US20070166109A1 - Truss semi-submersible offshore floating structure - Google Patents
Truss semi-submersible offshore floating structure Download PDFInfo
- Publication number
- US20070166109A1 US20070166109A1 US11/332,707 US33270706A US2007166109A1 US 20070166109 A1 US20070166109 A1 US 20070166109A1 US 33270706 A US33270706 A US 33270706A US 2007166109 A1 US2007166109 A1 US 2007166109A1
- Authority
- US
- United States
- Prior art keywords
- semi
- offshore structure
- truss frame
- floating offshore
- submersible floating
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
- B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING
- B63B39/00—Equipment to decrease pitch, roll, or like unwanted vessel movements; Apparatus for indicating vessel attitude
- B63B39/06—Equipment to decrease pitch, roll, or like unwanted vessel movements; Apparatus for indicating vessel attitude to decrease vessel movements by using foils acting on ambient water
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
- B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING
- B63B1/00—Hydrodynamic or hydrostatic features of hulls or of hydrofoils
- B63B1/02—Hydrodynamic or hydrostatic features of hulls or of hydrofoils deriving lift mainly from water displacement
- B63B1/04—Hydrodynamic or hydrostatic features of hulls or of hydrofoils deriving lift mainly from water displacement with single hull
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
- B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING
- B63B1/00—Hydrodynamic or hydrostatic features of hulls or of hydrofoils
- B63B1/02—Hydrodynamic or hydrostatic features of hulls or of hydrofoils deriving lift mainly from water displacement
- B63B1/10—Hydrodynamic or hydrostatic features of hulls or of hydrofoils deriving lift mainly from water displacement with multiple hulls
- B63B1/107—Semi-submersibles; Small waterline area multiple hull vessels and the like, e.g. SWATH
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
- B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING
- B63B35/00—Vessels or similar floating structures specially adapted for specific purposes and not otherwise provided for
- B63B35/44—Floating buildings, stores, drilling platforms, or workshops, e.g. carrying water-oil separating devices
- B63B35/4413—Floating drilling platforms, e.g. carrying water-oil separating devices
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
- B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING
- B63B77/00—Transporting or installing offshore structures on site using buoyancy forces, e.g. using semi-submersible barges, ballasting the structure or transporting of oil-and-gas platforms
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
- B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING
- B63B11/00—Interior subdivision of hulls
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
- B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING
- B63B1/00—Hydrodynamic or hydrostatic features of hulls or of hydrofoils
- B63B1/02—Hydrodynamic or hydrostatic features of hulls or of hydrofoils deriving lift mainly from water displacement
- B63B1/04—Hydrodynamic or hydrostatic features of hulls or of hydrofoils deriving lift mainly from water displacement with single hull
- B63B2001/044—Hydrodynamic or hydrostatic features of hulls or of hydrofoils deriving lift mainly from water displacement with single hull with a small waterline area compared to total displacement, e.g. of semi-submersible type
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
- B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING
- B63B39/00—Equipment to decrease pitch, roll, or like unwanted vessel movements; Apparatus for indicating vessel attitude
- B63B39/06—Equipment to decrease pitch, roll, or like unwanted vessel movements; Apparatus for indicating vessel attitude to decrease vessel movements by using foils acting on ambient water
- B63B2039/067—Equipment to decrease pitch, roll, or like unwanted vessel movements; Apparatus for indicating vessel attitude to decrease vessel movements by using foils acting on ambient water effecting motion dampening by means of fixed or movable resistance bodies, e.g. by bilge keels
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
- B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING
- B63B2207/00—Buoyancy or ballast means
- B63B2207/02—Variable ballast or buoyancy
Definitions
- the invention is generally related to floating offshore structures and more particularly to semi-submersible floating offshore structures.
- the semi-submersible is a type of floating structure that has vertical columns supporting topsides and supported on large pontoons. The structure is held in position by the use of spread mooring lines that are anchored to the seafloor.
- the semi-submersible has a number of unique characteristics compared with other floating structures such as a spar and TLP (tension leg platform). These advantages include:
- the semi-submersible has good stability because of a large footprint and low center of gravity for the topsides.
- the hull requires lower steel tonnage.
- the hull can be a new build or converted from an existing drilling semi.
- the semi-submersible may include drilling capability.
- the semi-submersible can support a large number of flexible risers or SCRs (steel catenary risers) because of the space available on the pontoons.
- the topsides can be integrated at quayside and thus reduce cost and save scheduling time.
- the semi-submersible has a relatively short to medium development schedule. The initial investment is relatively low.
- the semi-submersible also has several deficiencies when compared with the spar and TLP.
- the most significant is the large heave motion because of the shallower draft and large pontoons.
- the dry tree riser arrangement has significant economic benefit for well completion, work-over, and intervention during the life of the offshore production facility.
- Another problem from the large motion of the semi-submersible is that it causes fatigue in the SCRs more easily, which requires more stringent fatigue design for the SCRs and thus costs more. For a platform in ultra deepwater with large diameter SCRs, the solutions to this problem could become technically or economically unfeasible.
