Structural regime and its impact on the mechanism and migration pathways of hydrocarbon seepage in the southern Gulf of Suez rift: An approach for finding new unexplored fault blocks

• At Gebel El-Zeit, Gulf of Suez rift, a natural active seepage zone of oil occurs on the land surface.
• An integrated geological and geophysical study was achieved to put up a reasonable origin of the onshore active oil seep.
• The study proves the existence of an unexplored fault block which may has been charged by the migrating oil.
• The original oil in place of the predicted reservoir is estimated to be more than 47.5 MMBO.

A Natural active oil seepage occurs at the intersection of the NW-oriented rift coastal fault and a NE-oriented cross fault which bound the southwest dipping Little Zeit tilted fault block at the southwestern side of the Gulf of Suez, Egypt. Detailed surface geological mapping followed by subsurface mapping using aeromagnetic, seismic and borehole data of Ras El Ush oilfield (the nearest oil field to the seepage) provide a reliable hydrocarbon migration pathway model of the area.The proposed model suggests that hydrocarbons migrated upward at the intersection of a NE-oriented and the NW-oriented rift coastal faults where they found their way to the surface. The Nubia Sandstone occurs south of Ras El Ush oilfield in a trap door structure and probably entrapped some of the migrating hydrocarbons while a probable oil-water-contact at −1000 m which resulted into the migration of hydrocarbon through the damage zone of the northeast fault.The original oil in place of the predicted reservoir is estimated to be more than 47.5 MMBO which encourages the design makers for more investigation of this reservoir to increase its certainty and putting it in the plan of the future investments.