The Influence of Incipient Rift Geometries on Early Syn-Rift Deposition in the Suez Rift, Egypt

By

Karl G. Henck¹, Mohamed Ramzy²

(1) BP, Cairo, Egypt (2) Gulf of Suez Petroleum Co, Cairo, Egypt

 Syn-rift deposits are primary exploration targets in the Suez Rift, Egypt. In the southern Suez Rift, the Nukhul Formation records early syn-rift deposition and is an important exploration target and major producing zone. Production from the Nukhul Formation in the Hilal, East Zeit, and Shoab Ali fields averages 4 million barrels of oil per well. However, Nukhul sand thickness is highly variable and predicting the distribution of Nukhul sands within individual fields much less between fields is difficult. Defining the depositional setting for these sands is critical to opening this play for future exploration.

Deposition of the Nukhul Formation appears to be controlled by pre-rift structural fabrics. High-resolution magnetic data calibrated by subsurface well data and 3D seismic provides a tool to identify and model the initial rift geometry. The data indicate that early faults defined a system of NE-SW striking horsts and grabens, possibly related to earlier Syrian Arc or Precambrian basement features. As rifting progressed, exploitation of the older trends was abandoned in favor of dip slip movement related to the principle extension direction. Large scale rift-parallel oriented (NW-SE striking) normal faulting that dominates the Suez Rift basin has subsequently overwhelmed and masked the incipient, Nukhul-age, rift geometries.