- the first is a deep draft semi-submersible.
- the concept is to increase the draft from the normal range from sixty to eighty feet to one hundred to one hundred ten feet so that the wave action at the keel is reduced and, thus, the structure will have less motion.
- This makes the semi-submersible option feasible in some locations where the conventional semi-submersible would not be chosen because of the difficulties in dealing with the SCR riser fatigue issues.
- the heave motion is still relatively large compared with spars and TLPs.
- the dry tree arrangement is still not feasible.
- the SCRs deployed on the deep draft semi-submersibles usually still need to be strengthened to meet the fatigue life requirement.
- the second is a semi-submersible with a heave plate.
- the basic idea is to add a heave plate or pontoon at the keel that extends in deep draft.
- the heave plate or pontoon adds damping and added mass to the platform which will reduce its heave motion under wave conditions.
- heave plate or pontoon As an extendable part at the bottom of the semi-submersible hull.
- the heave plate or pontoon is retracted at the fabrication yard and during transportation. After the hull is located on site, the heave plate or pontoon is then extended or lowered to a deeper elevation and locked at that position.
- the known designs suffer several deficiencies.
- the hull has to be a new build and conversion of an existing semi-submersible hull is not possible.
- the extendable columns take too much deck space. In some cases it could be as much as thirty percent of the total deck space, which is impractical from a topsides equipment layout point of view.
- the column-to-deck connections are complicated. They are hard to build, risky during installation, and difficult to maintain.
- the advantage of a large pontoon area for riser supports from the conventional semi-submersible hull is compromised.
- the present invention addresses the deficiencies in the known art.
- the hull includes four columns that are supported by two pontoons. The columns support the topsides and the topsides structural framing serves as horizontal framing between the columns. Additional braces may be added between columns and topsides framing as necessary.
- a truss space frame is attached to the columns.
- the truss space frame preferably includes heave plates and possibly a keel tank.
- the truss space frame extends downward below the pontoons a sufficient distance in the water column that minimizes motions caused by wind and wave forces and eliminates the deficiencies in the known art.
- the hull section integrated with topsides and the truss space frame are constructed separately and assembled together at the offshore site where the structure is used for drilling and/or production.
- FIG. 1 is a side elevation view of the invention.
- FIG. 2 is an enlarged detail view of the area indicated by numeral 2 in FIG. 1 .
- FIG. 3 is an enlarged detail view of the area indicated by numeral 3 in FIG. 1 .
- FIG. 4 is a side elevation view of the invention rotated ninety degrees from that in FIG. 1 .
- FIG. 5 is a view of the invention taken along lines 5 - 5 in FIG. 1 .
- FIG. 6 is a view of the invention taken along lines 6 - 6 in FIG. 1 .
- FIG. 7-9 illustrate the general assembly of the invention in the field.
- FIG. 10 illustrates an alternate embodiment of the invention.
- Semi-submersible floating offshore structure 10 is generally comprised of a buoyant hull 12 and a truss frame 14 .
- the hull 12 is comprised of four columns 16 that are supported on their lower ends by at least two pontoons 18 .
- the topside structural framing 20 serves as horizontal bracing between the columns 16 .
- the general construction, arrangement, and assembly of the pontoons, columns, and topside structural framing is generally known.
- Additional braces 42 seen in FIG. 7 , may be provided on the hull 12 if desired. For ease of illustration, the braces 42 are only shown in FIG. 7 .
- the preferred design is to use pontoons that are larger and deeper and columns that are smaller in cross section. This preferred arrangement will provide better control of motions that have been a source of the above-referenced problems with conventional semi-submersible designs.
- more columns can be provided between the two columns on the same pontoon. This would result in three or more columns on each pontoon.
- the truss frame 14 is a space frame, preferably with a constant cross section.
- Adjustable ballast means may be included in the truss frame 14 .
- adjustable ballast means illustrated is in the form of a keel tank 22 . When the keel tank 22 is used, it is normally flooded with sea water when the structure is at its ballasted, operating position. Heavier slurry material can also be used as fixed ballast if required by design.
- Other ballast means may include the use of ballast material in the legs 24 of the truss frame 14 .
- the truss frame 14 is comprised of four truss legs 24 connected together with horizontal braces 26 (best seen in FIGS. 5 and 6 ) and X-braces 28 .
- a horizontal plate 30 (heave plate) is attached to the truss frame 14 and preferably spans across the horizontal plane of the truss frame 14 . While the horizontal plate 30 may be positioned at any vertical location on the truss frame 14 , it is preferably provided at each horizontal framing location, except for the top framing location.
- the bottom horizontal plate 30 will include the keel tank 22 when it is included in the structure.
- the horizontal plates 30 are provided with bores 32 that allow passage of risers 34 used for drilling or production.
- the solid portion of the plates 30 preferably extends across the entire width and diameter of the truss frame 14 and also preferably are sized and formed so as to extend beyond the truss legs 24 as seen in FIGS. 1 and 4 . Having the plates 30 extend beyond the truss legs 24 increases their effectiveness in controlling heave motions of the structure 10 . While a number of horizontal plates 30 are illustrated, it should be understood that one or more plates may be used or, as seen in the alternate embodiment of FIG. 10 , it is also possible to have no horizontal plates.
