Mediterranean Deep-water Tertiary Play Across a Typical Western Desert Domain (Offshore Matruh, Egypt)

By

Hossam Fathy¹, Adel R. Moustafa², Said M. Gouda³, Jan Schreurs⁴, Renaat Demyttenaere¹

(1) Shell Egypt N.V, Cairo, Egypt (2) Ain Shams University, Cairo, Egypt (3) Shell, Netherlands (4) PDO, Oman

 A deep-water (1-3 km) play across the southern Mediterranean shelf north of Matruh City exists in a NNE oriented U-shaped trough. Gravity and magnetic data suggest that this trough extends along the axis of the onshore Matruh inverted basin. This 35-45 km wide trough has steep eastern and western slopes and a northward dipping basal detachment. A 3-km thick sedimentary section of Oligo-Miocene age filled the trough and was later affected by northward gravitational gliding over a thick base Cretaceous shale section (>1400 m thick). Gravitational gliding of the basin fill formed several northward dipping listric normal faults soling down on the basal detachment and associated with rollover anticlines. The top part of these folded rocks was truncated during the Messinian crisis of the Mediterranean and covered later by a thin veneer of post-Miocene sediments.

Structural traps (anticlines and tilted fault blocks) and stratigraphic traps (lenticular bodies on the backside of folds and fault blocks) represent the main plays in the area. Jurassic and Lower Cretaceous shales underlying the trough are good source rocks. NNE oriented faults dissecting these source rocks form hydrocarbon migration conduits into the overlying Tertiary reservoirs. Oligo-Miocene sediments derived from the Western Desert are the main clastic reservoirs and shale sections within the trough are the main sealing rocks.