Regional Basement Interpretation and Its Impact on Ordovician and Silurian Structures (Ghadames Basin)

Abstract

Seismic interpretation of southern Tunisia (Ghadames basin) was carried out to identify the relationship between the geodynamic context and the petroleum play of the basin. This study encompasses the elaboration of regional structural maps of the different hydrocarbon bearing reservoirs (Paleozoic). These maps indicate that in Southern Tunisia, Ghadames basin is marked by master NE-SW trending faults interference with E-W and N-S direction. Advanced seismic interpretation (seismic attributes) was applied to evince that the reactivation of the ancient faults (inherited from the basement) played an important role in the structuration of the Paleozoic series. In fact, by using seismic attributes, we can prove that almost all faults affecting the Paleozoic are originated from the basement. We utilize seismic attributes to shed the light on the idea that high number of producing field of Ordovician and Silurian “which are traditionally admitted as purely stratigraphic traps” occur along faults alignment. This explains that these fields are in part the result of a specific depositional environment and in part the result of the basement involvement in the formation of these petroleum fields. This study illustrates that advanced seismic interpretation can provide additional understanding and a new concept about the prospectivity of southern Tunisia.