Being agile:

the only way

Bourbon Subsea Services (BSS) is collaborating closely on TetraSpar project for the development of a revolutionary new floater for floating offshore wind turbines, cheaper to manufacture and assemble than conventional floaters. The wind turbine will be transported from Denmark to waters off Norway and then installed, this summer. We discuss the project with offshore wind pioneer Henrik Stiesdal, who designed of the TetraSpar floater.

PartnerShip: Why are you involved in the development of floating offshore wind turbines?

Henrik Stiesdal: The International Energy Agency (IEA) recently declared that conventional offshore wind farms could be capable of delivering slightly more than the world’s present electricity load, which is of course good. But if transport and industry are to be made carbon-free, then we will have to produce very much more electricity than our present needs. According to the IEA, floating offshore wind is theoretically capable of delivering 10 times our current electricity load. There are a number of arguments in favour of floating wind. For one thing, conventional fixed-bottom offshore wind farms have to be installed in shallow waters. There are not so many suitable sites around the world. But for floating wind farms, you can go out to deeper water. Floating wind also has some less obvious advantages. The most important one is that one size fits all. Normally in fixed-bottom offshore wind, you have different foundations for different water depths. You often even need different foundations in a given project because on large wind farms the conditions are not the same for all the turbines. But with a floater, it’s always the same foundation, which is a big advantage for serial production.

 

PartnerSHIP: You are currently working on the TetraSpar demonstrator, in partnership with Bourbon Subsea Services. What are your objectives?

H.S.: I’m not trying to develop new wind turbines, because anything Vestas or Siemens can do is much better than what we could do. But they don’t do floaters. The problem is that construction of floaters still needs to be industrialised. So my idea was to develop a form of floater where modular components can be factory-produced, transported by road – one-by-one if necessary – to the quayside, where they can be assembled using an on-shore crane. Thanks to factory manufacture and on-shore assembly, significant cost savings are achieved. The whole process of manufacture and assembly of the TetraSpar closely mirrors that of the wind turbine itself, and this has never been done before. We are currently engaged on assembling a TetraSpar floater in Grenaa, Denmark, working closely with Bourbon Subsea Services, which has been working with us on the upstream engineering of the project. We are planning for it to be transported and installed off the coast of Norway during the summer, although the dates will depend on weather conditions and, of course, the additional problems for an international project like this posed by Covid-19 restrictions and quarantine regulations.

 

PartnerSHIP: Tell us about your collaboration with Bourbon Subsea Services.

H.S.: We knew that this project would involve doing complicated things that have never been done before, so we would need the most experienced player in transporting and installing floating offshore turbines. We issued a tender enquiry according to procurement rules, and BOURBON’s tender was the most attractive in every respect. The key to this cooperation really lies in the work done upstream, between us. BOURBON was involved since September 2019 to detail the impact of the installation phase on the design of the floater. They have given us excellent service in the fine-tuning of the concept so that the risks involved in using new processes are as small as we can make them. Many people might imagine that the main purpose of a demonstrator like this revolves around the weight of the structure, or the cost, or whatever, but matters most is ensuring that everything is done in a safe manner, and then, of course, at a low cost. BOURBON’s cooperation has been vital. It really has been a super, constructive collaboration, and we are extremely happy with it.

How the TetraSpar foundation works

The future of the offshore power sector lies in floating wind turbines, which can be sited in deep seas where wind speeds are greatest. But the production and installation of floaters have to be made cheaper for the energy source to be more economical. The TetraSpar Demonstrator, developed by Henrik Stiesdal, sets out to do just that by industrialising the process. The floater consists of modular tubular steel members that are factory-manufactured, and easily can be transported as individual elements to a large assembly zone at the quayside. The assembly itself is carried out using a special joining system developed for the project and a standard onshore crane. The finished triangular structure is about 65 metres long on the ground, and weighs just over 1,000 tonnes. It is associated with a much heavier keel, a ballasted structure weighing about 1,500 tonnes that is assembled separately, which ensures that the centre of gravity is lower than the centre of buoyancy. After the floater is lowered into the water, the fully assembled wind turbine in installed on it prior to being towed out to sea.

