Deconstruction works

Many of the oil & gas installations around the world are reaching the end of their economic production life. Decommissioning of offshore installations presents a major challenge from an environmental, technological and economical perspective. Scaldis offers an economical solution by using its multipurpose vessels Rambiz and Gulliver which allow all required operations to be executed from a single vessel.

Deconstruction works include the following activities : 

  • Heavy lift removal of obsolete oil & gas installations all over the world;
  • Deconstruction and demolition of abandoned installations;
  • Preparatory works;
  • Dismantling onshore.

Projects

Scaldis decommissions offshore platform in 3 days
Scaldis decommissions offshore platform in 3 days

In April 2016 Tullow Oil awarded SCALDIS with the contract to remove the offshore Horne & Wren platform. SCALDIS immediately started the extensive preparations and engineering works.

The Plugging & Abandonment (P&A) of wells and offshore preparatory works were carried out from the jack-up vessel ‘Kraken’. While Simultaneous Operations (SIMOPS) of the P&A took place, our team also performed Non-Destructive Testing (NDT) of the topside pad eyes, installed an access platform between the jacket and topside and placed a gangway landing platform on the jacket.

RAMBIZ, our heavy lift vessel, was mobilized from Flushing, the Netherlands, on March 10, 2017 and arrived at the offshore field two days later. Over the following three days, the complete platform was decommissioned; an in- and out-seabed survey was carried out; the topside was cut, lifted and sea fastened onboard the RAMBIZ; the jacket piles were dredged and cut; the Internal Lifting Tools (ILT’s) were installed; and the jacket was lifted. The RAMBIZ returned to a disposal yard in Flushing with the topside stowed on deck and the jacket suspended in the PS crane.

“The joint team effort from all parties involved including the outstanding cooperation from the client was key to this successful project,” said Igor Mastenbroek, Project Manager at SCALDIS. “The beautiful weather, excellent crew, detailed preparations and our good alliance with Tullow Oil also helped us to safely execute the decommissioning well ahead of schedule.”

“It has been an absolute pleasure to work closely with the SCALDIS team,” said Darin Scales, Senior Project Engineer for Tullow Oil UK Ltd. “Throughout the project lifecycle, SCALDIS has exceeded expectations and I would definitely recommend them for similar projects in the future. It was a slick and seamless operation.”

Decomm. of the Draugen Floating Loading Platform (FLP)
Decomm. of the Draugen Floating Loading Platform (FLP)

The Draugen Floating Loading Platform (FLP) has been in operation in the Draugen Field, Norway since 1993. It was removed from the offshore site and moored temporarily in Bømlafjord (Kvaerner Stord base), Norway, for further dismantling.

HLV Rambiz removed the helideck and topside from the spar, and positioned them onshore at Kvaerner decommissioning yard for further dismantling.

Kvaerner pre-installed a subsea lifting frame at the bottom end of the spar. With Rambiz alongside the rigging for the spar downending was connected to the subsea lifting frame. Rambiz lifted up the bottom end, while a steering tug controlled the heading of the top of the spar coming down. After completion of the downending into the horizontal floating position, the spar was transported suspended in the Rambiz cranes to the Kvaerner dry-dock. Then the  spar was placed in the dock for further dismantling. 

Removal of the K10-B platform
Removal of the K10-B platform

In June 2014, HLV Rambiz started the offshore removal phase of project K10-B. During this phase the bridge, the wellhead platform and the living quarters were removed. All items except the wellhead jacket were transported to the dismantling yard by barge. The wellhead jacket was lifted from the seabed and transported in the hooks of the HLV Rambiz to the dismantling yard. The Rambiz had to leave the K10-B field at this point due to other commitments. Further removal of the production platform was scheduled to be executed in September 2014.

Removal of the Camelot platform
Removal of the Camelot platform

In 2011 Scaldis was contracted by Helix USA to remove the Camelot platform from the southern part of the North Sea at the end of July 2012. The Camelot platform was located +/- 25 Nm offshore Great Yarmouth in UK waters. Both platform (weight of +/- 1200 tonnes) as well as supporting jacket structure (+/- 700 tonnes) needed to be scrapped at a disposal yard.

Upon arrival of the HLV Rambiz, the deck was cut from the jacket using flame cutting. The jacket piles were dredged to 4 metres below seabed and cut using an internal abrasive water jet cutting tool. The deck was transported on a cargo barge to the scrapping yard. The jacket was lifted from the seabed and transported in the hooks of the HLV Rambiz to the scrapping yard.

Decommissioning of the Welland platform
Decommissioning of the Welland platform

In 2010 Scaldis was contracted by Perenco UK limited to remove the Welland platform from the southern part of the North Sea.  The platform was to be re-used, while the supporting jacket structure was scrapped at a disposal yard.  The platform needed to be removed in January 2011.  In order to minimise the impact of the weather, Scaldis engineered various weather contingency systems so all available weather windows, no matter how short could be used.  Upon arrival of the HLV Rambiz, the deck was cut from the jacket using abrasive water jet cutting.  The jacket pins were dredged to four metres below seabed and cut using another abrasive cutting tool.

The deck was transported on a cargo barge, refurbished and re-lifted onto a jack-up barge several months later.  The jacket was lifted from the seabed and transported in the hooks of the HLV Rambiz to the scrappping yard.

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