Double pipe turntable and stinger
AssigneeShell Oil Company
InventorRobert T. Gilchrist, Jr.
Life of this patent
Estimating the term…
Abstract
A pipelay apparatus and method comprising a steel turntable and a stinger pipe guide which can be supported on the construction deck of a repair vessel or drill ship are provided. The turntable is framed so that loads from two hanging pipes can be securely supported. The table-supported framing members can be moved so the load centerline for each pipeline can be placed an appropriate distance from the center of turntable rotation, which is useful where the two pipelines are of different diameters. This apparatus permits a vessel to simultaneously handle different sizes of pipe and pass large diameter appurtenances without modifying the stinger pipe guide.
Claims18
An apparatus for supporting a plurality of pipes from a ship comprising:
- a) a horizontal circular rotatable turntable which can rotate relative to the ship, and from which the plurality of pipes may be suspended into water;
- b) a stinger which is symetrical about a vertical axis, the stinger being fixed to the ship and not rotatable with the turntable and located below the rotatable turntable, with an inside diameter large enough to pass the plurality of pipes, and fluted outward as it extends downward;
- and
- c) a means to support the plurality of pipes essentially vertically from the turntable against an inner diameter of the stinger.
A method to repair a subsea pipeline having a damaged segment between lengths of undamaged pipe comprising:
- a) severing the pipeline in the vicinity of the damaged segment;
- b) lifting a first severed end of the pipeline to a surface vessel;
- c) supporting the first severed end essentially vertically from a rotatable turntable on the surface vessel;
- d) removing any damaged pipe from the first end of the pipe;
- e) adding pipe to the first end of the pipeline until the surface vessel can be positioned approximately above the second end of the pipeline which remains at the sea floor;
- f) dropping a support member which is supported from the rotatable turntable to the second end of the pipeline which remains on the sea floor;
- g) connecting the support member to the pipeline which remains on the sea floor in the vicinity of the second end;
- h) alternately lifting the support member and adding pipe to the first end of the pipe until the second end of the pipe can be supported by the rotatable turntable;
- i) removing any damaged pipe from the second end of the pipe;
- j) connecting the first and the second end of the pipe;
- and
- k) laying the connected first and second pipe down onto the sea floor.
Dependencies are inferred from the claim text.