The reservoir compartments of Tamiang field, North Sumatra Basin has been properly determined based on the fault sealing analysis. This work is focused on Keutapang Formation particulary on layer 600 m. Tamiang field is a mature field and have been stage of secondary recovery. Therefore, Tamiang field needs strategy to enhance production by applying Enhanced Oil Recovery (EOR). One of the EOR techniques is waterflooding, which is intended to mantain reservoir pressure and increase the oil recovery. Thus, the fault seal analysis become significant information in performing water flooding. The objective paper is to investigate the characteristic of fault in term of sealing or leaking by analyzing the throw, shale gouge ratio (SGR), weigth SGR, and juxtaposition. All these parameters are associated with sealing and non-sealing zone, which is used as the basis to determine water flooding, and to define reservoir compartement. We normalized gamma ray to estimate the shale volume and identified fault properties, by using Allan diagram properties. The analysis result is then validated with production and injection wells data. Taming field has 23 faults with two differences dipping, one dipping fault to northwest and the other to south east. Thus, the fault direction is sinistral with direction from northwest to south east. The result of layer 600 has three compartments reservoir structure from whole fault analysis properties.