Subsurface Structural Setting and Hydrocarbon Potentiality of the Komombo and Nuqra Basins, South Egypt: A Seismic and Petrophysical Integrated Study

Sedimentary basins in south Egypt, in particular Komombo and Nuqra basins, have been paid more attention during the last few decades, due to their hydrocarbon prospectivity. The present article is an integrated seismic and petrophysical study aiming at evaluating the hydrocarbon potentiality of the Cretaceous sedimentary sequence in these two basins. Data of four drilled wells including a conventional core, and well log data, in addition to 20 2D seismic profiles (ten for each basin), were studied in detail. The study indicates that the sedimentary sequence in the two basins is represented by the Nubia Sandstone, which is subdivided (from base to top) into Komombo, Six Hills, Abu Ballas, Sabaya, and Maghrabi formations. This sequence in both basins is dissected by a set of NW-SE-trending faults, in addition to a younger set of NNE-SSW to NE-SW trending. The present study indicates that the Komombo Formation is characterized by a good oil potentiality of a net pay thickness up to 65 ft (1 ft = 0.3048 m) in the Komombo basin. The Six Hills Formation may also be prospective, especially near the depocenters of the Komombo and Nuqra basins, due to its wide extension, good thickness (up to 4150 ft), and presence of some oil shows. However, the reservoir of the studied sequence may be of low quality due to cementation with silica, compaction, and the presence of high shale content. Two reservoir rock types (RRTs) were assigned to the Six Hills Formation: RRT1 (clean siliceous sandstone) with good reservoir quality and RRT2 (argillaceous sandstone) with low reservoir quality.

Automated summary

The sedimentary basins in south Egypt, particularly the Komombo and Nuqra basins, have attracted attention for their hydrocarbon potential in recent decades. This study evaluated the hydrocarbon potential of the Cretaceous sedimentary sequence in these basins using seismic and petrophysical data from four drilled wells and 20 seismic profiles. The Nubia Sandstone dominates the sedimentary sequence, with potential oil reservoirs in the Komombo and Six Hills formations, despite challenges such as low reservoir quality due to cementation and shale content.