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Five crude oils from some producing wells in the southern part of the Gulf of Suez were characterized using a variety of organic geochemical parameters. The results reveal significant differences within the oils from the Gulf of Suez basin that suggest two oil types and one mixed type. Type 1 oils from Ras Fanar and East-Zeit fields show a high relative abundance of gammacerane indicating a marine saline-source depositional environment. Another related feature of these oils is the predominance of C 35 over C 34 17α( H )-homohopanes. Type 2 oils from Gama and Amal-9 wells show oleanane indices over 20%, indicating that they originated from an angiosperm-rich, Tertiary source rock. Type 3 oil from Amal-10 well has geochemical characteristics intermediate between those of types 1 and 2. This may reflect mixing of oils from the sources of both types 1 and 2. The geochemical characteristics of the oils vary sufficiently to suggest multiple sources. The type 1 oils possess geochemical characteristics consistent with Upper Cretaceous Brown Limestone or Lower Eocene Thebes Formation carbonate source rocks. Type 2 oils are very similar in geochemical character to the Lower Miocene Rudeis Formation source rocks.

Four groups of rocks, having more than 0.5% of organic carbon are defined within the subsurface section of Rahmi area, Gulf of Suez. The deduced types of indigenous kerogen are: algal-amorphous, inertinite-woody, and herbaceous. The algal-amorphous kerogen of Rudeis/Nukhul Formations (Lower Miocene), Eocene and pre-Eocene rocks is recognized as being oil prone, that is having high capacity for generating oil. The application of hydrocarbon liquid window concept shows that the LOM values fall within the range from 8.6 to 10.8, and the thermal alteration index for the different units is not extended into oil generation window, where it ranges from immature (Kareem Formation-Lower Miocene), to moderately mature (Paleocene), to the beginning of the thermal phase of oil generation (Senonian). The vitrinite reflectance values indicate a low level of thermal maturity. The formational temperatures increase towards the depocentral part of the basin and eastwards to the present Gulf of Suez. The thermal maturity index increases towards ancient stratigraphic units. The study of organic richness, quality and maturity revealed that, where the Nukhul, Eocene and Senonian rocks are buried deeper in the study area, would have been excellent source rocks for oil.