Mechanism of Oil Entrapment in Wadi Rayan Field, Western Desert, Egypt

By

M. Naguib El Gamry¹, Ali Khairy²

(1) Qarun Petroleum Company, Cairo, Egypt (2) Qarun Petroleum Company, N/A, Egypt

 A model for the trapping mechanism of Wadi Rayan field is presented in this study in order to throw light on the importance of the Cenomanian Abu Roash “G” Member as a good reservoir in the Western Desert of Egypt. Analysis of the borehole and seismic data of the field has shown that stratigraphic and structural factors are of equal importance in the trapping mechanism. The most pronounced stratigraphic factor is represented by a NW-SE oriented channel system in the Abu Roash “G” Member. The depositional model for the sandstones in this channel system is tide-dominated river estuarine system. Estuaries are highly efficient sediment traps and their deposits have high preservation potential because of their location within paleovalleys. As to the structural factor, the Wadi Rayan platform area was subjected to the Syrian arc compressional deformation that affected northern Egypt during the Mesozoic, up to late Senonian time. As a result of this compressional deformation, a NE-SW oriented fold was formed in the hanging wall of a reverse fault. In addition, E-W to ENE-WSW oriented faults of Precambrian age were rejuvenated by dextral wrenching.