Flow Behavior and Heat Transmission for Steam Injection Wells Considering the Tubing Buckling Effect

During the thermal recovery process, the tubing string buckles inside the wellbore and leans directly on the casing, which has a significant influence on the heat transmission between the wellbore and its surroundings. In this paper, a unified mathematical model is built to predict the flow behavior and heat transmission along the flow path by considering the tubing buckling effect. A classic tubing buckling model is introduced to determine the tubing-casing contact status. For the noncontact section, the heat transmission calculation follows the conventional "thermal resistance" method, whereas a new approach is proposed for the tubing-casing contact section. The tubing buckling model and the non-isothermal flow model are solved sequentially in an iterative process. The interaction between tubing buckling and non-isothermal flow is analyzed in detail. The results indicate that insulation tubing and telescopic tubing are welcomed in thermal recovery.