Modelling Friction Subsea

07 November 2011

The subsea simulator developed by Fugro GRL DeepWorks can now model friction, for example for cables and ROVs coming into contact with each other or the seabed.

This adds realism to subsea simulations, the company says.

Friction is an important component in forecasting the behaviour of both moving and stationary subsea objects.

DeepWorks can calculate friction forces resulting from any forces acting on the body including gravity. The friction depends on a number of factors including contact area, friction coefficients and, for seabeds, the relief profile.

The level of frictional resistance varies depending on the amount of contact, for instance, cables pulled linearly along the seabed will exhibit much less friction than cables pulled laterally across the seabed.

This enables more accurate simulation and visualisation of the motion and final resting place of dynamic bodies that come into contact with those parts of the seabed.

This is especially important for ROV supported templates or pipeline installation and for touchdown prediction during cable-lay operations.

DeepWorks now takes account of the combined effect of the prevailing currents and the frictional forces at the points of contact.

For ROV pilot training this enables better understanding of the demands on thrusters in moving the ROV from rest on the seafloor to a stand-off position around cables or structures - a routine procedure during construction support, and during inspection of installations for offshore oil and gas or offshore wind farms.