Subsurface Interpretation and Pre-Messinian Deposits Prospectivity of the Algerian Offshore Basin

摘要

The Algerian offshore area is located in the western mediterranean sea, East of alboran basin, and south of algero provencal basin. In geological perspective, it covers the area from the narrow continental shelf to the deep basin, water depth range from 0-2800m. Prospectivity is primarily associated with pre-messinian deposits, in addition to Pliocene. The seismic data consists mainly of 2D surveys, with relatively coarse coverage in addition to gravity and magnetic. The 2D seismic coverage acquired in 2011 (5000km) covers the main deep water area. The evaluation of the 2D seismic data has highlighted a number of significant leads with different sizes. They are related to different kind of traps (anticlines, faulted and tilted blocks, …). Only one deep well (4496.5m) and two core drills have been drilled. The onshore geological map reveals the extension toward the offshore of the Chelif basin. The petroleum potential of this onshore basin is proven since the 1940’s with the discoveries of Ain Zeft and Tliouanet oil fields. Reservoirs are expected to consist of sandstones related to Miocene, in addition to the Oligocene (Numidian flyshs) that can be found in the eastern part. The hydrocarbon potential interest in the eastern part could be enhanced by the positive discoveries in the Sicilian channel and also by the proven petroleum system of the Numidian in the onshore part of Tunisia and Algeria (Ain Regada).