Probabilistic assessment of the positioning accuracy for the installation of a gravity base structure

A model for probabilistic analysis of the positioning accuracy for a gravity base structure under installation at its planned offshore location has been defined. The model is applied to an analysis of the reliability of the positioning of a selected example platform over a seafloor template with predrilled oil wells. Uncertainties in the loading as well as in the damping are included together with operational uncertainties and uncertainties in the measurements of the position. The reliability is computed according to a second-order reliability method.