Patent ID: 8734055

Claim:
A method for assembling an operating rig for a fluid in a body of water, of the type comprising the following steps: bringing a buoy to a placement position at a surface of the body of water and at the placement position to which the buoy is brought, the buoy is substantially facing an anchoring region at the bottom of the body of water, the bringing of the buoy comprising displacing the buoy by towing the buoy, while the buoy is partly immersed in the body of water, between a remote position of the buoy which is remote from the placement position and the placement position of the buoy by displacing at least one floating towing structure for towing the buoy between the remote position located away from an anchoring region at the placement position and the placement position located facing the anchoring region, while maintaining the buoy partly immersed at the surface of the body of water during the towing; when the buoy is at the placement position; connecting a downstream point of a fluid transport pipe to the buoy; completely immersing the buoy under the surface of the body of water before or after the connection step; deploying in the body of water an intermediate section of the transport pipe from the downstream point to at least as far as an upstream point of the pipe; anchoring the upstream point on an anchoring element fixed on the bottom of the body of water in the anchoring region; tensioning the intermediate section of the transport pipe between the downstream point and the upstream point under the effect of the buoyancy of the buoy, in order to maintain the intermediate section substantially vertical in the body of water; connecting on the intermediate section a lower section intended to be connected to the bottom assembly and an upper flexible section intended to be connected to the surface assembly; wherein the buoy has a height, taken along a vertical axis (A-A′) when the intermediate section is tensioned, of less than 1.5 time its maximum transverse dimension, taken transversely with respect to the vertical axis (A-A′); and the intermediate section is formed by a flexible pipe, the flexible pipe being capable of being wound and unwound reversibly without any significant plastic deformation on a drum or on a basket.