A Study of Microfacies and Petrophysical Analysis of Some Subsurface Cretaceous Rocks of Abu Gharadig-34 Well, Western Desert, Egypt

Abstract

The main aim of this study is to shed light on the microfacies association, petrophysical parameters, and depositional environment of different rocks such as sandstone, limestone, shale, siltstone, and dolomite of subsurface Cretaceous rock units (Abu Roash “C” member, Abu Roash “E” Member, and Bahariya Formation) from Abu Gharadig-34 well in the north western desert, Egypt. In this study, nine microfacies were identified. These microfacies include calcareous siltstone, bioclastic wackstone, ferruginous sublithic arenite, dolomitic lithic arenite, lithic arenite, fossiliferous bioclastic wackstone, glauconitic dolomitic sublithic arenite, ferroan dolomite, and ferruginous sandy siltstone. Generally, subsurface Cretaceous rock units are deposited in different depositional environments ranging from tidal flats to open circulation passes through restricted circulation shelves. Statistical analysis of the petrophysical data showed that the highest porosity was concentrated at Abu Roash “C” member, which had very good porosity and high permeability. The porosity increased when the bulk density decreased. The permeability of the studied samples was the same as the porosity, which increased when the bulk density decreased. It can be concluded that Abu Roash “C” member is a good reservoir in the Abu Gharadig-34 well.