Drilling vessel wave motion compensator - with pneumatically pressurized rams between travelling block and drill string supports

摘要

To compensate for the rise and fall of a drilling vessel, the drill string support is carried by at least one chain which extends from the support over a pulley carried by one of two relatively moveable members defining a pneumatically pressurised chamber, the other member being connected to a frame carried by the travelling block, the other end of the chain also being connected to one frame. The pressure in the chamber is adjustable to a desized level which will remain virtually constant during movement of the vessel.