Heat losses in oil wells can be very significant, especially when comes to EOR Steam injection wells. the loss of thermal energy through the well completion is unavoidable, However, the knowledge of the amount of heat loss is important and can only done if the value of overall heat transfer coefficient is known. This study aims to calculate theoverall heat transfer coefficient and analyze the effect of changing completion design and other parameters inside the well to study the effect of different completion and surface components on the overall heat transfer coefficient. © 2011 IEEE.