GEOLOGY AND HYDROCARBON HABITAT IN A RIFT SETTING - SOUTHERN GULF OF SUEZ, EGYPT

The southern Gulf of Suez in Egypt is located at the junction of the A frican and Arabian plates, and has excellent hydrocarbon potential. Th e stratigraphic units in the area are grouped into two main megasequen ces, the pre-rift (PreOligocene) and the syn-rift (Oligocene-Recent) l ithostratigraphic units. Gravity, magnetic, seismic and well data were used to delineate outlines of several narrowly elongated northwest-tr ending depositional troughs, separated by structural ridges. Several p re-rift and syn-rift rich source units occur and are mature enough in the deep troughs to generate hydrocarbons. A geochemical study of sour ce rocks and oil samples showed two groups of oil: 1. Gulf of Suez oil s from pre-rift sediments; and 2. southern Gulf of Suez oils from Midd le Miocene carbonates. The reservoirs are also classified into: 1. pre - rift reservoirs, such as fractured and weathered Precambrian basemen t, Nubia sandstone, Cretaceous sandstone and fractured Eocene limeston e; and 2. syn-rift reservoirs such as Lower and Middle Miocene carbona tes and sandstones. Most oil fields in the region have multiple, produ cing reservoirs. The Miocene Evaporite Group forms the primary seal fo r most of the reservoirs, and the shales and dense carbonates of both the pre-rift and syn-rift sections form secondary seals. Trap types in clude structural, stratigraphic and combination traps. The southern Gu lf of Suez, which shares more than one-third of the whole Gulf of Suez reserves, remains high in hydrocarbon potential with many untested pl ays.