Nile Delta -- Where is the Oil?

By

Magda M. Nour El Din¹

(1) Shell Egypt, Cairo, Egypt

 With many companies now concentrating their exploration and production efforts on the Nile Delta, new insights into the origin of charge are urgently required. The geological controls on oil versus gas distribution in the Nile delta are also still debated.

Regional geochemistry data together with seepage data (via piston coring and fluid inclusion results) have been used to improve the understanding of the Nile Delta hydrocarbon system - specifically addressing charge, potential source rocks and hydrocarbon typing issues.

The identification of additional prolific source rocks with multiple oil-prone sources in several stratigraphic intervals provides additional working hydrocarbon systems which should provide new exploration opportunities.

The most likely source for gas appears to be a kerogeneous source rock of different maturities. Dry gas found in shallower reservoirs with reservoir temperature less than 70 degrees C and depth less than 2000m, may have undergone a degree of bacterial alteration.

On the other hand, oils are inferred to originate from Tertiary & Mesozoic source rocks, deposited under marine-paralic conditions. The postulated involvement of Cretaceous-Jurassic source rocks in the origin of crude oil is attractive because of the lack of potential source rock and thermal immaturity of Tertiary rocks in some areas.

The overall distribution of oil and gas / condensate is depth- dependent, controlled probably by type of source rock, maturity levels and reservoir conditions.