T he need for energy resources is getting higher, on the other hand production is decreasing. One way to overcome this is to find new potential in existing wells. This study aims to determine the fluid content in the study area. The "CD" field research area is located in the West Natuna Basin, Natuna Islands. The main target of the research is Reservoir in Zone A and Zone C with the constituent lithology is sandstone. This study discusses the fluid content in the sandstone layers of Zone A and Zone C, starting from data assessment, and analysis of well data. Log data and core data were analyzed to determine lithology, facies and depositional environment and petrophysical parameters. The results of the analysis are to determine the fluid content of the sandstone layer in the study zone. In the study area interpreted there are three types of facies, including: channel, lacustrine and fluviatile channel. The depositional environment is included in lacustrine. The facies channel has a porosity value of 21% (very good) with water saturation of 37.5%. The fluviatile channel facies has a porosity value of 21.2% (very good) with water saturation of 37.7%. Zones A and Zone C are dominated by fluid with oil content and some contain gas with oil water contact (OWC) in Zones A and C at 2798 Ft and gas oil contact (GOC) in Zones A and C at 3700 Ft.