 The Yamama formation in the Ratawi oilfield of Basra city, southern Iraq consists of seven main faces and several secondary faces. These faces are characterized by their grain or mud supported or on the appearance of the configuration. They are further classified based on their appearance under a microscope and compared to the well locks to identify their electrophyses. The formation has been divided into several environments depending on the faces and electrophyses characteristics of the formation, including a lagoon environment, open marine environment, shoal environment, and slope environment. This article was authored by Isra A. Eliasa and Wang Ji-jong.