US3855656A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Underwater buoy for a riser pipe
Assignee: BP America Production Co
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Filing: 1973-03-30
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Granted: 1974-12-24
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Expires: 1993-03-30
Abstract
Abstract This describes an underwater buoy for a riser pipe which extends from a deep water subsea well to a vessel supported by a body of water. A hollow shell is attached to the riser to give an upper buoyant force. The water depth may be as deep as 10,000 feet and the buoy may be 600 feet or more beneath the surface of the body of water. Non-vertically directed hydrofoils are attached to the outer wall of the shell. The chord of each hydrofoil makes an angle of attack with the vertical such that should the riser pipe break beneath the buoy, the buoy would be propelled or rise at an angle and surface away from the vessel instead of rising vertically and having a collision with the vessel.
Inventors
- 👤 K Blenkarn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 00:28
CPC Classifications
E; E21; E21B; E21B17/00; E21B17/01; E21B17/012; B; B63; B63B; B63B22/00; B63B22/18; B63B2207/00; B63B2207/02
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
72 words
An underwater buoy for a riser pipe which extends from an underwater well to a vessel supported by a body of water which comprises: a hollow shell attached to said riser to give an upward buoyancy force thereto; non-vertically directed hydrofoil means attached to said shell for directing said shell upwardly through said water in a nonvertical direction to avoid striking said vessel in event said riser pipe fails below said shell.
Claim 2
Dependent Claim
72 words
An underwater buoy for a riser pipe which extends from an underwater well to a vessel supported by a body of water which comprises: a hollow shell attached to said riser to give an upward buoyancy force thereto; non-vertically directed hydrofoil means attached to said shell for directing said shell upwardly through said water in a nonvertical direction to avoid striking said vessel in event said riser pipe fails below said shell.
Claim 3
Dependent Claim
30 words
A buoy as defined in claim 1, including: a port in a lower portion of said shell, means to supply gas to the interior of said shell above said port.
Claim 4
Dependent Claim
17 words
A buoy as defined in claim 2, including means to detect loss of gas from said shell.
Claim 5
Dependent Claim
46 words
A buoy as defined in claim 3 in which said means to detect loss of gas comprises a liquid level indicator positioned on the inside of said shell above said port and including means to transmit information concerning the position of said level to said vessel.
Claim 6
Dependent Claim
50 words
A buoy as defined in claim 4 in which said means to supply gas includes variable position discharge means to change the level in said shell at which said gas is discharged into or released from the interior of the shell independent of vertical movement of said liquid level indicator.
Claim 7
Dependent Claim
31 words
A buoy as defined in claim 5 in which said variable position discharge means includes a hollow pipe vertically disposed within said shell and means to move said pipe vertically therein.
Claim 8
Dependent Claim
44 words
A buoy as defined in claim 1 in which said hydrofoil means includes a plurality of hydrofoils in which the chord of each hydrofoil makes an angle of attack theta with the vertical which is in the range of between about 30* and 60*.
Claim 9
Dependent Claim
46 words
An apparatus as defined in claim 1 including pressure sensing means for detecting pressure of fluid inside said riser pipe near the bottom of said body of water, means to adjust the buoyancy of said shell in response to pressure detected by said pressure sensing means.
Claim 10
Dependent Claim
78 words
In an apparatus as defined in claim 2 including a hollow stinger pipe vertically disposed within said shell, the lower end of said stinger pipe connecting said means to supply gas, pressure sensing means for detecting the pressure of fluid inside said riser pipe at a level near the lower end of said riser pipe, means to adjust the level of the top of said stinger pipe in response to the pressure detected by said pressure sensing means.
Claim 11
Dependent Claim
21 words
An underwater buoy as described in claim 1 wherein said hydrofoil means is attached to the outer wall of said shell.
Claim 12
Dependent Claim
70 words
A buoy system for a riser pipe which extends from an underwater well to a vessel sUpported by a body of water which comprises a hollow shell attached to said riser pipe to give an upward buoyancy force thereto, pressure sensing means for detecting pressure of fluid inside said riser pipe, means to adjust the buoyancy of said shell in response to the pressure detected by said pressure sensing means.
Claim 13
Dependent Claim
70 words
A buoy system for a riser pipe which extends from an underwater well to a vessel sUpported by a body of water which comprises a hollow shell attached to said riser pipe to give an upward buoyancy force thereto, pressure sensing means for detecting pressure of fluid inside said riser pipe, means to adjust the buoyancy of said shell in response to the pressure detected by said pressure sensing means.
Claim 14
Dependent Claim
41 words
A buoy system as defined in claim 11 including hydrofoil means for directing said shell away from said vessel in event said riser pipe breaks beneath said shell when said shell is positioned beneath the surface of said body of water.
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) | 1977-12-23 | 1978-06-24 | 1978-12-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-23 | 1982-06-24 | 1982-12-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-23 | 1986-06-24 | 1986-12-24 | $7700.00 | Window Closed / Lapsed |