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Publication numberUS3648638 A
Publication typeGrant
Publication dateMar 14, 1972
Filing dateMar 9, 1970
Priority dateMar 9, 1970
Publication numberUS 3648638 A, US 3648638A, US-A-3648638, US3648638 A, US3648638A
InventorsKenneth A Blenkarn
Original AssigneeAmoco Prod Co
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Vertically moored platforms
US 3648638 A
Abstract
This invention relates to a structure floating on a body of water. Three or more spar buoy-type floats support the structure above the water. The structure is connected to anchors in the floor of the body of water by elongated members such as large diameter pipe. There are no other anchoring connections in the system. Each spar buoy has a unique structure so that vertical forces and overturning moments on the floating structure are minimized. The spar buoys have a buoyancy means having a volume of two parts. The first part can be defined as resulting from a straight, vertical, prismatic shape which runs the entire vertical length of the buoyancy means. The volume of this prismatic portion comprises between about 40 and 80 percent of the total displacement. The buoyancy means have a second or auxiliary volume of displacement which runs considerably less than the vertical length of the prismatic portion. This critical arrangement of buoyancy between these two parts as taught in this invention minimizes mooring forces imposed on the vertical elongated members, such as occur to react forces on the structure due to passing waves.
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Blenkarn VERTICALLY MOORED PLATFORMS [72] Inventor. Kenneth A. Blcnkarn, Tulsa, Okla.

[73] Assignee: Amoco Production Company, Tulsa, Okla.

[22] Filed: Mar. 9, 1970 21] Appl. No.: 17,485

Related US. Application Data [63] Continuation-impart of Ser. No. 754,628, Aug. 28,

1968, abandoned.

[52] US. Cl. ..ll4/0.5 D, 61/465 [51] int. Cl. .3631: 35/00, B63b 35/44 [58] Field of Search ..l14/0.5, 0.5 D, 43.5; 61/465 [56] References Cited UNITED STATES PATENTS 2,399,656 5/1946 Armstrong ..1l4/0.5 D 3,224,401 12/1965 Kobus ...l14/0.5 D 2,939,291 6/1960 Schurman et al.. 114/05 D 3,154,039 10/1964 Knapp .114/O.5 D 3,327,780 6/1967 14/0.5 D X Primary Examiner-Trygve M. Blix Attorney-Paul F. Hawley and John D. Gassett [57] ABSTRACT This invention relates to a structure floating on a body of water. Three or more spar buoy-type floats support the structure above the water. The structure is connected to anchors in the floor of the body of water by elongated members such as large diameter pipe. There are no other anchoring connections in the system. Each spar buoy has a unique structure so that vertical forces and overturning moments on the floating structure are minimized. The spar buoys have a buoyancy means having a volume of two parts. The first part can be defined as resulting from a straight, vertical, prismatic shape which runs the entire vertical length of the buoyancy means. The volume of this prismatic portion comprises between about 40 and 80 percent of the total displacement. The buoyancy means have a second or auxiliary volume of displacement which runs considerably less than the vertical length of the prismatic portion. This critical arrangement of buoyancy between these two parts as taught in this invention minimizes mooring forces imposed on the vertical elongated members, such as occur to react forces on the structure due to passing waves.

42 Claims, 40 Drawing [Figures 8 3 6 RM m 3 22 sheets sheat 2 INVENTOR. KENNETH A. BLENKARN ATTORNEY Patented March 14, 1972 3,648,638

22 Sheets-Sheet 5 INVENTOR. KENNETH A. BLENKARN BY M A T TORNEY Patented March 14, 1972 3,648,638

22 Sheets-Sheet 4.

O I I 1- 1 FIG. 4

INVENTOR. KENNETH A. BLENKARN ATTORNEY Patented March 14,, 1972 22 Sheets-Sheet 5 l0 TOTAL DISPLACEMENT 92 STILL WATER DRAFT= I25 FT KENNETH A. .BLENKARN INVENTOR.

WTQM ATTORNEY VARIATION OF NET VERTICAL FORCE DISRL...)

Patented March 14, 197 3,648,638

22 Sheets-Sheet 6 T 5L2 FT, I I0 SEC. WAVE 0 l FIG. 6A

. I00 FT, l4 SEC. WAVE -.30 I00 FT, 20 SEC. WAVE I00 FT, 20 SEC. wAvE WAVE 0 FIG. 68

SEC. WAVE -.|o

.2 FT, IO SEC. WAVE I00 FT, l4 SEC.WAVE I FIG. 60

I00 FT, 20 SEC.WAVE

TROUGH LEADING CREST CREST FOLLOWING CREST INVENTOR.

