Influência da Flambagem Termomecânica na Otimização de Rotas de Dutos Submarinos

Resumo

The planning of subsea pipeline routes has great relevance for exploration and production projects,
as they ensure a safety operation of subsea systems. With the advance of oil exploration in deep and ultra-deep
waters, which means a rise in the operation severity, where the equipment works in an environmental with high
pressure and temperature levels. These factors can lead the large vertical or lateral displacement in the pipeline
initial condition (as laid), that is because the temperature variations leading to the occurrence of the phenomenon
of thermomechanical buckling. The aim of this work is to study the weight of buckling in pipelines submitted by
HT / HP (high temperature / high pressure) flow in the penalty criteria on submarine pipeline route synthesis and
optimization tools, using evolutionary algorithms. In ways to do a better representation of buckling, the pipelines
are assumed laid on the seabed, subjected to environmental loading as current and passive soil resistance due
the soil mobilization around the pipe, with or without thermal coating, and also with a hot internal fluid. Once the
classic formulation of pipeline buckling proposed by Hobbs is based in an infinite rigid soil, in this work a modified
Hobbs formulation is considered, so this secure that the resistance and all intrinsic penetration soil properties are
represented. Thus, a safety factor indicated in the practical recommendation of DNV-OS-F101 and DNV-RP-F110
is calculated and compared with the limit safety factor pre-established in the project. With the results obtained
by the pipeline section defined in the project, a depth profile graph is generated showing the critical sections
considering the buckling. In this way, the tool assists the designer in the assessment of submarine pipeline routes
considering thermomechanical criteria and environmental factors.