Seismic and sequence stratigraphy contributions to Oligo-Miocene deep aquifer characterization in the Tunisian Sahel Foreland Basin (North Africa)

Eastern Tunisia is a semi-arid to arid area, located in the southern Mediterranean side, in North Africa. It is facing water scarcity, overexploitation, and decreasing water quality of the phreatic water table. Water supply and storage do not respond to the demographic and economic growth and demand. In addition, only 5 10 9 m 3 of water from 35 10 9 m 3 per year renewable rain water supply can be retained and remobilized as surface, dams, and groundwater resources. Geologic, seismic reflection, and wireline logging studies are carried out in order to investigate new deep reservoirs of semi-confined and confined aquifers. In this paper, we focused on the study of the Late Oligocene Rupelian-Early Miocene Aquitanian Fortuna sandstones, in the Sahel domain, because of their lack of studies and exploitation in these regions, despite their proven water reservoir potential elsewhere in Tunisia. They represent the semi-confined to confined aquifers. This study involves new seismic approach to highlight the hydrogeologic potential of these levels for their eventual exploitation in the future. Seismic reflection, sequence stratigraphy, tectonics, geology, and hydrogeology are integrated to highlight the identification and the structuring of these multi-layered extended sandstone reservoir horizons.