Current 3-D seismic data with state of the art processing and interpretation technology has revealed a clear picture of the reservoir boundaries, extension and characteristics. Consequently significant Original Oil In Place increment has been recognized in a field offshore Abu Dhabi, U.A.E., which is unusual case in this region. Several approaches were applied to achieve accurate reservoir images. Seismic sequence stratigraphy, AI inversion, waveform classification etc., were utilized to define the reservoir limit. Vertical stretch and map migration methods were applied to investigate the sensitivity to the velocity hence achieve more reliable depth structure map. Co-blending of several 3-D seismic attributes was applied to identify subtle faults and fracture swarms. New structures were identified with a great degree of accuracy through statistical analysis and sensitivity test of depth conversion, with narrow uncertainties ranges to optimize well location and field development plan.