Seabed ploughing: modelling for infrastructure installation

Soil ploughing, an activity carried out by man for thousands of years for agriculture, is now used at a much larger scale on the seabed to connect offshore energy production and generation devices to the supply network. In the next 50 years many more of these offshore devices (wind, wave, current and oil & gas) will be installed, meaning that considerably more seabed ploughing will be undertaken. However, we do not possess the same level of understanding of the mechanical and hydraulic processes associated with soil ploughing as we have developed for other soil-structure interaction problems. This means that ploughing schemes and equipment have to be designed on the basis of semi-empirical and conservative approaches, leading to financial uncertainty. In this project, new computational methods will be applied to the simulation of seabed ploughing to provide better estimates of key parameters such as the towing force and speed of ploughing in a given seabed deposit along with insights into plough stability. Given the likely ploughing activity in the next 20-50 years in UK waters and elsewhere, we expect that this new predictive approach will result in major savings for industry.

Beyond academia this research project will lead to economic and environmental impacts.
Cheaper installation costs:
(a) the key advance in this project will be provision of a numerical method to allow economic design of cable and pipeline ploughing projects where there is none of sufficient accuracy at present. This will lead to reductions in the costs of these operations and since this is a highly competitive industry, these cost reductions will be passed on to clients, who are major energy companies and government bodies.
(b) The cost of delivering offshore wind energy projects and in the future, marine energy projects will be reduced, as cabling of these installations will be cheaper.
(c) The new tool will also allow cabling contractors to choose routing with more confidence, allow cabling in areas of the seabed where perhaps they would be less willing to work in due to a lack of previous cabling projects.
(d) There are many cases where offshore pipeline laying projects incur huge additional costs because of an inability of the ploughing operation to achieve the correct depth, and the only solution is costly rock-dumping, e.g. the Breagh development in Canada which cost £566m compared to an expected £485m, www.sterling-resources.com/news/2012/nr0068.html

The project work indirectly supports environmental goals for renewable energy sources, making offshore projects more feasible, but there are many other environmental benefits, e.g.

Hazard Avoidance:
(a) The tool can be used not just for ploughing predictions but also to predict the scouring behaviour of icebergs (which are a hazard for shallow cabling in seabeds).
(b) Shallow burial of pipelines is also cited as a potential factor in various oil pipeline leaks which have occurred, e.g.
www.telegraph.co.uk/finance/newsbysector/energy/oilandgas/8698916/Shell-battles-to-stem-North-Sea-oil-leak.html
www.bbc.co.uk/news/uk-scotland-north-east-orkney-shetland-18540318

The project will also develop the skills of two Post-Doctoral Research Assistants in experimental geotechnics and computational geotechnics respectively.

We will also disseminate our findings to the general public by employing local communications expertise to design and disseminate press releases targeting publications deemed most likely to reach the broad general public. These will communicate our excitement about our research and why our work is necessary to achieve the above-stated beneficial goals.