Abstract

Discovery of oil/gas pools at shallower depths in Ankleshwar field initially generated lot of interest. However, subsequent exploration efforts targeting the shallow Miocene pays of Babaguru/Tarkeshwar formations have, so far, met with only limited success, because of poor seismic imaging and insufficient understanding of depositional setting and hydrocarbon entrapment mechanism in the area. Hence, to chase existing leads and identify new areas of interest, it is imperative to develop better geological understanding, while being equipped with seismic data of enhanced quality. Seismic data re-processing with focus primarily on shallow data (? 1000ms) led to significant improvement in quality, better continuity of events and filling up of data gaps through advance 5D interpolation technique. Mapping of shallow horizons and reservoir characterization with a high degree of confidence was thus made possible, first time in the basin. Litho-facies based depositional modelling and analyses of various seismic attribute studies like amplitude, P-Impedance, seismic facies and spectral decomposition, in conjunction with well behavior were very insightful in understanding sand dispersal patterns and reservoir geometries. Based on G&G interpretation, low impedance-high amplitude- fluvial channel model for Babaguru pays and high impedance-high amplitudedistributary model for Tarkeshwar pays have been proposed and correlated with global analog of such pays. Model has significantly explained the existing fluid distribution pattern and brought out the prospective areas for exploration exploitation.