‘Green’ Arctic Marine Operations - -Efficient Ice Fracturing Technologies

1. Introduction
Due to the presence of rich natural resources in the Arctic and also its strategically important location (e.g., the Northern Sea Route), there has been a continuous growing interest for the Arctic. Comparing to open water experiences, any design of offshore structures and marine operations would be further complicated and challenged by the presence of sea ice. For safe and economical operations in this harsh, yet fragile environment, sufficient knowledge and solid technologies should be developed, tested and verified.

2. What?
Currently, in order for safe and economical design and operation of Arctic offshore structures, the so-called ‘Ice Management (IM)’ operations were often employed. The IM operation is characterised by breaking the incoming ice by several icebreakers, such that the downstream offshore structures are protected from dangerous ice features.

IM is a comprehensive and interconnected system that involves ‘detection’, ‘tracking’, ‘forecasting’, ‘decision making’, and eventually ‘breaking/fracturing’ the identified threatening ice features. Nowadays, practical questions such as ‘how many icebreakers are needed?’; ‘how to deploy the available icebreaker fleet to effectively defend an offshore structure?’ are often addressed with rather simplified models (e.g., the kinematical model). As opposed to this, a more physically based simulation model, involving explicitly modelling the fracture of particular sea ice features at operational scale, shall yield a quantified evaluation of any icebreaker fleet deployment; thereby boosting the efficiency and ensure the safety of the chosen Arctic Marine Operation strategies, leading to the so-called ‘Green’ Arctic Marine Operations.

Under the project ‘Green Arctic Marine Operations’, I shall focus on developing ‘efficient ice fracturing technologies’. In this regard, two interconnected issues shall be studied under the intended funding of VISTA.

• First, I shall study the fracture properties of sea ice based on large scale experiments.

• Second, with known fracture properties of sea, I shall investigate various techniques leading to effective ice fracturing technologies.

3. How?
The above two research activities shall be investigated with comprehensive approaches involving ‘experiments’, ‘theories’, and ‘simulations’.

We have carried out ‘large scale field fracture tests’ on around 50 purposely cut ice floes of various sizes from 2015 to 2018. A treasure of fracture data is available to uncover the fracture properties of sea ice. As a continuation of my previous research effort, the VISTA funding shall help me to continue the investigation of these fracture data and eventually nail down the fracture properties of sea ice.  

At the same time, field IM operational tests were carried out and lots of operational data shall contribute to the formulation of methodologies and strategies leading to effective ice fracturing techniques. Moreover, all these observations, experiences, measurements and the to-be-developed effective ice fracturing strategies shall be quantified by a simulator, which is capable of simulating ice fracturing at operational scale (i.e., several tens of kilometers). This simulation tool shall benefit from and contribute to applied operational theories on ‘how to effectively fracture sea ice’.

In the meantime, fundamental studies of sea ice’s ‘fracture properties’ is one part of the important inputs to the simulator, which in turn, gives validations to our measured and analyzed fracture properties of sea ice.

Eventually, the deliverables of this project shall be ‘knowledge on sea ice’s fracture properties’, ‘useful models and tools to guide Arctic Marine Operations, e.g., IM tactics or/and strategy design’, and ‘the further enrichment of the existing numerical simulator’. All of these shall have a great contribution potential in various aspects of future Arctic related operations.

4. Summary
The physical process of ice fracturing plays an important role in the design and operation of Arctic marine structures. In this regard, we formulated research questions concerning ‘effective ice fracturing technologies’, which eventually contribute to the ultimate goal of ‘Green’ Arctic marine operations. With the VISTA funding, I shall carry out two interconnected research activities. First, I shall study the fracture properties of sea ice based on large scale ice fracture experiment data. Second, I shall study the ice fracturing efficiency of different operation strategies based on our available field IM operational tests and a numerical simulator, which is under continuous development. A combined theoretical, numerical and experimental approach shall be employed to comprehensively address these issues. The deliverables of this research project have great contribution potential in various aspects of future Arctic related operations, e.g., autonomous Arctic marine operations.

Publicaitons:

Lu, W., Cold Regions Science and Technology (2018), https://doi.org/10.1016/j.coldregions.2018.07.010

Lu, W., Cold Regions Science and Technology (2018), https://doi.org/10.1016/j.coldregions.2018.07.011