The Mars™ tethered BOP system arrests BOP stack motions above the wellhead, substantially reducing wellhead cyclic stress, enhancing fatigue life, and increasing the rig watch circle. This solution makes it possible to access wells in cases where the wellhead was not designed to handle the loads and strain induced by modern, large and heavy BOPs.
A specially designed, winged suction pile is placed on the seabed from an installation vessel to act as a foundation for the tensioner units, with an ROV executing proper placement. Next, a tensioner is lowered onto the anchor, and the ROV makes sure it is mounted securely.
Four suction piles with mounted tensioners are placed strategically around the wellhead. When the tensioners are all in place, the BOP is installed on the wellhead, and the ROV pulls the mooring lines to connection points on the BOP. The mooring lines are pulled taut to predetermined values to secure the BOP and arrest its movement.
The BOP tethering system improves wellhead integrity, providing stability and subsea safety by reducing extreme bending to ensure the capacity of the wellhead and casings are not exceeded.
