Determination of the Petro-physical and Natural Radioactivity Properties of Nubian Sandstone Aquifer at the Area of Northwest El Ain Village, Sharq El-Oweinat Area, Southwestern Desert, Egypt

Abstract

The Nubian sandstone aquifer's hydrogeophysical and natural radioactivity parameters at the Northwestern part of El Ain village, Sharq El Oweinat, Southwestern desert, Egypt are resolved using geophysical well logging and natural radioactivity techniques. The study aims to monitor the phenomenon of appearing an unusual high gamma-ray at a zone of high resistivity record. A nest of well logs is collected to assess how the phenomenon is widespread. Results of correlated well logs are clarified that this phenomenon at zone between 80 and 100 m and zone of 200 and 230m depth is noticed. The petro-physical properties are estimated from the recorded well logs. The results showed that the percentage of the average of effective porosity % varies between 20 and 28.2%, while average vary from 2 to 12.5 %, which indicates that the aquifer of Nubian Sandstone is classified as a clean aquifer. The natural radioactivities of the studied area in the rock samples were evaluated using high-purity germanium (HPGe) detector. The results indicated that the average value of Th-232 is (51.32 ±4.92%) Bq/kg, Ra-226 is (29.03 ± 4.68%) Bq/kg while the radioactivity concentration of K-40 exists only in one sample with low concentration.

Trace Elements Characterization in Rocks Using Neutron Activation Analysis, Northwestern Coast, Ras El-Hekma–Egypt

“…Many techniques by destructive procedures such as ICP-AES, ICP-MS, Atomic Absorption, and UV, have been used to determine the elemental compositions in the solid samples [14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29]. Neutron activation analysis (NAA) stands out among the highly precise and sensitive analytical methods currently in use in that it does not require prior sample preparation, such as acid digestion, which greatly improves both precision and accuracy in determining the content of major and trace elements in rocks [3,30].…”