Structural assessment of the Belayim formation for future potential CO2 storage, Gulf of Suez, Egypt

Egypt aims to reduce CO₂ emissions by 90.7 million metric tons by 2030, with 65 % of this reduction, equivalent to 1.7 million metric tons of CO₂ equivalent, targeted within the oil and gas sector. To determine whether an oil field can be considered a CO₂ storage site, geological characteristics are a crucial criterion. Therefore, this research focuses on evaluating the structural compatibility of the Belayim reservoir in the Shoab Ali oil field after its depletion for potential future use as a CO₂ storage site. The study utilized 2D seismic lines as well as borehole data to construct a 3D structural model for the targeted units. Three faults were delineated intersecting the Belayim Formation, all inclined in the NW-SE direction with normal slip. Two methods of fault seal analysis, Juxtaposition diagrams and the Shale Gouge Ratio (SGR) algorithm, were applied to identify potential leakage pathways along the fault planes. Fault F2 demonstrates strong fluid trapping potential due to its juxtaposition with the salt of the South Gharib Formation. In contrast, Faults F1 and F3 exhibit greater potential for leakage, attributed to the carbonate self-juxtaposition at the top of the Belayim Formation (Hammam Faraun Member). While Fault 1 and Fault 3 exhibit higher SGR values compared to Fault 2, the depth map of the Belayim Formation reveals a fault-bounded trap defined by Faults F1 and F2, both dipping in the NW-SE direction. The net closure volume is estimated to range from 0.23 × 10⁸ m³ to 0.3 × 10⁸ m³.