- the horizontal plates 30 form bays between the plates in the frame that effectively trap a certain amount of water between the plates during movement caused by wave forces.
- the trapped water increases the effective mass of the structure and thus reduces the motions of the structure that are normally caused by these environmental forces.
- the hull can be fabricated in the same way as a conventional semi-submersible with topsides integrated at a fabrication yard quayside.
- the truss frame can be fabricated in a similar manner to a conventional jacket in a fabrication yard.
- Installation is carried out in the following manner.
- the hull 12 with integrated topsides may be wet towed to the offshore site and connected to the mooring lines 44 in a similar manner to the installation of a conventional FPS (Floating, Production, and Storage structure) for storm safe securing of the structure.
- FPS Floating, Production, and Storage structure
- the truss frame 14 may be transported to the offshore site on any suitable vessel such as a material barge or a launch barge.
- the truss frame is then put into the water either by any suitable means such as lift, launch, or float off. Once in the water, the truss frame 14 is upended and ballasted to a position in which the top portion of the truss legs 24 are above the water line.
- the truss frame 14 is then pulled into position under the hull 12 by any suitable means such as tug boats and/or winches on the hull.
- the upper ends 36 of the truss legs 24 are aligned with sleeves 38 and connectors 40 .
- the truss frame is deballasted so that the upper ends 36 of the legs 24 are received through the sleeves 38 and into contact with the connectors 40 . This is best seen in the enlarged detail views of FIGS. 2 and 3 .
- the upper ends 36 of the legs 24 are rigidly attached to the connectors 40 by any suitable means such as welding. Grippers not shown may be used at the sleeves 38 to hold the legs 24 firmly in position until the welding is completed. Once welding to the connectors 40 is completed, it is preferable that the sleeves 38 and legs 24 be grouted together to increase the security of the connection between the hull 12 and truss frame 14 .
- the entire structure is then ballasted down to its normal operating draft.
- the truss frame extends downwardly from the hull a sufficient distance in the water such that the horizontal plates effectively trap water in a manner that reduces the motions of the entire structure as described above.
- FIG. 10 illustrates an alternate embodiment of the invention wherein no horizontal plates are used.
- Adjustable ballast means if desired in the truss frame 14 , may be provided in the legs 24 .
- the invention provides several advantages over the known art.
- the reduced motions of the invention allow the use of a dry tree riser arrangement.
- the spacing of the columns 16 and number of bays in the truss frame 14 may be configured so that the semi-submersible 10 behaves hydrodynamically similar to a conventional semi-submersible or a truss spar.
- the hull and truss frame may be fabricated at different locations, which can result in greater ease of fabrication and transportation planning.
- the number and elevations of the heave plates can be designed to suit different environmental conditions.
- the keel tank can be designed with or without fixed ballast to suit different environmental conditions.
- the weight of the truss frame does not increase the hull buoyancy requirement since it replaces the weight of the ballast used in the pontoons in the prior known art.
- the semi-submersible hull and truss frame are proven and accepted structures in the offshore industry.
- the structure is easily decommissioned simply by reversing the installation process after it is towed to a chosen site.
- the structure can accommodate both drilling and production operations.
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- Ocean & Marine Engineering (AREA)
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- Civil Engineering (AREA)
- Architecture (AREA)
- Structural Engineering (AREA)
- Transportation (AREA)
- Earth Drilling (AREA)
- Polyoxymethylene Polymers And Polymers With Carbon-To-Carbon Bonds (AREA)
- Nitrogen Condensed Heterocyclic Rings (AREA)
- Revetment (AREA)
- Bridges Or Land Bridges (AREA)
- Other Liquid Machine Or Engine Such As Wave Power Use (AREA)
Abstract
Description
- The invention is generally related to floating offshore structures and more particularly to semi-submersible floating offshore structures.
- The semi-submersible is a type of floating structure that has vertical columns supporting topsides and supported on large pontoons. The structure is held in position by the use of spread mooring lines that are anchored to the seafloor. The semi-submersible has a number of unique characteristics compared with other floating structures such as a spar and TLP (tension leg platform). These advantages include: The semi-submersible has good stability because of a large footprint and low center of gravity for the topsides. The hull requires lower steel tonnage. The hull can be a new build or converted from an existing drilling semi. The semi-submersible may include drilling capability. The semi-submersible can support a large number of flexible risers or SCRs (steel catenary risers) because of the space available on the pontoons. The topsides can be integrated at quayside and thus reduce cost and save scheduling time. The semi-submersible has a relatively short to medium development schedule. The initial investment is relatively low.
- The semi-submersible also has several deficiencies when compared with the spar and TLP. The most significant is the large heave motion because of the shallower draft and large pontoons. As a result it has not been suitable for a dry tree riser arrangement. The dry tree riser arrangement has significant economic benefit for well completion, work-over, and intervention during the life of the offshore production facility. Another problem from the large motion of the semi-submersible is that it causes fatigue in the SCRs more easily, which requires more stringent fatigue design for the SCRs and thus costs more. For a platform in ultra deepwater with large diameter SCRs, the solutions to this problem could become technically or economically unfeasible.