Bourbon Mobility has successfully completed an innovative four-month contract with Subsea 7 (Sept. to December 2020). The end-to-end “Airport-to-Rig” service covered the organisation and execution of all aspects of transportation for more than 1,000 personnel rotations during the Zinia 2 project on Block 17, Angola. Jointly designed with the client, the service increases efficiency and cuts costs. One of the architects of the service, Guillaume Vassout, Chartering Development Manager – Global Projects Centre at Subsea 7, shares his experience with us.

PartnerSHIP: How did the idea of the Airport-to-Rig contract come about?

Guillaume Vassout: It was the culmination of a collaboration based on a long-standing relationship between Subsea 7 and the BOURBON Group. Rodolphe Bouchet from BOURBON and I had discussed improved ways of working and collaborating together during this time.Three years ago, we held a BOURBON Day at our head office in Suresnes, near Paris. Your team came to talk with our management and all our operational departments. It’s rare for a client to organise a full day like that for a supplier, but it allowed both sides to talk in total transparency. The day was very positive for both groups, solidifying our partnership, and one of the things that emerged was the “airport-to-rig” concept. I would like to thank David Bertin (VP GPC & AP) and Frederic Cescutti (Supply Chain Director GPC & AP) for their participation during this Bourbon day and their support to the implementation of the Airport-to-Rig concept.


PartnerSHIP: The first contract has now been completed. How would you say it went?

G.V.: It’s been very positive for us, because BOURBON has been a facilitator, and has helped us deal with Covid restrictions as well as with decrees in Angola that obliged us to make some changes to our plans. The solutions that Bourbon Mobility found enabled us to keep the project on course. They also helped us to meet local requirements with regard to using local personnel in the project management team, logistic team and onboard vessels. I think it’s also been positive for BOURBON, because it has been able to introduce an innovative concept. It’s created a new business model. I’d say that BOURBON and Subsea 7 have learned together. Without their collaborative spirit, transparency and openness, it could never have happened. Changing working methods that have been solidly established for decades is difficult. Many people are afraid of change. But we decided to move ahead and learn together.
 

PartnerSHIP: How do you think the service could be improved?

G.V.: It’s important to provide the right level of accommodation, corresponding to the standards the crews expect. It’s fair to say there were a few challenges to overcome at the beginning. But we were extremely impressed at how quickly Bourbon Mobility and its local organisation, Sonasurf, acted when we told them about our concerns, the issue was rapidly resolved and that created an extremely good impression. And it was also unfortunate that the timing of the contract, due to impact of Covid-19, added further challenges. Two months before it was due to launch, we had to make radical changes to our plans to comply with the restrictions. Hotels had to be changed, quarantine periods had to be managed, and so on. Once again, the speed with which Bourbon Mobility reacted was very impressive Overall, it’s been a great successand I’m proud that we’ve been able to do this together.

PartnerSHIP: What was the feedback from Subsea 7 personnel?

G.V.: The feedback has been very positive, both locally and at the level of our operations management. It was quite a challenge for our Project Director Benoit Vigot who trusted BOURBON – and trusted me, for that matter! – because it wasn’t necessarily easy to have confidence in a system that had never been tested. Overall, everyone was very satisfied with the way the surfers were managed, and once the teething troubles had been resolved, and especially in the context of the pandemic that we were all facing, the feedback was positive.

PartnerSHIP: What will the next phase be? 

G.V.: We’re already working with François Leslé, Bourbon Mobility CEO, on a pandemic-free “2.0 version” of the service. There could be other forms of collaboration, and we could be looking at countries other than Angola. The concept should work in countries where BOURBON is established and we are not yet present.

Equipped with two UHD ROVs, the Bourbon Evolution 802 will carry out a seismic support mission in the summer off the coast of Nigeria. PartnerShip takes this opportunity to look back at the principle of such operations, which are so vital in the context of oil exploitation.

Seismic surveys are designed to determine the potential of an oil field. This operation is generally carried out using sensors (streamers) towed by a vessel, recording the signals emitted by detonations of compressed air emitted by the vessel towards the seabed. When the return of this shock wave is interpreted, it provides information on the geology of the seabed, estimates the state of the oil reserves and makes it possible to give a valuable assessment of future exploitation.

