Page 28: of Offshore Engineer Magazine (Jan/Feb 2021)

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FEATURE PLUGGING & ABANDONMENT

Setting up the test rig; left to right:

Andy Moore (Rawwater), Adam

Thomas (Rawwater) and Wellstrøm

Tools ready for offshore mobilization from isol8 UK base. CEO, Gert Rege.

Source: isol8

Source: Rawwater string but this time forming a 7-inch barrier. After that, isol8 hybrid P&A barriers in combination with competent cement.

is going to isolate a 7-inch perforated well out to the 8 ¼ inch rock in their ?rst subsea well application. This is a water shut BiSN breaks own records off project, to seal beyond the 7-inch casing and isolate a low- UK-based BiSN, which works with thermite to melt er zone from an upper zone. The next North Sea project will bismuth-based alloys into plugs, has also been hitting mile- then be a 3 ½ tool to form a bonded-alloy barrier inside4-½ stones. The ?rm surpassed its record for the largest bismuth tubing and the 9 5/8-inch annulus. plug with a 15,382kg (33,911lbs) P&A tool deployed in a

As well as using a solid thermite heater, isol8 also ?uidizes 30-inch casing in a well on Aker BP’s Valhall ?eld in the thermite to ?ll the wellbore. For the 4-½ by 9 5/8-inch an- Norwegian North Sea, 290km south of Stavanger – equiva- nulus P&A project, for example, instead of a solid thermite lent to the size of 11 cars, the ?rm highlighted. Its previous heater, isol8 will ?uidize the thermite to create a platform record was a 4,695kg (10,351lbs) tool inside an 18 5/8-inch through the perforated annulus on to which the alloy can set casing on the same ?eld in 2018. The latest plug, based on to form an ultra-high expansion seal. But Louden says that BiSN’s Wel-lok M2M technology, was an environmental whilst isol8’s technology can be used as an alternative to ce- plug, set in September last year. The weight required the use ment, he expects that alloy-based plugs will be used to form of special lifting cradles to be able to lift the tool, measuring 28 OFFSHORE ENGINEER OEDIGITAL.COM