Identifying and evaluating the hydrocarbon-bearing zones within the Cretaceous reservoirs using well logging data in El-Fayoum Concessions, Egypt

The goal of the study is to find effective pay reservoir zones through petrophysical analysis and formation evaluation of the Cretaceous reservoirs in El-Fayoum Concessions. This is done by analyzing the petrophysical properties of these reservoirs. These properties are used with cross-plots and cut-off techniques to ascertain the distribution of lithologies and pay zones. The interpretation of well logs revealed that the field includes four lithologies: interbedded sand, limestone, shale, and siltstone. Additionally, they demonstrate that the upper Bahariya Formation, Abu Roash F, and G members contain seven possible hydrocarbon-bearing zones. The F member and upper Bahariya are argillaceous limestone, whereas the Abu Roash G member is shaly sandstone laminated to scattered shale. There is a substantial shale bed beneath and above these reservoir zones, which serves as a possible source and/or seal rock. The potential petroleum system of the area is influenced by the thick stratigraphic succession, the time of trap formation, and the highly porous and permeable zones. Due to lower shale volume (13%-29%), higher effective porosity (5%-10%), and lower water saturation (27%-67%), the carbonate of Abu Roash F member, along with the lower sandstone of Abu Roash G and upper Bahariya, is considered the most promising zone for oil prospecting due to its high net pay thickness. Also, the iso-parametric maps show that the Abu Roash F member at the Silah-1X drilled well in the northwest direction has higher effective porosity, lower water saturation, and shale volume content. This indicates that the western and southwestern parts are best suited for exploration and drilling operations.