US3858401A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Flotation means for subsea well riser
Assignee: Baker Hughes Holdings LLC
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Filing: 1973-11-30
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Granted: 1975-01-07
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Expires: 1993-11-30
Abstract
Abstract Flotation is provided for a subsea well riser conduit. A plurality of open bottom but otherwise airtight buoyancy gas receiving chambers are mounted about the riser conduits. A gas conduit connects each chamber with a source of compressed gas on the drilling vessel. Valves are provided in the gas conduit for introducing gas in selectable amounts into the chambers to displace water entrained therein out the open bottom of the chamber to provide a selectable amount of buoyancy to the riser conduit. The gas valve includes an associated float for holding open the valve when the water level is above a predetermined level in the chamber and for closing the valve when the water level falls below the level to avoid loss of gas out the open bottom of the chamber. The flange which forms the top wall of the chamber is adapted to allow adjacent riser conduits to be fit together. Additionally, the chambers and the associated flanges provide a passageway for associated drilling control apparatus.
Inventors
- 👤 Bruce J Watkins
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 17:29
CPC Classifications
E; E21; E21B; E21B7/00; E21B7/12; E21B7/128; E21B17/00; E21B17/01; E21B17/012; E21B17/02; E21B17/08; E21B17/085; E21B17/0853
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
103 words
Flotation means for a subsea well riser conduit run between a floating vessel provided with a source of compressed gas and a subsea wellhead, said flotation means comprising: a plurality of open bottomed buoyancy gas receiving chambers and means for mounting them about and along said riser conduit; and gas supply means including gas conduit means connected between said source of compressed gas and each of said chambers for introducing gas in selectable amounts into each of said chambers independently of the others, displacing water entrained therein out open bottoms of said chambers, to provide selectable amounts of buoyancy to said riser conduit.
Claim 2
Dependent Claim
103 words
Flotation means for a subsea well riser conduit run between a floating vessel provided with a source of compressed gas and a subsea wellhead, said flotation means comprising: a plurality of open bottomed buoyancy gas receiving chambers and means for mounting them about and along said riser conduit; and gas supply means including gas conduit means connected between said source of compressed gas and each of said chambers for introducing gas in selectable amounts into each of said chambers independently of the others, displacing water entrained therein out open bottoms of said chambers, to provide selectable amounts of buoyancy to said riser conduit.
Claim 3
Dependent Claim
81 words
The flotation means of claim 1 wherein gas valve means are provided at one or more of said chambers, each of said gas valve means including a valve member and float means mechanically connected thereto for holding said valve means open when the water level is above a predetermined level in the associate chamber and for closing said valve means when the water level falls below said level to avoid loss of gas out through said open bottom of said chambers.
Claim 4
Dependent Claim
40 words
The flotation means of claim 1 wherein Means for restricting gas flow is provided between each chamber and the gas conduit means to provide for a generally equal and simultaneous distribution of gas from said gas conduit to said chambers.
Claim 5
Dependent Claim
78 words
The flotation means of claim 1 wherein one or more of said plurality of open bottomed buoyancy chambers comprises: an annular flange formed integrally of and extending radially outwardly of each of a plurality of riser conduit sections; a plurality of generally cylindrical shells; and mounting means for mounting said shells about said riser conduit in airtight and depending relation to an associated annular flange to thereby provide airtight top and side walls of the open bottomed chambers.
Claim 6
Dependent Claim
21 words
The flotation means of claim 4 further including aperture means through said annular flange for passing said gas conduit means therethrough.
Claim 7
Dependent Claim
52 words
The flotation means of claim 1 wherein said gas conduit extends into one or more of said chambers through the upper ends of said chambers closer to the floating vessel, and gas in said conduit flows in a direction from the source of compressed gas through said upper ends of said chambers.
Claim 8
Dependent Claim
39 words
The flotation means of claim 6 wherein gas valve means are provided in one or more of said chambers near said open bottom of said chambers to allow gas to pass only from said gas conduit into said chambers.
