Laying of underwater pipelines
AssigneeCompagnie Generale pour les Developpements Operationnels des Richesses Sous-Marines "C.G. Doris"
InventorJacques E. Lamy
Life of this patent
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Abstract
For laying a pipeline on the bed of the sea, a plurality of pipeline sections are successively towed by a tug exerting a traction effort at a point spaced to the rear of the front end of a pipeline section being towed, while another tug exerts a holding effort at a point spaced in front of the rear end, the front and rear ends being maintained near to the surface by a system of floats and trail-ropes and the intermediate portion of the pipeline section being ballasted so as to be supported on the sea bed, whereafter the front end of the pipeline section is welded to the rear end of a preceding section, and so on.
Claims5
A method of laying a pipeline on the sea bed, comprising the steps of:
- (a) towing a first pipeline section from a shore towards the open sea while maintaining a front end portion of the first pipeline section near the surface of the sea,
- (b) preparing a second pipeline section ashore and towing the second pipeline section towards the open sea past the first pipeline section, while maintaining front and rear end portions of the second pipeline section near the surface of the sea and supporting a length of the second pipeline section intermediate said end portions on the sea bed,
- (c) joining the rear end of the second pipeline section to the front end of the first pipeline section, and
- (d) allowing the joined ends to descend to the sea bed.
A method of laying a pipeline on the sea bed, comprising the steps of:
- (a) towing a first pipeline section from a shore towards the open sea while making a front end portion of the first pipeline section buoyant to maintain a front end of the first pipeline section near the surface of the sea,
- (b) preparing a second pipeline section ashore and towing the second pipeline section towards the open sea past the first pipeline section, while making front and rear end portions of the second pipeline section buoyant to maintain front and rear ends of the second pipeline section near the surface of the sea, and while giving a length of the second pipeline section intermediate said end portions a negative buoyancy to support the same on the sea bed,
- (c) joining the rear end of the second pipeline section to the front end of the first pipeline section, and
- (d) ballasting said front end portion of the first pipeline section and said rear end portion of the second pipeline section to rest the same on the sea bed.
Dependencies are inferred from the claim text.