The Lower Cenomanian siliciclastic Bahariya Formation represents one of the main producing reservoirs in the north Western Egyptian Desert. A few previous subsurface studies exist that integrated core, petrographic, scanning electron microscope (SEM), and X-ray diffraction (XRD) analyses to study the reservoir quality of this formation. Consequently, the present study is carried out to fill this gap and outline the sedimentological, petrophysical, and digenetic characteristics of this siliciclastic reservoir in addition to the impact of these characteristics on reservoir quality. Detailed microscopic examination, XRD, SEM, and conventional core analyses were applied on the available cores. Five distinct microfacies types were petrographically identified, belonging to the arenite and wacke facies. These microfacies are represented by quartz arenite, subarkose, argillaceous quartz wacke, calcareous quartz wacke, and calcareous feldspathic greywacke. The formation was subjected to compaction and was affected by four types of cement; silica, calcite, kaolinite, and pyrite cementation. It has three types of porosities: primary intergranular and secondary porosity (microporosity and dissolution). The studied core samples of the Bahariya Formation are discriminated into two reservoir rock types (RRTs) and exhibit extreme heterogeneity. RRT1 comprises mainly quartz arenite, whereas RRT2 comprises quartz wacke. RRT1 has a reservoir quality of tight to poor due to porosity/permeability occluding by the different cementations.

In contrast, RRT2 has a reservoir quality of tight to fair, despite the presence of the clay matrix. The tight to fair quality is possibly attributed to the dissolution of feldspars and authigenic clays. The Lower Cenomanian reservoir is considered a second cycle deposition and represents a tight to a fair quality reservoir in the studied wells.

下森诺曼阶硅质碎屑 Bahariya 组是埃及西北部沙漠的主要生产储层之一。之前的一些地下研究存在集成岩心、岩相学、扫描电子显微镜(SEM) 和 X 射线衍射 (XRD) 分析，以研究该地层的储层质量。因此，本研究旨在填补这一空白，并概述该硅质碎屑岩储层的沉积学、岩石物理和成岩特征，以及这些特征对储层质量的影响。对可用的岩心进行了详细的显微镜检查、XRD、SEM 和常规岩心分析。在岩相学上确定了五种不同的微相类型，分别属于砂岩和瓦克相。这些微相以石英砂岩、亚长石、泥质石英岩、钙质石英岩和钙质长石灰岩为代表。地层受到压实并受到四种水泥的影响；二氧化硅、方解石、高岭石和黄铁矿胶结物。它具有三种类型的孔隙：原生粒间孔隙和次生孔隙（微孔和溶解）。所研究的 Bahariya 组岩心样本被区分为两种储层岩石类型 (RRT)，并表现出极端的非均质性。RRT1 主要包括石英砂，而 RRT2 包括石英砂。由于不同胶结物的孔隙度/渗透率，RRT1 的储层质量从致密到差。

相比之下，尽管存在粘土基质，RRT2 的储层质量从致密到一般。从严格到一般的质量可能归因于长石和自生粘土的溶解。下森诺曼阶储层被认为是第二旋回沉积，代表了研究井中质量较好的致密储层。