To prepare graphs of average velocity, mean velocity To prepare graphs of average velocity, mean velocity and Iso-velocity, to investigate the lateral and vertical and Iso-velocity, to investigate the lateral and vertical variation in velocity.variation in velocity.

Marking and Identification of Seismic Horizons by Marking and Identification of Seismic Horizons by using well top data.using well top data.

To prepare the Time Contour Map and Depth Contour To prepare the Time Contour Map and Depth Contour Map using K-tron X-Work and surfer and interpret the Map using K-tron X-Work and surfer and interpret the subsurface structuresubsurface structure..

To develop an understanding of tectonic, stratigraphic To develop an understanding of tectonic, stratigraphic and structural framework of the area.and structural framework of the area.

To prepare two way Time contour maps, Depth contour and To prepare two way Time contour maps, Depth contour and Surface Maps using the lines 856-SGR-52,846-SGR-45, Surface Maps using the lines 856-SGR-52,846-SGR-45, 856-SGR-55 and 856-SGR-62 of Basal Formation which is 856-SGR-55 and 856-SGR-62 of Basal Formation which is a reservoir formation. For this purpose K-tron X-Work and a reservoir formation. For this purpose K-tron X-Work and surfer softwares are used.surfer softwares are used.

Reverse Modeling of Seismic section into Impedance Reverse Modeling of Seismic section into Impedance section using Advance surfer.section using Advance surfer.

Correlation of four wells by Log plot software using well Correlation of four wells by Log plot software using well tops data.tops data.

PART-IPART-I

STRUCTURAL AND STRATIGRAPHICAL STRUCTURAL AND STRATIGRAPHICAL INTERPRETATIONINTERPRETATION

PART-IIPART-II

REVERSE MODELLING OF SEISMIC SECTION INTO REVERSE MODELLING OF SEISMIC SECTION INTO IMPEDANCE SECTION AND WELL CORRELATIONIMPEDANCE SECTION AND WELL CORRELATION

ANDAND

ITS GENERAL GEOLOGY AND TECTONICSITS GENERAL GEOLOGY AND TECTONICS

www.mapzones.com

Latitude 27Latitude 27 43’ to 28 43’ to 28 05’ North 05’ North

Longitude 69Longitude 69 35’ to 69 35’ to 69 57’ East 57’ East

www.googlearth.com

.

K-tron Precision Matrix

Kazmi & Jan, 1997

Source RocksSource Rocks

Sembar Formation.Sembar Formation. Reservoir RocksReservoir Rocks

Parh Limestone, Basal sand of Lower Goru Parh Limestone, Basal sand of Lower Goru Formation and Ranikot Formation.Formation and Ranikot Formation.

Caps Rocks Caps Rocks

Shale and Marl of Upper Goru.Shale and Marl of Upper Goru.

STRATIGRAPHY STRATIGRAPHY

OF OF

THE STUDY AREATHE STUDY AREA

(www.ogdcl.com).

SEISMIC SECTIONSEISMIC SECTION

LinesLines 856-SGR-52 and 856-SGR-55 856-SGR-52 and 856-SGR-55 AreaArea Sanghar Sanghar OrientationOrientation NW-SE NW-SE NatureNature Dip Line and Strike Line Dip Line and Strike Line Well on the Line Sachal and Barkat is near toWell on the Line Sachal and Barkat is near to

SGR-55 line SGR-55 line Energy Source DynamiteEnergy Source Dynamite S.P 101-667 and 101-1215S.P 101-667 and 101-1215 Number Of FoldsNumber Of Folds 80 Folds 80 Folds Company Company OGDCL OGDCL

Reflectors marked 4Reflectors on both Sections Reflectors marked 4Reflectors on both Sections Faults 6 Normal faults on SGR-52 Faults 6 Normal faults on SGR-52

5 Normal faults on SGR-55 5 Normal faults on SGR-55 Major Structure Horst and Graben Major Structure Horst and Graben

PART-IPART-I

STRUCTURAL STRUCTURAL

AND AND

STRATIGRAPHICAL STRATIGRAPHICAL

INTERPRETATIONINTERPRETATION

To mark the reflectors.To mark the reflectors. To prepare the Average Velocity Graph Of the line To prepare the Average Velocity Graph Of the line

856-SGR-52 and 856-SGR-55.856-SGR-52 and 856-SGR-55. To prepare the Mean Velocity Graph.To prepare the Mean Velocity Graph. To prepare the Iso Velocity Map.To prepare the Iso Velocity Map. To prepare the Time and Depth Section of the line To prepare the Time and Depth Section of the line

856-SGR-52 and 856-SGR-55.856-SGR-52 and 856-SGR-55. Time and Depth contour maps for identification of Time and Depth contour maps for identification of

Structure.Structure. To Identify and name the Reflectors with the help To Identify and name the Reflectors with the help

of Well tops of Bobi,Barkat,Sachal and Hartungu.of Well tops of Bobi,Barkat,Sachal and Hartungu.

