Abstract Recoverable reserves in approximately 320 fields in Libya's Sirt, Ghadamis, Murzuq, and Tripolitania Basins exceed 50 billion barrels of oil and 40 trillion cubic feet of gas. Approximately 80% of these reserves were discovered prior to 1970. Since then, there has been a less active and more conservative exploration effort. Complex, subtle and, in particular, deep plays were rarely pursued during the 1970s and 1980s because of definitive imaging technologies, limited knowledge of the petroleum systems, high costs, and risk adversity. Consequently, extensive undiscovered resources remain in Libya. These resources could be accessed if geologic and geophysical knowledge, innovation, and advanced technologies were used effectively. Three-dimensional seismic acquisition will be required to some degree for reliable trap definition and stratigraphic control. Predictably, most of the undiscovered resources will be found in the vast, underexplored deep areas of the producing basins. Six areas are exceptional in this regard: the south Ajdabiya trough, the central Maradah graben, and the south Zallah trough–Tumayam trough in the Sirt Basin, and the central Ghadamis Basin, the central Murzuq Basin, and the offshore eastern Tripolitania Basin in the west. These highly prospective basin sectors encompass a total area of nearly 150,000 km 2 , with an average well density for wells exceeding 12,000 ft of 1 well/5000 km 2 .

Abstract The integrated use of the geological, geophysical, and geochemical data of northern Tunisia onshore and offshore led to an inversion model from the Tethyan rifting and subsequent evolution of the North African passive margin to the Late Cretaceous–Tertiary orogeny, inducing the fold and thrust belt and associated foreland deformations. Respective deposits characterize each tectonic cycle; Triassic synrift and Jurassic-Cretaceous open-marine series are related to the Mesozoic opening, and Paleogene–Neogene clastic sequences are closely controlled by the Tertiary shortening. For hydrocarbon prospectivity and despite its early stage of exploration, this domain could be considered as an emerging area with encouraging ingredients, particularly three fractured carbonate reservoirs, two sandy reservoirs, five source rocks, and numerous potential structural and stratigraphic traps. The main feature in this area is the close relationship between the Tertiary tectonics and the evolution of the petroleum systems. Hence, the Numidian turbidites identified both as reservoir and source rock were deposited in a foredeep directly generated by the Paleogene thrusting and later displaced as far-traveled nappes above the Ypresian fractured limestones defined also as a source rock and reservoir. The maturity of these source rocks is closely related to the nappes displacement, which assumes the overburden and increases the heat flow. Fracturing is also generated by these events.