Study of Subsurface Structural Trend and Stratigraphic Architecture Using Seismic Data A Case Study from Zindapir Inner Folded Zone, Sulaiman Sub-Basin, Pakistan

Abstract

This study involves the interpretation of structural styles and stratigraphy of an area named Drazinda in Zindapir Inner Folded Zone, Sulaiman sub-basin based on the Seismic reflection data and well information. The seismic reflection method has advantage over other methods due to a greater penetration, higher resolution and accuracy. Depths to the reflecting interfaces are estimated from the recorded time and velocity information can be obtained from reflected signals.The detailed stratigraphiccorrelation and structural interpretationof approximately 44 kilometers has been carried out with the help of well data, formation tops and general stratigraphy of the area. Nine reflectors of different formations were marked on North-South seismic profile using the well tops of nearest wells Ramak-01 and Domanda01 well and also based on the prominent reflection. The reflectors were named as 1. Litra, 2. Vehowa, 3. Chitarwata, 4. Drazinda, 5. Pirkoh, 6. Domanda,7. Habib Rahi, 8. Baska and 9. Ghazij Shale from top to bottom respectively. A syncline named as Drazinda Syncline has also been interpreted which lies North side of Domanda-01well. Values of Interval Velocity, Root Mean Square Velocity, Average Velocity and Mean Average Velocity for each Common Depth Point has been calulated and also were plotted.Finally time section was plotted for seismic profile. Interpretation of seismic data suggests that Tertiary Formations are present in the core of Drazinda Syncline while the Litra (Pliocene), Vehowa (Miocene) and Chitarwata (Oligocene) are exposed at the surface. On the South-Eastern part of the profile Domanda-01 well was drilled up to a depth of 3409 m and only Ghazij Formation encountered up to total depth.