SeaThor engineers have extensive experience within the subsea oil, gas and renewable offshore industries.

Global Dynamic Analysis (Orcaflex)

Global dynamic analysis is performed to assess the dynamic response of varying offshore marine systems using world leading package Orcaflex.

SeaThor engineers have extensive experience within the subsea oil and gas and renewable offshore industries which has been developed and refined through working on a variety of dynamic analysis projects and activities throughout the years.

Analysis includes:

• Installation analysis (subsea power cables)
• Floating offshore wind (subsea power cables)
• Oil & gas, fixed platforms (subsea power cables, dynamic risers, and umbilicals)
• Tidal generators (subsea power cables)
• Fixed bottom offshore wind (subsea power cables, and CPS systems)
• Ancillary hardware optimisation (subsea products and terminations)

SeaThor can perform electromagnetic analysis of subsea cables and umbilicals, typically this analysis is performed utilizing Comsol 2D functionality however more detailed 3D studies can also be performed if required.

Studies are generally performed to assess maximum magnetic flux density of a current carrying component, the studies can also be expanded to assess several current carrying components in proximity to assess electromagnetic inference and subsequent minimum required separation distances as a result.

Thermal Analysis (Comsol Multiphysics)

SeaThor has performed a range of thermal analysis studies using software package Comsol Multiphysics.

Detailed 3D backgrounds are generated within the software using pre-defined geometry and material properties, electromagnetic modules are fully coupled with fluid flow and heat transfer modules within the software to generate a representative temperature profile throughout the system. Assessments are typically performed to verify:

• Subsea hardware remain within allowable temperature limits
• Limiting subsea power cable continuous current ratings

Local Stress Analysis (DNV Helica)

DNV Helica is specialist simulation software for analysis of cables, flexible pipes and umbilicals.

The following types of analyses are considered:

• Load-sharing between elements considering axis-symmetric analysis
• Calculation of cross-sectional stiffness properties (axial, torsional and bending stiffness)
• Helix element bending performance analysis to describe stresses in helix elements during bending considering stick/slip behavior due to interlayer frictional forces
• Tabulation of stresses in selected interior components due to combined bending and tensile loading on the cross-section
• Assessment of capacity curves for combined bending and tensile loading of the cross-section

It is of critical importance that stick/slip friction effects of subsea umbilical inner components (which are typically laid helically) are assessed to ensure that stress in these components is accurately predicted.

SeaThor can perform these calculations to determine the maximum stress in a particular component and thus derive component fatigue life using output from dynamic analysis and material SN data.