Detection of flow units of Quseir Formation (Lower Campanian) as a potential reservoir using experimental correlations of capillary pressure derived parameters, Gebel el-Silsila, Egypt

Abstract

Sandstone surface samples were collected from Quseir Fm., a member of Nubian Sandstone at Gebel el-Silsila and subjected to petrographical investigation using polarizing microscope. X-Ray diffraction was carried out to determine mineralogy. Scanning electron microscope also was utilized for the morphological characterization of the rock components. This sandstone petrofacies is mainly quartz arenite. The depositional environment of the studied sandstones is fluvial to fluvial-marine, and they suffered post-depositional alterations. Alterations include diagenesis (clay infiltration and original detrital grains disintegration), weathering, deterioration phenomena as erosion, voids existence due to dissolution and absence of bound materials. Mineralogical characterization indicated that quartz is the main constituent of sandstone in addition to kaolinite clay mineral as a cementing material. Petrophysically, the studied samples subjected to porosity and permeability measurements. The measurements showed that the samples are highly porous and permeable. Permeability–porosity relation displayed two groups (A and B). Although porosity values are close to great extent, permeability is quite different for the two groups due to the different distributions of pore throats, perhaps as a result of uneven clay distribution within the two groups of samples. Many capillary pressure-derived parameters were calculated using experimental correlations. The results confirmed the presence of two flow groups, macroport group (group A) and megaport group (group B) that is the best in terms of reservoir quality. The two groups reflect the excellent properties for the studied potential reservoir.