| dc.description.abstract | Offshore production systems are required to support the extraction, lifting, and shipment of deep-seabed minerals. Increasing the knowledge about such novel systems is important to identify constrained parameters and potentially reduce costs and improve performance. With few systems design solutions developed and tested, a holistic and exploratory approach is used in this research work to gain knowledge about the technical, operational, and commercial performance of a conceptual offshore production system for deep-sea mining. This research work aims to study the relationship between marine systems design for deep-sea mining and marine systems performance. The research questions (RQs) are:
RQ1: How can the performance of conceptual offshore production systems for deep-sea mining be explored?
RQ2: How could the Norwegian maritime offshore oil and gas competency support the marine systems design of deep-sea mining solutions?
The related research objectives (ROs) are:
RO1: Identify important early stage decisions in marine systems design for deepsea mining
RO2: Explore vessels from the offshore oil and gas industry in the design of deepsea mining vessel solutions and test their value robustness
RO3: Conduct conceptual design of deep-sea mining vessels using experience from the offshore oil and gas industry
RO4: Model a deep-sea minerals production system and identify weak links in terms of overall performance
The investigation design of this research work is a concurrent mixed-methods approach, and the methods are case studies and simulation. The data collection involves literature review, interviews, and archival data. Literature reviews are conducted extensively to gather information and data from a wide range of sources. Interviews are used both quantitatively and qualitatively: One survey and a series of unstructured interviews of experts in different disciplines are carried out. These experts are typically ship designers, shipbuilders, ship owners, mining engineers, dredging engineers, geologists, and companies targeting deep-sea mining activities. Further, hindcast wave data sets are applied for the significant wave height (Hs). Vessel data is collected from archival data, as well as Ulstein’s internal comprehensive vessel segment database. The Accelerated Business Development (ABD) framework is applied in RO1 and RO3. For RO2, the Responsive Systems Comparison (RSC) method is used. RO3 is also approached with the System-based Ship Design (SBSD) method. For RO 4, a simulator is developed using Model based Systems Engineering (MBSE) and Discrete Event Simulation (DES).
The main results from the RO1 work are a business proposition, performance expectations for various stakeholders, and an assessment of the competitive situation and project risks. The assessment of the competitive situation identified the landbased mining industry as the main threat to the project. Yet, two distinct advantages of deep-sea mining were pointed out when contrasting to land-based mining: metal grades and overburden. Seabed ores have reported elevated metal concentrations than mines onshore. Further, there is no overburden for the case studied and subsequently no disposal cost related to the overburden. Some key aspects are essential in making this a viable business, such as a mobile marine system, production continuity, vertical integration with onshore processing facilities, and alternative use of assets. Moreover, the Levelised Cost of Mining (LCOM) is introduced as a bench-marking index for deep-sea mining.
RO2 presents an exploration of relevant and hypothetical technologies on board a future deep-sea mining vessel and a discussion of how this equipment will work for different mine sites. The work elaborates on the consequence of technology choices on commercial considerations, such as the vessels’ second-hand value in the market and alternative uses. A vessel specialised for the deep-sea mining segment has few other uses in its “as is” condition. If the vessel were to change mission and remove its specialised equipment, it could potentially go to the standardised bulk market as a handymax (<60k dwt), panamax (<80k dwt), or aframax (<120k dwt) vessel. The vessel might also be used as a self-unloader.
RO3 deals with the conceptual design of deep-sea mining vessel solutions. LCOM is calculated for the proposed concepts, and analyses of different vessel solutions show the importance of utilising the economies of scale effect, if the mine site allows. The analyses also show that, despite the higher CAPEX, larger vessels are favourable: The extra space gives better stability characteristics, more workspace for the crew, and space to allow higher production rates. However, costs should not be added without getting more functionality and operability.
The main output from the RO4 work is the development and use of a simulator calculating the production output of an industrial deep-sea mining system. A mean production of 1 Million tonnes of ore per year is estimated for the operation in the Norwegian Sea using Monte Carlo simulation. Depending on the limiting design wave height of the marine operations, the estimated production output ranges from 280,000 tonnes to 1.8 Million tonnes per year. The results show that the allowable wave height limit for ship-to-ship transfer is a critical parameter for annual ore production. If this technology has a low design wave height, the operation will have trouble getting the necessary weather window to proceed with operations. Thus, the ship-to-ship transfer becomes a weak link in the overall chain of events in the production of deep-sea minerals.
The results are clear on different levels of analysis: Both variations in technology properties and variations in chosen vessel solutions for deep-sea mining impact the systems performance, in some cases to a large extent. Therefore, this research finds evidence that a marine systems design approach for deep-sea mining can be used to explore the marine systems performance. This work applies information and knowledge from the offshore oil and gas industry. The analyses conducted depend on the use of these data. As such, the value of the Norwegian maritime offshore oil and gas competency in designing deep-sea mining solutions is high. One essential aspect to keep in mind is that the products in oil and gas and deep-sea mining are different. Solutions that are opted to handle the intrinsic characteristics of oil and gas may not be applicable in a deep-sea mining setting. When adopting data from the offshore oil and gas industry for deep-sea mining purposes, data awareness is key. The insights gathered from this work can be used to better understand how technical, operational, and commercial considerations of the offshore production system may ease the transition to this nascent industry. The scope of this study is the conceptual design stage and the findings can only be said to be applicable within this scope. Whether the findings will be true in the detailed engineering and actual operation stages will only be known if these systems are fully designed and operated.
The PhD project has three main contributions:
Main contribution 1: This research work provides a collection and description of deep-sea mining based on literature and interviews.
Main contribution 2: This research work extends existing theories, methodologies, and tools to the deep-sea mining domain.
Main contribution 3: This research work introduces, discusses, and calculates the Levelised Cost of Mining (LCOM) as a performance bench-marking index. | en_US |
