Unveiling Reservoir Dynamics: Influence of Mineralogy and Rock Architecture on Petrophysical Properties in the Bahariya Formation, Gebel El Dist, Western Desert, Egypt

This study focuses on the surface analogy of the Bahariya reservoir, located in Gebel El Dist. It includes mineralogical, architectural and petrophysical investigations on its rock types. Three sandstone facies are recognized in the Section, these are: quartz arenite (QA), quartz wacke (QW), and mudstone (M). The X-Ray Diffraction Analysis (XRD) revealed that these facies are composed of quartz, feldspars, dolomite, pyrite, siderite goethite, hematite, clay minerals, glauconite, and gypsum. These minerals represent the grain framework and binding materials of depositional and diagenetic origin. The quartz arenite and the quartz wacke facies represent the two main types of reservoir rocks in the studied section. The conducted laboratory measurements addressed both reservoir rock and fluid properties. The measured petrophysical and fluid properties are helium porosity (ϕ), grain density (ρg), gas permeability (k), cementation index (m), saturation (n) exponent. The acoustic velocities and all related Elastic moduli were measured as well. All results were statistically analyzed to obtain several meaningful and/or applicable relationships. The raised petrophysical models relate minerals proportion deduced from the XRD to the laboratory measured petrophysical properties. These models were found beneficial in reservoir evaluation and confirming the impact of the mineralogy and the rock architecture on these characteristics.