This proposal addresses the vital issue of prediction of multiphase flows in large diameter risers in off-shore hydrocarbon recovery. The riser is essentially a vertical or near-vertical pipe connecting the sea-bed collection pipe network (the flowlines) to a sea-surface installation, typically a floating receiving and processing vessel. In the early years of oil and gas exploration and production, the oil and gas companies selected the largest and most accessible off-shore fields to develop first. In these systems, the risers were relatively short and had modest diameters. However, as these fields are being depleted, the oil and gas companies are being forced to look further afield for replacement reserves capable of being developed economically. This, then, has led to increased interest in deeper waters, and harsher and more remote environments, most notably in the Gulf of Mexico, the Brazilian Campos basin, West of Shetlands and the Angolan Aptian basin. Many of the major deepwater developments are located in water depths exceeding 1km (e.g. Elf's Girassol at 1300m or Petrobras' Roncador at 1500-2000m). To transport the produced fluids in such systems with the available pressure driving forces has led naturally to the specification of risers of much greater diameter (typically 300 mm) than those used previously (typically 75 mm). Investments in such systems have been, and will continue to be, huge (around $35 billion up to 2005) with the riser systems accounting for around 20% of the costs. Prediction of the performance of the multiphase flow riser systems is of vital importance but, very unfortunately, available methods for such prediction are of doubtful validity. The main reason for this is that the available data and methods have been based on measurements on smaller diameter tubes (typically 25-75 mm) and on the interpretation of these measurements in terms of the flow patterns occurring in such tubes. These flow patterns are typically bubble, slug, churn and annular flows. The limited amount of data available shows that the flow patterns in larger tubes may be quite different and that, within a given flow pattern, the detailed phenomena may also be different. For instance, there are reasons to believe that slug flow of the normal type (with liquid slugs separated by Taylor bubbles of classical shape) may not exist in large pipes. Methods to predict such flows with confidence will be improved significantly by means of an integrated programme of work at three universities (Nottingham, Cranfield and Imperial College) which will involve both larger scale investigations as well as investigations into specific phenomena at a more intimate scale together with modelling studies. Large facilities at Nottingham and Cranfield will be used for experiments in which the phase distribution about the pipe cross section will be measured using novel instrumentation which can handle a range of fluids. The Cranfield tests will be at a very large diameter (250 mm) but will be confined to vertical, air/water studies with special emphasis on large bubbles behaviour. In contrast those at Nottingham will employ a slightly smaller pipe diameter (125 mm) but will use newly built facilities in which a variety of fluids can be employed to vary physical properties systematically and can utilise vertical and slightly inclined test pipes. The work to be carried out at Imperial College will be experimental and numerical. The former will focus on examining the spatio-temporal evolution of waves in churn and annular flows in annulus geometries; the latter will use interface-tracking methods to perform simulations of bubbles in two-phase flow and will also focus on the development of a computer code capable of predicting reliably the flow behaviour in large diameter pipes. This code will use as input the information distilled from the other work-packages regarding the various flow regimes along the pipe.

The Ocean-REFuel project brings together a multidisciplinary, world-leading team of researchers to consider at a fundamental level a whole-energy system to maximise ocean renewable energy (Offshore wind and Marine Renewable Energy) potential for conversion to zero carbon fuels. The project has transformative ambition addressing a number of big questions concerning our Energy future: How to maximise ocean energy potential in a safe, affordable, sustainable and environmentally sensitive manner? How to alleviate the intermittency of the ocean renewable energy resource? How ocean renewable energy can support renewable heat, industrial and transport demands through vectors other than electricity? How ocean renewable energy can support local, national and international whole energy systems? Ocean-REFuel is a large project integrating upstream, transportation and storage to end use cases which will over an extended period of time address these questions in an innovative manner developing an understanding of the multiple criteria involved and their interactions.

