Structural control on basin architecture and hydrocarbon play types of the Miocene carbonate reservoirs, southern Gulf of Suez rift, Egypt

Abstract

The complex architecture of syn-rift carbonate reservoirs remains challenging in hydrocarbon exploration and development in rift basins such as the Gulf of Suez basin. The analysis of subsurface data of five boreholes, including composite logs, stratigraphy, and core data, was supported by 3D seismic data. Additional surface geological data were obtained from a syn-rift Miocene carbonate exposure in the western onshore area of the rift. Together, these data provided insights into the architecture of syn-rift Miocene carbonate depositional basin and the impact of structural control and diagenetic processes on reservoir quality. Structural reconstruction of the displacement of major normal faults of the rift illustrates the effect of structural geometry on the paleogeography and bathymetry. The study highlights how structural controls significantly influenced syn-rift carbonate deposition and played a critical role in shaping reservoir quality. Facies analysis revealed the presence of four key facies associations (lime mudstone, wackestone, packstone, and boundstone) with varying reservoir qualities based on porosity-permeability relationships. Diagenetic processes, such as dolomitization and dissolution variably impacted the reservoir quality across different structural settings. The Miocene carbonate play models in the southern Gulf of Suez basin have been classified to address the impact of structures on reservoir development and quality. These insights aim to encourage the re-evaluation of undeveloped hydrocarbon discoveries. They also improve hydrocarbon reserve assessment of complex carbonate reservoirs in the southern Gulf of Suez basin with advanced exploration strategies.