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Removal and recycling of H7

When AF was commissioned to remove and recycle platform H7 from an area in the North Sea exposed to extreme weather, completely new methods were developed and patented for the easy installation of a lifting point on structures to be lifted offshore.

Project status

    Jun 2011
    Jun 2013

    About the project

    After thorough and extensive surveys and planning, 9,000 tonnes of steel on platform H7 was removed and transported ashore for source separation and recycling. AF developed a completely new method for removing structures from offshore locations where wind and snow could present a challenge. By using a so-called jack-up ship, the platform was lifted piece by piece onto the ship, which stood steady on six legs on the seabed.

    • NOK 420 million

      Contract value

    • 9000

      Total weight of steel

    AF Gruppen

    Raunes Vats

    New and innovative method

    H7 operated in the German sector of the North Sea from 1977 and was connected to the Norpipe gas pipeline, which runs from Ekofisk to Germany. Through the Oslo–Paris Convention (OSPAR), Norway has committed itself to the responsible removal and recycling of platforms that are not in use. AF's task was to remove steel, mechanical equipment, pipes, cables, concrete, marine biofouling and anodes. 

    A new and patented method in which windmill vessels with six legs, which can be jacked down to a depth of 80 metres, where they stand steady on the seabed, was used. The ship was then raised so that it reached the height of the platform’s deck. From this point, the platform was dismantled piece by piece and transported to the AF Environmental Base at Vats for source separation and recycling. The same solution was subsequently used when AF removed B11, another compressor platform in the North Sea. 

    H7 was removed in 2013 within budget and the stipulated time frame, and without any lost-time injuries.

    The same AF team designed and carried out the project. The transfer of knowledge from H7 meant that AF used 39 fewer days to remove B11 than H7. This equates to 30% less time usage. 

    The B11 platform was removed in 2015 within budget and the stipulated time frame, and without any lost-time injuries.

     

     

     

    Project info

    Project type: Removal and disposal offshore
    Business unit: AF Offshore Decom
    Customer: Statoil på vegne av Gassco

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