Enhancing the Interpretation of Rift Structures in Sudan Using AVO Analysis and Seismic Inversion

摘要

Uncertainty in structural complexities and rock heterogeneities is a major challenge that controls oil exploration and drilling operations in the rift basins of Sudan. Wide ranges of depositional environments developed within these reservoirs: e.g., fluvial, shallow and deep lacustrine, fluvio-deltaic systems. Multi-phase rift development from rift initiation to late post-rift introduced good oil traps and very heterogeneous reservoir rocks situations. Advances in seismic inversion techniques and AVO analysis maximize the probabilities of valid interpretation and lithology delineation in such rift structures thereby reducing the associated uncertainty limit. Accuracy of interpretation depends on the quality of seismic data. Therefore, there is an urgent need to introduce innovative techniques in seismic processing to improve seismic resolution prior to any inversion work. This paper explains an-integrated workflow using seismic data conditioning and inversion methods applied for detailed interpretation and advanced reservoir characterization applications in these rift basins. The seismic data conditioning and inversion workflow implementation comprises three main steps: beginning with data conditioning (seismic and logs), wavelet estimation, and relative acoustic impedance inversion. The conditioned seismic and relative acoustic impedance volumes are used to improve horizons and faults. This interpretation can be used further to build a low-frequency models for absolute acoustic impedance inversion and porosity transformation.