By Sigrún Stanton
Part of the Spotlight Series
The long anticipated Offshore Red Sea International Bid Round 2019 has been launched and includes acreage for ten blocks in the Egyptian Red Sea (Figure 1), introducing new investment opportunities to the region. The closing date for the submission of bids is August 1, 2019.
The prolific Gulf of Suez Basin forms a northerly extension to the much larger, yet underexplored, Red Sea Basin, but shares key petroleum system elements of this petroleum province. Previous exploration in the Egyptian Red Sea has been limited and there are no commercial discoveries. However, oil and gas shows suggest that an active petroleum system is in place. Recent exploration along the Saudi Red Sea margin has led to several gas discoveries within pre-salt plays. Using the Neftex® Insights portfolio and regional analogues, we shed light on the potential plays that might be developed in this area.
Pre-rift Cretaceous (Nubian) sandstones charged by pre-rift Late Cretaceous marls and shales (Duwi Formation)
Syn-rift sandstones charged by the Duwi Formation or syn-rift Miocene marine shales (Rudeis Formation)
Syn-rift carbonates charged by the Duwi Formation and/or the Rudeis Formation.
Structural mapping and source-to-sink analysis were used to predict the likely distribution of reservoir sandstones outlined above. Analogues from the Gulf of Suez suggest that the largest modern-day catchment areas will likely dictate the distribution of the thickest syn-rift reservoirs in the Egyptian Red Sea.
A critical, still unresolved issue is the occurrence of Cretaceous pre-rift reservoirs and source rocks. Geochemical analysis of oil shows in offshore wells suggests that oils can be typed to both pre- and syn-rift source rocks (Gordon et al., 2010). Although Nubian sandstones and Cretaceous source rocks are prevalent along the onshore Egyptian Red Sea rift shoulders, offshore wells (e.g. Quseir A-1X) have yet to penetrate the Cretaceous, largely because the few wells that penetrated basement in the Red Sea were drilled on fault block highs. New play types in the Egyptian Red Sea are potentially located in the hanging walls of basin bounding faults. These play types would compare with the Kingfisher Field of Uganda and Ngamia Field of Kenya. Overall, the prospectivity of the Egyptian Red Sea is good, with the Gulf of Suez providing a suitable analogue. Fundamental differences in structural and thermal histories between the two sectors means that comparisons must be undertaken with caution. High and variable heat flow, variable burial depths and thick, mobile salt deposits likely contribute to significant variation in source rock maturity and uncertainties with charge. The exploration of pre-salt plays is likely to be complicated further by difficulties in seismic imaging beneath the salt.
(Map showing the distribution of existing wells in the Egyptian Red Sea, indicating those with hydrocarbon shows and dry holes. The 2019 license blocks and hydrocarbon fields in neighboring basins are displayed).