The Bourbon Evolution 802 will be carrying out a “4D” seismic campaign to determine the evolution of the subsurface over time, as oil exploitation has already begun. The MPSV will place sensors (known as “nodes”) at a depth of about 1000 m, positioned with precision by UHD (Ultra Heavy Duty) ROVs. These sensors will receive the shockwaves from the detonations of the transmitting vessel, before being brought to the surface and deposited again remotely. This operation is repeated over 60 days and calls for a dedicated double ROV team of 13 people on board.

This mission shows the versatility of the Bourbon Evolution 800 series. The vessel and its equipment have undergone evolutions to meet the client’s requirements: the vessel’s acoustic positioning system has been optimised and the ROVs’ tether has been extended to increase their horizontal excursion possibilities and thus accelerate the deployment and recovery of the seismic sensors as the vessel is advancing simultaneously.

In anticipation of an activity recovery, BOURBON has recommissioned several vessels in recent weeks, which means significant investments in PMPs (Planned Maintenance Periods) requiring an increasingly agile internal organization. Gontran de la Souchère, Head of Business at Bourbon Marine & Logistics, sheds light on these strategic maintenance operations for PartnerSHIP.

PartnerSHIP: Vessels are being recommissioned after several years of supply chain slowdown in our industry. Does this imply that the trend is being reversed?

Gontran de La Souchère: Recovery is real, but I would call it timid or prudent. New contracts often concern projects that were delayed or postponed and especially over the past year due to Covid crisis. Although we see some visible signs of recovery, we remain cautious with reactivation decisions and will avoid speculative ones. Our strategy is to have recommissioning plans ready for execution based on contract awards. Considering the time it takes to recommission vessels, it requires responsiveness and agility from all those concerned to meet our clients' needs in a complex Covid context. Similar to the PMPs of vessels under contract, these recommissions illustrate the Group's capacity to invest in order to guarantee our clients the highest possible technical availability of our vessels.


PS: What exactly does a PMP consist of?

G. L. S.: It is a guarantee of compliance with regulations and reliability to be able to continue to operate, or to resume service in the case of recommissioning. A PMP generally includes the inspection and maintenance of the engines, propulsion, and all the equipment of the vessel, as well, of course, as hull maintenance when it is in drydock. The vessel must also pass the regulatory inspections required to renew its certification. So, the scope of the operation is very wide. In addition to the preparatory work upstream, i.e. the establishment of the specifications for the work to be performed and the budget, these PMPs take nearly four months to complete after the decision is made to start work. This time is necessary for the purchase and shipping of spare parts, the mobilization of the various operators and the shipyard, as well as the real time necessary for the work, which takes 30 to 45 days. Recommissioning a vessel that has recently been laid up and whose certificates are still valid is an easier process, but even then we do not accept any complacency. No PMP is insignificant and we must make the vessels available to our clients on the required date.
 

PS: Who are the main actors?

G. L. S.: The final objective is to deliver a vessel that complies with our client's contract and expectations, but a PMP is the materialization of a much broader process involving many entities within the Group: The shipmanager in charge of the vessel is the key element and the contracting party for the project. They are responsible for the smooth operation of the PMP in relation with our in-house Bourbon Tech Solutions department (see the box) but also with the affiliate which manages the contract and with Bourbon Marine & Logistics’ sales department. The interactions between all these teams, upstream and downstream, contribute to the effective achievement of the PMP. Similarly, once the PMP is finished, the mobilization of the vessel and its delivery require anticipation and coordination among all parties, especially in the international context we are all aware of today.

PS: Let's go back to the vessels. What criteria are they selected on?

G. L. S.: Once again, we have to be agile and anticipate. When client projects were postponed in 2020, we identified the best candidates for future recommissioning. The main criteria are the condition of the vessel, the duration of its lay-up, and its ability to respond to market needs. But other factors are also essential in the management of a PMP, such as the reactivity of the shipyard. Moreover, we can't ignore the impact of Covid, which may still delay maintenance operations in some countries. It is a factor of uncertainty or complications in order to carry out the work within the allotted time. So, all these factors must be controlled as much as possible, and the PMPs of these last few weeks have comforted us as to the validity of our organization. Being agile and adaptable are undoubtedly our main challenges in this period...