Characterizing and Predicting High-Permeability Flow Zones in the Shuaiba Formation of a Giant Carbonate Onshore Oilfield Through Stratigraphic, Diagenetic, and Dynamic Integration

This study examines the high permeability flow zones (HPFZs) on reservoir performance in the Shuaiba Formation of a giant carbonate onshore oilfield located in Abu Dhabi, UAE. The objective is to characterize and predict HPFZs by enhancing the stratigraphic framework and permeability architecture through the integrated sedimentological, petrophysical, and dynamic data. The study focuses on HPFZs resulting from preserved primary porosity, diagenetic enhancement, and structurally induced fracturing associated within fault systems to assess the impact of these features on waterflood performance and support the optimization of hydrocarbon recovery. A multi-disciplinary, data driven workflow was implemented combining core description, borehole image log interpretations, well test analyses, and production log data across more than 500 wells. High-resolution stratigraphic correlations were used to delineate depositional architectures and facies stacking patterns, which were then calibrated with pressure and saturation trends. HPFZs were recognized through contrasts between core permeability and dynamic responses from PLT and well test data. Structural features such as fault-related fracture corridors were assessed using borehole image logs and seismic attributes to enable spatial prediction of fluid conduits and barriers. This integration enabled a clearer understanding of the spatial extent and interaction of HPFZs. Analysis of the Shuaiba Formation reveals that a small number of laterally continuous, high-permeability rudist-rich facies, account for a high permeability HPFZs and subsequently disproportionate share of fluid production and injection response. These HPFZs are frequently associated with shallower depositional periods and regressive parasequences and exhibit multi-Darcy permeabilities compared to the background matrix (<10 mD). Diagenetic overprinting, including leaching, was observed to further enhance permeability in localized zones. Structural mapping indicates that subtle fault damage zones occasionally coincide with HPFZ pathways, enhancing vertical connectivity and exacerbating early water breakthrough in crestal producers. A significant permeability contrast between HPFZs and surrounding matrix rock contributes to poor flood conformance, evidenced by bypassed pay and irregular saturation trends. Integration of dynamic surveillance with stratigraphic modeling enabled the refinement of the static model to account for HPFZ influenced flow behavior. These results support the need to condition simulation models with deterministic HPFZ distributions, particularly in the southern area, near the Graben Region in the central area and crestal sectors of the field where water encroachment is most severe. These findings underscore the necessity of incorporating HPFZs deterministically into simulation models to minimize conformance issues, reduce bypassed pay, and improve recovery factors This work delivers the first integrated stratigraphic-dynamic-structural HPFZ mapping of the Shuaiba Formation in the giant oilfield. By integrating depositional architecture, diagenetic trends, and dynamic flow diagnostics, it introduces a predictive framework for HPFZ identification and incorporation into reservoir models, offering a scalable methodology for optimizing recovery in carbonate reservoirs with complex permeability heterogeneity.