2-D Seismic Interpretation Of Sukkur Area,Central Indus Basin Pakistan

Abstract

The aim of this dissertation is to interpret 2D-Seismic Reflection time sections of the Sukkur Area (Sindh Province) Pakistan. These seismic sections are Post-stacked time migrated sections and were provided by the Department of Earth And Environmental Sciences, Bahria University Islamabad and the lines bear the title P2291-OMV-19 oriented in NESW direction, P2291-OMV-14 oriented in N-S direction and P2291-OMV-41 oriented in N-S direction. OGDCL acquired data in October 1991. The velocity information is in the form of RMS, DIX interval, and DIX average at different times is given and is provided at selected S.Ps. For interpretation of the Seismic sections, five horizons R1, R2, R3, R4, and R5 were marked online P2291-OMV-19 which were then shifted to Lines P2291- OMV-14 and P2291-OMV-41 with the help of seismic tie lines, these horizons were marked on the basis of prominent reflections from subsurface horizons due to changes in lithology and diffractions. Using the RMS velocity given in the velocity panels on the seismic section for selected shot points, I calculated the times on a constant velocity interval of 100m/sec. From the Seismic Section, arrival times (two ways) of each marked reflector are determined. Using these arrival times, Time Sections have been prepared for the three selected lines. Also using these arrival times, I calculated the average velocity for these times on mean line graphs, and then the depth of each reflector has been calculated using S=(v*t)/2 and is represented in Depth Sections of the three selected lines. Depth Sections provide a reliable picture of reflectors and structures present in the subsurface of the area. Well, correlation is also done, which satisfies the calculated depths, so horizons have been marked. Interpretation of the Project Area shows that an extensional regime and calm environment prevails in the area. Reflectors are almost flat-lying, whereas Horst and Graben structures have been found.