Habshan Seismic Stratigraphy Framework to Reveal Stratigraphic Play Potential in Southeast Abu Dhabi, UAE

Abstract The Lower Cretaceous (Berriasian to Valanginian) of Southeast Abu Dhabi, U.A.E. consists of a large carbonate platform system and the Habshan Formation is a major carbonate reservoir in the region, hosting significant hydrocarbon potential with more than 1,000 feet in reservoir thickness. The progressive nature and clinoform structures have been highlighted through many vintages of seismic imaging and previous stratigraphic studies. This underlines the necessity of understanding sequence stratigraphy to appreciate the variations and distribution of facies by the integration of all available geological and geophysical data in the study area. Seismic data interpretation based on a high-resolution 3D survey covering more than 4,400 sq-km was conducted to identify geological features and variations in the Habshan Formation. Data-driven interpretation utilizing different types of 3D seismic attribute volumes, including acoustic impedance volume, was used to identify main cycles and their internal stratigraphic architectures. Well correlation was also conducted to build well-scale stratigraphic framework. Core, logs, and well test data were integrated to understand reservoir properties and distribution. Updated Gross Deposition Environment (GDE) maps and depositional sketches were produced through the integration of seismic data analysis, the revised stratigraphic understanding and well correlation. A seismic-based revision of the existing sequence stratigraphic interpretation allowed for the identification of better-defined sequences and their systems tracts. The Habshan Formation is interpreted to comprise four main cycles (I, II, III and IV), while the Zakum Member represents one cycle (V). The seismic-based interpretation of the cycles is supported by core and log data and is in line with published data from various locations in Oman. The enhanced sequence stratigraphic understanding resulted in a better definition and prediction of reservoir development and distribution across the study area, by filling the gaps between the sparse available drilled wells. The study results allowed the identification of potential hydrocarbon plays in different stratigraphic settings, by highlighting the geometry and reservoir quality variations of each cycle. This work demonstrates the role of in-depth, refined data interpretation and integration in identifying possibly overlooked subtle traps through the understanding of sequence stratigraphic signatures in seismic and well data. The results of this work can be used as a basis for the understanding and exploration of the Habshan Fm. and other similarly stratigraphically complex formations in the study area and beyond.