BMT has completed a project for Heerema Marine Contractors (HMC) providing marine simulation studies which have supported the installation of Shell’s Appomattox Floating Production System.

The topside and hull of Appomattox, Shell's largest floating platform in the Gulf of Mexico, were integrated at Kiewit Offshore Services (KOS), Ingleside, Texas prior to installation. The completed platform was then wet-towed from the KOS integration yard to the installation site.  

Frans Lichtenbeld, Towmaster at HMC comments: “One of the biggest risks associated with this tow was the inshore tow from the integration yard to the sea buoy at the end of the Aransas Pass.  The departure through the La Quinta and Corpus Christi ship channels presented some particularly challenging maneuvering, control and navigation issues.”

To facilitate this operation, BMT delivered a multi-user training simulator to enable HMC to investigate towage operation obstacles and maneuvering characteristics of the hull during the inshore part of the tow, covering La Quinta, Corpus Christi Ship Channel and Aransas Pass.  These studies played an integral role in identifying overall obstacles during the towage operation and developing operating strategies. Furthermore, the studies helped to determine rational weather and tidal operating limits and provide training and familiarization for the towmasters, tug captains, pilots and other marine personnel who were involved in the tow.  

Suba Sivandran, Director of Data Analysis, Modelling & Consulting at BMT comments: “There were a number of phases to the simulation studies HMC required.  Firstly, Computational Fluid Dynamics (CFD) calculations were developed to determine the hydrodynamic and propulsion properties of the platform and the close-coupled tugs.  Once those CFD calculations were in place, physical model testing of the platform and close-coupled tugs in a shallow water basin were carried out to confirm results of the CFD analysis.”

BMT further developed a hydraulic simulation of the tidal and non-tidal current flow through the Corpus Christi channels which provided a time series of the currents likely to be encountered during the tow.  The final phase was delivery of the training simulator suite to the customer’s site in Texas and to construct simulation models of the tow using BMT’s industry-leading navigation simulator, REMBRANDT which incorporated the tow handling and environmental models developed in the preceding stages.

Mumanthi Mvuria, Specialist Engineer at HMC says: “This preparation work was a critical part of the planning phase and as such, resulted in the safe arrival of the system to its final destination in the Gulf of Mexico.”