Basin Inversion and Mesozoic HC Potential Offshore N. Sinai - Egypt
By
Maher H. Ayyad1
(1) BG - Egypt, Cairo, Egypt
Mesozoic rocks play a significant role in the hydrocarbon system on the NE
African shelf. Sediments are widely distributed, in time and space, over the
entire region and are found to be Oil and Gas bearing in some places. The Early
Mesozoic (Triassic - Early Cretaceous) sediments were deposited under an
extensional tectonic regime in separate half-grabens. The sequence comprises
source, reservoir
and seal type rocks favourable for working hydrocarbon
systems. The Syn-rift clastics, derived from the south, built fan deltas of
variable geometries. Following a prolonged episode of transpressional stresses,
the depocenters inverted and intermittent erosion, with variable magnitudes,
took place. Younger sediments successively on-lapped the truncated surfaces of
the Syn-rift sequence. The regional Mesozoic basin is bounded from the north by
the so-called Pelusium line, in the offshore and runs almost parallel to the
coastline. It approximately coincides with the northern bounding faults of the
Goliath, Mango, NS-21 and Tineh inverted trend. Successive interaction of such
tectono-stratigraphic events obviously disrupted the hydrocarbon system and the
entrapment set-up, one way or another, within the involved sequences.
A thorough examination and clear understanding of the geologic history of
such highly deformed features have been highlighted and proved essential in
assessing the effectiveness of entrapment mechanisms
, thus minimizing
exploration risks.