Finite Element Analysis of Subsea Pipe-in-Pipe Installation with Reel-Lay

The installation procedure with reel-lay was simulated numerically for a pipe-in-pipe (PIP) in an oil field of 1500 m in water depth. The interaction between the carrier pipe and the flowline was studied by carrying out plane strain analysis of PIP cross-section. Accordingly, the relationship between contact force and displacement was equivalent to the nonlinear contact property between the carrier pipe and the flowline. Finite element model was set up to simulate the installation procedure of PIP with reel-lay. The aims are to investigate the load effect and elastic-plastic deformation of PIP and quantify the thickness reduction of insulation layer between pipes during installation process. The results show that most of the tension force is taken by the carrier pipe. Moreover, it is found that two cycles of elastic-plastic stress and strain occur with the maximum accumulated plastic strain of 4.13% and 5.07% for the flowline and the carrier pipe, respectively. The maximum thickness reduction of the insulation layer after installation is 26.2%. ©, 2015, Tianjin University. All right reserved.