- The ideas that have been explored by the industry to overcome the semi-submersible motion problem generally fall into the two categories below.
- The first is a deep draft semi-submersible. The concept is to increase the draft from the normal range from sixty to eighty feet to one hundred to one hundred ten feet so that the wave action at the keel is reduced and, thus, the structure will have less motion. This makes the semi-submersible option feasible in some locations where the conventional semi-submersible would not be chosen because of the difficulties in dealing with the SCR riser fatigue issues. However, the heave motion is still relatively large compared with spars and TLPs. Also, the dry tree arrangement is still not feasible. The SCRs deployed on the deep draft semi-submersibles usually still need to be strengthened to meet the fatigue life requirement.
- The second is a semi-submersible with a heave plate. The basic idea is to add a heave plate or pontoon at the keel that extends in deep draft. The heave plate or pontoon adds damping and added mass to the platform which will reduce its heave motion under wave conditions.
- Most concepts based on the heave plate have the heave plate or pontoon as an extendable part at the bottom of the semi-submersible hull. The heave plate or pontoon is retracted at the fabrication yard and during transportation. After the hull is located on site, the heave plate or pontoon is then extended or lowered to a deeper elevation and locked at that position.
- The known designs suffer several deficiencies. The hull has to be a new build and conversion of an existing semi-submersible hull is not possible. The extendable columns take too much deck space. In some cases it could be as much as thirty percent of the total deck space, which is impractical from a topsides equipment layout point of view. The column-to-deck connections are complicated. They are hard to build, risky during installation, and difficult to maintain. The advantage of a large pontoon area for riser supports from the conventional semi-submersible hull is compromised.
- The present invention addresses the deficiencies in the known art. The hull includes four columns that are supported by two pontoons. The columns support the topsides and the topsides structural framing serves as horizontal framing between the columns. Additional braces may be added between columns and topsides framing as necessary. A truss space frame is attached to the columns. The truss space frame preferably includes heave plates and possibly a keel tank. The truss space frame extends downward below the pontoons a sufficient distance in the water column that minimizes motions caused by wind and wave forces and eliminates the deficiencies in the known art. The hull section integrated with topsides and the truss space frame are constructed separately and assembled together at the offshore site where the structure is used for drilling and/or production.
- The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming part of this disclosure. For a better understanding of the present invention, and the operating advantages attained by its use, reference is made to the accompanying drawings and descriptive matter, forming a part of this disclosure, in which a preferred embodiment of the invention is illustrated.
- In the accompanying drawings, forming a part of this specification, and in which reference numerals shown in the drawings designate like or corresponding parts throughout the same:
-
FIG. 1 is a side elevation view of the invention. -
FIG. 2 is an enlarged detail view of the area indicated bynumeral 2 inFIG. 1 . -
FIG. 3 is an enlarged detail view of the area indicated bynumeral 3 inFIG. 1 . -
FIG. 4 is a side elevation view of the invention rotated ninety degrees from that inFIG. 1 . -
FIG. 5 is a view of the invention taken along lines 5-5 inFIG. 1 . -
FIG. 6 is a view of the invention taken along lines 6-6 inFIG. 1 . -
FIG. 7-9 illustrate the general assembly of the invention in the field. -
FIG. 10 illustrates an alternate embodiment of the invention. - The invention is generally indicated by
numeral 10 inFIGS. 1 and 4 . Semi-submersible floatingoffshore structure 10 is generally comprised of abuoyant hull 12 and atruss frame 14. - The
hull 12 is comprised of fourcolumns 16 that are supported on their lower ends by at least twopontoons 18. The topsidestructural framing 20 serves as horizontal bracing between thecolumns 16. The general construction, arrangement, and assembly of the pontoons, columns, and topside structural framing is generally known. Additional braces 42, seen inFIG. 7 , may be provided on thehull 12 if desired. For ease of illustration, the braces 42 are only shown inFIG. 7 . - Even though the conventional semi-submersible hull design can be used for the invention, the preferred design is to use pontoons that are larger and deeper and columns that are smaller in cross section. This preferred arrangement will provide better control of motions that have been a source of the above-referenced problems with conventional semi-submersible designs.
- As an alternative embodiment, more columns, not shown, can be provided between the two columns on the same pontoon. This would result in three or more columns on each pontoon.
