ABSTRACT: Evaluation of Petroleum Possibilities of Subsurface Lower Miocene Deposits in the Gulf of Suez-Egypt
M. Y. Zein El-Din, M. A. Aboul-Fetouh, N. A. Abdel-Hafez, E. M. Shaltout
The lower Miocene deposits represented in the study area (from base to top) by Nukhul, Rudeis, and Kareem formations are composed of limestones, marls, anhydrites, and sandstones with shale streaks. Core and ditch samples collected from wells drilled in the area were subjected to microfacies analysis, mineralogical analysis using X-ray diffraction and infrared methods, and geochemical analysis (determination of major and trace elements, kerogen type, total organic carbon, pyrolysis, etc).
Microfacies studies of the lower Miocene limestones reveal mineralogical and textural variations within the different limestone bands, prevalence of conditions favorable for development of life. Fossils are commonly badly preserved owing to high crystallization and dolomitization processes. The prevailing climate was arid, hot and dry, and the energy level was mainly thermal.
The X-ray analysis revealed that Nukhul and Rudeis formations were deposited under littoral conditions close to landmass that supplied quartz sands. At the beginning of Kareem Formation, deposition was under littoral conditions in arid climate causing the formation of evaporites, whereas the end of Kareem deposition was marked by shallow-marine environment of the neritic zone close to landmass that supplied quartz sands.
The chemical analysis indicates that Nukhul and Kareem formations were deposited in high salinity environment under oxidizing conditions, while Rudeis Formation was deposited under reducing conditions.
The study revealed also that Rudeis Formation deposits are of very good source potential and have mature composition, while the rocks of Kareem and Nukhul formations have fair source potential and are immature to early mature.
AAPG Search and Discovery Article #90097©1990 Fifth Circum-Pacific Energy and Mineral Resources Conference, Honolulu, Hawaii, July 29-August 3, 1990