Wireline Magazine Autumn 2020 Issue 49

Allseas' Pioneering Spirit removes topsides from the Tyra field, Denmark. By offering windows of work, operators enable the supply chain to string together projects like these into more effective campaigns.

Robert believes is a differentiator for the company in terms of costs. This also avoids the potential for encountering last- minute structural or engineering issues just prior to lifting. “The last thing you want is a very expensive vessel sitting alongside and you’re not able to use it,” he notes. “Our preference was to de-risk this and complete preparation work in advance. So we do preparation work off the drilling rig and shelter a lot of the activities whilst we do well decommissioning.” As with Shell U.K., Chrysaor gives its contractors flexibility – in this case one calendar year – to plan their removal activities. Contracts were offered in four portfolios across the 38 SNS assets and were awarded to four different companies via separate tender processes. “The lesson is that one size doesn’t fit all,” adds Robert. While the team initially thought the first contract would simply be extended for more work, “the reality was there were different solutions out there for different companies; they all have different approaches, different strengths and vessel capabilities.” “It does mean there is a small amount of additional work as you have to do marine assurance and vetting on multiple vessels, but on the whole it gives us the optimumsolution and it has helped usmanage capacity,” he continues. Onshore disposal of the structures is also handled by the removal contractors, with material brought to two UK yards for dismantling. One thing he reports from regular engagement with contractors is that some providers are further along

the process of being dismantled. According to Chrysaor’s decommissioning, removal and disposal manager, Robert Stevenson, 2020 has seen the removal of ten of those platforms via lift vessels and completion and removal preparations at several others, as well as the decommissioning of 20 wells. At the same time, three subsea campaigns have been completed for various works, two by removal contractors and one by Chrysaor itself. All of which is to say that while COVID-19 has proved challenging, it has not halted progress. “We had no interruptions as a result of COVID on our two lift vessels this year,” Robert affirms. Themain impact forChrysaor’s operations was the implementation of quarantine periods and testing of staff, effectively creating bubbles on the vessels. Robert says COVID management plans were developed to cover mobilisation, operations and emergency, all of which allowed work to continue. “We were pretty keen right from the start that we had COVID management plans in place with each of our contactors and fortunately they bought into this with us,” he says. The physical removals work has largely been handled by one contractor using two heavy lift vessels, over two campaigns running April-July and July-September. However, these lifts mark the end of a much longer process of preparation work on the assets themselves. Chrysaor’smethod is tomobilise its removal preparation teams and its well decommissioning teams on the same rig, allowing well decommissioning work to happen in tandem with topside and jacket preparation, something

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