Thermal Stress Calculation and Its Application to Bending Angle Design of Flowlines of Subsea Christmas Tree

Based on diverse situations of the flowline of subsea Christmas tree installation and its working conditions, a theoretical model for calculation of the flowline is proposed by taking comprehensive considerations of different influencing factors, such as water depth, temperature of petroleum and gasoline, and angles of the flowline. By using the ABAQUS software, a finite element model for the flowline operating in an oil field in South China Sea is developed for verification of the proposed theory. The analysis and calculation present the variation of the thermal stress with different water depth, different oil & gas temperature and different bending angle of the flowline, and provid a theoretical support for the appropriate bending angle design of the flowline in the specific fields.