Fault-Propagation Folding in the October Field, Northern Gulf of Suez, Egypt

By

 Tamer Mohamed Reda¹, Adel Ramadan Moustafa², Ali Mohamed Abd-Allah³, John Dolson⁴

(1) Gulf of Suez Petroleum Company, Cairo, Egypt (2) Ain Shams University, Egypt (3) Ain Shams University, Cairo, Egypt (4) BP, Egypt

 A detailed study of seismic and well data of the giant October Field in the northern Gulf of Suez, Egypt shows a steeply dipping monoclinal western flank dissected by normal and reverse faults. A major southwest dipping rift parallel normal fault, formed during early rifting, dissects pre-Miocene (pre-rift) rocks, forming the western (up dip) boundary of the field. Upward propagation of this fault through the overlying, predominantly ductile Miocene syn-rift rocks at later stages of rifting is accommodated by a fault-propagation fold.

Although the monoclinal flank of this fold is dissected by steeply dipping normal faults and a few reverse faults, the predominantly shale-rich syn-rift section acts as a good lateral seal for pre-Miocene reservoirs of the field. Fault-propagation folds are a common structure bounding the updip side of several tilted fault blocks in the rift on the surface and in the subsurface. Similar folds have previously been mapped on the Sinai Peninsula, the eastern exposed margin of the Suez rift. We compare and contrast these outcrop features with those of the subsurface at October Field.