The local consumption and the high importation cost of the imported bentonite to Egypt lead to find local substitute solutions for economical aspects. Hence, this paper presents composition and activation capability of clays collected fromclaystone quarries in KomOshimarea at El-Fayoum province, Egypt for the application as a drilling fluid (water-based mud). It is an attempt to minimize the importation cost of the imported bentonite to Egypt by a local solution and maximize the usage of the studied clay sediments. The physical, chemical, thermal andmineralogical characteristics of five Egyptian clay samples were studied. The rheological properties of the prepared slurries fromthese samples and their activation characterization during studying the influence of NaOH and POLYPAC-R polymer as activators were investigated. It was found that the non-activated samples canÂt be used as a drilling mud but it could be after the activation process where some significant changes in the rheological propertieswere observed. The experimental results revealed that the activated fitted samples may express as mediumgrade bentonitic clay and this type of clays can be used as a drilling fluid for shallow depth wells.