US3893305A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of bending a continuous flowline
Assignee: Fluor Corp
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Filing: 1973-10-01
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Granted: 1975-07-08
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Expires: 1993-10-01
Abstract
Abstract A method and apparatus for terminating a subsea flowline at an offshore structure by providing a bend in the continuous flowline at the bottom of the offshore structure to provide an upstanding flowline end portion adapted to be secured to the offshore structure. A pipe bending device comprising a plurality of spaced cylindrical segments sleeved over a selected location on the flowline with adjacent segments pivotally interconnected to each other on one side of the flowline and end cylindrical segments pivotally interconnected to each other by a cylinder and piston means on the opposite side of the flowline. The device is fixed to the flowline at an end segment thereof. Actuation of the cylinder and piston means imposes a bending force on the flowline within the cylindrical segments for imparting a bend of selected radius to the flowline within the cylindrical segments. In the method of subsea bending of the flowline, such initial bending forces by the bending device assure bending of the flowline, which is normally under tension during laying, at a desired location as the vessel laying the flowline reduces tension therein to bring the upward rising flowline pipe portion into position for connection to the offshore structure.
Inventors
- 👤 Raymond W Walker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 10:52
CPC Classifications
F; F16; F16L; F16L1/00; F16L1/12; F16L1/14; F16L1/15; B; B21; B21D; B21D7/00; B21D7/10; E; E21; E21B; E21B43/00; E21B43/01; E21B43/0107
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
174 words
In a method of terminating a flowline at an offshore structure with an upstanding end portion of the flowline to be attached to the structure comprising, the steps of: trailing a flowline from a moving vessel to the sea floor alongside and past an offshore structure to which the flowline is to be attached; attaching a flowline bending unit to a selected portion of said flowline along its length, said portion to be located at the bottom of the offshore structure; carrying said bending unit on said flowline as the flowline is being laid; actuating from a remote location the flowline bending unit; imparting bending forces to opposite ends of the bending unit to bend the portion of the flowline to be located adjacent the bottom of the offshore structure; moving the end portion of the pipe into upstanding position alongside the offshore structure during such bending and providing a bend of selected arc in said flowline portion at said sea bottom; and securing the upstanding portion of the pipe to the offshore structure.
Claim 2
Dependent Claim
174 words
In a method of terminating a flowline at an offshore structure with an upstanding end portion of the flowline to be attached to the structure comprising, the steps of: trailing a flowline from a moving vessel to the sea floor alongside and past an offshore structure to which the flowline is to be attached; attaching a flowline bending unit to a selected portion of said flowline along its length, said portion to be located at the bottom of the offshore structure; carrying said bending unit on said flowline as the flowline is being laid; actuating from a remote location the flowline bending unit; imparting bending forces to opposite ends of the bending unit to bend the portion of the flowline to be located adjacent the bottom of the offshore structure; moving the end portion of the pipe into upstanding position alongside the offshore structure during such bending and providing a bend of selected arc in said flowline portion at said sea bottom; and securing the upstanding portion of the pipe to the offshore structure.
Claim 3
Dependent Claim
41 words
In a method as stated in claim 1 including the step of: initially imparting bending forces to said flowline unit of a magnitude less than tension forces imposed upon the flowline in its path from the vessel to the sea bottom.
Claim 4
Dependent Claim
37 words
In a method as stated in claim 2 including the step of: reducing said tension forces in said flowline by retarding the rate of advance of the vessel to cause initiation of bending at said bending unit.
Claim 5
Dependent Claim
30 words
In a method as stated in claim 1 including the step of: protecting the bend in said flowline at the sea bottom by retaining said bending unit on the flowline.
Claim 6
Dependent Claim
187 words
In a method for bending a flowline during laying of the flowline under subsea conditions, comprising the steps of: laying a flowline along a sea bottom from a moving vessel provided with a supply of flowline, the flowline extending from the vessel to the sea bottom and being under selected tension; attaching a flowline bending unit to said flowline at said vessel at a selected location on said flowline related to the location of the desired bend in the flowline at the sea bottom; carrying said bending unit on said flowline as said flowline is being laid; initially imposing a bending force at said location on said flowline in an amount less than the tension force in said flowline to avoid deforming said flowline; reducing the tension force on the flowline whereby the tendency of the flowline to bend because of such decrease in tension and gravitational forces acting on the flowline will initiate bending at the flowline bending unit; and imposing selected bending forces to opposite ends of the flowline bending unit to move said bending unit and associated flowline portion to a selected bending radius.
Claim 7
Dependent Claim
187 words
In a method for bending a flowline during laying of the flowline under subsea conditions, comprising the steps of: laying a flowline along a sea bottom from a moving vessel provided with a supply of flowline, the flowline extending from the vessel to the sea bottom and being under selected tension; attaching a flowline bending unit to said flowline at said vessel at a selected location on said flowline related to the location of the desired bend in the flowline at the sea bottom; carrying said bending unit on said flowline as said flowline is being laid; initially imposing a bending force at said location on said flowline in an amount less than the tension force in said flowline to avoid deforming said flowline; reducing the tension force on the flowline whereby the tendency of the flowline to bend because of such decrease in tension and gravitational forces acting on the flowline will initiate bending at the flowline bending unit; and imposing selected bending forces to opposite ends of the flowline bending unit to move said bending unit and associated flowline portion to a selected bending radius.
Claim 8
Dependent Claim
30 words
In a method as stated in claim 5 including the step of: protecting the completed bend in the flowline by retaining the bending unit on the flowline at the bend.
Claim 9
Dependent Claim
26 words
In a method as stated in claim 6 wherein the step of reducing the tension force on the flowline includes changing the motion of said vessel.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-07-07 | 1979-01-06 | 1979-07-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-07-07 | 1983-01-06 | 1983-07-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-07-07 | 1987-01-06 | 1987-07-08 | $7700.00 | Window Closed / Lapsed |