Deep ocean mining systems will have to operate often in harsh weather conditions with heavy sea states. A typical mining system consists of a Mining Support Vessel (MSV) with a Vertical Transport System (VTS) attached to it. The transport system is a pump pipeline system using centrifugal pumps. The heave motions of the ship are transferred to the pump system due to the riser-ship coupling. Ship motions thus will have a significant influence on the internal flow in the VTS.
In this paper, the influence of heave motions on the internal flow in the VTS for a typical mining system for Seafloor Massive Sulfide (SMS) deposits in Papua New Guinea is analyzed. Data on the wave climate in the PNG region is used to compute the ship motions of a coupled MSV-VTS. The ship motions then are translated into forces acting on the internal flow in order to compute fluctuations in the internal flow. In this way, the workability of the mining system with respect to the system’s production can be assessed.
Based on a detailed analysis of the internal flow in relation to ship motions, the relevance of a coupled analysis for the design of VTS is made clear. This paper provides a method for performing such analyses.