Deep water riser or column for connecting floating support to underwater point, comprises flexible part connected to underwater point, and rigid part connected to flexible part and floating support

A deep water pipe for transferring a fluid between a floating support (1) and a point below and along the surface, has a flexible part (7) connected at one end to the underwater point and a rigid part (6) connected at one end to the flexible part and at the other to the floating support by a holder (9) allowing it to be put under tension by its own weight Preferred Features: The flexible part is defined by establishing the extreme movements of the floating support, supposing that the movements of the top of the flexible part are identical to those of the floating support, and choosing a position (Ph) for the top end of the flexible part in the vertical and dimensioning the flexible part to take at least the predetermined movements taking into account the following parameters: the internal pressure (Pint), the external pressure (Pext), the type of fluid, maximum forces such as maximum traction (Tmax) seen by the flexible part, and the value of the maximum allowable curvature (courbmax). If the flexible part cannot achieve the conditions of use, the position Ph is changed. The rigid part is defined for given means of holding and a diameter (Dr). Its length (Lr) is chosen to be equal to the distance in equilibrium conditions between the top of the flexible riser and the means of holding. Its thickness (er) is defined to fit the constraints of: the weight of the pipe, the hydrodynamic forces, And forces induced by movement of the floating support and internal and external pressures. The rigid part of the riser inside or next to the floating support is checked to ensure it does not come into contact with the floating support. The stages of dimensioning the two parts of the riser are done under static conditions or under dynamic conditions. Means of thermal insulation are includes on at least the rigid and/or flexible parts. Conduite pour grandes profondeurs d'eau permettant le transfert d'un fluide entre un support flottant (1) et un point situé en dessous et à une distance éloignée de la surface de l'eau, caractérisée en ce qu'elle comporte :- au moins une partie flexible (7) en liaison par une de ses extrémités avec le point situé en dessous de la surface, et- au moins une partie rigide (6) en liaison avec la partie flexible par une de ses extrémités et par la deuxième extrémité avec le support flottant,- ladite partie rigide étant maintenue au support flottant à l'aide de moyens de maintien (9) permettant à cette dernière d'être essentiellement mise en tensi