Integrated Workflow for Petroleum System Analysis: Application to the East Beni Suef Basin, Egypt

Integrating geological and 2D basin modeling of the East Beni Suef Basin, located in north-central Egypt, allows extending burial and thermal history modeling into the deeper parts of the basin, which are not explored by drilling activities thereby evaluating the hydrocarbon potential of the actual kitchen areas. In addition, this regional approach allows us not only to study the hydrocarbon generation potential of the deeper kitchen area but also the migration and accumulation history of the basin. The East Beni Suef Basin (EBSB) is an extensional rift basin, which was initiated following the opening of the NeoTethys and Atlantic oceans and the associated tectonic motion of Africa with respect to Eurasia during the Early Cretaceous. Its stratigraphy comprises five main rock units of mixed siliciclastic-carbonates ranging from the Albian to the Eocene from base to top as follows: Kharita Formation, Bahariya Formation, Abu Roash Formation, Khoman Formation, and Apollonia Formation. The Upper Cretaceous Abu Roash Formation is divided into seven members based on the siliciclastic to non-clastic ratio and includes the main petroleum system elements of the basin, where the carbonate “F” Member is the source rock, while the siliciclastic portions of the “E” and “G” members constitute the reservoir rocks. This study aims to gain insight into the geological evolution of the EBSB and to improve our understanding of its Upper Cretaceous petroleum system, in terms of burial and thermal histories, source rock maturity, and hydrocarbon generation, migration, and accumulation. Thus, an integrated geological and basin modeling workflow was employed, making use of two basin-wide seismic sections, crossing the EBSB in SW-NE and NW-SE directions, and three boreholes with well data. The interpreted 2D seismic lines served as the basis to define the geometrical and structural framework and the development of the subsequent 2D basin modeling of the basin. Modeling results indicate that the Abu Roash “F” source rock maturity ranges from the early oil window at the basin margins to the main oil window in the center. The main phase of hydrocarbon generation occurred during the Eocene after trap formation in the Late Cretaceous. Generated hydrocarbons have migrated both laterally and vertically, most likely from the central part of the basin toward the basin margins, particularly eastward to the structural traps. The model predicts low accumulation rates for the EBSB, which are caused by the ineffective sealing capacity of the overburden rocks and normal faults. In addition to the proven kitchen for the charging of the Abu Roash “E” reservoirs, an additional kitchen to the west of the basin is suggested for the Abu Roash “G” reservoirs. The results of this work can better elucidate the present-day distribution of the Upper Cretaceous accumulations in the EBSB for further successful exploration activities.