- The
truss frame 14 is a space frame, preferably with a constant cross section. Adjustable ballast means may be included in thetruss frame 14. One example of adjustable ballast means illustrated is in the form of akeel tank 22. When thekeel tank 22 is used, it is normally flooded with sea water when the structure is at its ballasted, operating position. Heavier slurry material can also be used as fixed ballast if required by design. Other ballast means may include the use of ballast material in thelegs 24 of thetruss frame 14. - The
truss frame 14 is comprised of fourtruss legs 24 connected together with horizontal braces 26 (best seen inFIGS. 5 and 6 ) and X-braces 28. A horizontal plate 30 (heave plate) is attached to thetruss frame 14 and preferably spans across the horizontal plane of thetruss frame 14. While thehorizontal plate 30 may be positioned at any vertical location on thetruss frame 14, it is preferably provided at each horizontal framing location, except for the top framing location. The bottomhorizontal plate 30 will include thekeel tank 22 when it is included in the structure. Thehorizontal plates 30 are provided withbores 32 that allow passage ofrisers 34 used for drilling or production. However, the solid portion of theplates 30 preferably extends across the entire width and diameter of thetruss frame 14 and also preferably are sized and formed so as to extend beyond thetruss legs 24 as seen inFIGS. 1 and 4 . Having theplates 30 extend beyond thetruss legs 24 increases their effectiveness in controlling heave motions of thestructure 10. While a number ofhorizontal plates 30 are illustrated, it should be understood that one or more plates may be used or, as seen in the alternate embodiment ofFIG. 10 , it is also possible to have no horizontal plates. - The
horizontal plates 30 form bays between the plates in the frame that effectively trap a certain amount of water between the plates during movement caused by wave forces. The trapped water increases the effective mass of the structure and thus reduces the motions of the structure that are normally caused by these environmental forces. - The hull can be fabricated in the same way as a conventional semi-submersible with topsides integrated at a fabrication yard quayside. The truss frame can be fabricated in a similar manner to a conventional jacket in a fabrication yard.
- Installation is carried out in the following manner.
- The
hull 12 with integrated topsides may be wet towed to the offshore site and connected to themooring lines 44 in a similar manner to the installation of a conventional FPS (Floating, Production, and Storage structure) for storm safe securing of the structure. Thetruss frame 14 may be transported to the offshore site on any suitable vessel such as a material barge or a launch barge. - The truss frame is then put into the water either by any suitable means such as lift, launch, or float off. Once in the water, the
truss frame 14 is upended and ballasted to a position in which the top portion of thetruss legs 24 are above the water line. - As seen in
FIG. 7 , thetruss frame 14 is then pulled into position under thehull 12 by any suitable means such as tug boats and/or winches on the hull. The upper ends 36 of thetruss legs 24 are aligned withsleeves 38 andconnectors 40. - As seen in
FIG. 8 , the truss frame is deballasted so that the upper ends 36 of thelegs 24 are received through thesleeves 38 and into contact with theconnectors 40. This is best seen in the enlarged detail views ofFIGS. 2 and 3 . - The upper ends 36 of the
legs 24 are rigidly attached to theconnectors 40 by any suitable means such as welding. Grippers not shown may be used at thesleeves 38 to hold thelegs 24 firmly in position until the welding is completed. Once welding to theconnectors 40 is completed, it is preferable that thesleeves 38 andlegs 24 be grouted together to increase the security of the connection between thehull 12 andtruss frame 14. - As seen in
FIG. 9 , the entire structure is then ballasted down to its normal operating draft. At the normal operating draft, the truss frame extends downwardly from the hull a sufficient distance in the water such that the horizontal plates effectively trap water in a manner that reduces the motions of the entire structure as described above. -
FIG. 10 illustrates an alternate embodiment of the invention wherein no horizontal plates are used. Adjustable ballast means, if desired in thetruss frame 14, may be provided in thelegs 24. - The invention provides several advantages over the known art.
- Known and proven construction techniques and equipment can be used without the need for experimentation to develop special construction techniques.
- The generally known advantages of a conventional semi-submersible are present, with the additional advantages of reduced motions and superior stability.
- The reduced motions of the invention allow the use of a dry tree riser arrangement.
- The spacing of the
columns 16 and number of bays in thetruss frame 14 may be configured so that the semi-submersible 10 behaves hydrodynamically similar to a conventional semi-submersible or a truss spar. - The hull and truss frame may be fabricated at different locations, which can result in greater ease of fabrication and transportation planning.
- The number and elevations of the heave plates can be designed to suit different environmental conditions.
- The keel tank can be designed with or without fixed ballast to suit different environmental conditions.
- The weight of the truss frame does not increase the hull buoyancy requirement since it replaces the weight of the ballast used in the pontoons in the prior known art.
- The semi-submersible hull and truss frame are proven and accepted structures in the offshore industry.
- Connection of two structures using a float over method is a proven and accepted installation method in the offshore industry.
- The structure is easily decommissioned simply by reversing the installation process after it is towed to a chosen site.
- The structure can accommodate both drilling and production operations.
- While specific embodiments and/or details of the invention have been shown and described above to illustrate the application of the principles of the invention, it is understood that this invention may be embodied as more fully described in the claims, or as otherwise known by those skilled in the art (including any and all equivalents), without departing from such principles.
