Patent ID: 9410381
Filing Date: 2016-08-09
CPC Classification: E21B

Claim Text:
1. A riser tension protector for a riser used in operations on a floating vessel comprising: a pair of pneumatic cylinders spaced apart from one another, the pneumatic cylinders having a respective cylinder barrel and a piston head and a piston rod translatable therein, a free end of the piston rods being operatively associated to a top drive system and a lower end of the cylinder barrels being fixed relative to a flowhead assembly; wherein the pneumatic cylinders are charged with a pneumatic pressure sufficient to cause the piston rods to remain fully retracted and stationary in the barrels when an axial load on the riser is under a predetermined operating load threshold and to extend on an upheave of the floating vessel when the axial load on the riser exceeds the predetermined operating load threshold.