BY am ATTORNEY Patented March 14, 1972 3,648,638

22 Sheets-Sheet 7 SlNGLE AMPL.

1 OF PITCH KENNETH A. BLENKARN f, .INVENTOR.

3 BY FIG. IO %4 fiM ATTORNEY Patented March 14, 1972 OVERTURNING MOMENT m FT. KIPS 22 Sheets-Sheet 8 OVERTURNING MOMENTS I0O FT. -20 SEC. WAVE 200 NET OVERTURNING MOMENT IOO- WIND vERTIcAL WIND DRAG LIFT HORIZONTAL DRAG \MOMENT DUE TO COUPLING 0F HORIZONTAL FORCES RIsER ENO MOM -I00- -I5O- -200 I \M FOLLOWING TROUGH LEADING CREST FOLLOwINO CREST CREST CREST FIG. 8

KENNETH A. BLENKARN INVENTOR.

ATTORNEY.

Patented March 14, 1972 3,648,638

22 Sheets-Sheet 9 6% i 4 0- 2 a s E m a as i. w 3 Z O P- Lu 0 g 0 f, 5|.2'IOSEC. LL 3 WAVE 0 Lu 6 .O5- l g g 4 |00'-|4 SEC. WAVE 2 C1: -.|0-.

|o0-20 SEC. WAVE -.I5- I FOLLOWING TROUGH LEADING CREST FOLLOWING CREST CREST CREST FIG. 9

BY%Z% a A T TORNE Y.

Patented March 14,, 1972 NET VARIATION OF MOORING FORCE, LEG NO 0 DISPL. PER LEG) 22 Sheets-Sheet 1O NET VERTICAL FORCE IOO ET,

I00 FT, IA

FIG. HA 0 VARIATION DUE TO COUPLING OF NET -O.l35 VERTICAL FORGE ON VARIATION DUE TO INDIVIDUAL. LEGS VARIATION DUE TO OVERTURING IOOFT, ZOSEGWAVE MOMENTS -0.I35 -O.I37

FOLLOWING TROUGH LEADING CREST CREST SLZ FT Io SEC. WAVE CREST FOLLOWING CREST PLATFORM POSITION RELATIVE TO WAVE KENNETH A. BLENKARN INVENTOR.

BY ATTORNEY Patented March 14, 1972 NET VARIATION OF MOORING FORCE, LEG IIIOQ o DISPL PER LEGI 22 Sheets-Sheet l1 VARIATION DUE TO 50 NET VERTI1CAL FORCE\ VARIATION DUE TO OVERTURING MOIIIIEN I00 FT, 20 SEC WAVE (VARIATION COUPLING VERTICAL VARIATION LEG NO. 4

FIG. I2A

DUE TO OF NET FORGE ON INDIVIDUA L LEGS FIG I25 5I2 FT,

IO SEC. WAVE 2Q IOO FT, I4 SEC. WAVE I IOO PT, 20 SEC. WAVlE FOLLOWING TROUGH LEADING CREST FOLLOWING CREST CREST CREST PLATFORII/I POSITION RELATIVE TO WAVE KENNETH A. BLENKARN INVENTOR.

ATTORNEY Patented 7 March 14, IlIIji.

(' 3 DISPL PER LEG) 22 Sheets-Sheet 1 .2

VARIATION CREST LEG N04 /VARIATION DUE To NET I/ERTIOAI. FOROE FIG. BA (VARIATION 1: T DUE TO COUPLING OF gg g l' VARIATION DUE TO 'NDMDUAL LEGS OIVERTURNINGMOMENTS IOO FT, 20 SEC wAvE I0 SEC. WAVE FIG. I3 B T /IOO FT, 2osEOwAvE IOO FT, I4sEc.wAvE FOLLOWING TROUGH LEADING CREST FOLLOWING CREST CREST PLATFORM POSITION RELATIVE TO WAVE KENNETH A. BLENKARN INVENTOR.

ATTORNEY 7 PM@@&@& Man-ah 3,548,638 22 shets-Sheet 1s MAXIMUM DESIGN WAVE HEIGHT=|OO FT. LEG SPACHNG 56G FT. ERAFT I25 FT. TQTAL DISPLACEMENT 28,675 kips PLATFORM MASS l8,675 kips TOTAL MOORlNG FORCE |0,000 kips 0.5 |.O |.5 r 2.0 2.5 3.0 FIG. [4

KENNETH A. BLENKARN INVENTOR.

all (7: fl w ATTORNE Y pammmfi 14, 1972 22 Sheets-Sheet l4 MAxlMuM OEsTON \NAvE HE|GHT=IOO FT.

