The pipeline engineering students at Cranfield University are using SAGE Profile to explore new frontiers for their group projects and master theses. Recently, a group of motivated students has successfully completed an assignment on the prediction of susceptibility to upheaval buckling for buried pipelines. In addition, master theses are on-going to investigate structural reliability of free spanning pipelines, dynamic loading in SAGE Profile and the simulation of pipe-in-pipe systems.
SAGE Profile used for Fatigue Analysis of Free Spans Subjected to VIV
Vortex induced vibration is a major cause of fatigue failure in submarine oil and gas pipelines and steel catenary risers. In their paper “Fatigue Analysis of Free Spanning Pipelines Subjected to Vortex Induced Vibrations”, dr. ir. Filip Van den Abeele and ir. Frédérique Boël, present a case study from the offshore industry, in association with Shell Exploration & Production. For a deepwater pipeline in the Gulf of Mexico, the remaining fatigue capacity of a long slender span subjected to VIV was analyzed using the DNV-RP-F105 span check offered by SAGE Profile. This powerful capability provides a quick and easy tool to evaluate the severity of free spans for a given pipeline route, and hence can save a tremendous amount of time and money associated with seabed rectification.
In this paper, an integrated numerical framework is presented to predict and identify free spans that may be vulnerable to fatigue damage caused by vortex induced vibrations (VIV). Sensitivity analyses are performed to study the influence of the seabed conditions, where special emphasis is devoted on the selection of pipe soil interaction parameters.
The paper has been presented at the International Conference on Offshore Mechanics and Arctic Engineering (OMAE 2013).
>> Read more – 2013
Journal of Pipeline Engineering covers SAGE Profile simulations
The December 2012 issue of the Journal of Pipeline Engineering presents an overview of numerical modelling and analysis for offshore pipeline design, installation, and operation. SAGE Profile 3D is used to demonstrate the added value of numerical modelling as a design aid and decision tool throughout the entire life of an offshore pipeline.
In their article on ‘Numerical Modelling and Analysis for Offshore Pipeline Design, Installation and Operation’, SAGE Profile experts dr. ir. Filip Van den Abeele and ir. Raphaël Denis present case studies on pipe-soil interaction, free span evaluation, lateral buckling, upheaval buckling and pipeline walking. This comprehensive review demonstrates the versatility of finite element methods as a powerful support tool in offshore pipeline design.
>> Read more – 2012
New generation pipeline analysis software
SimPipe, an explicit finite element solver was developed to power SAGE Profile 3D
The mandatory initial stage of any pipeline analysis consists of laying the pipeline on the seabed.
A realistic and computationally efficient approach was adopted to model this laying process onto a 3D seabed with the assistance of digital terrain modelling (DTM) techniques. Advanced tools (e.g. a customised graphical display) were developed to rapidly locate problem areas and re-route the pipeline.
Advanced pipe-soil interaction models in finite element pipeline analysis
Offshore pipelines laid on the seabed are exposed to hydrodynamic and cyclic operational loading. As a result, they may experience on-bottom instabilities, walking and lateral buckling. Finite element simulations are required at different stages of the pipeline design to check the different loading cases. Pipeline design is dependent on accurate modelling of axial and lateral soil resistances (Bruton, 2008). The pipe-soil interaction of surface laid pipelines is still too often modelled using single frictional factors in the axial and lateral directions. These assumptions are too simplistic, especially in soft deepwater clay. Improved modelling of the pipe-soil interaction can help significantly reduce costs through optimising pipeline design.
Based on recent research, these simple models were improved and implemented in a finite element software program for pipeline analysis, to better simulate the pipe-soil interaction of surface laid pipelines and to more accurately simulate full routes. In this paper, the main features of the soil models are explained. There are several improvements. A more recent pipe-soil vertical reaction law that models plastic unloading is built into the program. It considers lay and dynamic installation effects to compute a more representative pipeline embedment. Axial and lateral resistance is now linked to pipeline embedment. Finally, peak-residual axial and lateral reaction laws are implemented.
>> Read more – 2009