2D Seismic Interpretation of Chaknaurang Area

Abstract

The aim of this dissertation is to interpret the 2D-Seismic Reflection time section of District Chakwal, Pakistan. The seismic lines used are Migrated Seismic Sections and were provided by the Director General Petroleum Concessions (DGPC), Islamabad. These lines bear the vintage 884-CW-104, 884-CW-105, and 884-CW-108. The total length of these lines is 66 KM and is oriented in SE-NW and S-N directions. OGDCL acquired and processed this data in 1988. Prominent reflectors were marked on the seismic sections which represent different chosen formations. A time section is produced from the seismic section using the SPs and the two-way time to the reflector and fault. The velocity information from the seismic section is in the form of RMS velocity and interval velocity at different times and is provided at selected CDP locations. RMS velocities vary from 2100m/s to 5000 m/s. The average velocities were then used to find the depth of the formations for the depth section. Three reflectors are marked on the seismic sections on the basis of observed reflection events. The marked horizons show deformation in the area caused by compressional forces. I have marked thrust and normal fault present in my dip lines 884-CW-104, and 884-CW-105. Subsurface contour mapping is also done with the help of a surfer to generate the time and depth contour maps to see an extension of respective faults. The time and Depth Section provides a reliable picture of reflectors and structures present in the subsurface of the area. These structures indicate the involvement of tectonic activity because of the presence of thrust faults and popup structures. In propagation folds, a decollement feature is present in Precambrian salt; Pop down structure is also present as shown in time and depth sections.