3D Reservoir Geometry, Environments and Sequences - A Model for Jurassic Rift Systems - Gebel Maghara, North Sinai, Egypt

By

Mohamed Darwish¹, Nazih Tewfik², Djin Nio³

(1) EREX Consultant, Cairo University, Cairo, Egypt (2) Earth Resources Exploration, EREX, Cairo, Egypt (3) Enres International, N/A, Netherlands

 Gebel Maghara, a NNE-oriented doubly plunging anticline, in Northern Sinai, has the thickest and complete Jurassic outcrop (~ 2200m) of alternative clastic and carbonate sequences. Three-dimensional outcrops offer typical models of detailed field observations and measurements of the fluvial to shallow marine sands being developed during the successive rifting stages. In the Early stage of Jurassic rifting, fluviatile to fluvio-lacustrine sequences were accumulated that were flooded by the organic-rich shallow marine carbonates.

Syn-depositional tectonics continued during the Middle Jurassic and resulted in block faulting, tilting and rotation that controled the deposition of deltaic and shallow marine sand bodies. The tectono-stratigraphic events lead to the lateral shift of the depocenters, sand-bodies progradation and partial stacking.

Sequence stratigraphic and Cyclostratigraphic concepts were applied where systems tracts and flooding surfaces could be defined and correlation marker events were elucidated. The events are not only relevant to the understanding of the petroleum geological aspects of the eastern Mediterranean area of north Western Desert and North Sinai ; but also for other Jurassic rift basins as the case of the North Sea. Relationship to Jurassic sedimentary section of the Arabian Gulf will be discussed.