DTM Import and Pipeline Route Definition

SP3D uses Fugro latest technology to handle digital terrain model (DTM). It can rapidly load large survey files and use them for the analysis. Different format are supported.

Pipeline plan route is defined by defining the Intersection Points (IP). Route definition can either be imported (supported file format is *.flf), copy paste from Excel in the IP table of the Editor module or define graphically on a 2D map. IP list with coordinates can be exported in several formats.

Pipe model

In SP3D, pipeline is modelled by beams of finite length bounded at either end by nodes. It uses a circular pipe section and different steel models are available, ranging from linear elastic to non-linear, either by using Ramberg-Osgood coefficients or by defining stress-strain curves.

Solver

SP3D finite element engine – SimPipe – was developed by Fugro specifically to model pipeline. SimPipe is a dynamic explicit finite element analysis engine, designed to be used with the interface modules.

Capabilities include 2D and 3D analysis, non-linear soil support properties, touch-down and lift-off modelling, non-linear pipe bending moment-curvature relations, and large deformation analysis. Pipe internal and external loading and the effects on the hoop and axial stresses are modelled.

Main features include:

• Analysis of the pipe structure using a transient dynamic explicit integration kernel
• 6 degrees of freedom (DOF) two-nodes beam elements
• Realistic 3D laying procedure onto a 3D DTM and based on user-defined target pipeline plan route
• Specification of the tension and angle of the steering/ feeding point
• Re-meshing capability after completion of the lay process
• Analyses can be run in graphic mode, allowing the user to check during laydown the feasibility of the selected route.

Pipe-soil interaction

In order to get accurate results, the pipe interaction with the seabed has to be modelled properly. Fugro has an extensive experience in modeling soils and a particular capability of SP3D is the pipe-soil interaction models. Soil is modelled at the pipe nodes using soil springs in three directions.

Soil properties are defined by zone of uniform soil properties along the pipeline route, allowing to model the soil conditions variability. For each zone, the pipe-soil interaction behaviour can be defined either by:

 

• providing standard geotechnical parameters and selecting predefined standard models (e.g. DNV RP-F105, Verley and Lund) or more advanced models (including plastic deformation), or
• defining the soil force displacement curves in a table, or
• using the external soil library.

Thanks to the external soil library, the user can program himself the pipe-soil interaction behaviour. There is thus no more limits in the possibilities!

Code and span checks

Results from the finite element engine may be passed automatically through the code-checking post-processors (compliant with PD8010, DNV OS-F101, API RF 11.11, including the ASME31.4 and ASME31.8 check). A report of conformance or non-conformance is generated.

When running an analysis in SP3D, a pipe span summary is created. At the same time, the spans can be checked against DNV recommended practice (DNV 1981 or DNV RP-F105) or user-defined span length limits. A report of conformance or non-conformance is output.

Viewer

The seabed and pipeline profiles and results of the analysis program (e.g. bending moment, bending stress, equivalent stress, etc.) can be graphically displayed in the Viewer interface module.

Several analyses’ results can be loaded at the same time and different parameters viewed simultaneously. Interactive pan and zoom features allow users to easily traverse the pipeline and examine areas of particular interest, both in 2D and 3D. All graphs may be customised and templates saved. At the same time, data are also available in tabular format.

Main features:

• Multiple load cases can be plotted simultaneously for comparison purposes.
• Template for the charts definition can be saved, allowing to produce complex graphs in 2 mouse clicks.
• Results can be printed or exported (WMF).
• Template for printed/ exported output can be defined by the user, including frames, QA boxes and client logo.
• Possibility to export numerical results in CSV file format.

Input Specifications

• DTM file format: *.bin, *.xyz
• Route file format: *.flf, *.csv