REAL-TIME SIMULATIONS OF OFFSHORE MARINE OPERATIONS

The paper describes an advanced numerical tool which is capable of simulating offshore marine operations in real-time including main-in-the-loop interactions. It operates with a realistic environment consisting of the full effects from wind, current and waves. Special attention is given to the positioning of jack-up rigs. A newly developed leg module models the forces on the legs from wind, current and waves, and also a realistic spud-can/bottom interaction is included. Sine the interaction between the spud-cans and the bottom is modelled quite realistically it is possible to perform real-time simulations of rig moves until final position has been reached. Wave forces on the hull are pre-determined by a 3-D diffraction program and includes first and second order drift forces. Forces on the jack-up hull and legs are determined on the basis of model experiments made with a planar motion mechanism. Tug force and direction as well as anchor mooring lines are modelled and controlled by the crew. This simulation tool can be used for several purposes such as: planning and training of a specific offshore marine operation, determination of max allowable weather conditions, or to judge whether a specific operation is possible or not with the specified equipment. By way of the realism obtained in the real-time simulation, including the fact that all controls are conned by human beings, this tool can also constitute the background for risk analysis and damage assessments with due account for the very important human factor.