WorldOil

Rig floor equipment: New diverter technology improves sealing

Drilling offshore in deep water poses unique challenges over drilling on land or from a jackup fixed to the seafloor in relatively shallow water. Whereas fixed platforms allow for little to no vertical movement of equipment, in deep water floating drilling and production structures must be able to move, while the drillstring remains fixed and in tension. These floating systems are differentiated in two ways: 1) wellheads are attached to the seafloor instead of the platform and 2) vertical movement, heave and rotation, occurs. When an offshore drilling rig heaves or rotates, its position shifts relative to the drill pipe. A diverter attached to the vessel's drillfloor moves up and down around the drill pipe with the rig, possibly 30 ft or more. In the past, if a floating rig experienced a blowout, the diverter would be closed around the pipe and return lines to send gas to the atmosphere.