Q&A: Ian Merchant discusses the subsea market

Materials World magazine
4 Mar 2013

Ian Merchant, Principal Materials Engineer in the Offshore Engineering
Division at Technip UK Limited, speaks to Melanie Rutherford about the
UK subsea market, materials challenges faced by deepwater developments,
and why Britain is leading the way in subsea engineering technology.


What is your background in the industry? 

I graduated in 1988 with a degree in Metallurgy and Materials Science from the University of Nottingham, UK. I took up various research roles in ceramics, cements and glasses, including the attainment of a PhD from the University of Sheffield in 1997, ending up at the University of Aberdeen.  

In 2001, I took up a role in the development of expandable downhole casing material (jointly between University of Aberdeen and Shell E & P) before moving to Materials Engineering, Aberdeen to perform failure investigation analyses, primarily oil & gas related within the North Sea.  

I moved to my present role in 2007. As part of a corporate group, I support all materials activities for rigid pipeline systems throughout the world, meeting the ever demanding challenges set for deepwater and the higher operating conditions of production facilities. This involves the correct selection of materials, procurement support and design of cathodic protection systems. I’m also a member of the board of Petroleum and Drilling Engineering Division of IOM3.  

How big is the UK subsea market and how does it compare with the rest of the world? 

The UK subsea market is worth around £6bln a year, but only a fraction of that is in UK waters – at the moment, probably only about 20%. But by the nature of the North Sea region, which extends from the east coast of Britain towards Norway, the UK has always been the world leader in subsea technology. We’re always naturally driving for innovation and improvement, so the UK is well suited to this area. The Americans have done it in the Gulf of Mexico and there has been a certain amount done in the Middle East, but at shallower depths and certainly not in such hostile conditions. After the UK put in the big infrastructure of the old fields, we started accessing smaller fields and tying them back to that infrastructure. The North Sea was the first area to be doing that routinely, and we’ve been doing it for the last 25 years.  

What have been the milestone developments throughout this time? 

In the early days it was more about getting things working subsea with diver intervention – at the time, the use of divers at that scale was pretty leading edge. However, divers can normally only work down to about 300–400 metres, so any deeper and everything has to be done remotely. From the very beginning the aim was to go deeper, so the focus has always been on designing diverless interventions. Quite often this failed, but the engineers kept learning nonetheless. Take the Shell underwater manifold centre (UMC), for instance, which was designed and put in place in the 1980s. While divers were still used on it, what the engineers learned enabled them to work towards diverless interventions. This is probably the biggest milestone to overcome, because being diverless gives you access to working at much greater depths. Diverless intervention involves underwater robots as well as placing things on the seabed and moving them around from the surface, which becomes more or less a civil engineering project.  

What are the main materials challenges? 

Deepwater is more complicated because it requires more flexibles. The general term used in the industry is SURF technology – that is, subsea umbilical risers and flexibles. When you’re producing hot hydrocarbons in equipment that’s very close to the bottom of the sea, equipment has to cope with big temperature changes – in shallower waters you don’t have those temperature issues.  

In terms of equipment, the main three challenges are corrosion, attack from the hydrocarbons, and pressure. The deeper you go, the more pressure the equipment is subject to externally – at 1,000 metres down at the bottom of the sea, that can reach 800psi, so equipment must be capable of withstanding these high pressures. We’ve got to make things work deeper with fluids that are changing phase, and we don’t yet understand some of the boundaries we’re facing.  

How long will it take for these challenges to be overcome? 

Generally, any major step forward in technology takes around 10 years. These will be big steps forward but they take a while to bring to fruition. Because the costs of a subsea operation are so high, they have to be reliable – you can’t afford for something to go wrong in 10,000 metres of water because you can’t really get down there to put it right.  

What is the most exciting thing happening in the industry right now? 

Working these new, very deep waters – we’re now starting to access depths of up to 3,000 metres. With a lot of the systems that enable such deep access, the surface structures are no longer permanently attached to the seabed. Companies are trying to do more and more on the seabed, even to the point of separating and storing oil there and only offloading it into tankers when it’s needed. These smaller accumulations mean pipelines don’t need to be working all the time into new fields – they can start branching off to smaller fields and not necessarily have to tie back to large infrastructure. Many of the current mooring systems lie beneath the surface, so it’s only when a tanker comes along and attaches itself that they actually interact with anything on the surface.  

Are other markets catching up with the UK? 

The North Sea tends to be where subsea technology is first applied. Once they’ve been proven up, they then tend to be applied around the world as required. It’s partly a case of ‘if you can make it work in the North Sea, you can make it work elsewhere’, and partly because a lot of companies (such as Comex, Oceaneering, Subsea 7 and Technip) grew up, and are still located, around the North Sea basin. After all, it’s better to have your problems closer to home than on the other side of the world.  

How do you see technology developing in the future?  

The more well-known areas in the North Sea are now seen as old fields – the last 10 years has seen the movement of the big oil companies to deepwater environments and these are the big fields of the future. For example, the Ormen Lange field off Norway, which is 800–1,100 metres deep, provides 25% of UK gas. The build-up has been going on for a while, but the amount of resources coming from these areas is only going to get greater. There are currently a lot of deepwater finds, and these will go into long-term production. Also, we’ll be learning to do the things in deepwater that aren’t currently done in conventional oil and gas wells – intervention to include recovery, for instance. These sorts of areas are going to make subsea used even more in future. This is a growing industry, and that’s before you even start considering renewables.  

What other challenges does the UK subsea industry face?  

Recruitment is one. Currently around 60,000 people are employed in the UK subsea industry, but we need to find more suitably qualified people to meet the current and future growth of the industry. Also, because a lot of military spend was previously adapted for the subsea industry, the recent Government cuts could be a threat.  

How are companies addressing these issues?  

Efforts are being made to speed subsea production along, and with less intervention. Early production is vital because the costs are so high, so the quicker you can go into production the less time – and money – is spent waiting around. A good example comes from the Apache Bacchus project, which prepared a 7km umbilical on-land and then towed it offshore, connecting the subsea wellheads back to a collection point (back to the old 1940s platform structures). Because it was just floated out and plugged in, the field became operational very quickly.  

Any there any other industries that subsea can learn from?  

First there’s the wind turbine industry. They have to lay cables and attach offshore structures to the seabed, and there are even talks of floating wind turbines. Then there are the tidal turbine systems, which are all going to need subsea equipment, such as cables to carry power. This is all in the same vein and subsea will inevitably be part of it – it has to be, as a lot of the groundwork has already been done in the oil and gas industry.  

For more information, contact Ian Merchant, IMMa@iom3.org