This research focused on re-assessment for Sarhit and shdeha fields in Euphrates graben. The two fields is mainly anticline structure which is consist of two horsts Sarhit and Shdeha fields separated by a graben Sarhit. Nine wells has been drilled in Sarhit field, and eleven wells in Shdeha field, all the wells are producers, except (SHD111). The research based on new seismic interpretation using GeoFrame program. Create new velocity models using two different methods (linear regression, V0K algorithm), using Petrel program. To confirm the study results, we created geological models for each velocity model, then calculated the Stuck Tank Oil Initial In Place (STOIIP), and the recovery factor (RF), for each field. The first chapter summarized the geology of Euphrates graben, and general information about the two fields including: the geology of study area and reservoir properties. More over the research objectives and the data availability. The second chapter consist of structural seismic interpretation in terms of traditional workflow (horizons and faults interpretation), and created seismic attribute maps. The third chapter: the waves and seismic velocities overview. Build velocity models using two different methods: linear regression, v0k algorithm. Then for each velocity method, we built geological model, calculated the STOIIP and RF, for each field. As a result we have noticed a decrease in the RF for the two fields by using V0K algorithm, comparing with linear regression method. Chapter four: results and recommendations