The hydrocarbon prospectivity of the Egyptian North Red Sea basin

Abstract

Recent work by a multi-disciplinary team has led to a significantly better understanding of the prospectivity of the North Red Sea. New regional biostratigraphic and environmental analysis from north to south through the Gulf of Suez and into the Red Sea have placed the Nubian sequences into a regional chronostratigraphic framework. The Nubian Upper Cretaceous pre-rift sandstones are observed in the field on both the Egyptian and Saudi Arabian side of the North Red Sea. This regionally extensive sequence was deposited in a continental to shallow marine setting fringing the Mesozoic Tethys Ocean, which lay further north. Extensive onshore fieldwork and mapping of sediment input points, fault orientations and fault linkages have helped to develop an understanding of the expected controls on syn-rift sandstone and carbonate deposition offshore. Thick halite with interbedded evaporite and clastics in the Late Miocene sequences of the Red Sea pose seismic imaging challenges. Recent reprocessing and newly acquired seismic data have produced a step change improvement in imaging of the prospective pre-rift section. Petroleum systems modelling incorporating new information on rift timing and crustal thinning as well as onshore core analysis for source rock properties and temperature variation through time indicates that oil expulsion occurs in the inboard section of North Red Sea -Block 1. This is supported by hydrocarbon shows in the drilled offshore wells which can be typed to pre-rift source rocks from stable isotope and biomarker data. All the key elements of the Gulf of Suez petroleum system exist in the North Red Sea. An integrated exploration approach has enabled prospective areas in the North Red Sea -Block 1 to be high-graded for drilling in early 2011.

Reconstructing the level of the central Red Sea evaporites at the end of the Miocene

“…In the map of the S‐reflection surface topography (Figure 6), near to the coasts, where the evaporites are loaded by denser terrigenous sediment, the reflection is commonly strongly depressed. As a result of that loading, diapirs are common in seismic data near to many of the coasts of the Red Sea (Bosworth & Burke, 2005; Colombo et al., 2014; Davison et al., 1996; Gordon et al., 2010; Heaton et al., 1995; Ligi et al., 2019; Miller & Barakat, 1988; Mitchell et al., 2019; Mougenot & Al‐Shakhis, 1999; Richter et al., 1991; Rowan, 2014; Savoyat et al., 1989). However, the Plio‐Pleistocene sediments overlying the evaporites in deep water away from the coasts in the central Red Sea are typically hemipelagic.…”

Geophysical Evidence for Magmatism Southwest of the Brothers Islands, Northern Red Sea (Offshore Quseir, Egypt)

“…3D seismic data were used to interpret the subsurface structural and seismo‐stratigraphic elements of the study area. The database was acquired in 1999 by British Gas and covered 1,600 km 2 offshore central Egypt between Safaga and Quseir and west of the Brothers Islands (Figure 2; Gordon et al., 2010). Time migrated, reflection seismic profiles are organized in NW‐SE oriented inlines and related orthogonal crosslines, 25 and 12.5 m spaced, respectively.…”

“…At and south of Quseir, the Egyptian coast is dominated by a sizable onshore half‐graben generated by a west‐dipping master fault (the “Gebel Duwi fault”) that runs sub‐parallel to the shoreline (Figure 1a). Offshore, the system is complicated by several irregular salt domes and many prominent salt walls that lead to complex structural patterns, especially at depth (Bosworth et al., 2020; Gordon et al., 2010; Mitchell et al., 2019). Faults cut the syn‐kinematic Rudeis, Kareem, and Belayim Formations, as evidenced by interpretations on the published seismic profiles, but the presence of salt challenges the identification of deep structures on the seismic profiles.…”

Birth of an ocean in the Red Sea: Oceanic-type basaltic melt intrusions precede continental rupture

“…The block of 3D seismic reflection data from offshore Egypt (Fig. 1) was acquired in 1999 for BG (Gordon et al, 2010). A few details of acquisition and processing methods are available to us.…”

“…We interpreted a 3D seismic reflection survey of an area west of Shaban Deep, in the African side of the northern Red Sea (Gordon et al, 2010) (Figs 1 and 2), where the summit of a NW-SE elongated uplifted crustal block emerges in the two small Brothers islands (Fig. 2), that…”