FoundOcean, the subsea and offshore grouting specialist for the global energy construction industries, has won the offshore grouting contract for the North Rankin B (NRB) platform installation, Western Australia, through Heerema Marine Contractors Australia.
The North Rankin B jacket is to be secured to the seabed by 16 primary piles arranged in clusters of four at each of the four corner legs of the jacket. The primary piles are to be inserted through jacket pile sleeves. Connection between the primary piles and the sleeves will be achieved by placing grout into the pile / sleeve annulus.
The jacket will stand at 150m tall in approximately 125m of water. The piles will be inserted to a depth of 306m below sea level into a drilled hole 182m deep and 2.5m in diameter – that is wide enough to drive a standard family car down.
The grouting operation is likely to start in August 2011 and will take approximately two months to complete. The project is set to recover remaining low pressure gas from the North Rankin and Perseus gas fields. The North Rankin B platform will be connected by two 100m bridges to the existing North Rankin A platform.
Jim Bell, managing director at FoundOcean, is excited to have been awarded this contract. “This is a very interesting project for FoundOcean as the NRB foundations are mammoth compared to a ‘regular’ jacket. This will be our biggest pile grouting project by cement grout volume, although we have pumped larger volumes for different applications.” He continues: “The seabed in Western Australia is particularly complex, which means that the foundations will need to be drilled. The piles will be inserted into pre-drilled holes 182m below the sea bed and then grout will be pumped into these sockets to secure the platform to the seabed.”
FoundOcean has completed foundation grouting for 170 platforms for Heerema since 1974.