الفهرس 
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Abstract
Oligocene sands in northern Egypt are one of the most important economic assets due to their great hydrocarbon potentialities. The recent huge emerging field discoveries in the offshore Mediterranean have turned all eyes to this province. The importance of Oligocene sediments is represented in either being source rocks producing Natural gases or acting like reservoirs in the Nile Delta province.
On the other hand, Cenozoic sediments hold within it the key to solve a century-established controversy over the Nile history. The real debate is about the timing of the connection between the Ethiopian plateau and the Mediterranean. In another way, the question was when the Nile River started to bring its sediments from Ethiopia? Whether it was at Oligocene or later times. Answering such question aid in a better understanding of the different fairways of Nile cone sediments, which subsequently achieves the maximum benefit of these sediments by mapping out the potential reservoirs.
The current study aims to investigate the provenance of the Oligocene sandstones exposed at Gebel Qatrani Formation at the Fayum province and analogues subsurface Oligocene sandstone intervals cored from 2.7 to 5.12 Km at the Nile Delta. The analysis and quantification of heavy mineral assemblages revealed that the two sites maintain similar heavy mineral suites but with variable concentrations and different patterns. The provenance reliable heavy mineral indices indicate that the exposed Oligocene sandstones at Gebel Qatrani Formation are much more mature than those of the Oligocene sandstone intervals at the Nile Delta. Gebel Qatrani Formation consists of three members lower, middle and upper. The lower and the upper members of Qatrani Formation display heavy mineral contents indicating more maturation than the middle member which reflects an influx of less mature sandstone. The middle member may reflect a tectonic reconfiguration of the hinterland during its deposition. The reliable heavy mineral indicators of the Oligocene sandstones at the Nile Delta maintain their higher values at different depths along the entire wells indicating a significant rejuvenation of the source area and hence sand supply from a source(s) that was not far distance. In contrast, Habbar-1well sand samples (cored from 3.8 to 4.5 km) display the highest pyroxene values along with considerable contents of amphibole, mica, sillimanite and kyanite indicating transport from a shorter distance source including a metamorphic one. Thirty seismic cross sections are interpreted and used to construct isopach maps which revealed the diagenetic effect of the heavy mineral suits with depth. That will subsequently affect the reserving characteristics of Oligocene sand intervals. Moreover, the available complete log sets of four wells were used to evaluate the reserving characteristics (shale volume and parameters, porosity estimation, water and hydrocarbon saturation and reservoir evaluation) of the Oligocene interval (the Dabaa Formation) in the Nile Delta and offshore Mediterranean. according to the estimated petrophysical parameters, the Oligocene intervals in Habbar-1 and Port Fouad Marine Deep-1 wells are very promising with a total net reservoir thickness 302.9m and net pay thickness 135.64m.