(K-tron VAS)(K-tron VAS)

(K-tron VAS)(K-tron VAS)

(K-tron VAS)(K-tron VAS)

(K-tron VAS)(K-tron VAS)

(K-tron VAS)(K-tron VAS)

(K-tron VAS)(K-tron VAS)

(K-tron VAS)(K-tron VAS)

(K-tron VAS)(K-tron VAS)

(K-tron Visual Oil)

(K-tron Visual Oil)

(K-tron X-Work)

(K-tron X-Work)

(K-tron X-Work)

(K-tron X-Work)

Depth (m) = Depth (m) = VTVT

22

Where, T = Two way vertical time (s)Where, T = Two way vertical time (s)

V = Average velocity (m/s) for V = Average velocity (m/s) for

each respective timeeach respective time

(K-tron X-Work)

(K-tron X-Work)

(K-tron X-Work)

(K-tron X-Work)

(K-tron X-Work)

(K-tron X-Work)

Following conclusion were deduced based on the current Following conclusion were deduced based on the current studies:studies:

The study area is dominated by Normal Faults.The study area is dominated by Normal Faults. The Normal faulting in the area shows that the area was The Normal faulting in the area shows that the area was

deformed by the extensional tectonic movement.deformed by the extensional tectonic movement.

Since the area is under extension so horst & graben Since the area is under extension so horst & graben structure is present in the study area.structure is present in the study area.

From the structural and stratigraphic interpretation it is From the structural and stratigraphic interpretation it is concluded the structure formed in the area may act as a concluded the structure formed in the area may act as a favorable trap for the accumulation of hydrocarbons favorable trap for the accumulation of hydrocarbons

REVERSE MODELLING OF SEISMIC SECTION INTO REVERSE MODELLING OF SEISMIC SECTION INTO

IMPEDANCE SECTIONIMPEDANCE SECTION

ANDAND

WELL CORRELATIONWELL CORRELATION

INTERVAL VELOCITYINTERVAL VELOCITY

Vint = Z2-Z1/t2-t1Vint = Z2-Z1/t2-t1

INSTANTANEOUS VELOCITYINSTANTANEOUS VELOCITY

Vinst = dZ/dt Vinst = dZ/dt ROOT-MEAN-SQUARE VELOCITYROOT-MEAN-SQUARE VELOCITY

Vrms=√ (sum of product of square of interval velocities and time/sum of one way travel times)

STACKING VELOCITYSTACKING VELOCITY

t=√t²○+x²/V²stackt=√t²○+x²/V²stack

CONCLUSIONCONCLUSION

Vav≤Vrms≤ Vst Vav≤Vrms≤ Vst

(Dobrin , 1976)(Dobrin , 1976)

LATERAL VARIATIONS IN SEISMIC VELOCITIES

VERTICAL VARIATIONS IN SEISMIC VELOCITIES

CORRELATION BETWEEN VELOCITY TYPESCORRELATION BETWEEN VELOCITY TYPES Sq. Vint,n = (Sq.Vrms,n*Tn)-(SqVrms,n-1*Tn-1) Sq. Vint,n = (Sq.Vrms,n*Tn)-(SqVrms,n-1*Tn-1)

Tn-Tn-1Tn-Tn-1

Vint,n = (Vav,n*Tn)-(Vav,n-1*Tn-1) Vint,n = (Vav,n*Tn)-(Vav,n-1*Tn-1)

Tn-Tn-1 Tn-Tn-1

Vav,n = (Vint,n*Tn-Tn-1)+(Vav,n-1*Tn-1) Tn Vav,n = (Vint,n*Tn-Tn-1)+(Vav,n-1*Tn-1) Tn

