Estudio de trabajo a fatiga en ductos marinos para una unidad flotante de producción, almacenamiento y descarga (FPSO) usando un sistema pasivo de compensación de rolido : análisis estático o cuasiestático en ductos marinos con elementos finitos.

Abstract

The production, storage and offloading units (FPSOs) have the objective of store the hydrocarbons produced on the seabed. This floating unit contains balcony risers, which are pipelines with an attachment point at the top of the duct and a contact point in the seabed. In this project, a preliminary design of the pipeline and a finite element model for a J-type configuration were carried out, which was realized a static and quasi-static analysis. The purpose of each analysis is to find the stresses and strains produced in the curvature zone and attachment point of the riser. For a static tension of 0.88 MN, a maximum stress of 36.51 MPa and a maximum strain of 6.4𝑥10−4 were obtained at the attachment point. On the other hand, a maximum stress of 109 MPa and a maximum strain of 9.6𝑥10−4 were obtained at the curvature zone. With a study where the tension was varied, a critical case was obtained. The simulation of this critical case was carried out with a tension of 1.144 MN; where a maximum stress of 74.85 MPa and a maximum strain of 7.8𝑥10−4 were obtained at the attachment point. On the other hand, a maximum stress of 134.69 MPa and a maximum strain of 1.17𝑥10−3 were obtained at the curvature zone. Using results from the static analyses, it observed that the stresses and the unit strains decrease 23.5%. In addition, it indicated that the most critical section of the riser is the curvature zone.