The document discusses seismic interpretation work done on seismic lines 856-SGR-52 and 856-SGR-55 in the Sanghar area. The work included: 1) Marking seismic reflectors and identifying them using well data 2) Preparing average, mean and iso-velocity graphs 3) Making time and depth structure maps 4) Interpreting the subsurface structure including normal faults 5) Reverse modeling the seismic into impedance sections and correlating wells The interpretation shows the area has a horst and graben structure formed by normal faulting during extensional tectonics. Anomalous zones detected on the impedance sections may indicate hydrocarbons.

3.  To prepare graphs of average velocity, mean velocity
and Iso-velocity, to investigate the lateral and vertical
variation in velocity.
 Marking and Identification of Seismic Horizons by
using well top data.
 To prepare the Time Contour Map and Depth Contour
Map using K-tron X-Work and surfer and interpret the
subsurface structure.
 To develop an understanding of tectonic, stratigraphic
and structural framework of the area.

4.  To prepare two way Time contour maps, Depth contour and
Surface Maps using the lines 856-SGR-52,846-SGR-45,
856-SGR-55 and 856-SGR-62 of Basal Formation which is
a reservoir formation. For this purpose K-tron X-Work and
surfer softwares are used.
 Reverse Modeling of Seismic section into Impedance
section using Advance surfer.
 Correlation of four wells by Log plot software using well
tops data.

5. PART-I
 STRUCTURAL AND STRATIGRAPHICAL
INTERPRETATION
PART-II
 REVERSE MODELLING OF SEISMIC SECTION INTO
IMPEDANCE SECTION AND WELL CORRELATION

6. AND
ITS GENERAL GEOLOGY AND TECTONICS

7. www.mapzones.com

8. Latitude 27° 43’ to 28° 05’ North
Longitude 69° 35’ to 69° 57’ East
www.googlearth.com

9. .
K-tron Precision Matrix

10. Kazmi & Jan, 1997

11.  Source Rocks
Sembar Formation.
 Reservoir Rocks
Parh Limestone, Basal sand of Lower Goru
Formation and Ranikot Formation.
 Caps Rocks
Shale and Marl of Upper Goru.

12. STRATIGRAPHY
OF
THE STUDY AREA

13. (www.ogdcl.com).

14. SEISMIC SECTION

15.  Lines 856-SGR-52 and 856-SGR-55
 Area Sanghar
 Orientation NW-SE
 Nature Dip Line and Strike Line
 Well on the Line Sachal and Barkat is near to
SGR-55 line
 Energy Source Dynamite
 S.P 101-667 and 101-1215
 Number Of Folds 80 Folds
 Company OGDCL

16.  Reflectors marked 4Reflectors on both Sections
 Faults 6 Normal faults on SGR-52
5 Normal faults on SGR-55
 Major Structure Horst and Graben

17. PART-I
STRUCTURAL
AND
STRATIGRAPHICAL
INTERPRETATION

18.  To mark the reflectors.
 To prepare the Average Velocity Graph Of the line
856-SGR-52 and 856-SGR-55.
 To prepare the Mean Velocity Graph.
 To prepare the Iso Velocity Map.
 To prepare the Time and Depth Section of the line
856-SGR-52 and 856-SGR-55.
 Time and Depth contour maps for identification of
Structure.
 To Identify and name the Reflectors with the help
of Well tops of Bobi,Barkat,Sachal and Hartungu.

19. (K-tron VAS)

20. (K-tron VAS)

21. (K-tron VAS)

22. (K-tron VAS)

23. (K-tron VAS)

24. (K-tron VAS)

25. (K-tron VAS)

26. (K-tron VAS)

27. (K-tron Visual Oil)

28. (K-tron Visual Oil)

29. (K-tron X-Work)

30. (K-tron X-Work)

31. (K-tron X-Work)

32. (K-tron X-Work)

33. Depth (m) = VT
2
Where, T = Two way vertical time (s)
V = Average velocity (m/s) for
each respective time

34. (K-tron X-Work)

35. (K-tron X-Work)

36. (K-tron X-Work)

37. (K-tron X-Work)

38. (K-tron X-Work)

39. (K-tron X-Work)

