Dutch contractors very active on emerging decommissioning market

DUTCH CONTRACTORS VERY ACTIVE ON EMERGINGDECOMMISSIONING MARKET

by Paul Schaap, PAS Publicaties

Just as in the offshore installation market, Dutch contractors have also acquired a leading role in the emerging market for the decommissioning and re-use of offshore oil and gas structures. Above all the willingness to invest in special heavy-lift vessels that have pushed boundaries ever further has earned them global respect. And there is still no end in sight.

Over the past few years, Allseas has attracted most attention to itself with its innovative, single-lift installation/ decommissioning and pipelay vessel Pioneering Spirit, the largest of its kind in the world. This attention reached a milestone in 2017 when a new world lifting record was established in the British sector of the North Sea during the removal of the 24,000-tonne topside from the Brent Delta platform operated by Shell UK. This project is part of a major decommissioning programme that also includes removing a jacket and three other topsides from the Brent field, ranging in weight from 16,000 to 30,000 tonnes. For this year, the decommissioning of the Brent

Bravo topside is scheduled. Using the Pioneering Spirit, topsides weighing up to 48,000 tonnes can be removed or installed at sea. The same applies to jackets weighing up to 20,000 tonnes, in a single section. Also for this vessel, Schiedam-based Huisman has now built a large crane with a lifting capacity of 5,000 tonnes. This crane is to be mounted on the aftership, and will be suitable for deployment in decommissioning work. Later this year, the Pioneering Spirit will be carrying out a decommissioning project on behalf of Aker BP in the Norwegian sector of the North Sea. This project involves removing the topside and bridge from the Valhall QP living quarters platform,

The removal of the Brent Delta topside by the Pioneering Spirit operated by Allseas was a ground-breaking project. (Photograph: Allseas)

at sea. Already on the drawing board at Allseas is yet another new design for an even larger offshore vessel than the Pioneering Spirit. In the future, this vessel will be able to remove topsides from the sea, with a maximum weight of 72,000 tonnes. This gigantic catamaran will be christened Amazing Grace.

New crane vessels Heerema Marine Contractors (HMC) are also shifting their boundaries with the deployment of a brand-new semi-submersible crane vessel that is soon to be handed over. The vessel in question is the Sleipnir, that following her launch will be the largest semi-submersible crane vessel in the world. The vessel is equipped with two cranes built by Huisman, each with a lifting capacity of 10,000 tonnes. In tandem, they are capable of lifting loads up to a maximum of 20,000 tonnes. Even during the construction period, HMC was able to acquire installation and decommissioning contracts for the Sleipnir. Expectations suggest that the crane vessel will be deployed later this year in the Danish sector of the North Sea, as part of the Tyra Development Project on behalf of Total. In the framework of that project, as well as a range of installation work, HMC will also be required to remove 17,000 tonnes of platform parts and bridges, from the sea. Over the past few years, HMC has already removed around 250,000 tonnes of steel from the sea, and expects to remove a further 180,000 tonnes over the coming years. As compared with the last twenty years, this represents massive growth. Alongside the Sleipnir, HMC can also deploy its semi-submersible crane vessels Thialf and Balder, and the monohull crane vessel Aegir.

Other projects due to be undertaken involve the removal of four platforms from the sea in the Norwegian Ekofisk field, as part of the Ekofisk 1 Cessation Plan on behalf of ConocoPhillips Skandinavia. HMC has also been contracted over the coming period to remove seven old gas production platforms from five gas fields off the coast of Nova Scotia, as part of the Sable Island Offshore Energy Project for ExxonMobil. Together with AF Offshore Decom, two new decommissioning contracts were also signed. The first involves the engineering, preparation, removal and disposal of the Brae Bravo platform operated by Marathon Oil, and the second is for the removal of the topside from the Dunlin Alpha platform for Fairfield. Both projects will be carried out in the British sector of the North Sea. The Dunlin Alpha project involves a total of around 20,000 tonnes.

Moreover, HMC has developed and tested a new method that will further push the boundaries of lifting operations. The method in question is the QUAD lifting method that enables HMC to integrally install or remove oversized topsides and jackets. This new method was tested with the semi-submersible crane vessels Thialf and Balder. The Sleipnir can also employ the same method, in combination with either the Thialf or Balder.

Other players Other Dutch contractors active in the decommissioning market include Seaway Heavy Lifting (SHL) and Royal Boskalis. For this work, SHL operates the monohull crane vessels Seaway Strashnov and Seaway Yudin. Although in 2018 both vessels mainly carried out installation work in the wind energy sector, in September 2018, the Seaway Yudin was responsible for removing the twenty year-old

One of the semi-sumersible heavy-lift crane / accomodation vessels ofOOS International. (Photograph: OOS International)

With its Seaway Yudin, SHL recently removed a gas productionplatform from the Markham field. (Photograph: PAS Publicaties)

topside and jacket from the ST-1 gas production platform operated by Spirit Energy, from the Markham field in the British sector of the North Sea, in two single lifts. For a number of years, Boskalis has also been heavily involved in removing satellite platforms from the sea, in particular in the British sector of the North Sea. The company usually deploys Taklift floating sheerlegs for this work, but recently took delivery of the Bokalift 1. This monohull crane vessel is equipped with a Huisman crane with a lifting capacity of 3,000 tonnes.

A recent arrival to the market is the jack-up vessel Apollo operated by GeoSea, built according to a design by GustoMSC. This brand-new vessel was responsible for removing the Q1 Halfweg production platform from the Dutch sector of the North Sea at the end of 2018.

Another newcomer keen to play an important role in the decommissioning market is OOS International. On behalf of this Dutch contractor, three semi-submersible heavylift crane/ accommodation vessels are currently under construction in China. The first, the OOS Serooskerke,

is due to be handed over in the second quarter of this year. Number two, the identical OOS Walcheren, will follow in the first quarter of 2020. Both vessels will be equipped with two 4400-tonne cranes to be fabricated by Huisman. The third vessel, that will be christened OOS Zeelandia, will be equipped with two cranes each with a lifting capacity of 12,500 tonnes, making this one of the largest semi-submersible crane vessels in the world, alongside the Sleipnir.

Nexstep Another party closely involved in the decommissioning and re-use market is the national platform Nexstep, established in 2016 in the Netherlands. The platform is a joint initiative by EBN (the Dutch State) and the Dutch oil and gas industry, represented by NOGEPA. The aim of the platform is to promote safety during decommissioning projects, to reduce decommissioning costs by around 30 percent and to deliver a solid contribution to ensuring the removal and re-use of oil and gas structures from the sea, in the Netherlands, in the most environmentally friendly manner possible n

The world’s largest semi-submersible crane vessel Sleipnir operating for HMC will also play an important role in the decommissioning market.(Photograph: Piet Sinke/maasmondmaritime.com)