_____________________________________________________________________________________________________ *Corresponding author: E-mail: ayman_mass@yahoo.com; Asian Journal of Environment & Ecology 15(4): 37-55, 2021; Article no.AJEE.70730 ISSN: 2456-690X Determination the Petrophysical and Natural Radioactivity Properties of Nubian Sandstone Aquifer at the Area of Northwest El Ain Village, Sharq El-Oweinat Area, Southwestern Desert, Egypt Mohamed Z. Twfiq 1 , Fardous M. Zarif 1 , A. Massoud 2* and Ayman M. Al-Temamy 1 1 Geophysical Exploration Department, Desert Research Center, P.O.Box 11753, El Matariya Cairo, Egypt. 2 Nuclear Chemistry Department, Hot Labs Center, Egyptian Atomic Energy Authority, P.O.Box 13759, Inshas, Egypt. Authors’ contributions This work was carried out in collaboration among all authors. All authors read and approved the final manuscript. Article Information DOI: 10.9734/AJEE/2021/v15i430236 Editor(s): (1) Dr. Edward Ching-Ruey, Luo, National Chi-nan University, China. Reviewers: (1) Muhammad Ramli, Hasanuddin University, Indonesia. (2) Muralitharan Jothimani, Arba Minch University, Ethiopia. Complete Peer review History: https://www.sdiarticle4.com/review-history/70730 Received 10 May 2021 Accepted 16 July 2021 Published 19 July 2021 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 (Φeff )% varies between 20 and 28.2%, while average (v  ) 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 Original Research Article