Integration of magnetic, gravity, and well-logging data interpretation to delineate the structural framework and formation evaluation of Bahariya Formation, North Diyur area, northern Western Desert, Egypt

The Bahariya Formation in Egypt's Western Desert is a major source for minerals and hydrocarbon accumulation. It is also characterized by a relatively high radiation content because it contains iron oxide deposits that attract radioactive elements. The main objectives of our study are to establish depth to basement, basement configuration and related structural elements, and thickness and configuration of the overlain sedimentary section. In addition to the analysis of well-logging data, many advanced techniques have been applied to analyze magnetic and gravity data, including depth estimation, 2D magnetic and gravity modeling, and 3D inversion of potential field data. By integrating all available data, we can determine the structural control of the study area and evaluate the subsurface parameters. Well logging has been used for interpretation of porous and permeable zones, water saturation calculation, and basic lithology identification. The depth to basement in our study ranges from −1700 to −4500 m. The basement is shallow in the northern parts of the study area and deeper in the southern parts. The main clay minerals of the formation are montmorillonite, chlorite, and a mixed clay layer. The Bahariya Formation is composed mainly of sandy clay and sandstone, and therefore it is considered an excellent reservoir.

Geophysical assessment and hydrocarbon potential of the Cenomanian Bahariya reservoir in the Abu Gharadig Field, Western Desert, Egypt

In this study, the sandstones of the Bahariya Formation in the Abu Gharadig Field, which is a promising oil reservoir in the Abu Gharadig Basin, Western Desert, Egypt, were assessed. The wireline logs from three wells (Abu Gharadig-2, Abu Gharadig-6, and Abu Gharadig-15) were studied using seismic and petrophysical analyses. Based on seismic data, the study area contains an ENE–WSW anticlinal structure, which is divided by a set of NW–SE normal faults, reflecting the effect of Late Cretaceous dextral wrench tectonics on the northern Western Desert. The visual analysis of the well logs reveals a potential zone within well Abu Gharadig-2 located between depths of 10,551 and 10,568 ft (zone A). In contrast, potential zones were detected between depths of 11,593–11,623 ft (zone B) and 11,652–11,673 ft (zone C) in well Abu Gharadig-6. In well Abu Gharadig-15, potential zones are located between depths of 11,244–11251ft (zone D) and 11,459–11,467 ft (zone E). The quantitative evaluation shows that the intervals B and C in well AG-6 are the zones with the highest oil-bearing potential in the Abu Gharadig Field in terms of the reservoir quality. They exhibit the lowest shale volume (0.06–0.09), highest effective porosity (0.13), minimum water saturation (0.11–0.16), lowest bulk volume of water (0.01–0.02), high absolute permeability (10.92–13.93 mD), high relative oil permeability (~ 1.0), and low water cut (~ 0). The apex of the mapped fold represents that the topmost Bahariya Formation in the Abu Gharadig Field for which the drilling of additional wells close to well AG-6 is highly recommended.

Study The Severe Effects of Iron Compounds Presenting in Sandstone on the Deterioration of Wall Paintings of Archaeological Tombs in Bahariya Oasis - Egypt

The Wall paintings in Bahariya oasis expose to various deterioration factors, especially the resulted deterioration from the geological nature of sandstones' supports; sandstone of Bahariya formation is considered the weakest sandstone type in Egypt because of its geological formation which contains a very big percentage of iron oxides. Sandstone samples were taken, analyzed and examined by x-ray diffraction and scanning electron microscope, the iron oxides are thecement material in sandstone which affect negatively on the wall paintings in the selected tombs (Badi –Ishtarand Bannantiu tombs),they caused a lot of deterioration phenomena to the wall painting layers like: layers loss,black spots, cracking through all the layers and sandstone support weakness that threatens the remaining wall paintings and the safety of the tombs. Iron oxides percentage in Badi – Ishtartomb is more than Bannantiu tomb and this is reflected on the wall paintings case in Badi – Eshtar. This research sheds the light on this phenomenon and its effect on the wall painting's deterioration.