Integrated geophysical and geological study and petroleum appraisal of Cretaceous plays in the Western Gulf of Gabes, Tunisia

• Three unconformities have been identified in this area.
• Mapping of the identified unconformities using seismic and well data.
• NW–SE principal trend has been demonstrated in depth maps.
• Important number of prospect and lead has been highlighted.
• The succession of tectonic events helps for migration from source to reservoirs.

An integrated study of available seismic and calibrated wells has been conducted in order to ascertain the structural development and petroleum potential of the Cretaceous Formations of the Western Gulf of Gabes. This study has resulted in an understanding of the controls of deep seated Tethyan tectonic lineaments by analysis of the Cretaceous deposits distribution. Three main unconformities have been identified in this area, unconformity U1 between the Jurassic and Cretaceous series, unconformity U2 separating Early from Late Cretaceous and known as the Austrian unconformity and the major unconformity U3 separating Cretaceous from Tertiary series. The seismic analysis and interpretation have confirmed the existence of several features dominated by an NE–SW extensive tectonic regime evidenced by deep listric faults, asymmetric horst and graben and tilted blocks structures. Indeed, the structural mapping of these unconformities, displays the presence of dominant NW–SE fault system (N140 to N160) bounding a large number of moderate sized basins. A strong inversion event related to the unconformity U3 can be demonstrated by the mapping of the unconformities consequence of the succession of several tectonic manifestations during the Cretaceous and post-Cretaceous periods. These tectonic events have resulted in the development of structural and stratigraphic traps further to the porosity and permeability enhancement of Cretaceous reservoirs.