The need for the UK to shift to NetZero was highlighted at COP26 in Glasgow, and there is a clear need for UK energy security. UK policy to achieving these is based on massive expansion of off-shore wind. In 2022 Crown Estate Scotland "ScotWind" auctioned 9,000 km2 of sea space in the northern North Sea, with potential to provide almost 25 GW of offshore wind. Further developments are planned elsewhere, for example, the 300 MW Gwynt Glas Offshore Wind Farm in the Celtic Sea. These developments mark a shift in off-shore wind generation, away from shallow, well mixed coastal waters to deeper, seasonally stratified shelf seas This shift offers both challenges and opportunities which this proposal will explore. Large areas of the NW European shelf undergo seasonal thermal stratification. This annual development of a thermocline, separating warm surface water from cold deep water, is fundamental to biological productivity. Spring stratification drives a bloom of growth of the microscopic phytoplankton that are the base of marine food chains. During summer the surface layer is denuded of nutrients and primary production continues in a layer inside the thermocline, where weak turbulent mixing supplies nutrients from the deeper water and mixes oxygen and organic material downward. Tidal flows generate turbulence; the strength of turbulence controls the timing of the spring bloom, mixing at the thermocline, and the timing of remixing of the water in autumn/winter. Determining the interplay between mixing and stratification is fundamental to understanding how shelf sea biological production is supported. Arrays of large, floating wind turbines are now being deployed over large areas of seasonally-stratifying seas. These structures will inject extra turbulence into the water, as tidal flows move through and past them. This extra turbulence will alter the balance between mixing and stratification: spring stratification and the bloom could occur later, biological growth inside the thermocline could be increased, and more oxygen could be supplied into the deep water. There could be significant benefits of this extra mixing, but we need to understand the whole suite of effects caused by this mixing to aid large-scale roll-out of deep-water renewable energy. eSWEETS will conduct observations at an existing floating wind farm in the NW North Sea to determine how the extra mixing generated by tides passing through the farm affect the physics, biology and chemistry of the water. We will measure the mixing of nutrients, organic material and oxygen within the farm, and track the down-stream impacts of the mixing as the water moves away from the wind farm and the phytoplankton respond to the new supply of nutrients. We will use autonomous gliders to observe the up-stream and down-stream contrasts in stratification and biology all the way through the stratified part of the year. We will use our observations to formulate the extra mixing in a computer model of the NW European shelf, so that we can then use the model to predict how planned renewable energy developments over the next decades might affect our shelf seas and how those effects might help counter some of the changes we expect in a warming climate. Stratification is so fundamental to how our seas support biological production that we will develop a new, cost-effective way of monitoring it. We will work with the renewables industry and modellers at the UK Met Office on a technique that allows temperature measurements to be made along the power cables that lie on the seabed between wind farms and the coast. Our vision is that large-scale roll-out of windfarms will lead to the ability to measure stratification across the entire shelf. This monitoring will help the industry (knowledge of operating conditions), government regulators (environment responses to climate change) and to operational scientists at the UK Met Office (constraining models for better predictions).

Hydrocarbons and their derivative products are central to today's society. We know that the source of hydrocarbons are products of buried ancient plants and animals. Less clear, and question that petroleum geoscientists both academic and industrial are challenged with, is establishing the time that hydrocarbons, such as oil, form and how they are trapped in petroleum systems large enough to be exploited. To address this question of the origin and time of formation of hydrocarbons, the naturally occurring isotopic clock of 187Rhenium-187Osmium present in oil is utilized. This ability to directly date oil and not rely on multi-component models are important because petroleum explorers, need to know the origin of hydrocarbons in a sedimentary basin to constrain where they might be able to accumulate, or whether they are able to accumulate at all. With oil exploration drillholes costing multiple millions of dollars, every piece of data informing site location is of immense worth. Whilst the potential utility of the Rhenium-Osmium system to petroleum systems is now proven, its wide scale application and routine development by industry during exploration is still very much in its infancy. Thus, engagement with industry is needed to develop a portfolio of asset-based case studies needed to improve the understanding of Rhenium-Osmium systematics and assess the general applicability of the method to hydrocarbon-bearing basins worldwide. Work related to Objective (a) (see Objectives section above) will be to create a multi-company (BP, Total, Statoil, ConocoPhillips, Chevron, Shell, Chemostrat) Re-Os Advisory Board (ROAB) with two main purposes (as noted above). Work related to Objective (b) will involve ROAB members to become a strategic partner based on established relationships with companies already engaging in the use of Re-Os; and companies with shared interest in the application of Re-Os system above and beyond its current use. All of the founding ROAB members have global expertise in petroleum exploration and thus compliment, support and develop the PI and Co-I research capabilities establishing a strong-integrated research team, e.g., traditional industrial applied techniques (basin modeling, organic geochemistry) with novel Re-Os geochemistry and fracture network models. Work related to objective (c) includes a 2 workshop hosted by the PIs at Durham which will include a summary of the current knowledge base and will be followed by a think tank session on how the Rhenium-Osmium system can be better understood and developed for the end-user. An Impact Case Study will be developed with the help of a science writer in the Durham University Media Office.

The decarbonisation of industrial clusters is of critical importance to the UK's ambitions of cutting greenhouse gas emissions to net zero by 2050. The UK Industrial Decarbonisation Challenge (IDC) of the Industrial Strategy Challenge Fund (ISCF) aims to establish the world's first net-zero carbon industrial cluster by 2040 and at least one low-carbon cluster by 2030. The Industrial Decarbonisation Research and Innovation Centre (IDRIC) has been formed to support this Challenge through funding a multidisciplinary research and innovation centre, which currently does not exist at the scale, to accelerate decarbonisation of industrial clusters. IDRIC works with academia, industry, government and other stakeholders to deliver the multidisciplinary research and innovation agenda needed to decarbonise the UK's industrial clusters. IDRIC's research and innovation programme is delivered through a range of activities that enable industry-led, multidisciplinary research in cross-cutting areas of technology, policy, economics and regulation. IDRIC connects and empowers the UK industrial decarbonisation community to deliver an impactful innovation hub for industrial decarbonisation. The establishment of IDRIC as the "one stop shop" for research and innovation, as well as knowledge exchange, regulation, policy and key skills will be beneficial across the industry sectors and clusters. In summary, IDRIC will connect stakeholders, inspire and deliver innovation and maximise impact to help the UK industrial clusters to grow our existing energy intensive industrial sectors, and to attract new, advanced manufacturing industries of the future.