Page 36: of Offshore Engineer Magazine (Mar/Apr 2020)

35 37

FEATURE EPIC

Source: Aker Solutions ormally unmanned installations (NUI) aren’t new. platform when it started production in 2018 – now called an

In the 1970s and 1980s a large number of mini- unmanned wellhead platform (UWP, also trademarked). mum facility platform designs were adopted in the A big enabler for that was the growing availability of walk-

NGulf of Mexico to exploit marginal ?elds. Minimum to-work vessels, initially developed for the offshore wind in- facilities are common in the UK’s southern North Sea where dustry but that have been used in oil and gas, not least after a shallow water made them economical as satellites to hubs. spate of helicopter crashes that made alternatives attractive, as

However, there’s now increasing activity in the unmanned well as increasing decommissioning work, where extra work- platform space; ?xed and ?oating. Some of this activity was ers can be housed on ?otels and walk across to platforms, a reaction to rising subsea costs. While subsea offered an un- embedding these gangway systems into the industry. Use of manned solution, it was becoming increasingly uneconomic, walk-to-work vessels meant that a helideck and the ancillary

Equinor argued, and instead decided to develop the Oseberg equipment needed to service it was no longer needed, reduc-

Vest?anken 2 project as an unmanned platform (“wellhead on ing costs of the wellhead on a stick. a stick”, as it was called at the time), having made public its Aker BP took a similar approach with its Valhall Flank West concern over the competitiveness of subsea costs. project, using an unmanned platform, and even hailing its ?rst

That led to the remote operated Oseberg H platform, oper- campaign using a gangway for access from a vessel to facility, ated from Oseberg central, billed as Norway’s ?rst unmanned for hook up operations, in a press release, although day-to-day 36 OFFSHORE ENGINEER OEDIGITAL.COM