LEG SPACING=I6O FT.

L ORAFT=125 FT.

TOTAL O1sPLAOEMENT=28,eT5 kips PLATFORM MASS=I8,675 kips TOTAL MOORING FORCE=l0,000kips 05 L0 L5 v 2'.O 5 0 F|G.l5B

L ELL 0.5 2 H 02 .20 18161414161820 IATIMAX) m BEsT COMBINATION OF PARAMETERS b RANGE OF MOsT PRACTICAL COMBINATIONSO162 I l l 0.5 L0 1.5 2.0 2.5 3.0

FIG. 15A

ATTORNEY.

Pmwm TTT K,

22 Sheets-Sheet 15 A T TORNEY.

3 XIMUM DESIGN WAVE HEIGHT=IOO FT.

LEG sPAcTTTe I40 FT. 0 2 DRAFT=|25 FT.

TOTAL, D|SPLACEMEMT=28,675 kips OT -PLATFORM MASS T8575 kips 0 TOTAL TyTooRTTTe ToRcE=Tppoo kip s I To If) V 2.0 2.5 3.0

FIG. I68

0.3 I IMAX O I I l l J 0.5 L0 L5 r 2.0 2.5 3.0

' FIG IGA KENNETH A. BLENKARN INVENTOR.

Patented March 14,, 197

22 Shams-Sheet 16 MAXIMUM DESIGN WAVE HEIGHT=|OO FT.

15c SPACING=2OO FT. 0RAFT=|25 FT TOTAL DISPLACEMENT=28,675 kips O PLATFORM MASS= |8,675 kips TOTAL MOORING FORCE=I0,000 kips l I I l 0.5 |.0 l5 2.0 2.5 3.0

O l l l l 0.5 L0 L5 V 2.0 2.5 3.0 FIG [7A KENNETH A. BLENKARIV INVENTOR.

ATTORNEY.

Patented March 14, 1972 22 Sheets-Sheet l7 FIG. |8B

MAXIMUM DESIGN WAVE HEIGHT=IOO FT. LEG SPACING=I6O FT. DRAFT=|OO FT.

TOTAL DISPLACEMENT=28,675 kips PLATFORM MASS |8,675 kips TOTAL MOORING FORCE=I0,000kips l l l l 0.5 L0 L5 r 2.0 2.5 3.0

0 I l I l l KENT/v5 TH A. BLENKAR/V INVENTOR.

A T TOR/V5 Y.

Patented March 14, 1972 MAXIMUM DESIGN WAVE HEiGHT I00 FT.

22 Sheets-Sheet l8 0 LEG SPACING=I6O FT.

'O 2 DRAFT= I50 FT.

TOTAL DISPLACEMENT 28,675 kips O l-PLATFORM MASS= |8,675 kips TOTAL MOORING FORCE=IO,OOO kips I 0.5 1.0 l5 r 2.0 2.5 3.0

FIG. |9B

L/ i( m s 0.6- H 2 H O.3- IATI MAX l l I 0.5 1.0 |.5 V 2.0 2.5 3.0

. M KENNETH A. BLENKARN INVENTOR.

A T TORNE Y.

Patented March 14, 1972 3,648,638

22 Sheets-Sheet 19 RAT|= (Wm /H =00 150 SPACING= T60 FT. 0 2 DRAFT =75 FT.

' TOTAL DISPLACEMENT=28,675 kips PLATFORM MASS |0,0T5 kips TOTAL MOORING FORCE=I0,000 kips l I l l l 0.5 |.0 T5 y 2.0 2.5 30

FIG. 20B

MAX 0.5-

2( H 0.4- \g 03 I IMAX 20).|6f.20=( b .l8 .l8

O l l l 0 KENNETH A. BLENKARN INVENTOR.

