Riser support system

Abstract

A device is described for supporting a riser ( 10 ) which is suspended from a vessel ( 1 ). The riser is suspended via a gimbal. According to the invention the gimbal consists of two frame parts ( 26, 28 ) surrounding an intermediate tubular ring ( 30 ) which is filled with a fluid. Substantial bending moments on the riser due to the vessel's movements can thereby be avoided.

1 . A suspension device for at least one riser which extends from a floating vessel, the floating vessel including a drill floor with an opening through which the riser extends, the suspension device comprising:
 a gimbal which comprises two frame parts, one of which is secured to the riser and the other of which is secured to the vessel, the frame parts being spaced apart from each other; and   an intermediate, flexible element which is mounted between the frame parts and is filled with an incompressible fluid.   
     
     
         2 . A device as indicated in  claim 1 , further comprising means for regulating the pressure in of the fluid in the element. 
     
     
         3 . A device as indicated in  claim 1 , wherein the element is stiffened by a reinforcing material. 
     
     
         4 . A device as indicated in  claim 3 , wherein the reinforcing material is at least one selected from the group consisting of carbon, Kevlar, glass and metal. 
     
     
         5 . A device as indicated in  claim 1 , wherein the gimbal is supported on a rotary table on the vessel. 
     
     
         6 . A device as indicated in  claim 1 , wherein the gimbal comprises a number of locking devices for releasably locking the first and second frame parts together.