New stratigraphic hydrocarbon prospects for the subsurface Cretaceous: tertiary succession within Abu Gharadig Basin in the framework of sequence stratigraphic analyses, north Western Desert, Egypt

The Abu Roash Formation (late Cenomanian-Coniacian) signifies one of the potential hydrocarbon reservoirs in Abu Gharadig Basin, northern Western Desert. This paper aims to carry out sequence stratigraphic analyses (based on seismic and well logs data) as well as petrophysical appraisal for Abu Roash Formation within Abu Gharadig field, eastern Abu Gharadig Basin. The sequence stratigraphic analysis exposed that Abu Roash Formation is classified into six (third) order depositional sequences: SQ-1 (Abu Roash G Member), SQ-2 (Abu Roash F and Abu Roash E Members), SQ-3 (Abu Roash D Member), SQ-4 (Abu Roash C Member), SQ-5 (Abu Roash B Member) and SQ-6 (Abu Roash A Member). The seismic interpretation step revealed that the study area is affected by ENE-WSW anticline plunges toward the NE direction and that this anticline segmented by NW-SE normal faults reflected the impact of the Late Cretaceous dextral wrench tectonic on the sedimentary basins located in the northern Western Desert, including the Abu Gharadig Basin. The petrophysical appraisal has exposed the presence of three oil-rich intervals in the study area. The first interval is located within the sandstones of the highstand systems tract of SQ-2, the second oil-rich zone occurred in the limestone of the transgressive systems tract of SQ-3, and the third favourable oil zone is associated with the sandstones of the transgressive systems tract of SQ-4. Taking into consideration the lack of the structural closures in the mapped horizons of the sequence boundary-3, sequence boundary-4 and sequence boundary-5, it is expected that the interpreted oil zones represent potential stratigraphic traps rather than structural traps. The outcomes of this study will improve the development of the Late Cretaceous stratigraphic plays in Abu Gharadig Basin in addition to the neighbour sedimentary basins in the northern Western Desert.