Abstract: A device includes an upstream section defining a water introduction inlet; an injector for injecting a process fluid into the water introduced into the upstream section; an intermediate section mounted downstream of the injector for receiving the water containing the process fluid; a downstream section for conveying water to the fluid transport pipe being laid. The device also includes a liquid volume compensation reservoir, having a variable receiving volume of water discharged from the fluid transport pipe, a connector to which are connected the intermediate section, the downstream section and the liquid volume compensation reservoir, wherein the inlet cross-section of the compensation reservoir is greater than 40 times the internal cross-section of the intermediate section taken at the connector. This device operates reliably even when the stretch of water is rough.

Abstract: A device includes an upstream section defining a water introduction inlet; an injector for injecting a process fluid into the water introduced into the upstream section; an intermediate section mounted downstream of the injector for receiving the water containing the process fluid; a downstream section for conveying water to the fluid transport pipe being laid. The device also includes a liquid volume compensation reservoir, having a variable receiving volume of water discharged from the fluid transport pipe, a connector to which are connected the intermediate section, the downstream section and the liquid volume compensation reservoir, wherein the inlet cross-section of the compensation reservoir is greater than 40 times the internal cross-section of the intermediate section taken at the connector. This device operates reliably even when the stretch of water is rough.

Abstract: A device includes a hollow rigid member (40) and a curvature limiter (42) movable relative to the hollow rigid member (40). A releasable device (46) for axial immobilization of the curvature limiter (42) on the flexible line (18) in at least one first direction along a travel axis (X-X?). The axial immobilization device (46) includes a locking member (90) axially secured to the flexible line (18), and a member (92) for fitting the locking member (90), axially secured to the curvature limiter (42). Those members (90, 92) are movable relative to each other around the travel axis (X-X?) between a configuration for axial immobilization of the flexible line (18) on the curvature limiter (42), and a configuration for axial travel of the flexible line (18) across the curvature limiter (42).

Abstract: 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.

Abstract: A device includes a hollow rigid member (40) and a curvature limiter (42) movable relative to the hollow rigid member (40). A releasable device (46) for axial immobilization of the curvature limiter (42) on the flexible line (18) in at least one first direction along a travel axis (X-X?). The axial immobilization device (46) includes a locking member (90) axially secured to the flexible line (18), and a member (92) for fitting the locking member (90), axially secured to the curvature limiter (42). Those members (90, 92) are movable relative to each other around the travel axis (X-X?) between a configuration for axial immobilization of the flexible line (18) on the curvature limiter (42), and a configuration for axial travel of the flexible line (18) across the curvature limiter (42).

Abstract: 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.