TVO’s Hercules™ high-strength BOP tethering system makes it possible for a deepwater floater fitted with a dynamic positioning system to work safely in shallow water.
In a standard installation, four large, winged suction piles, designed for loading above the mudline, are positioned on the seabed to anchor the components of the tensioning units. The units are lowered onto the suction piles from an installation vessel and positioned on the anchors
by an ROV, which pulls the tethering lines from each unit to the BOP, where the lines are attached. With the lines secured, the tensioners tighten the mooring lines to limit movement over the wellhead.
Once the components of the system are connected, the system is passive. If a drift off or drive off occurs, any load increase transfers to the tensioners and suction piles, which hold the BOP in position and ensure well integrity is not compromised.
