On-Bottom Stability Study of Non-Metallic Pipeline Due To Hydrodynamic Loadings

In order to prolong the service life, the integrity and stability of the submarine pipeline always been a concern of the oil and gas industry. However, conventional steel subsea are subjected to corrosion in sour service and even sweet service. Inspection of the subsea pipeline are frequently scheduled to ensure the integrity of the pipeline which is very costly. The non-metallic pipeline are introduced to be replacement of the steel pipeline. The non-metallic properties is known to have highly resistance to corrosion yet it also has lighter weight which lead to on-bottom stability problem. Hence, this project aim to determine the minimum weight of chain per unit length for the subsea non-metallic pipeline to be stabilized. The on-bottom stability study will based of DNV recommended practice with the use of finite element analysis package. This project also will include a finite element analysis of the submarine pipeline by using ABAQUS. The water velocity and acceleration are generated from the sea surface wave and current given the sea state in the South China Sea. The weight of chain is determine from the optimization of the simulation. The simulation’s result by using one year return waves and currents show 32.32kg/m of chain can stabilize the non-metallic pipeline with 0.7654 m lateral displacement