THE SHEAR WAVE VELOCITY

Vp = 1.16Vs + 1.360

THE DENSITY DETERMINATIONTHE DENSITY DETERMINATION

ρ = 0.31 * (Vp) 0.25

THE COMPRESSIONAL WAVE IMPEDANCETHE COMPRESSIONAL WAVE IMPEDANCE

Impedance = ρ*Vp

THE SHEAR WAVE IMPEDANCETHE SHEAR WAVE IMPEDANCE

Impedance = ρ*Vs

P-waves impedance showing hydrocarbons Zone

S-waves impedance showing hydrocarbons Zone

P-waves impedance showing hydrocarbons Zone

S-waves impedance showing hydrocarbons Zone

Anomalous(Hydrocarbons)Zones can be detected with Anomalous(Hydrocarbons)Zones can be detected with

help of impedance. In Sanghar Area similar zone has help of impedance. In Sanghar Area similar zone has

been detected by P-Waves impedance that is confirmed been detected by P-Waves impedance that is confirmed

then by S-Waves impedance.then by S-Waves impedance.

It can be studied further with the help of enhanced data It can be studied further with the help of enhanced data

and advance approach.and advance approach.

It is a direct method to investigate depositional setting of It is a direct method to investigate depositional setting of

an area by correlating different stratigraphic an area by correlating different stratigraphic

successions encountered in different wellssuccessions encountered in different wells

Using well tops data of four wells Bobi-01, Barkat-01, Using well tops data of four wells Bobi-01, Barkat-01,

Sachal-01 and Harthangu-01drilled at Sanghar area Sachal-01 and Harthangu-01drilled at Sanghar area

lithologies are studied by using Log Plot Software. To lithologies are studied by using Log Plot Software. To

study the stratigraphic variations in an area usually wells study the stratigraphic variations in an area usually wells

are correlated. In well correlation we observe the are correlated. In well correlation we observe the

thickness and depth of each strata. thickness and depth of each strata.

Kadri I.B., (1995), “Petroleum Geology of Pakistan’’, Kadri I.B., (1995), “Petroleum Geology of Pakistan’’,

PPL, Karachi, Pakistan.PPL, Karachi, Pakistan.

Kamran, M. and Ranki, U., (1987). “Pakistan oil data, Kamran, M. and Ranki, U., (1987). “Pakistan oil data,

Hydrocarbon Development Institute of Pakistan”.Hydrocarbon Development Institute of Pakistan”.

Khan, K.A., 2000. Integrated Geo Systems - A Khan, K.A., 2000. Integrated Geo Systems - A

Computational Environment for Integrated Computational Environment for Integrated

Management, Analysis and Presentation of Petroleum Management, Analysis and Presentation of Petroleum

Industry Data, In: T. C. Coburn and J. M Yarus (Eds.), Industry Data, In: T. C. Coburn and J. M Yarus (Eds.),

Geographic Information Systems in Petroleum Geographic Information Systems in Petroleum

Exploration and Development, American Association of Exploration and Development, American Association of

Petroleum Geologists, AAPG Book on Computers in Petroleum Geologists, AAPG Book on Computers in

Geology, pp.215-226.Geology, pp.215-226.

Khan, K. A., Akhtar, G., Ahmed, Z., Khan, M.A., Khan, K. A., Akhtar, G., Ahmed, Z., Khan, M.A., and Naveed, A., 2006, Wavelets - A Computer and Naveed, A., 2006, Wavelets - A Computer Based Training Tool for Seismic Signal Processing, Based Training Tool for Seismic Signal Processing, Pakistan Journal of Hydrocarbon Research, Vol. Pakistan Journal of Hydrocarbon Research, Vol. 16, pp.37-43.16, pp.37-43.

Khan, K.A., Akhtar, G., Ahmad, Z., and Rashid, M., Khan, K.A., Akhtar, G., Ahmad, Z., and Rashid, M., 2008, Development of a Projection Independent 2008, Development of a Projection Independent Multi-Resolution Imagery Tiles Architecture for Multi-Resolution Imagery Tiles Architecture for Compiling an Image Database of Pakistan, Compiling an Image Database of Pakistan, Proceedings of 2nd International Conference on Proceedings of 2nd International Conference on Advances in Space Technologies Islamabad, Advances in Space Technologies Islamabad, Pakistan, p.164-170 Pakistan, p.164-170

To all my faculty members but special Thanks to To all my faculty members but special Thanks to

Sir Anees Ahmed Bangash whose guidance Sir Anees Ahmed Bangash whose guidance

leads me to touch this stageleads me to touch this stage