Depositional sequence and hydrocarbon reservoir evaluation of the Cretaceous succession, Ras Budran Field, Gulf of Suez Basin, Egypt

Abstract

The Ras Budran Field, Gulf of Suez Basin, exhibits a complex structural and stratigraphic architecture that governs Cretaceous reservoir distribution. However, existing studies typically address either structural configuration, petrophysical properties, or sequence stratigraphy in isolation, leaving a critical gap in integrated predictive models for reservoir distribution in structurally complex rift settings. To address this, we integrate 20 depth-converted 2D seismic profiles combined with wireline log data from four wells. Seismic interpretation delineates a fault-block architecture dominated by NW-SE-trending clysmic faults intersected by NE-SW cross-faults, generating pronounced compartmentalization and a prominent NE-SW-trending anticlinal high in the southwestern part of the field. Depth structure and isopach maps indicate that syn-rift thickness variations and structural highs exert a primary control on reservoir distribution within the Nubia, Raha, and Matulla intervals. Petrophysical evaluation identifies the Nubia Sandstone as the premier reservoir, with net-pay up to 338 ft (~ 103.0 m), effective porosity of 0.10 to 0.16, extremely low shale content (0.00–0.03), and hydrocarbon saturation exceeding 90%. The Raha Formation exhibits of stacked pay zones of 15–50 ft (~ 4.6–15.2 m) thick with low shale volume (0.02–0.10) and effective porosity of 0.12–0.21. While the Matulla Formation displays thinner pay intervals (5–30 ft) (~ 1.5–9.1 m) with moderate effective porosity (0.12–0.18), and hydrocarbon saturation ranging from 0.55 to 0.65. Sequence stratigraphic analysis reveals seven third-order depositional sequences, bounded by eight sequence boundaries, partitioned into lowstand, transgressive, and highstand systems tracts, whose lateral variability of reflects the interplay of differential sedimentation and syn-depositional tectonic activity. This integrated provides a predictive model for reservoir characterization and exploration in structurally complex rift basins.