Claims (21)
Priority Applications (13)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US11/332,707 US20070166109A1 (en) | 2006-01-13 | 2006-01-13 | Truss semi-submersible offshore floating structure |
BRPI0602591-9A BRPI0602591A (en) | 2006-01-13 | 2006-06-30 | maritime semi-submersible lattice floating structure |
AU2006202864A AU2006202864A1 (en) | 2006-01-13 | 2006-07-06 | Truss semi-submersible offshore floating structure |
MYPI20063251A MY158850A (en) | 2006-01-13 | 2006-07-07 | Truss semi-submersible offshore floating structure |
CN2006101059008A CN100999247B (en) | 2006-01-13 | 2006-07-11 | Truss semi-submersible offshore floating structure |
MXPA06009449A MXPA06009449A (en) | 2006-01-13 | 2006-08-17 | Truss semi-submersible offshore floating structure. |
ES06255520T ES2342190T3 (en) | 2006-01-13 | 2006-10-26 | SEMISUMERGIBLE FLOATING STRUCTURE OF ARMOR FOR HIGH SEA. |
EP06255520A EP1808369B1 (en) | 2006-01-13 | 2006-10-26 | Truss semi-submersible floating structure |
AT06255520T ATE464226T1 (en) | 2006-01-13 | 2006-10-26 | SEMI-LOWERABLE FLOATING TRUSS STRUCTURE |
DE602006013587T DE602006013587D1 (en) | 2006-01-13 | 2006-10-26 | Semi-lowerable floating truss structure |
NO20070226A NO20070226L (en) | 2006-01-13 | 2007-01-12 | Semi-submersible floating offshore structure |
US12/037,341 US7871222B2 (en) | 2006-01-13 | 2008-02-26 | Truss semi-submersible offshore floating structure |
AU2010200964A AU2010200964B2 (en) | 2006-01-13 | 2010-03-12 | Truss semi-submersible offshore floating structure |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US11/332,707 US20070166109A1 (en) | 2006-01-13 | 2006-01-13 | Truss semi-submersible offshore floating structure |
Related Child Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US12/037,341 Division US7871222B2 (en) | 2006-01-13 | 2008-02-26 | Truss semi-submersible offshore floating structure |
Publications (1)
Publication Number | Publication Date |
---|---|
US20070166109A1 true US20070166109A1 (en) | 2007-07-19 |
Family
ID=37980682
Family Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US11/332,707 Abandoned US20070166109A1 (en) | 2006-01-13 | 2006-01-13 | Truss semi-submersible offshore floating structure |
US12/037,341 Expired - Fee Related US7871222B2 (en) | 2006-01-13 | 2008-02-26 | Truss semi-submersible offshore floating structure |
Family Applications After (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US12/037,341 Expired - Fee Related US7871222B2 (en) | 2006-01-13 | 2008-02-26 | Truss semi-submersible offshore floating structure |
Country Status (11)
Country | Link |
---|---|
US (2) | US20070166109A1 (en) |
EP (1) | EP1808369B1 (en) |
CN (1) | CN100999247B (en) |
AT (1) | ATE464226T1 (en) |
AU (2) | AU2006202864A1 (en) |
BR (1) | BRPI0602591A (en) |
DE (1) | DE602006013587D1 (en) |
ES (1) | ES2342190T3 (en) |
MX (1) | MXPA06009449A (en) |
MY (1) | MY158850A (en) |
NO (1) | NO20070226L (en) |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20100130953A1 (en) * | 2008-11-26 | 2010-05-27 | Fung Paul Y | Tampon overwrap |
US20110219999A1 (en) * | 2010-03-11 | 2011-09-15 | John James Murray | Deep Water Offshore Apparatus And Assembly Method |
US20120114421A1 (en) * | 2009-07-13 | 2012-05-10 | Arno Laurentius Michael Van Den Haak | Semi-submersible floating structure |
US20120167813A1 (en) * | 2009-08-26 | 2012-07-05 | Technip France | Heave stabilized barge system for floatover topsides installation |
US20130032076A1 (en) * | 2010-04-26 | 2013-02-07 | Aker Subsea Inc. | Dry-tree semi-submersible production and drilling unit |
CN107972828A (en) * | 2017-12-13 | 2018-05-01 | 中海石油(中国)有限公司上海分公司 | A kind of offshore platform |
Families Citing this family (19)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN101475049B (en) * | 2009-01-20 | 2012-07-04 | 大连理工大学 | DDMS deep draft column platform |
US20100260554A1 (en) * | 2009-04-09 | 2010-10-14 | Yun Ding | Heave plate on floating offshore structure |
US7849810B2 (en) * | 2009-04-24 | 2010-12-14 | J. Ray Mcdermott, S.A. | Mating of buoyant hull structure with truss structure |
US8251003B2 (en) * | 2009-11-08 | 2012-08-28 | Ssp Technologies, Inc. | Offshore buoyant drilling, production, storage and offloading structure |
CN102116017B (en) * | 2011-01-04 | 2012-08-15 | 广西电力工业勘察设计研究院 | Foam platform for drilling on waterways |
