Tectonic evolution and hydrocarbon potential of the Aptian series in the Mahdia offshore area, Tunisia

The present study was initiated with the aim to highlight the remaining hydrocarbon potential of the Mahdia area and to guide the future exploration activities.This study was based on subsurface data. Seismic mapping shows that the area is dominated by series of NW-SE horst and grabens. This present day structural configuration is the result of multiple tectonic events which affected the study area from Cretaceous to Quaternary.The active petroleum system of the Mahdia area was proved by the oil discovery of the Mahdia-1 well. The Allam and Aptian carbonates are the main considered reservoirs in the region; the Albian Fahdene formation represents the main source rock of these Aptian carbonates and the overlaying upper Fahdene shale and marls provide their effective top seal.The Mahdia-1 structure appears as a faulted anticline. The migration pathways could be either throw fault plans and/or throughout major unconformities. During Cretaceous to Early Paleogene, the Mahdia offshore area was affected by series of volcanic activities. This volcanism has increased significantly the geothermal gradient and accelerated the source rock maturity.Within the Mahdia area, several prospects and leads remain undrilled and could replenish the operators' portfolio.

► We study the prospectivity of the Aptian series in the Mahdia offshore area.
► Discuss the relationship between tectonic evolution and hydrocarbon trapping mechanism.
► Relative timing of hydrocarbon generation and trap formation.
► Determination of several prospects and leads.