Abstract: This invention concerns a seabed device to support tubing connected to a wellhead.The device comprises a flange at the bottom end of the tubing, fitting into a rigid frame attached to and detachable from a framework located on the seabed, the said flange being connected to the wellhead by the same number of flexible pipes as there are passages in the tubing, with a connection-disconnection device to attach these flexible pipes to the wellhead.This device relieves the wellhead of stresses transmitted by the tubing.

Abstract: In a method of immersion of a massive part such as a hydrocarbon storage tank on the ocean floor, the storage tank is placed over the immersion site, then lowered by means of ballast floats so that the top of the tank is close to the surface of the water. The lower end of a first rigid column also fitted with ballast floats is attached to the tank and pivotally displaced from a horizontal position at the surface of the water to a totally submerged vertical position. A number of columns are attached successively in end-to-end relation and pivotally displaced until the storage tank reaches the ocean floor.

Abstract: A device for connecting successive duct sections, especially between a sea-bed petroleum storage tank and a surface platform, comprising a flexible tubular joint secured at both ends to two cylindrical coupling units slidably mounted respectively within two duct sections to be coupled together, remotely operated means for anchoring each coupling unit within an end-shoe and remotely operated means for forming a tight seal between the external surface of the coupling units and the internal surface of the duct sections.