Structural Configuration of Middle Miocene Carbonate Buildup and Its Impact on Hydrocarbon Prospection in Central Gulf of Suez Rift, Egypt

Abstract

Abstract The Middle Miocene carbonate buildup is one of the main hydrocarbon reservoirs in the central NE-dip province of the Gulf of Suez rift and this is documented by Ras Gharib, Shoab Gharib, Ras Fanar and El Hamed Oil Fields. Initially, the structural framework and set up of their carbonate buildup reservoir which is known as ‘Nullipore’ was established by the interpretation of the 2D seismic dataset. The present work presents a refined structural model based on the interpretation of 3D seismic, borehole data and field work from the three dimensionally exposed Miocene synrift platform along the uplifted margins of the Gulf of Suez rift. According to the resultant model, structural shaping of the concerning rotated rift block and its carbonate platform was initially formulated by two major synthetic rift-related faults of SW-verging which are named as Gharib and Belayim Coastal Faults (GF and BCF). At the Oligocene early rift phase and to the east of GF, an antithetic fault of NE-verging dissected the hanging wall of the ACF active as a counter fault forming the west Belayim basin and east Gharib horst block with the GF. This was indicated by the symmetry of synrift sediments (Gharandal Group) within west Belayim basin. Continuous basinal subsidence was associated with differential uplifting and erosion of the east Gharib horst block. By the Middle Miocene time, the linked faults segments controlled the lateral and vertical facies variation within the carbonate builds up on the east Gharib horst block. These facies variations are correlated with the Gharamoul carbonates of the outcrops of Abu Share El Qabli and El Bahari on the southwestern margin of the Gulf of Suez. Structurally, three distinct ENE-trending transfer zones were distinguished and named as Northern, Central and Southern Fanar Transfer zones (NTZ, CTZ and STZ). These were expressed by their transfer fault cutoff and offsetting and/or displacement variations of the boundary faults of east Gharib block and preservation of various Nullipore facies and their reservoir units. According to the constructed geologic model, new prospects can be defined within the carbonate platform northward and southward of the present production activity of Ras Fanar Oil Field.

AAPG Datapages/Search and Discovery Article #90194 © 2014 International Conference & Exhibition, Istanbul, Turkey, September 14-17, 2014