US3611734A - Foundation anchor for floating marine platform - Google Patents

Foundation anchor for floating marine platform Download PDF

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Publication number
US3611734A
US3611734A US11998A US3611734DA US3611734A US 3611734 A US3611734 A US 3611734A US 11998 A US11998 A US 11998A US 3611734D A US3611734D A US 3611734DA US 3611734 A US3611734 A US 3611734A
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United States
Prior art keywords
anchor
casing
platform
pad
section
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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.)
Expired - Lifetime
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US11998A
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English (en)
Inventor
George E Mott
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Texaco Inc
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Texaco Inc
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Filing date
Publication date
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Publication of US3611734A publication Critical patent/US3611734A/en
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
    • B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING 
    • B63B21/00—Tying-up; Shifting, towing, or pushing equipment; Anchoring
    • B63B21/50—Anchoring arrangements or methods for special vessels, e.g. for floating drilling platforms or dredgers

Definitions

  • the invention relates to a separable component foundation anchor adapted for positioning an offshore floating platform or other floatable vessel at a desired deep water well drilling site.
  • the anchor includes a relatively heavy pilot member and a submergible casing or ballast section.
  • the anchor further includes means to engage the lower end of the offshore platform to minimize movement of the latter at the waters surface.
  • the ballast section cooperates with the pilot member, functioning sequentially as a transport means to the offshore site, and after being ballasted and submerged supplements the Weighted pilot section.
  • Said ballast section further may hold a quantity of fluids used in an oil drilling or producing operation such as drilling mud, crude oil and the like whereby to minimize the need for additional platform space to store such materials.
  • One form of drilling platform believed to be particularly desirable in deep water comprises a floating vessel or platform at the waters surface which is maintained in a relatively fixed location by a rigid tethering column which extends to the ocean floor.
  • the lower end of the tethering structure is normally anchored at a single point thereby allowing the surface platform to oscillate Within a limited arc in response to wind and wave displacing forces.
  • the anchor means must of necessity be efficient, and have adequate weight and bearing area to withstand lateral forces applied to both the floating vessel, and to the tethering structure.
  • the anchor is normally formed of concrete or other material embodying weight and bulk to provide the necessary down pull whereby to achieve the desired vessel stabilization function.
  • Such anchors because of their weight, are awkard to handle at the waters surface. This applies not only to the fabrication of the anchor but also to transporting the unit to an offshore site and to controllably lowering the same to the ocean floor.
  • a further object is to provide a readily submergible and salvageable anchor adapted for reuse.
  • a still further object is to provide a multi-component anchor, being self-supporting while at the waters surface and which is controllably buoyant whereby to facilitate its being transported and submerged.
  • Still another object is to provide a multicomponent anchor Which is separable into discrete components whereby each component can be individually submerged to or raised from a resting place at the ocean floor.
  • a still further object is to provide an anchor, a portion of which can be used for under water liquid storage.
  • FIG. 1 is a top view shown in partial cross-section of the presently contemplated foundation anchor.
  • FIG. 2 is a cross-sectional view taken along line 2-2 in FIG. 1.
  • FIGS. 3 to 6 inclusive illustrate the sequential steps fol lowed in installing the separable anchor in conjunction with the placing of an offshore marine platform.
  • FIG. 7 illustrates a locking mechanism used to secure the pilot member to the ballast section of the anchor for transport to a job site and for securing the two units together at the ocean floor.
  • the anchor includes at least two members so connected as to permit their separation while at the waters surface whereby each member can be sequentially lowered to the ocean floor.
  • the anchor includes a pilot member formed of concrete or a similar material to provide an initial anchoring base. Said member is further provided with outwardly projecting connector means for engaging the lower end of a floating platform, or other vessel through a rigid tethering structure pivotally connected to the anchor and extending therefrom, to the vessel.
  • the ballast or support section preferably fabricated in the form of a series of closed tubular members, is adapted to securely anchor the pilot member, or alternately to supportably suspend the latter as it is being lowered through the water.
  • the ballast section embodies a plurality of internal, discrete compartments connected to manifold means whereby the Weight and the buoyancy of said section can be adjusted.
  • Means is also provided for storing a flowable fluid such as crude oil or drilling mud. In the instance of the drilling mud, the latter may also function as ballast to maintain the position of the ballastable section at the ocean floor.
  • FIG. 6 illustrates an anchor 10 of the type contemplated partially imbedded into the floor of a body of water.
  • a marine platform 15 extends in a vertical direction from a point adjacent the ocean floor to a distance above the latters surface.
  • a deck 16 is carried at the upper end of the platform, which may hold drilling equipment, producing equipment, ballasting equipment, instruments and the like.
  • the platform includes a plurality of elongated legs or columns 17 having buoyancy tanks 18 in the upper end. In its normal operating position platform 15 extends substantially vertically in the body of water. The lower end of one or more of legs 17 separably engages coupling means carried on anchor 10. The platform can thus oscillate in a restrained manner in response to wind and water displacing forces about the fixed anchor position and yet remain relatively stable to permit continuous drilling producing or other operations from the deck 16.