CN103010415B (en) * | 2011-09-22 | 2015-08-19 | 江门强光海洋工程股份有限公司 | Support the prestressed concrete floating platform of offshore wind turbine and ocean power generator |
CN102530189A (en) * | 2012-03-08 | 2012-07-04 | 中国海洋石油总公司 | Catamaran for ocean engineering |
CN102936888B (en) * | 2012-11-09 | 2015-01-28 | 中国水电顾问集团华东勘测设计研究院 | Self-installation type offshore booster station structure and installation method thereof |
CN103010416A (en) * | 2012-12-17 | 2013-04-03 | 中国海洋石油总公司 | Semi-submersible platform with heave plates and installing method of heave plates |
US9022693B1 (en) * | 2013-07-12 | 2015-05-05 | The Williams Companies, Inc. | Rapid deployable floating production system |
CN103718735B (en) * | 2013-12-24 | 2016-03-16 | 大连海洋大学 | Semi-submersible kelp harvest ship |
CN105857532B (en) * | 2015-07-06 | 2018-04-06 | 周剑辉 | General offshore platform and its buoyancy adjustment method and stable electric generation method |
KR20180027589A (en) * | 2015-07-13 | 2018-03-14 | 엔스코 인터내셔널 인코포레이티드 | Subtype structure |
CN106761407A (en) * | 2016-11-29 | 2017-05-31 | 中国地质大学(武汉) | A kind of exploration on water device |
CN106741697A (en) * | 2017-01-06 | 2017-05-31 | 上海利策科技股份有限公司 | A kind of semisubmersible platform |
CN108583795A (en) * | 2018-05-14 | 2018-09-28 | 重庆大学 | A kind of semi-submersible type offshore wind turbine platform |
CN109720510B (en) * | 2018-12-29 | 2020-10-16 | 武船重型工程股份有限公司 | Double-ship carrying system |
CN109866888B (en) * | 2019-03-25 | 2020-03-03 | 中国海洋石油集团有限公司 | Relative motion restraining device for dry tree semi-submersible platform heave plate and main hull |
CN111802295B (en) * | 2020-07-31 | 2023-08-08 | 深圳埃吉尔海洋科技有限公司 | Intelligent new energy rigid rocker arm connection type deep-sea cultivation complex |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5558467A (en) * | 1994-11-08 | 1996-09-24 | Deep Oil Technology, Inc. | Deep water offshore apparatus |
US20020139286A1 (en) * | 2001-03-29 | 2002-10-03 | Lee James J. | Heave-damped caisson vessel |
US6637979B2 (en) * | 2001-09-04 | 2003-10-28 | Cso Aker Maritime, Inc. | Telescoping truss platform |
US6666624B2 (en) * | 2001-08-07 | 2003-12-23 | Union Oil Company Of California | Floating, modular deepwater platform and method of deployment |
Family Cites Families (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3986471A (en) | 1975-07-28 | 1976-10-19 | Haselton Frederick R | Semi-submersible vessels |
DE2641040C3 (en) | 1976-09-11 | 1980-05-14 | Marine Service Gmbh, 2000 Hamburg | Floating tank as a carrier for a gas liquefaction plant |
ES451483A1 (en) | 1976-09-13 | 1983-10-16 | Fayren Jose Marco | Floating apparatus and method of assembling the same |
US6340272B1 (en) * | 1999-01-07 | 2002-01-22 | Exxonmobil Upstream Research Co. | Method for constructing an offshore platform |
DE60013272D1 (en) * | 1999-04-21 | 2004-09-30 | Ope Inc | SEPARATOR PLATFORM IN SATELLITE ARRANGEMENT |
US6761124B1 (en) | 2002-09-28 | 2004-07-13 | Nagan Srinivasan | Column-stabilized floating structures with truss pontoons |
US6942427B1 (en) * | 2003-05-03 | 2005-09-13 | Nagan Srinivasan | Column-stabilized floating structure with telescopic keel tank for offshore applications and method of installation |
US6884003B2 (en) * | 2003-06-16 | 2005-04-26 | Deepwater Technologies, Inc. | Multi-cellular floating platform with central riser buoy |
-
2006
- 2006-01-13 US US11/332,707 patent/US20070166109A1/en not_active Abandoned
- 2006-06-30 BR BRPI0602591-9A patent/BRPI0602591A/en not_active IP Right Cessation
- 2006-07-06 AU AU2006202864A patent/AU2006202864A1/en not_active Abandoned
- 2006-07-07 MY MYPI20063251A patent/MY158850A/en unknown
- 2006-07-11 CN CN2006101059008A patent/CN100999247B/en not_active Expired - Fee Related
- 2006-08-17 MX MXPA06009449A patent/MXPA06009449A/en active IP Right Grant
- 2006-10-26 DE DE602006013587T patent/DE602006013587D1/en active Active
- 2006-10-26 AT AT06255520T patent/ATE464226T1/en not_active IP Right Cessation
- 2006-10-26 ES ES06255520T patent/ES2342190T3/en active Active
- 2006-10-26 EP EP06255520A patent/EP1808369B1/en not_active Not-in-force
-
2007
- 2007-01-12 NO NO20070226A patent/NO20070226L/en not_active Application Discontinuation
-
2008
- 2008-02-26 US US12/037,341 patent/US7871222B2/en not_active Expired - Fee Related
-
2010
