The offshore operation consist in installation platform at a depth of 32 meters.
This platform consists of :
• a 36″ conductor pipe through which the well is drilled ;
• an underwater structure made of two oblique bracons and fixed onto the sea bottom with two 30″ piles. The fixing of the platform was done by grouting. However, to grout the required areas, inflatable seals were required which acted as formwork cores. In addition, these inflatable seals had to have enough power to hold the platform without it being fixed. This can be achieved with inflatable annular seals enable to support the whole platform in case of meteorological event, without being cemented.
We have designed a system made of annular inflatable seals and slugs enable to transmit the pneumatical force onto another pipe. Centering and tightness are achieved through the compression and extension forces. The permissible axial strength was so considerable so that the inflatable seals has a shearing movement and not a crawler movement.
The inflatable annular seals were inflated at 15 bar and could support a weight of 150 tons.
The operation was achieved successfully.