  • the multi-component, though separable anchor includes in essence a controllably positioned pilot member 11 which is substantially surrounded by, and retained in contact with a ballastable casing section 12.
  • the external configuration of the pilot member bears significant relevance only to the extent that the flat, pad-like configuration will facilitate its holding function by providing suflicient weight and adequate bearing area to prevent the anchor from sinking too deeply into a soft substratum.
  • Pilot member 11 comprises a relatively heavy reinforced slab or pad 13 cast of concrete. Said pilot member as shown, assumes a planar, pad-like configuration having opposed upper and lower surfaces 21 and 22 respectively. A primary reason dictating a generally flat disposition to this member is, as noted above, the desirability of providing an undersurface with a relatively broad bearing area for seating against a soft substratum without excessive sinking into the latter.
  • undersurface 22 is provided with an enclosing lip 23 formed at the pad member periphery, thereby defining a shallow internal cavity 24.
  • Lip 23 is provided with a downward or terminal edge having an abrupt or sharp corner to permit ease of entry of lip 23 when lowered onto a substratum surface.
  • a beveled surface 60 and slot 61 are provided to receive shear pins 62 which are used to lock ballast section 12 to anchor weight 11.
  • Shear pins 62 are in turn housed in hydraulic cylinders 63 which can be actuated by a pump 64 forcing hydraulic fluid from a reservoir 69, through lines 65, to cylinders 63.
  • the pressurized fluid acts against pistons 64 which in turn compresses spring 66 and retracts pins 62.
  • pins 62 are free to retract from the downward weight of ballast section 12.
  • the hydraulic system is used to release weight section 11 from buoyant section 12 while both are floating at the surface of the water.
  • Pad 13 is further provided with transverse passages 19 which extend from the pad upper face to the lower face, thereby affording communication for mud and water between the internal cavity and the surrounding water as pad 13 is lowered onto a penetrable substratum.
  • Said pad member 13 is further provided with a coupling means adapted to operably engage a corresponding element of the leg 17 whereby to restrain lateral movement of platform with a limited degree.
  • Said coupling means includes at least one, and preferably a plurality of upstanding coupling posts 27 spaced horizontally apart at the pad upper surface. Posts 27 are uniform in diameter, having the lower end firmly imbedded in the concrete pad body to fix the posts in a firm upright disposition.
  • the ballastable or casing section 12 comprises in essence one or more tanks interconnected to a pumping system adapted to vary the buoyancy of said section 12 whereby to permit the casing to optionally float at the waters surface, or to be submerged.
  • Said casing 12 includes a plurality of hollow members 28, 29, 31 and 32, preferaby cylindrical in cross-section, which are disposed about the casing outer edge.
  • Said hollow members are formed of heavy walled cylindrical tubing or pipe,
  • pad 13 and casing section 12 are shown as being rectangular the actual configuration utilized is dependent on a number of factors.
  • Each cylindrical member at the casing section is provided with one or more internal panels such as 33, disposed transversely of said member whereby to define a tank such as 34 and 36 adjacent said panels.
  • said tanks 34 and 36 may be provided with transverse perforated baflies 37 and 38 Whereby movement of contained water or drilling mud is dampened.
  • ballastable section 12 cooperatively engages the peripheral seating edge 21 of foundation pad 13 along the contoured seat on the latter.
  • casing section 12 is shown as overhanging the edge of the foundation pad 13, it is understood that such an arrangement is not essential since the casing can function as well were the latter to be disposed directly on top of the foundation pad.
  • Casing section 12 futrher includes transversely disposed structural cross braces 56 and 58 which extend between the opposed cylindrical sections.
  • the cross bracing sections intersect a central main brace 39, and are provided with spaced apart intermediate guide rods 41 and 42 whereby to define a relatively limited guide opening 43 therebetween.
  • the one or more guide openings are so arranged in the casing 12 to cooperatively register with and engage the respecting coupling posts 27 depending upwardly from the foundation pad.
  • the said casing section 12 further embodies pumping means connected to the respective tanks 34 and 36 within the casing.
  • Said pumping means may either be located on platform 15 or be remotely controlled from the waters surface.
  • Said pumping means includes for example a manifolding arrangement represented by upward extending line 44 which connects to a pump means 46 which is either disposed within the tank section 36 or on platform deck 16.
  • the flow of material either ballasting water or drilling mud, is controlled through a series of valves represented by control valves 47 and 48, Said valves may either be located on platform deck 16 located on the bottom. In the latter case the valves would be remotely controlled from platform deck 16 or other surface vessel.
  • the casing section 12 functions as a transport vehicle for the entire assembled anchor 10
  • the easing and the foundation pad 13 are fixedly engaged at the waters surface.
  • foundation pad 13 is entirely submerged to minimize the buoyancy lift required of the casing 12. In such condition the unit can be towed at the surface of the water until reaching the place of submergence at the underwater well site.
  • the respective pilot member 11 and casing section 12 are connected by means whereby the respective parts can be readily separated to permit lowering of the foundation pad 13 to the ocean floor.
