1. EXPLORATION GEOPHYSICS

2. EARTH MODEL

3. NORMAL-INCIDENCE REFLECTION AND TRANSMISSION COEFFICIENTS
DENSITY r1
VELOCITY V 1
DENSITY r 2
VELOCITY V2
WHERE: r1 = DENSITY OF LAYER 1
V1 = VELOCITY OF LAYER 1
r 2 = DENSITY OF LAYER 2
V2 = VELOCITY OF LAYER 2

4. SEISMIC
ACQUISITION

5. GEOPHONE STRUCTURE

6. GEOPHONE TYPES & FREQUENCY

7. SOURCE TRUCKS

8. 3D-SEISMIC COVERAGE

9. CDP & FOLD STACK

10. MARINE SEISMIC
CABLE LAYOUT

11. MULTIPLE RAYPATH

12. FACTORS AFFECTING AMPLITUDE

13. ATTENUATION TECHNIQES

14. SEISMIC
DATA
PROCESSING

15. PROCESSING FLOWCHART

16. OBJECTIVE OF PROCESSING
REAL EARTH
EARTH PROPERTIES
PULSE
SEISMIC TRACE
PROCESSING
MODEL EARTH

17. EFFECT OF STACKING ON NOISE
SIGNAL PLUS RANDOM AT SIX-DETECTOR ARRAY
NOISE
SIGNAL
SIGNAL + NOISE
SIGNAL + NOISE
EACH RECEIVER
SUMMED OUTPUT

18. PURPOSE: TO COMBINE TWO DATA SETS FOR A MORE COMPLETE INTERPERATION
SEISMIC-WELL TIES
PURPOSE: TO COMBINE TWO DATA SETS FOR A MORE COMPLETE INTERPERATION
SEISMIC DATA
TWO WAY TIME
SEISMIC VELOCITY
SEISMIC IMPEDENCE
SEISMIC SEQUENCES
SEISMIC FACIES
STRUCTURE
WELL DATA
LINEAR DEPTH
VELOCITY
DENSITY
GEOLOGIC AGE
LITHOLOGY
FAULT ORIENTATION

19. ACOUSTIC STRUCTURE OF EARTH
LAYERED EARTH
SONIC
DENSITY RC

20. CONVOLUTION

21. DETAILED SYNTHETIC SEISMOGRAM

22. DETAILED SYNTHETIC SEISMOGRAM

23. POST-STACK PROCESSING
RESIDUAL STATICS
DISPLAY ENHANCEMENT
MIGRATION
ATTRIBUTE ANALYSIS
INVERSION
TIME-DEPTH CONVERSION

24. SUMMARY OF SEISMIC PROCESSING
DATA ARE GATHERED AND CMP-ORDERED GATHERS ARE FORMED
VELOCITY ANALYSIS IS PERFORMED ON SELECTED GATHERS
THE GATHERS ARE MOVEOUT CORRECTED, STACKED, AND PLOTTED
STACKING MAY BE FOLLOWED BY ADDITIONAL PROCESSING

25. VELOCITY ANALYSIS NORMAL MOVEOUT (NMO) X = TX - T0 TX T0 IMAGE POINT
WHERE
T0 = ZERO OFFSET TIME

26. NMO-ISOTROPIC LAYER X A C Z B
WHERE
THEREFORE D
IMAGE POINT

27. ASSUMED RAYPATH FOR VNMO CALCULATION
MULTI-LAYER CASE
ASSUMED RAYPATH FOR VNMO CALCULATION X
TX,1 Z V1
T0,1
T0,2
TX,2
ACTUAL RAYPATH
FOR LAYER 1:
FOR LAYER 2:
VNMO = NORMAL MOVEMEOUT VELOCITY

28. FOR EACH TRACE T AND X VALUES ARE DETERMINED
HOW IS VNMO DETERMINED?
FOR EACH TRACE T AND X VALUES ARE DETERMINED

29. VELOCITY ANALYSIS Y=b+mX
T2 - X2 PLOT
X2
OFFSET2
t2
HYPERPOLA PLOTS AS A STRAIGHT LINE ON T2 - X2 GRAPH
Y=b+mX
WHERE

30. VMNO CORRECTION
KNOWING THE VNMO, T AND OFFSET, THE TIME CORRECTION NECESSARY TO SHIFT EACH TRACE CAN BE CALCULATED

31. INTERVAL VELOCITY DETERMINATION FROM SEISMIC
FROM VELOCITY ANALYSIS, WE KNOW
VNMO1,T0,1
VNMO2, T0,2
SUBTITUTING THESE VALUES INTO THE DIX EQUATION

32. MIGRATION EFFECTS
FLAT HORIZONS REMAIN UNCHANGED IF THERE ARE NO VELOCITY ANOMALIES ABOVE
DIPPING HORIZONS BECOME STEEPER, SHALOWER, AND MOVE LATERALLY UPDIP
SYNCLINES BECOME BROADER, WITH ANY BOW TIES ELIMINATED
ANTICLINES BECOME NARRWER
DIFRACTIONS COLLPSE TO POINTS

33. RAY PATH MIGRATION t x WHERE  = TRUE DIP OF REFLECTOR
REFLECTION
REFLECTOR x t
WHERE
 = TRUE DIP OF REFLECTOR
= APPERENT DIP OF REFLECTOR
V= VELOCITY

34. WHY MIGRATE? TIME DEPTH DEPTH MODEL ARRIVAL TIMES
IF BEDS ARE DIPPING, APPERENT POSITION OF EVENTS ON A STACKED SECTION DIFFERS FROM THEIR TRUE POSITION
DEPTH MODEL
ARRIVAL TIMES
7 KFT/SEC
TIME
DEPTH
9 KFT/SEC
11 KFT/SEC

35. ASSUMPTION UNDERLYING MIGRATION
ALL EVENTS ARE PRIMARIES-
NO NOISE, NO MULTIPLES, NO SHEAR WAVES
ALL EVENTS COME FROM THE PLANE VERTICALLY
BENEATH THE SEISMIC LINE-
NO SIDEWIPE
VELOCITY ARE KNOWN EVERY WHERE

36. MIGRATION MOVES DIPPING HORIZONS

37. FOCUSING EFFECT OF A SHARP SYNCLINE

38. DEFOCUSING EFFECT OF AN ANTICLINE

39. FOCUSING EFFECT OF A SYNCLINE

40. 3-D MIGRATION
ELIMINATES ASSUMPTION OF 2--D MIGRATION THAT ALL DATA COMES FROM WITHIN PLANE OF SECTION
REQUIRES 3-D DATA COLLECTION TO INSURE CLOSELY SPACED TRACES IN BOTH X, Y DIRECTIONS
MOVES ENERGY IN BOTH INLINE AND CROSSLINE DIRECTIONS
INLINES AND CROSSLINES TIE AFTER 3-D MIGRATION
MAP MIGRATION IS AN ALTERNAIVE FOR COARSE GRID OF 2-D LINES

41. TIME VS. DEPTH SECTIONS

42. CDP GATHER AFTER DEMULTIPLEXING

43. CDP GATHER AFTER AMPLITUDE CORRECTION

44. CDP GATHER AFTER DECONVOLUTION

45. VELOCITY ANALYSIS

46. CDP GATHER AFTER NMO CORRECTION

47. CDP GATHER AFTER MUTING STRETCHED ZONES

48. CDP STACKED SECTION

49. CDP STACKED SECTION WITH TVF FILTER