A T TORNE X

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2399656 *Dec 7, 1944May 7, 1946Edward R ArmstrongFloat
US2939291 *Jun 6, 1955Jun 7, 1960California Research CorpAnchoring system for floating drill structure
US3154039 *Jul 25, 1962Oct 27, 1964Jersey Prod Res CoStable floating foundation
US3224401 *Apr 13, 1964Dec 21, 1965Shell Oil CoStabilized floating drilling platform
US3327780 *Mar 15, 1965Jun 27, 1967Exxon Production Research CoConnection of underwater wells
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3780685 *Apr 9, 1971Dec 25, 1973Deep Oil Technology IncTension leg offshore marine apparatus
US3976021 *Sep 8, 1975Aug 24, 1976Standard Oil Company (Indiana)Installation of vertically moored platform
US3978804 *Oct 15, 1973Sep 7, 1976Amoco Production CompanyRiser spacers for vertically moored platforms
US3982492 *Apr 25, 1975Sep 28, 1976The Offshore CompanyFloating structure
US3993273 *Jul 28, 1975Nov 23, 1976Standard Oil Company (Indiana)Spacers for vertically moored platform riser bundles
US4062313 *Feb 10, 1977Dec 13, 1977Standard Oil Company (Indiana)Installation of vertically moored platforms
US4167279 *Sep 18, 1978Sep 11, 1979Standard Oil Company (Indiana)Vertically moored platform deck casinghead
US4169424 *Aug 16, 1976Oct 2, 1979Yarrow And Company LimitedTension leg buoyancy structure
US4226555 *Dec 8, 1978Oct 7, 1980Conoco, Inc.Mooring system for tension leg platform
US4293146 *Oct 4, 1978Oct 6, 1981Standard Oil Company (Indiana)VMP Casing tieback
US4297965 *Sep 6, 1979Nov 3, 1981Deep Oil Technology, Inc.Tension leg structure for tension leg platform
US4298218 *Aug 30, 1979Nov 3, 1981Standard Oil Company (Indiana)Latching assembly for riser pipe spacers
US4305466 *May 5, 1980Dec 15, 1981Conoco Inc.Offshore platform having three decks
US4344721 *Aug 4, 1980Aug 17, 1982Conoco Inc.Multiple anchors for a tension leg platform
US4351258 *Apr 9, 1980Sep 28, 1982The Offshore CompanyMethod and apparatus for tension mooring a floating platform
US4352599 *Aug 4, 1980Oct 5, 1982Conoco Inc.Permanent mooring of tension leg platforms
US4354446 *Aug 22, 1980Oct 19, 1982Conoco Inc.Temporary mooring of tension leg platforms
US4359095 *Aug 4, 1980Nov 16, 1982Conoco Inc.Well support system
US4417831 *Apr 24, 1981Nov 29, 1983Brown & Root, Inc.Mooring and supporting apparatus and methods for a guyed marine structure
US4431059 *Jul 6, 1981Feb 14, 1984Standard Oil CompanyVertically moored platform anchoring
US4451056 *Jul 18, 1980May 29, 1984Armco Inc.Remotely operated underwater tension connector
US4459066 *Feb 2, 1982Jul 10, 1984Shell Oil CompanyFlexible line system for a floating body
US4468157 *May 3, 1982Aug 28, 1984Global Marine, Inc.Tension-leg off shore platform
US4540314 *Dec 21, 1984Sep 10, 1985Fluor Subsea Services, Inc.Tension leg means and method of installing same for a marine platform
US4789271 *Jul 29, 1987Dec 6, 1988Halliburton CompanyRemote fluid transfer system and method for sub-sea baseplates and templates
US4850744 *Sep 2, 1988Jul 25, 1989Odeco, Inc.Semi-submersible platform with adjustable heave motion
US4983073 *Feb 19, 1987Jan 8, 1991Odeco, Inc.Column stabilized platform with improved heave motion
US5114276 *Mar 8, 1990May 19, 1992Union Oil Company Of California, Dba UnocalApparatus and method for mooring a floating vessel
US5722797 *Feb 21, 1996Mar 3, 1998Deep Oil Technology, Inc.Floating caisson for offshore production and drilling
US6190089May 1, 1998Feb 20, 2001Mindoc, LlcDeep draft semi-submersible offshore structure
US6244347Jul 29, 1999Jun 12, 2001Dril-Quip, Inc.Subsea well drilling and/or completion apparatus
US8157481Jan 2, 1997Apr 17, 2012Shell Oil CompanyMethod for templateless foundation installation
USH1815 *Mar 24, 1997Nov 2, 1999Exxon Production Research CompanyMethod of offshore platform construction using a tension-moored barge
USRE32119 *Jul 22, 1985Apr 22, 1986Brown & Root, Inc.Mooring and supporting apparatus and methods for a guyed marine structure
EP0039596A2 *May 1, 1981Nov 11, 1981Conoco Inc.Offshore drilling and production system
Classifications
U.S. Classification114/265, 405/202
International ClassificationB63B21/50, B63B35/44
Cooperative ClassificationB63B21/502, B63B2035/442, B63B2001/044, B63B35/4413
European ClassificationB63B21/50B, B63B35/44B