A method is provided for installing a pipeline on the seabed from a marine pipelaying vessel, including initiation, pipelaying, and abandonment of the pipeline. An embodiment of the abandonment of the pipeline includes halting pipelaying and engaging a hang-off clamp with the pipeline at a position below one or more tensioners, transferring the weight onto the hang-off clamp and holding the seagoing pipeline in the firing line, severing the pipeline, connecting the initiation cable to the lower end of the pipeline held by the one or more tensioners, transferring pipeline tension onto the initiation cable, releasing the one or more tensioners, so that a section of the pipeline is held in the firing line between the pipeline diverter and the initiation cable, vacating the firing line by at least displacing both the pipeline diverter and the initiation cable sheave and thereby displacing said section of the pipeline from the firing line, arranging the A&R cable in the firing line, connecting the A&R cable to the upper end of the seagoing pipeline held in the firing line, releasing the hang-off clamp, and operating the A&R winch and thereby lowering the pipeline onto the seabed.

A method is provided for installing a pipeline on the seabed from a marine pipelaying vessel, including initiation, pipelaying, and abandonment of the pipeline. An embodiment of the abandonment of the pipeline includes halting pipelaying and engaging a hang-off clamp with the pipeline at a position below one or more tensioners, transferring the weight onto the hang-off clamp and holding the seagoing pipeline in the firing line, severing the pipeline, connecting the initiation cable to the lower end of the pipeline held by the one or more tensioners, transferring pipeline tension onto the initiation cable, releasing the one or more tensioners, so that a section of the pipeline is held in the firing line between the pipeline diverter and the initiation cable, vacating the firing line by at least displacing both the pipeline diverter and the initiation cable sheave and thereby displacing said section of the pipeline from the firing line, arranging the A&R cable in the firing line, connecting the A&R cable to the upper end of the seagoing pipeline held in the firing line, releasing the hang-off clamp, and operating the A&R winch and thereby lowering the pipeline onto the seabed.

The invention concerns a process and a device for laying a subsea pipeline according to the J-lay or S-lay method wherein straight sections are mounted onshore, dried and degassed then closed by plugs. The sections are loaded on a pipe-laying ship, are separated from their plugs before the welding. At the welding of each bulkhead a short pumping is operated to reduce the pressure in the part of the annulus located between the two last bulkheads and then the opening leading to the annulus are sealed.

The invention concerns a process and a device for laying a subsea pipeline according to the J-lay or S-lay method wherein straight sections are mounted onshore, dried and degassed then closed by plugs. The sections are loaded on a pipe-laying ship, are separated from their plugs before the welding. At the welding of each bulkhead a short pumping is operated to reduce the pressure in the part of the annulus located between the two last bulkheads and then the opening leading to the annulus are sealed.

A system includes a foundation with a post mounted on the foundation top surface and a pipe module configured to couple to the foundation. The pipe module has a yoke to cooperate with the post to engage the pipe module with the foundation. The pipe module is connected to the end of a pipeline and is configured to slide along the foundation responsive to longitudinal and angular movements of the end of the pipeline. A method includes deploying a foundation subsea and securing the foundation to a seafloor. The foundation has a post. The method includes deploying the pipe module via the pipeline suspended by a pipe module installation machine. The pipe module has a yoke. The method includes engaging the yoke with the post, paying out the pipeline to lower the yoke, and lowering and engaging the pipe module with the foundation.

This device comprises a drum (42) to be driven in rotation about a central axis (B-B′), wherein the drum (42) defines a circumferential casing (50) for winding the elongate element around the central axis (B-B′), wherein the elongate element is intended to form at least one turn around the central axis (B-B′) on the circumferential casing (50). It comprises a mechanism (44) for driving the turn(s) of the elongate element along the circumferential casing (50). The drive mechanism (44) comprises at least one assembly (80) following movement of the turn in a direction of movement (D) forming a non-zero angle with the local axis of the turn, taken at a contact region of the turn on the movement assembly (80).

This device comprises a drum (42) to be driven in rotation about a central axis (B-B′), wherein the drum (42) defines a circumferential casing (50) for winding the elongate element around the central axis (B-B′), wherein the elongate element is intended to form at least one turn around the central axis (B-B′) on the circumferential casing (50). It comprises a mechanism (44) for driving the turn(s) of the elongate element along the circumferential casing (50). The drive mechanism (44) comprises at least one assembly (80) following movement of the turn in a direction of movement (D) forming a non-zero angle with the local axis of the turn, taken at a contact region of the turn on the movement assembly (80).

A method of laying a pipeline from a laying vessel into a body of water includes guiding the pipeline along a supporting structure of a laying ramp. The method also includes acquiring a first data item correlated to a position of the pipeline at a free end of the laying ramp using an optical sensor or an acoustic sensor. The method further includes determining whether the acquired first data item is within an acceptance range predetermined as a function of a configuration of the supporting structure and a size of the pipeline. Additionally, the method includes emitting an control signal when the acquired first data item is not within the acceptance range. Determining whether the acquired first data item is within the acceptance range includes processing the acquired first data item to compare it the first data item to an information stored in a memory.

A method of laying a pipeline from a laying vessel into a body of water includes guiding the pipeline along a supporting structure of a laying ramp. The method also includes acquiring a first data item correlated to a position of the pipeline at a free end of the laying ramp using an optical sensor or an acoustic sensor. The method further includes determining whether the acquired first data item is within an acceptance range predetermined as a function of a configuration of the supporting structure and a size of the pipeline. Additionally, the method includes emitting an control signal when the acquired first data item is not within the acceptance range. Determining whether the acquired first data item is within the acceptance range includes processing the acquired first data item to compare it the first data item to an information stored in a memory.

A method for installing an accessory onto a pipeline to be laid on the seabed, includes launching the pipeline from a first position of a tower in which the tower is at an angle α with respect to the vertical; stopping the launch of the pipeline, and hanging off the launched pipeline in a hang off module; positioning an accessory in a tower firing line; attaching the accessory to the launched pipeline in the hang off module and to at least one A&R cable; suspending the accessory and the launched pipeline from an A&R system; disengaging the hang off module from the launched pipeline; pivoting the pipeline launch tower to an accessory launch position in which the tower is at an angle γ that differs substantially from angle α, such that a pipeline launch trajectory is created which is large enough to launch the accessory and the launched pipeline with the A&R system.