40.  Following conclusion were deduced based on the current
studies:
 The study area is dominated by Normal Faults.

 The Normal faulting in the area shows that the area was
deformed by the extensional tectonic movement.
 Since the area is under extension so horst & graben
structure is present in the study area.
 From the structural and stratigraphic interpretation it is
concluded the structure formed in the area may act as a
favorable trap for the accumulation of hydrocarbons

41. REVERSE MODELLING OF SEISMIC SECTION INTO
IMPEDANCE SECTION
AND
WELL CORRELATION

42.  INTERVAL VELOCITY
Vint = Z2-Z1/t2-t1
 INSTANTANEOUS VELOCITY
Vinst = dZ/dt
 ROOT-MEAN-SQUARE VELOCITY
Vrms=√ (sum of product of square of interval velocities and
time/sum of one way travel times)
 STACKING VELOCITY
t=√t²○+x²/V²stack

43. CONCLUSION
Vav≤Vrms≤ Vst
(Dobrin , 1976)

44.  LATERAL VARIATIONS IN SEISMIC VELOCITIES
 VERTICAL VARIATIONS IN SEISMIC VELOCITIES
CORRELATION BETWEEN VELOCITY TYPES
Sq. Vint,n = (Sq.Vrms,n*Tn)-(SqVrms,n-1*Tn-1)
Tn-Tn-1
Vint,n = (Vav,n*Tn)-(Vav,n-1*Tn-1)
Tn-Tn-1
Vav,n = (Vint,n*Tn-Tn-1)+(Vav,n-1*Tn-1) Tn

45.  THE SHEAR WAVE VELOCITY
Vp = 1.16Vs + 1.360
 THE DENSITY DETERMINATION
ρ = 0.31 * (Vp) 0.25
 THE COMPRESSIONAL WAVE IMPEDANCE
Impedance = ρ*Vp
 THE SHEAR WAVE IMPEDANCE
Impedance = ρ*Vs

49. P-waves impedance showing hydrocarbons Zone

50. S-waves impedance showing hydrocarbons Zone

54. P-waves impedance showing hydrocarbons Zone

55. S-waves impedance showing hydrocarbons Zone

56.  Anomalous(Hydrocarbons)Zones can be detected with
help of impedance. In Sanghar Area similar zone has
been detected by P-Waves impedance that is confirmed
then by S-Waves impedance.
 It can be studied further with the help of enhanced data
and advance approach.

57.  It is a direct method to investigate depositional setting of
an area by correlating different stratigraphic
successions encountered in different wells

58.  Using well tops data of four wells Bobi-01, Barkat-01,
Sachal-01 and Harthangu-01drilled at Sanghar area
lithologies are studied by using Log Plot Software. To
study the stratigraphic variations in an area usually wells
are correlated. In well correlation we observe the
thickness and depth of each strata.

60.  Kadri I.B., (1995), “Petroleum Geology of Pakistan’’,
PPL, Karachi, Pakistan.
 Kamran, M. and Ranki, U., (1987). “Pakistan oil data,
Hydrocarbon Development Institute of Pakistan”.
 Khan, K.A., 2000. Integrated Geo Systems - A
Computational Environment for Integrated
Management, Analysis and Presentation of Petroleum
Industry Data, In: T. C. Coburn and J. M Yarus (Eds.),
Geographic Information Systems in Petroleum
Exploration and Development, American Association of
Petroleum Geologists, AAPG Book on Computers in
Geology, pp.215-226.

61.  Khan, K. A., Akhtar, G., Ahmed, Z., Khan, M.A.,
and Naveed, A., 2006, Wavelets - A Computer
Based Training Tool for Seismic Signal Processing,
Pakistan Journal of Hydrocarbon Research, Vol.
16, pp.37-43.
 Khan, K.A., Akhtar, G., Ahmad, Z., and Rashid, M.,
2008, Development of a Projection Independent
Multi-Resolution Imagery Tiles Architecture for
Compiling an Image Database of Pakistan,
Proceedings of 2nd International Conference on
Advances in Space Technologies Islamabad,
Pakistan, p.164-170

62. To all my faculty members but special Thanks to
Sir Anees Ahmed Bangash whose guidance
leads me to touch this stage