Petrophysical Characteristics of the Nukhul Clastic Formation in The Southern Province of the Gulf of Suez, Egypt

Abstract

The Nukhul reservoir (Lower Miocene) representing the most prolific target in the Gulf of Suez that deposited during the early stage of the Gulf rift with gross thickness reach to 140 ft. The lithofacies of the Nukhul reservoir in the study area could be differentiated into two facies 1) Shaly carbonates that is represented by zones 1and 3 which reflecting non reservoir intervals, 2) sandy facies that is
represented by zones 2 and 4 which reflect a small pay zones intervals localized mainly within the sandstone beds. The present work is achieved by analysis of the well logs and core samples data sets. The petrophysical analysis of the detected lithofacies types of Nukhul reservoirs reflect that sandy facies (zone 2 and 4) show that the shale content has minor amount by a wetted average values ranges
(4% - 5%), whereas the effective porosity is recorded with high values (19 % - 20%) , indicating a reversible trend between shale and porosity. The average permeability ranges from 111.4 md to 245.5 md. The water saturation value ranged between 31 % and 21%. The hydrocarbon saturation is represented with average 69 % and 79 %; The pay zones yield 14 ft and 10 ft for zones 2 and 4 respectively. The sandy intervals (zone 2 and 4) are characterized by high gas records during drilling. Conversely, the shaly carbonates facies (zones 1 and 3) reflected the bad petrophysical properties. Petrophysical characters of Nukhul reservoir including Vsh, Phie, Sw, So and net pay thickness are represented vertically by constructing the litho-saturation crossplot.