THERE ARE DIFFERENT OBJECTIVES IN PERFORMING SEISMIC RESERVOIR CHARACTERIZATION STUDIES BUT AMONG ALL OF THEM LITHOLOGY AND PORE FLUID PREDICTION ARE TWO OF THE MOST IMPORTANT ONES. IN SEISMIC RESERVOIR CHARACTERIZATION, DIFFERENT TECHNIQUES ARE APPLIED TO EXTRACT THE MOST VALUABLE RESULTS FROM THE AVAILABLE SEISMIC DATA, ESPECIALLY IN PLACES WITH LIMITED WELL CONTROL AND LOW QUALITY SEISMIC DATA. EXTENDED ELASTIC IMPEDANCE (EEI) INVERSION IS A TECHNIQUE THAT PROVIDES A SIMPLE ROBUST MEANS OF DERIVING LITHOLOGICAL AND FLUID SENSITIVE SEISMIC IMPEDANCE VOLUMES BY DEFINING AN ANGLE CALLED CHI ANGLE (Χ) AND USING THIS ANGLE AS A ROTATION IN INTERCEPT-GRADIENT SPACE, TO COMPUTE THE VOLUME TO BE INVERTED. EEI AT VARIOUS CHI ANGLES IS PROVED TO BE PROPORTIONAL TO NUMEROUS ELASTIC AND PETRO-PHYSICAL PROPERTIES SUCH AS DENSITY, S-IMPEDANCE, VP/VS RATIO, SHEAR MODULUS, CLAY VOLUME, POROSITY AND WATER SATURATION. IN THIS CASE STUDY EEI ANALYSIS IS PERFORMED TO ESTIMATE VP/VS RATIO AND WATER SATURATION CUBES TO EVALUATE AN OIL PRODUCING RESERVOIR. AFTER DETERMINATION OF THE PROPER CHI ANGLES, THE EEI REFLECTIVITY DATA WERE GENERATED BY INTEGRATION OF A (INTERCEPT) AND B (GRADIENT) VOLUMES (ESTIMATED FROM AVO ANALYSIS). THEN LP SPARSE SPIKE INVERSION PROCEDURE WAS PERFORMED TO GENERATE DESIRED CUBES.GENERATED VP/VS RATIO CUBE IN ADDITION TO WELL LOG DATA, WAS COMPARED WITH THE CORRESPONDING VP/VS RATIO CUBE ACQUIRED FROM PRE-STACK SEISMIC INVERSION. THE RESULTS REVEALED A PROPER MATCH AT WELL LOCATION AND ALSO AT PLACES FAR FROM THE WELL CONTROL. GENERATED WATER SATURATION RESULTS WERE ALSO COMPARED WITH AVAILABLE LOG DATA THAT AGAIN GOOD MATCH WAS OBSERVED. THE OUTCOMES OF THIS FAST SEISMIC RESERVOIR CHARACTERIZATION METHOD CAN HELP TO RANK PREVIOUSLY DEFINED DRILLING LOCATIONS AND ALSO DETERMINE NEW POTENTIAL LOCATIONS.