Abstract
offshore Basin represents one of the most important basins in Libya, It covers are an area a large part of the Tripoli-Gabes Basin , and a contains main structures as " B " which know Bouri Filed and ‘Bahr Essalam’ area ( NC41 ) is known as " C "structure and located in the North-western offshore Libya. The Metlaoui group (El-Garia Formation ) is main reservoir ( Lower Eocene age) in Bahr Essalam Field , consists of Nummulites limestone and tidal dolomites witnessing a regressive pulse in the basin evolution Limestone with average thickness more than 500 feet. The main purpose of this study is to evaluate and investigated the petrophysical characteristics of El-Garia Formation in Field , Bahr Essalam Field through the analysis of well log data available for five wells distributed in Concession NC41. The well logs signature indicate, the limestone is main lithology. With 16-22% Average porosity and 9.1% average water saturation with 198 ft average net pay . In this study the repeat formation test was used for delineate type of hydrocarbon ,the result indication the gas represent the main type of fluid .