Abstract: 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.

Abstract: An arrangement for supporting a well pipe emerging from the sea bottom adjacent a drilling platform which is articulated on a base by means of a universal joint, the base being mounted on the sea bottom adjacent the point where the well pipe emerges. A second base surrounds the portion of the well pipe emerging from the sea bottom, and supports a cylindrical seat by means of a universal joint at a point vertically aligned with the well pipe and horizontally aligned with the universal joint which supports the drilling platform. The upper part of the cylindrical seat surrounds the well pipe in such a manner that the well pipe can slide longitudinally within the seat. A generally horizontal arm is articulated at one end to the drilling platform at a point vertically above the universal joint which supports the platform.