Contribution of Outcrop and Seismic Data for Better Understanding of Hydrocarbon Potential in the Egyptian Red Sea Basin

Abstract

Abstract The main objective of this paper is to provide new insights on the structural architecture and hydrocarbon potential of the Egyptian Red Sea basin. Interpretation of the long-offset (12-km offset, 14-s record length) broadband 2D regional seismic survey acquired over the Egyptian Red Sea in 2018 has improved our understanding of the structural elements affecting this Late Oligocene-Early Miocene rift basin. The Subsurface evaluation is complemented with surface geology, Landsat images, geochemistry data, and compilation of vertical stratigraphic sections from field excursion to the Gebel Duwi and Safaga-Quseir districts along the Egyptian Red Sea coast. The surface analogues of these areas offer distinctive model for the syn- and pre-rift structural and stratigraphic pattern, which has significant control on equivalent successions extending in the offshore. Integration of surface and subsurface geology provided coherent pattern of the fault complex and the structural relations of fault linkage and transfer zones affecting the Precambrian basement rocks. Seismic cross sections and subsurface mapping of top basement show large rotated fault blocks bounded by NW-SE master faults (Clysmic trend) and dissected by NE-SW fault system parallel to the Aqaba fault trend. The syn-rift sedimentary successions attain an average thickness of ~4,500 m in offshore penetrations. The pre-Miocene potential source rocks are proven from the tunnels, mines, and cores along Red Sea onshore area in Egypt's Eastern Desert. These source rock intervals are sporadically cropping out in the Gebel Duwi area. Equivalent successions extending in the offshore are anticipated to be preserved in the depocentres and minibasins. This is supported by seismic reflection data and offshore penetrations. The thick Middle Miocene reefal and shelf carbonates exposed in Ras Benas area, or their offshore marine equivalents, may act as additional source and reservoir rocks. The Middle Miocene reservoirs exhibit oil and gas shows and reservoir quality with porosity ranges between10-15%. The South Gharib massive salt intervals provide the high capacity top and lateral sealing in addition to the fault seal juxtaposition of shale intervals. However, further understanding of the subtle stratigraphic traps and reservoir distribution in the pre-salt successions can be improved by evaluating the newly acquired 3D seismic data (during 2022 and 2023), which cover ~12,000 km2 in the northwestern Red Sea. These data improved the subsalt seismic imaging. Therefore, Comprehensive 3D seismic interpretation and drilling of exploratory wells are essential in the next step toward successful exploration of the Egyptian Red Sea basin.