Introduction & Example Files

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Introduction & Example Files

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Introduction

Note

This example is simplified in PipeLay Starter Edition where there is no coating stiffness effects, bend radius optimisation, DNV local buckling checks or fatigue analysis available. If you are using Starter Edition then you should ignore certain aspects of these articles, in particular parts of the ‘Results’ section.

 

Example 15 simulates a shallow water rigid S-Lay scenario. The model includes a lay vessel equipped with a rigid S-Lay stinger fitted with V-shaped roller boxes. A concrete coated pipeline runs along a set of vessel supports before passing over the stinger and down onto the seabed. The pipeline is restrained on the vessel deck by a tensioner. A static analysis, two dynamic analyses, one with a regular wave loading and the other a random sea loading are included in the example. A top tension of 3200 kN is specified as the installation criteria for the static configuration. A pipe bend radius for the stinger region of 250m is also targeted. Fatigue analysis and DNV local buckling checks are performed on the dynamic outputs from the example.

As part of this example a number of PipeLay optimisation techniques are to adopted in order to achieve the target bend radius. To demonstrate these techniques the static analysis is completed in a number of iterations each of which is vital to the overall optimisation process. This initially involves running an analysis on the standard set-up with no optimisation functionality specified before gaining an understanding of the initial level of bend radius in the pipeline. From this first pass a user-defined radius of curvature for a selected number of supports can be input. The user interface will then move the support positions to map a pipeline profile of desired curvature. A second pass static analysis should highlight improvements in the predicted bend radius. Due to concentration effects over roller boxes further fine tuning of the support elevations may be needed. Once instructed the analysis engine can automatically perform this fine tuning in a third pass analysis at which time the predicted static bend radius should be very close to the target value. This entire iterative process is outlined later in the 'Analysis Component' article for this example.

The initial model configuration for the scenario is illustrated respectively in the figure below.

Static Configuration

Static Configuration

 

Example Files

The input files for this example may be found in the directory ‘Example 15 – Shallow Water Rigid S-Lay’, which is located in the Examples subdirectory of your PipeLay installation directory. The input files are as follows:

Example 15 – Shallow Normal S-Lay.ppd

PipeLay project file

Lay Vessel.rao                

Vessel RAO file

     Python-Automation-Script.py

Example Python script

 

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