oa Structural interpretation of the Oued Gueterini field, Algeria

The small Oued Guetrini field, located in the Tellian Nappes in northern Algeria, was investigated with about 180 wells. Currently this field produces about 3,000 cubic meters/year of light oil. The field is situated between two deep faults (pre-Atlasic and Tellian faults) in an extremely complex geological setting involving thrust and collapse tectonics. Because of the complex tectonic setting the search for other fields in the area has not been successful.. Two structural models were previously considered for the evolution of the region. The first related the deformation to gravity tectonics (collapse structure) using the theory of allochthonous rock masses (Kiken, 1977). The second utilized a major deep detachment fault along a basal Triassic shearing-plane (BP, 1994; IFP 2005). Our structural interpretation of the seismic data showed that the zone is much more complex and that three detachment planes occur. The interpretation revealed that a combination of thrust and gravity tectonics affected the sedimentary cover (mixed model involving collapse and thrust features). The two tectonic regimes produced a ridge involving progressive deformation with a constant constraint direction. Nappes were emplaced during two stages: (1) thrust tectonics along deep detachment faults<br>during the Triassic-Jurassic and Aptian-Albian; and (2) collapse tectonics related to the Bibanics Uplift. With this model it is possible to develop new plays.