GUIDE TUBE FOR A FLEXIBLE UPRIGHT COLUMN (RISER) FOR MARINE PETROLEUM EXPLOITATION

摘要

A stress-limiting device for a flexible riser which stress-limiting device glides in a set of guides rigidly attached to an articulated structure emplaced in the deep sea. The device includes an elastic guide tube element coaxial to the riser, with the stiffness of the guide tube increasing progressively from the top to the bottom of said guide tube, whereby the stiffness characteristic is appreciable in the lower region of the guide tube, which lower region is affixed to a structure attached to a wellhead or the like via an aligned fitting, whereby the guide tube is held in contact with the riser by the intermediary of a plurality of support mechanisms one of which includes a fitted bushing which glides in the lower, rigid part of the guide tube. The device makes it possible to shut down and resume operation of offshore wells which have been equipped for production.