Provenance, depositional facies, and diagenesis controls on reservoir characteristics of the middle Miocene Tidal sandstones, Gulf of Suez Rift Basin: Integration of petrographic analysis and gamma-ray log patterns

The interpretation of depositional environment and diagenesis controls on petroleum reservoirs are a major challenge that has an impact on the petroleum system of hydrocarbon reservoirs. For the evaluation of hydrocarbon exploration and development, detailed depositional facies and reservoir characteristics are needed. However, some oil fields worldwide lack core samples, which are needed for accurate research. This research aims to analyze the consequences of integrating gamma-ray log patterns with petrographic analysis to describe the depositional setting in the Baba sandstone hydrocarbon reservoir within the Badri field in Egypt's south-central Gulf of Suez. The effect of diagenesis on the reservoir pore system network was also investigated. For this study, the available dataset includes wireline logs dataset and ditch cutting analysis to provide rock mineralogy, grain size, texture, sorting, cementation, accessory minerals, and lithology. Petrographic analysis reveals that Baba sandstone is dominated by medium-grained, moderately to poorly sorted, and arkose. Based on petrographic analysis data, the Baba sandstone provenance is constrained to the adjacent Precambrian Basement units of the Sinai peninsula. Thin section analysis and the point count method identify primary intergranular macroporosity, secondary intragranular macropores, and intercrystalline micropores within the studied sandstone. Based on petrographic analysis, grain–grain relationships, and framework grain–cement relationships of thin sections, the Baba sandstone has most likely been subjected to significant physical and chemical diagenetic processes, resulting in a decrease in primary porosity. The diagenetic analysis suggests that the sandstone has undergone significant alteration such as compaction, cementation, dissolution, and clay minerals alteration. Based on gamma-ray log investigation, the cylindrical gamma-ray pattern is the sole electrofacies that characterized the Baba sandstone. The tidal sand bar is the most likely depositional environment based on log pattern, petrographic analysis, and elongated depositional direction. The present study provides insights into how to solve the lack of core samples in petroleum reservoirs and it can be applied elsewhere to better interpretation of depositional settings, and diagenesis control on the reservoir pore system network.