Enhancing Operational Efficiency and Safety of Nodule Collection

Abstract

This thesis explores the potential for enhancing the operational efficiency of deep-sea mining through the semi-real-time modelling of the Vertical Transport System (VTS) and umbilical positioning. As the demand for rare earth minerals rises with the global shift toward renewable energy, deep-sea mining has emerged as a crucial method for resource extraction. However, the complex and dynamic nature of deep-sea environments presents significant challenges, particularly in ensuring the safety and efficiency of the mining equipment.

The thesis develops a computational model that simulates the position and dynamics of the VTS and umbilical in semi-real-time, providing predictive insights for operational decision-making. The model incorporates a shape calculator for the umbilical, jumper, and riser, a current finder to estimate ocean currents, collision detection, and a P-turn optimisation algorithm to improve manoeuvring efficiency during mining operations. By integrating sensor data and environmental conditions, the model offers real-time feedback and predictive analysis, aiding operators in minimising risks such as ground collisions and equipment entanglement.

The model’s accuracy was verified against OrcaFlex, a widely used marine simulation software, and data collected during a pilot mining test (PMT). The verification process demonstrated that the model’s predictions are within an acceptable error margin of less than 1% of the total length of the umbilical, confirming its reliability for practical application. Additionally, the model's P-turn optimisation showed the potential to reduce the distance travelled by the vessel during turns by up to 35%, translating into significant time and fuel savings for mining operations.

While the model offers valuable insights and improvements in operational efficiency, the research also acknowledges its limitations, including the simplification of certain environmental factors and the need for more detailed modelling of the riser. Future work is recommended to expand the model's capabilities, particularly in incorporating three-dimensional movement, enhancing fuel efficiency considerations, and further refining the optimisation process for P-turns.

Overall, this thesis demonstrates that semi-real-time modelling of the VTS and umbilical is a viable method for improving the efficiency and safety of deep-sea mining operations, contributing to the sustainable extraction of critical resources.