On-board fabrication of pipe-in-pipe assemblies
AssigneeShanghai Zhenhua Heavy Industries Co., Ltd.
InventorsAlessandro Fenini, Laurent Daney
Life of this patent
Estimating the term…
Abstract
A pipelay vessel having two pipe string manufacturing lines and a firing line, wherein the pipe string manufacturing lines are designed for simultaneously handling two different pipe outer diameters for use as an inner pipe and an outer pipe respectively. Further, the vessel has a pipe-in-pipe assembly workstation for assembling the inner pipe and the outer pipe in a pipe-in-pipe configuration. The vessel is designed with a lay-out which allows for producing offshore pipe-in-pipe strings from single joints, wherein available space is optimally used and pipe-in-pipe strings can be produced safely offshore.
Claims18
A pipelay vessel, comprising two pipe string manufacturing lines and a firing line, wherein the pipe string manufacturing lines are designed for simultaneously handling two different pipe outer diameters for use as an inner pipe and an outer pipe respectively and each comprise one or more workstations for the fabrication of multi-length strings from single joints, wherein the vessel further comprises a pipe-in-pipe assembly workstation for assembling the inner pipe and the outer pipe in a pipe-in-pipe configuration, and wherein the pipe-in-pipe assembly station is arranged to assemble inner and outer pipe strings on the firing line or parallel and adjacent to the firing line, such that a distance between the firing line and the pipe-in-pipe assembly station is less than 5 meters.
A method of laying a pipe-in-pipe pipeline from a pipe-laying vessel having two independent and separate pipe string manufacturing lines, a firing line and a J-lay tower, the method comprising deploying pipe from the vessel in J-lay mode by:
- a) introducing single pipe in a first workstation of each of the two pipe string manufacturing lines, whereby the first pipe string manufacturing line receives inner pipes and the second pipe string manufacturing line receives outer pipes, the inner pipes having a smaller outer diameter than the inner diameter of the outer pipes;
- b) fabricating double-joints in a first type workstation of each pipe string manufacturing line;
- c) introducing the double-joints into the firing line;
- d) joining doubles to form quad- or triple-joint pipe strings on the firing line;
- e) assembling the inner pipe and the outer pipe strings in a pipe-in-pipe configuration;
- f) presenting the pipe-in-pipe configuration to the J-lay tower;
- and
- g) connecting the pipe-in-pipe configuration to the pipeline and lowering the pipeline into a sea.
Dependencies are inferred from the claim text.