Petrophysical and petrographic evaluation of Sidri Member of Belayim Formation, Badri field, Gulf of Suez, Egypt

Abstract

Presence of sandstone streaks in Sidri Member within Belayim Formation that lies between two productive zones; Kareem Formation and Hammam Faraun Member, was the main reason to perform this study. It may represent a good hydrocarbon reservoir and will be added to the Egyptian oil production in some wells of Badri field. This Member has high resistivity signature on Electric-logs responses which attracted the attention to investigate its occurrence in the field, to delineate its distribution all-over the area, to evaluate the petrographic and petrophysical characteristics and to evaluate its productivity. Petrographic and petrophysical analyses of these sand zones were undertaken using thin section samples. The electric logs and subsurface geologic data was used to evaluate the main reservoir characteristics of the Sidri sandstone such as lithology, cementation, shale volume, porosity (Φ), effective porosity (Φ eff), estimated permeability (K), fluid saturation, fluid type and Net pay thickness.This study revealed that, Sidri sandstone facies was classified into two mainly sandy facies; blocky sandy facies which located at the northern part of the field and streaky sandy facies at the southern area of the field. These two facies are separated by shaley facies. Some wells were studied to represent the two sandy facies in Sidri Member and these sand intervals have not been tested yet. These sands consist of quartz grains with grey and pink feldspars as accessory minerals, with siliceous and calcareous cementation, with good porosity. Petrophysical evaluation of this sand unit indicated that it is hydrocarbon bearing formation in three wells and water bearing one in other wells. Electrical logs analysis (Resistivity, Density-Neutron, Sonic and Gamma-Ray) revealed that The volume of shale in this sandstone, the effective porosity, the water saturation, the estimated permeability, the hydrocarbon saturation, and the net-pay thickness are varying from 9 to 13%, 19%–22%, 26%–34%, 200 and 600 mD, 66 and 74%, 20–35 feet respectively. The fluid types are oil, gas and water.