- 2010-03-12 AU AU2010200964A patent/AU2010200964B2/en not_active Ceased
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5558467A (en) * | 1994-11-08 | 1996-09-24 | Deep Oil Technology, Inc. | Deep water offshore apparatus |
US20020139286A1 (en) * | 2001-03-29 | 2002-10-03 | Lee James J. | Heave-damped caisson vessel |
US6666624B2 (en) * | 2001-08-07 | 2003-12-23 | Union Oil Company Of California | Floating, modular deepwater platform and method of deployment |
US6637979B2 (en) * | 2001-09-04 | 2003-10-28 | Cso Aker Maritime, Inc. | Telescoping truss platform |
Cited By (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20100130953A1 (en) * | 2008-11-26 | 2010-05-27 | Fung Paul Y | Tampon overwrap |
US20120114421A1 (en) * | 2009-07-13 | 2012-05-10 | Arno Laurentius Michael Van Den Haak | Semi-submersible floating structure |
US20120167813A1 (en) * | 2009-08-26 | 2012-07-05 | Technip France | Heave stabilized barge system for floatover topsides installation |
US8844456B2 (en) * | 2009-08-26 | 2014-09-30 | Technip France | Heave stabilized barge system for floatover topsides installation |
AU2010289822B2 (en) * | 2009-08-26 | 2015-04-30 | Technip France | Catamaran system and method of stabilising |
US20110219999A1 (en) * | 2010-03-11 | 2011-09-15 | John James Murray | Deep Water Offshore Apparatus And Assembly Method |
US20130032076A1 (en) * | 2010-04-26 | 2013-02-07 | Aker Subsea Inc. | Dry-tree semi-submersible production and drilling unit |
US8807874B2 (en) * | 2010-04-26 | 2014-08-19 | Aker Solutions Inc. | Dry-tree semi-submersible production and drilling unit |
CN107972828A (en) * | 2017-12-13 | 2018-05-01 | 中海石油(中国)有限公司上海分公司 | A kind of offshore platform |
Also Published As
Publication number | Publication date |
---|---|
NO20070226L (en) | 2007-07-16 |
US7871222B2 (en) | 2011-01-18 |
AU2010200964B2 (en) | 2012-05-03 |
CN100999247B (en) | 2012-11-14 |
BRPI0602591A (en) | 2007-10-09 |
AU2006202864A1 (en) | 2007-08-02 |
AU2010200964A1 (en) | 2010-04-01 |
US20090158988A1 (en) | 2009-06-25 |
CN100999247A (en) | 2007-07-18 |
MXPA06009449A (en) | 2007-07-12 |
DE602006013587D1 (en) | 2010-05-27 |
EP1808369B1 (en) | 2010-04-14 |
MY158850A (en) | 2016-11-15 |
ATE464226T1 (en) | 2010-04-15 |
EP1808369A1 (en) | 2007-07-18 |
ES2342190T3 (en) | 2010-07-02 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US7871222B2 (en) | Truss semi-submersible offshore floating structure | |
EP2726362B1 (en) | Offshore platform with outset columns | |
US6899492B1 (en) | Jacket frame floating structures with buoyancy capsules | |
US7854570B2 (en) | Pontoonless tension leg platform | |
US8707882B2 (en) | Offshore platform with outset columns | |
US7934462B2 (en) | Offshore floating structure with motion dampers | |
US6840713B1 (en) | Device for positioning and lifting a marine structure, particularly a platform deck | |
US20100288178A1 (en) | Offshore Floating Platform with Motion Damper Columns | |
CN105035278B (en) | Low-heave semi-submersible offshore structure | |
AU746242B2 (en) | Buoyant substructure for offshore platform | |
GB2285773A (en) | Floating platform with buoyant raft | |
US6668746B1 (en) | Lifting vessel and method for positioning, lifting and handling a platform deck and a jacket | |
US20070224000A1 (en) | Deep draft semi-submersible offshore floating structure | |
CN105644705A (en) | Small water plane twin-hull platform | |
Xu et al. | An introduction to extendable draft platform (EDP) | |
Maher et al. | The cell spar for development of deep water fields offshore Brazil |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: J. RAY MCDERMOTT, S.A., TEXAS Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:DING, YUN;SOESTER, WILLIAM LAWRENCE;REEL/FRAME:017238/0888 Effective date: 20060203 |
|
AS | Assignment |
Owner name: CREDIT AGRICOLE CORPORATE AND INVESTMENT BANK, AS Free format text: SECURITY AGREEMENT;ASSIGNOR:J. RAY MCDERMOTT, S.A.;REEL/FRAME:024337/0604 Effective date: 20100503 |
|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- AFTER EXAMINER'S ANSWER OR BOARD OF APPEALS DECISION |
|
AS | Assignment |
Owner name: J. RAY MCDERMOTT, S.A, TEXAS Free format text: RELEASE OF INTELLECTUAL PROPERTY SECURITY AGREEMENT FOR PATENT, RECORDED ON REEL 024337, FRAME 0604;ASSIGNOR:CREDIT AGRICOLE CORPORATE AND INVESTMENT BANK;REEL/FRAME:032705/0288 Effective date: 20140416 |