Facies Analysis and Depositional Environments: A Case Study of the Upper Cretaceous Abu Roash "C" Member in the Karama Southwestern Field,Western Desert, Egypt

Abu Roach "C" Member (ARC Mbr) is an important hydrocarbon-bearing zone in Karama SW oil Field. The geometry and spatial distribution of Abu Roash C sandstone reservoir is a vital objective in the area in order to follow and delineate the reservoir extension for further oil production and field development. This study aims to explain the conditions and factors affecting sedimentological characters of ARC Mbr in the form of depositional model and facies analysis. The procedures have been conducted throughout the sedimentological analysis for mud logs, ditch cutting samples, electro-facies analysis for wire line logs, lithos-facies and routine core analysis of more than 30 feet cored interval against ARC Mbr reservoir, which is mainly composed of shale, siltstone and carbonate with one reservoir unit of sandstone near the base. It is clear that mentioned reservoir was deposited in a near shore environment with slightly high current energy and marine influx facies. Distributary channels of Abu Roash C sandstone are mainly oriented NE SW perpendicular to the ancient shore line in the area. Abu Roash C sandstone reservoir is calculated having an average 25 feet net pay with 22% porosity, 85% hydrocarbon saturation and 15% water saturation.