London, February 2008
Successful Installation of Disconnectable FPSO Turret Buoy and Mooring Lines
2H Offshore have been working to support Trident Offshore Ltd, a sister Acteon Group company, providing tow-out and deployment analysis for a disconnectable FPSO turret buoy.
2H Offshore produced complex finite element models for both the tow-out and hook-up operations, modelling the turret buoy, its nine mooring lines and tug vessels to assess the complete system response. Working closely with Trident, the analysis results were used to develop and define the procedures required for safe and effective tow-out and hook-up of the system. 2H supported Trident through to completion of the installation, considering various ballasting configurations and weather conditions.
During tow-out, the turret buoy was free-floating, with the top two sections of mooring line (around 150m) already connected to the buoy. These sections are clustered in three groups of three lines, each supported at the far end by a tug vessel. A fourth tug vessel provides the main tow line that drives the towing operation. Once on location, the ballasting and lateral positioning of the FPSO turret buoy was controlled to allow the connection of the mooring lines from the buoy to the remaining length of mooring line, pre-installed at the seabed.
This complex project showed 2H's finite element modelling and analysis strengths to their fullest and demonstrated the effectiveness of two Acteon companies collaborating to support the client both maximising their own individual strengths.
