6 th Saint Petersburg International Conference & Exhibition – Geosciences – Investing in the Future Saint Petersburg, Russia, 7-10 April 2014 Th CH 17 Mapping Reservoir Fluid Using AVO Inversion, Spectral Decomposition and Facies Classification A.A. Babasafari* (Oil Exploration Operation Company) & H. Khoshdel (Exploration Directorate) SUMMARY Seismic reservoir characterization helps to find more information about rock physics in oil and gas explorations. One of the important properties in reservoirs is hydrocarbon saturation. Fluid content discrimination on seismic data is possible if it is feasible in well data and seismic data has adequate quality. In this study a gas carbonate reservoir is evaluated to map fluid distribution using integration of AVO inversion and seismic attributes. Feasibility study of fluid content discrimination was certified in well data by cross-plotting Acoustic Impedance vs. Vp/Vs logs. AVO modeling represents fluid effect as well. Results of simultaneous pre-stack inversion were used to predict water saturation cube which completely discriminate gas from water around GWC on surface attribute map. By subtracting of far stack from near stack data and applying iso-frequency component attribute over the volume the pay zone was discriminated from non-pay zone around GWC. This was confirmed again by unsupervised facies classification. This field has been already interpreted structurally and depth map of reservoir has been built. The contour level of GWC on depth map somewhere was not coincided in comparison with the observed gas content as demonstrated above. It illustrates that calculated reserve will be increased.(Close to 0.2 STCF)