I (Jamal Ahmad) presented this on 21 Feb, 2009 to defend my M.Phil dissertation in Geophysics at QAU, Islamabad, Pakistan. For more information about this, you may contact me directly at jamal.qau@gmail.com.

4. The Dhodak gas field is the Pakistan’s largest gas and condensate producing field. The Dhodak field, with estimates 620Bcf of proven gas reserves and 30million barrels of condensate, is located in the Central Indus basin approximately 15KM North of Safed koh Block . Introduction to Area

5. Location of study area on surface tectonic map of Pakistan

6. Basemap of the data used

7. Divisions of Central Indus basin ( Raza et al, 1989 ) Cross Section along the Central Indus basin (Raza et al, 1989 )

8. General geology and stratigraphy

9. Surface geological map (Bakr & Jeckson, 1964 )‏ Surface geological map (sheikh et al, 1989)

10. Surface structure map and satellite map (Kellogg, 1936)‏

11. Stratigraphy of the area

13. Well Correlation along the Zindapir-Dhodak anticlines

14. Seismic data interpretation

15. Ricker wavelet Synthetic seismogram created using Ricker wavelet

16. Klauder wavelet Synthetic seismogram created using Klauder wavelet

17. Ormsby wavelet Synthetic seismogram created using Ormsby wavelet

18. Butterworth wavelet Synthetic seismogram created using Butterworth wavelet

19. Comparison of synthetics using all wavelets

20. Seismic sections used:

21. Interpreting well picks on seismic line 795-SK-06 using synthetics of dhodak-01 and 03 Dunghan Pab Sandstone Mughalkot

22. Interpreting well picks on seismic line 795-SK-06

23. Interpreting well picks and lithological strip on seismic line 795-SK-06 using Dhodak-03

24. Interpreting Well picks and lithological strip on seismic line 795-SK-06 using Dhodak-03

25. Time contour map: Dunghan Limestone

26. Depth contour map: Dunghan Limestone

27. Time contour map: Pab Sandstone

28. Depth contour map: Pab Sandstone

29. Time contour map: Mughalkot Formation

30. Time contour map: Chiltan Limestone

31. Time contour map: Alozai

32. Isochors map: Chiltan-alozai

33. Isochors map: Dunghan-Chiltan

34. RMS Velocities along seismic line: 795-SK-04 Average Velocities along seismic line: 795-SK-04

35. Fault Model

36. Time Surface grid at Dunghan level along with faults and well locations

37. Time Surface grid at Pab Sandstone level along with faults and well locations

38. Time Surface grid at Mughalkot level along with faults and well locations

39. Time Surface grid at Chiltan level along with faults and well locations

40. Time Surface grid at Alozai level along with faults and well locations

41. A-3D visualization with all interpreted Formations, faults and well locations

42. B-3D visualization with all interpreted Formations, faults and well locations

43. Dunghan surface with seismic line:795-SK-06

44. Dunghan, Chiltan & Alozai Formation along the seismic line: 805-SK-20

45. 3D-Movie

46. Interpreted seismic line: 795-SK-04 V ave V int V rms Bulk Modulus Shear Modulus Density Poisson Ratio V s V p

47. Interpreted seismic line: 805-SK-20

48. Average Velocities along the seismic line: 795-SK-04 Line:795-SK-04

49. Interval Velocities along the seismic line: 795-SK-04 Line:795-SK-04

50. RMS Velocities along the seismic line: 795-SK-04 Line:795-SK-04

51. Rock Physical properties along the seismic line 795-SK-04

53. Bulk Modulus along the seismic line: 795-SK-04 Line:795-SK-04

54. Shear Modulus along the seismic line: 795-SK-04 Line:795-SK-04

55. Density along the seismic line: 795-SK-04 Line:795-SK-04

56. Poisson Ratio along the seismic line: 795-SK-04 Line:795-SK-04

57. Shear Velocity along the seismic line: 795-SK-04 Line:795-SK-04

58. Primary Velocity along the seismic line: 795-SK-04 Line:795-SK-04

59. Well Log Interpretation

60. Well logs displayed for Dhodak-02

61. Well logs displayed for Dhodak-01

62. Well logs displayed for Dhodak-01

63. Well Lathe on Dhodak-03 from 165 SP of the seismic line: 795-SK-05R

64. Stratigraphic well correlation using four Dhodak wells:3-1-2-7 (S-N)

66. Sand-Shale analysis along the productive zone of Dhodak-02

67. Sand-Shale analysis along the Pab Sandstone zone of Dhodak-02

68. Lithological analysis along the Lower Ranikot zone of Dhodak-02

69. Lithological analysis along the Pab Sandstone zone of Dhodak-02

70. Lithological analysis along the Mughalkot zone of Dhodak-02

71. Lithological analysis along the Parh Limestone zone of Dhodak-02

72. Petro-Physics

73. Sonic-Density cross plot for Dhodak-01 with overlay on the generalized Sonic-Density lithological plot.

74. Sonic-Density cross plot for Dhodak-01 with overlay on the generalized three minerals crossplot.

75. Sonic-Neutron Porosity cross plot overlaid on the generalized cross plot for lithological interpretation

76. Sonic-Porosity cross plot overlaid on the generalized cross plot for lithological interpretation

77. Density-Porosity cross plot overlaid on the generalized cross plot for lithological interpretation

78. Density-Poisson Ratio cross plot Density-Shear sonic cross plot

79. Sonic-density cross plot Porosity-Shear Sonic cross plot

80. Porosity-Density cross plot Porosity-Poisson Ratio cross plot

81. Sonic-porosity cross plot Poisson Ratio-Shear Sonic cross plot

82. Poisson Ratio-Vs cross plot Density-Vp cross plot

83. Vp-Poisson Ration cross plot Vp-Shear Sonic cross plot

84. Vp-Vs cross plot Vs-Poisson Ratio cross plot

85. Sonic-Density Cross plot

86. Plots for Dhodak-02 well

89. Vp-Vp/Vs cross plot Vp-Vp/Vs cross plot overlay

90. SP – Volume of Shale cross plot GR-Volume of Shale cross plot

91. Pickett Plot

92. AVO/AVA Synthetics

94. AVA-AVO comparison

95. T psv = T pp ((1 + V p / V s ) / 2) Where:T psv is the P-SV travel time. Tpp is the P-P travel time. V p /V s is the ratio of P and S average velocities to the reflector Zoeppritz Equation: Shuey 2-term and 3-term equations:

96. AVO model for Dhodak-02

97. AVA model for Dhodak-02

98. AVA model for Dhodak-01 using Zoeppritz equation

99. AVA model for Dhodak-01 using Shuey02 equation

100. AVA model for Dhodak-01 using Shuey03 equation

101. AVO model for Dhodak-01 using Zoeppritz equations

102. AVO model for Dhodak-01 using Shuey2 equation

103. AVO model for Dhodak-01 using Shuey 03

110. Thanks

111. Questions.... ?