Study of the Hydrogeological Characteristics of the Deep Sandstone Aquifer Exploited in the Areas of Ghanima, Maslata

Abstract

This study aims to identify and evaluate the hydrogeological and hydraulic characteristics of the deep sandstone aquifer (Lower Cretaceous) exploited in the area extending from Qasr Khiyar to the west, Ghanima to the east, and Tarhuna city to the south, all located in northwestern Libya, covering an area of approximately 1927 km². After clarifying the location, geology, and topography of the area, the study begins by preparing and analyzing the geological and lithological description and the stratigraphic sequence of the water-bearing layers. This is achieved by drawing vertical sections based on drilling data from a set of targeted wells spread across the study area to determine the thickness, type, and number of exploited aquifers. The study revealed the presence of two exploited aquifers in the area: the Upper Cretaceous aquifer (Ain Nabat) and the Lower Cretaceous aquifer (Kakla deep). The thickness and dip of these aquifers increase as we move eastward and, to a lesser extent, southward.

Through the analysis of pumping test data from 18 targeted wells, it is evident that the hydraulic conductivity values of this aquifer range from good to excellent, with Transmissivity values ranging from 78.62 m²/day to 4510 m²/day, while hydraulic conductivity values range from 0.022 m/day to 33.38 m/day, Considering the storage coefficient results, in addition to drawing the geological sections , it is clear that the Upper and Lower Cretaceous formations are confined in the southeastern part of the study area, while they are unconfined in the northern and coastal areas of exploitation.