Applications of well logging techniques to evaluate the groundwater aquifers in the area between southwest Bani Sweif and west Asyoute governorate, upper Egypt.

The relevance of detecting aquifer characterization and aquifer potential has risen with the application of well logging techniques as the demand for water has increased. Apart from pumping data, 16 geophysical well logs (resistivity, gamma ray, self-potential, and nuclear logs) are utilized to achieve the main goal of estimating petrophysical parameters (porosity (∅), effective porosity (∅𝑒𝑓𝑓), hydraulic conductivity (k), permeability (K) and shale volume (𝑉𝑠ℎ)) of the Apollonia (Eocene fractured limestone aquifer), Upper and Lower Bahariya (Nubian sandstone aquifer) formations. The findings show that the Eocene fractured limestone aquifer has a carbonate in soft chalk with high K and ∅ as well as high k of 4974.39 mD at well ST-188 (a highly productive aquifer), whereas the Lower Bahariya formation is mostly fine to medium-grained sandstone and clay, suggesting that it formed in shallow marine environments with low K. On the other hand, Upper Bahariya was noted that having poor sand succession. As results shown, K of the most examined wells ranges from 2609.69 to 1486.812 mD at ST-258 and ST-38 wells respectively. The study appears that 𝑉𝑠ℎ, along with ∅ and K features, is regarded as an important attribute in aquifer evaluation where, estimated 𝑉𝑠ℎ over the studied area is ranges between 5.96% and 31.7% at ST-48 and WBS1 wells respectively. Overall, this study provides an important insight into the importance of evaluating groundwater aquifers over time to help in making decisions to save and protect groundwater aquifers in the future.