Dent Assessment of 16” Pipeline
As part of the project, two off dents, one at the Field Joint and the other one at broken concrete location on 16″ subsea pipeline was performed.
FE Analysis was performed using ABAQUS FE software package to model the dent using a 3D solid model. Metal loss, crack and corrosion was accounted for in the dent. Geometry of the dent was created using ABAQUS CAE and the geometry was analysed by denting with an indenter.
Stresses and strains were extracted from the FE model and were compared against the allowable stresses/strains. Fatigue analysis was also performed in accordance with DNV-RP-C208 to calculate the remaining operational cycles. Recommendations were made to PVGAS in respect of number of operational/shutdown cycles the pipeline could be operated for. Recommendations were also made to use a clamp at the dent location to provide additional safety to the dent to ensure containment of the pipeline fluid in case of failure.