STRUCTURAL INTERPRETATION OFBADIN AREA USING 2D SEISMIC DATA

Thesis proposal

Submitted by:Muhammad Ali

35978

Supervisor:Dr. Mubarik Ali

Karachi, PakistanMarch

RESEARCH PROPOSALRESEARCH TITLE:Structural interpretation of Badin area using 2d seismic data

INTRODUCTIONThe study area is the part of Southern Sindh Monocline. SindhMonocline is an important hydrocarbon producing area of Pakistanfromwhere a large number of hydrocarbon fields have been discoveredin the tilted fault blocks.The area is highly deformed and is characterized by extensionaltectonic activities which are related to rifting phases experienced by theIndo-Pakistan plate. Thus the study of structural styles formed due tothese tectonic activities is much important as the cretaceous riftingepisodes had a profound effect on the formation and occurrence ofhydrocarbons in Sindh Monocline.Sindh Monocline, commonly known as Badin Block Area.Study area is located of Badin district in Sindh province of Pakistan.The district is placed between 24 5N to 25 25N Latitude and 68 21E to 69 20 E Longitude and is bounded on the North by Hyderabaddistrict, on the South by Arabian Sea & Rann of Kutch, on the East byMirpurkhas & Tharparkar districts and on the West by Thatta andHyderabad districts .

TECTONIC OF AREATectonics of Indian platform of which Sind monocline forms a part hasbeen discussed by many authors. The northward movement of Indianplatform generated compression where accompanying anticlockwiserotation produced tension. As a result of tension the platform was splitinto grabens and horst. This tectonic setting provided the idealcondition for widespread deposition of sediments exhibiting a variety offacies, including organic rich Sember shale (Source rock) and highlyporous and permeable Lower Goru sands (Reservoir Rock) (Raza et al,1990).Two sets of faults indicting two different episodes of rifting aredeveloped in the platform. The first set of faults associated with earlycretaceous Kutch rift phase and the second set is a consequences ofLate cretaceous Cambay rift phase.Grabens are main areas for the generation of hydrocarbons while faultsare providing migration pathway for hydrocarbons from source toreservoir rocks.Faults are also providing the trapping mechanism for hydrocarbons.The tilted fault block traps were in existence at the time of hydrocarbongeneration. Fault associated with the structural closures are responsiblefor trapping oil and gas in lower Goru sand stones in the study andnearby areas.OBECTIVEThe purpose of this proposal is to study structural variations ofsubsurface using seismic and well log data of Badin area. Study of geology of area Structural interpretation of seismic data

1. Identification of faults and it types2. Folds and it types3. Structural mapping.4. identification of traps5. Finding prospect

METHODOLOGYINTERPRETATION :Interpretation is the transformation of seismic data into structural andstratigraphic picture through a series of different steps. Thus threadingtogether all the available geological and geophysical informationincluding the seismic and then integrating them all in a single picturecan only give a picture closer to the reality.STRUCTURAL ANALYSIS:In structural interpretation main emphasis is on the structural traps inwhich tectonics play an important role. Tectonic setting usually governswhich types of structures are present and how the structural features arecorrelated with each others, so tectonics of the area is helpful indetermining the structural style of the area and to locate the traps.Structural traps include the faults, anticlines, duplex etc. (Sheriff,1999).Seismic sections can predict the structure that scale up to few tens ofkilometers. For large scale interpretation we have to use the grids ofseismic lines. Unmigrated section is not suitable for structureinterpretation, because it creates many problems like synclines becomesnarrows and vice versa. Even a migrated section not fully fit forcomplex area like the area of study (Badley, 1984).Some seismic section contains images that can be interpreted withoutany difficulty. Discontinuous reflectors clearly indicate faults andundulating reflections reveals folded beds. Most interpretation ofstructural features are directly marked on seismic time sections(Robinson & Coruh 1988).Structural interpretation step:

1. Horizons picking2. seismic time section3. seismic depth section4. contour map5. time contour and surface map of basal sand6. depth contour and surface map of basal sand7. Identification of prospect

DATA REQUIREMENTSeismic lines are available in public domain are:

SOFTWARE REQUIREMENT:Seismic Interpretation will be carried out by using GeographixSoftware(SeisVision is a standard module of the LandmarkGeoGraphix) available with Bahria university Karachi campus. ThisSoftware is a Powerful, fully integrated 2D and 3D Seismicinterpretation tool that provides all facility to achieve my objectiveInterpretation and mapping tools.CONCLUSIONStructuring in the area provides basic elements of petroleum system.Grabens are main areas for generation of hydrocarbons while faults areproviding migration pathway for hydrocarbons from source rock toreservoir rocks. Faults are also providing trapping mechanism forhydrocarbons. The main constituents of petroleum system are presentas proven by number oil and gas discoveries in the area. data revealsthat as a result of major & minor tectonic events.

REFERENCE: Munir, A., S. Asim, S. A. Bablani and A. A. Asif, (2014). Seismic data

interpretation and fault mapping in Badin area, Sindh, Pakistan Sindh Univ.Res. Jour. (Sci. Ser). Vol. 46 No.2, 133-142.

Ahmad S. S. M., (2003). Zaur Structure- A Complex Trap in a Poor SeismicData Area, SPE-PAPG Annual Technical Conference 2003 Proceedings,147-163, Pakistan.

Iqbal B . Kadri Petroleum Geology of Pakistan Published (1995) byPakistan Petroleum Limited.