The Use of Seismic Inversion to Revisit the Reservoir Mapping of a Large Carbonate Brown Field

Abstract

We present an integrated seismic interpretation case study of a large heterogeneous carbonate brown field located on western offshore India. In this study, seismic inversion is used as the key driver to revisit the interpretation and mapping of the reservoirs. The seismic interpretation is developed in a stepwise approach, first on amplitude data and then on inversion data for achieving high level of accuracy and consistency in the final structure. This method is applied in order to overcome typical signal ambiguities and wavelet instability encountered across the field. Both relative acoustic impedance (RAI) and absolute acoustic impedance (AAI) derived from post-stack inversion are successively used to refine the interpretation as AAI provides a clearer image of the reservoir and fault compartments. Eventually, fault interpretation is fine tuned on edge enhancement attributes. The final time interpretation is then depth converted via an integrated velocity model based on geostatistical velocity modeling preserving seismic inversion well ties.