Sequence stratigraphy and wireline log analysis of the Sembar and Goru formations in the Miano area, middle Indus basin, Pakistan (T-1508) (MFN 4302)

Abstract

This document represents the subsurface structural and stratigraphic evaluation of the Upper Jurassic to Lower Cretaceous Sembar and Goru formations in Miano and adjoining area of the Middle Indus platform. Thorough regional and petroleum geological aspects of the study area are reviewed. Acquisition and processing parameters of the seismic data are discussed. Six horizons, Sui Main Limestone Formation, Upper Goru Formation, Top C Sands, Top B Sands, Top A Sands and Chiltan Limestone Formation were picked. Two way time maps of all the horizons, except Chiltan Limestone Formation, are prepared. Depth conversion is also done using linear velocity function (LVF). Normal fault pattern with horst and graben features are interpreted. Structurally the Miano area lies within a depression while the adjoining areas in the east and west are uplifted. On the suitable seismic sections, the Sembar and Goru (A-sand, B-sand and C-sand) strata are picked for every event to reveal the seismic geometries (onlap, downlap etc.). This picking is used to develop a seismic stratigraphic model. Two higher order sequences ( alternative TST and HST packages) and one complete third order sequences (LST, TST and HST packages) are identified within Sembar, whereas the Goru-A sand has one complete sequence comprising of LSW (Lowstand Wedge), TST (Transgressional System Tract) and HST (Hishstand System Tract). Areas for the potential plays are identified within Sembar Formation, slope fans and shelfal sand bodies are interpreted as potential site for reservoir quality sands.