Method of installing an underwater riser

摘要

A method of installing an underwater riser includes anchoring an installation to the seabed; coupling a tubular pipe to the installation; equipping the installation with a submersible float; submerging the float and the pipe, while the float and the pipe are being held from a surface vessel; a cable and a return device are installed on the seabed installation so that the cable can be connected to the pipe; attaching a submerged hauling buoy to the hauling cable; then removing ballast from the float in order to compensate for the tensile forces corresponding to the weight of the float and the pipe and to some of the load applied to the cable; and finally, anchoring of the hauling buoy to the installation and gradually releasing the float.