Claim 9
Dependent Claim
142 words
Buoyancy means for use with subsea well apparatus which includes a marine conductor conduit run from a floating vessel to a subsea well and which is formed of conduit sections connected together in an end-to-end relationship, said buoyancy means comprising: flange means extending radially outwardly from and about one or more of said plurality of conduit sections in airtight relation thereto; a plurality of airtight shells and mounting means for mounting said shells positioned about said one or more of said sections and extending downwardly from the associated flange means to form a plurality of annular buoyancy chambers which are open at their bottoms; and gas supply means for supplying selectable amounts of gas from a source on said vessel to each of said chambers; introduction of gas into said chambers displacing water therein out through said open bottoms of said chambers.
Claim 10
Dependent Claim
142 words
Buoyancy means for use with subsea well apparatus which includes a marine conductor conduit run from a floating vessel to a subsea well and which is formed of conduit sections connected together in an end-to-end relationship, said buoyancy means comprising: flange means extending radially outwardly from and about one or more of said plurality of conduit sections in airtight relation thereto; a plurality of airtight shells and mounting means for mounting said shells positioned about said one or more of said sections and extending downwardly from the associated flange means to form a plurality of annular buoyancy chambers which are open at their bottoms; and gas supply means for supplying selectable amounts of gas from a source on said vessel to each of said chambers; introduction of gas into said chambers displacing water therein out through said open bottoms of said chambers.
Claim 11
Dependent Claim
33 words
The buoyancy means of claim 8 wherein said gas supply means includes a gas line run from said vessel to said chambers and gas valve means within one or more of said chambers.
Claim 12
Dependent Claim
48 words
The buoyancy means of claim 9 wherein each of said gas valve means includes means for restricting gas flow associated with its gas line to regulate the rate of gas flow between the gas line and respective chamber to provide for a substantially equal pressurizing of said chambers.
Claim 13
Dependent Claim
106 words
The buoyancy means of claim 9 wherein each of said gas valve means comprises a valve seat and associated valve member for blocking the flow of gas through the valve means when said member is seated on said valve seat and float means connected to said valve member to open said valve means when said float is buoyed by surrounding water in said chamber, said valve means closing to stop the flow of gas into said chamber when the water level within said chamber recedes under the pressure of gas introduced therein so that said float no longer supports said valve member above said valve seat.
Claim 14
Independent Claim
99 words
The method of providing buoyancy to a marine conductor conduit run from a floating vessel to a subsea well comprising the steps of: providing a plurality of gas receiving buoyancy chambers with openings at their bottom ends in a vertical array along said marine conductor conduit; and after running of said conductor conduit to said well from said floating vessel, introducing gas from a source thereof on said vessel into each of said chambers independently of the others and forcing water entrained therein out through the openings at the chamber bottoms to provide a selectable amount of buoyancy therefor.
Claim 15
Independent Claim
99 words
The method of providing buoyancy to a marine conductor conduit run from a floating vessel to a subsea well comprising the steps of: providing a plurality of gas receiving buoyancy chambers with openings at their bottom ends in a vertical array along said marine conductor conduit; and after running of said conductor conduit to said well from said floating vessel, introducing gas from a source thereof on said vessel into each of said chambers independently of the others and forcing water entrained therein out through the openings at the chamber bottoms to provide a selectable amount of buoyancy therefor.
Claim 16
Dependent Claim
50 words
The method of claim 12 including the additional steps of: providing water level activated gas valves in said chambers and introducing said gas through said valves, and closing said valves by the lowering of the water level in said chambers during said step of forcing water out of said chambers.
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) | 1978-01-06 | 1978-07-08 | 1979-01-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-01-06 | 1982-07-08 | 1983-01-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-01-06 | 1986-07-08 | 1987-01-07 | $7700.00 | Window Closed / Lapsed |