image on to the plane of the reflector Un-migrated stacked data Migrated image Un-migrated image surface Migrated image surface A - 17

3. F. Imaging by seismic migration Un-migrated trace Migrated trace - Kirchhoff summation F - 9

4. F. Imaging by seismic migration Reflector surface Migration of stacked (ZSR) trace by Kirchhoff summation - Kirchhoff summation F - 10

5. F. Imaging by seismic migration Migration of a diffraction by Kirchhoff summation Diffraction hyperbola - Kirchhoff summation F - 13

6. F. Imaging by seismic migration Un-migrated stack Migrated stack - Kirchhoff summation F - 15

7. Un-migrated Model E. Seismic data processing - Pre-stack migration E - 26

8. Migrated Model End effect from the model Migration noise E. Seismic data processing - Pre-stack migration E - 25

9. Decimated Model (Every fifth trace) E. Seismic data processing - Pre-stack migration E - 27

10. Migrated Model (Single offset - 600 feet) E. Seismic data processing - Pre-stack migration E - 28

11. TRACE SWEEP AMIMATION POSTSTACK

12. ABCD Source Receiver A A

13. ABCD Source Receiver B B

14. ABCD Source Receiver C C

15. ABCD Source Receiver D D

16. Composite ABCD

17. F. Imaging by seismic migration Reflector surface Migration of stacked (ZSR) trace by Kirchhoff summation - Kirchhoff summation F - 10

18. Seismic section in depth showing productive intervals Case 3 6

19. - The problem with stacking Common mid-point Moveout in the presence of dip Stacked trace Moveout corrected traces Common mid-point gather F. Imaging by seismic migration F - 16

20. Source Location Receiver Location Single Seismic Trace Pre-stack Migrated E. Seismic data processing - Prestack migration E - 24

21. - The problem with stacking Common mid-point Image point gather Stacked trace Migrated traces Common image point Traces in time Common mid point Image point window 3D bin size F. Imaging by seismic migration F - 17

22. PreStack Migration Ellipse Sweep

23. - The problem with stacking A. The nature of the seismic image Common mid-point Image point gather Stacked trace Migrated traces Common image point Traces in time Common mid point Image point window 3D bin size A - 21

24. Common mid-point Image point window 3D bin size

25. Common mid-point 1

26. 2

27. 3

28. 4

29. 5

30. 6

31. 7

32. 8

33. 9

34. Image point window 3D bin size

35. Image point window 3D bin size Migrated traces Common image point

36. Stacking traces in the image point gather in offset ranges

37. Image point window 3D bin size These are all stacked traces, but they are stacked in offset ranges Migrated traces Common image point

38. Image point window 3D bin size Trace 1 Near offsets Common mid-point Current offset Migrated traces Common image point

39. Image point window 3D bin size Trace 1 Near offsets Common mid-point Current offset Migrated traces Common image point

40. Image point window 3D bin size Trace 1 Near offsets Common mid-point Current offset Migrated traces Common image point

41. Image point window 3D bin size Trace 1 Near offsets Common mid-point Current offset Migrated traces Common image point

42. Image point window 3D bin size Trace 1 Near offsets Common mid-point Current offset Migrated traces Common image point

43. Image point window 3D bin size Trace 1 Near offsets Common mid-point Current offset Migrated traces Common image point

44. Image point window 3D bin size Trace 1 Near offsets Common mid-point Current offset Migrated traces Common image point

45. Image point window 3D bin size Trace 1 Near offsets Common mid-point Current offset Migrated traces Common image point

46. Image point window 3D bin size Trace 1 Near offsets Common mid-point Current offset Migrated traces Common image point

47. Image point window 3D bin size Trace 2 Common mid-point Current offset Migrated traces Common image point

48. Image point window 3D bin size Trace 3 Common mid-point Current offset Migrated traces Common image point

49. Image point window 3D bin size Trace 4 Far offsets Common mid-point Current offset Migrated traces Common image point

50. Ray Tracing for the Reflections in the Gather

51. Image point window 3D bin size Migrated traces Common image point Trace 1 Near offsets

52. Image point window 3D bin size Migrated traces Common image point Trace 2

53. Image point window 3D bin size Migrated traces Common image point Trace 3

54. Image point window 3D bin size Trace 4 Far offsets Migrated traces Common image point

55. Common mid-point Image point window 3D bin size So we started with this

56. Common mid-point Image point window 3D bin size Image point window 3D bin size And ended up with this

57. AVO Display

58. TRACE SWEEP AMIMATION PRESTACK

59. ABCD Source Receiver A A

60. ABCD Source Receiver A B

61. ABCD Source Receiver A C

62. ABCD Source Receiver A D

63. ABCD Source Receiver B A

64. ABCD Source Receiver B B

65. ABCD Source Receiver B C

66. ABCD Source Receiver B D

67. ABCD Source Receiver C A

68. ABCD Source Receiver C B

69. ABCD Source Receiver C C

70. ABCD Source Receiver C D

71. ABCD Source Receiver D A

72. ABCD Source Receiver D B

73. ABCD Source Receiver D C

74. ABCD Source Receiver D D

75. Composite ABCD

76. F. Imaging by seismic migration V1 V2 V3 V4 Depth Time 3D time (stacked) data cube 3D depth velocity model3D ray tracing 3D “sweep” ray tracing Iso-time contours - Depth migration F - 22

77. Depth Migration Iso-time Map for the Shot Location

78. Depth Migration Iso-time Map for the Receiver Location

79. Depth Migration Iso-time Map for Both the Shot and Receiver Locations

80. The Sweep of a Single Prestack Trace Link to TCHART.exe

81. - Displays in depth and time A. The nature of the seismic image 0.0 0.5 1.0 1.5 2.0 2.5 3.0 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 Depth (Kilometers) Time (Seconds) A - 30

82. PRESTACK WAVE EQUATION AMIMATION

83. SOURCE

84. RECIEVER

85. SOURCE RECIEVER

86. SOURCE RECIEVER 200 Millisecond Image Source time 60 ms. Receiver time 140 ms.

87. SOURCE RECIEVER 200 Millisecond Image Source time 70 ms. Receiver time 130 ms.

88. SOURCE RECIEVER 200 Millisecond Image Source time 80 ms. Receiver time 120 ms.

89. SOURCE RECIEVER 200 Millisecond Image Source time 90 ms. Receiver time 110 ms.

90. SOURCE RECIEVER 200 Millisecond Image Source time 100 ms. Receiver time 100 ms.

91. SOURCE RECIEVER 200 Millisecond Image Source time 110 ms. Receiver time 90 ms.

92. SOURCE RECIEVER 200 Millisecond Image Source time 120 ms. Receiver time 80 ms.

93. SOURCE RECIEVER 200 Millisecond Image Source time 130 ms. Receiver time 70 ms.

94. SOURCE RECIEVER 200 Millisecond Image Source time 140 ms. Receiver time 60 ms.

95. SOURCE RECIEVER 200 Millisecond Image

96. F. Imaging by seismic migration 3D Post-stack Time Migration 3D Pre-ststack Depth Migration Data Courtesy of CGG - Depth migration F - 24