  • Said connecting means can assume a number of different forms any of which are adapted to maintain the separable relationship thereof.
  • the respective pilot member 11 and casing section 12 are provided with one or more and preferably at least two flexible lines 51 and 52 such as cable or chain.
  • the latter connect at their lower end to the foundation pad 13 prior to the pad being lowered to the ocean floor.
  • the cables are retained at the waters surface and tension controlled as pad 13 is lowered and casing 12 remains floating. Thereafter, with the respective flexible lines registered in the guide means 43 on the casing section 12, the latters 'buoyancy is adjusted to controllably sink the unit into the water and be guided to its position in engagement with the foundation pad 13.
  • connection system may include one or more cable wind-ups carried on the casing section 12 and provided with power winch means upon which the cable or chain is taken up.
  • the cables may also be controlled by an external means such as a derrick barge or the like at the waters surface which maintains th disposition of casing 12 as the latter is lowered to its point of engagement in the ocean floor.
  • the mode for installing an anchor of the type described, for use with the marine structure follows a sequence of steps.
  • the anchor 10 is towed with the pilot member 11 and casing section 12 joined to the desired offshore location.
  • the flexible guide lines 51 are connected to foundation pad 13 preferably at the upper end of the respective posts 27.
  • the said guide lines are registered in the respective guide openings 43 on the casing 12, the foundation pad is then lowered to the ocean floor.
  • the lowering operation is achieved by disconnecting the foundation pad 13 from the casing 12 and maintaining an orderly descent of the foundation pad either by the external derrick barge 54 or by controlling the speed of the respective support cables as they are unwound from the power winch on the casing.
  • buoyancy tanks 34 and 36 are selectively flooded to alter the buoyancy characteristics of said casing.
  • the upper ends of lines 51 are connected to buoys 57 at the surface for subsequent connection to platform 15.
  • Section 12 is then controllably lowered to the ocean floor along the guide lines 51, whereby the respective guide openings 43 register with the upstanding posts 27.
  • Casing 12 can be provided with one or more piles 56 having the lower edge depending from the underside of the casing 12.
  • the weight of the unit will cause the respective piles 56 to enter the substratum whereby to improve the ability of the anchor to maintain a fixed position against horizontal displacing forces.
  • the guide lines 51 are passed through the respective legs 17 of the marine structure 15.
  • the lower end of said structure is guidably lowered to the ocean floor whereby the respective leg ends register with the upstanding posts 27 in the foundation pad 13.
  • platform 15 is floated to disengage from pad 13.
  • the buoyancy of the casing 12 is next gradually altered such that the entire unit controllably rises to the surface of the water along the guide lines 51.
  • foundation pad 13 can be dislodged from its resting place and lifted to the surface.
  • the foundation pad 12 is imbedded to such an extent as to resist efforts to dislodge the same, it can be abandoned in favor of providing a similar pad adapted to engage casing 12, for the next installation at which the anchor is to function.
  • the usual ballasting material is water.
  • the respective ballasting tanks 34 and 36 can be provided in whole or in part with a fluid used in the drilling operations such as drilling mud or the like.
  • the drilling mud is pumped in liquid phase into the respective storage tanks 34 and 36, and maintained there until such time as the mud is required for the drilling operation.
  • the resulting space can be filled with water or other material to maintain the negative buoyancy of the casing 12.
  • each storage tank 34 and 36 may be provided with means for maintaining the mud in a solution or flowable suspension whereby to be suitably handled by the pumping and manifold system.
  • each of said storage tanks may include in effect, an agitating pump connected to have the suction side thereof submerged in the storedfluid, and being provided with one or more discharge nozzles which are redirected into the fluid whereby the latter are subjected to violent agitation and thus maintain its fluid status.
  • each of said compartments can alternately be provided with a stirring mechanism such as a motor mounted stirrer disposed within the compartment and surface control whereby to set in mo tion the contained drilling mud prior to its being withdrawn from the tank.
  • a base member having coupling means dependent therefrom for operably engaging a submerged end of said marine structure whereby to limit movement of the latter in said body of water
  • buoyant casing engaging said base member and adapted to be detachably separated therefrom
  • a pumping system in said buoyant casing being operable to controllably adjust the buoying capabilities thereof whereby to remotely regulate the attitude of said casing in said body of water
  • guide means connecting said respective base member with buoyant casing and being operable to lower said base member in said body of Water to the floor thereof when said base member is detached from the floating buoyant casing, and for further guiding said buoyant casing to re-engage the base member at said ocean floor when said casing is adjusted to a condition of negative buoyancy.
  • said base member includes; a relatively flat pad having opposed upper and lower surfaces, the latter forming a bearing area for engaging the underwater substratum.
  • said relatively flat pad includes; at least one transverse opening formed therein communicating said upper and lower surfaces.
  • said relatively flat pad includes; an upstanding lip depending downwardly from said lower surface thereby defining a cavity at said lower surface.
  • said upstanding lip comprises; a substantially continuous member that extends about the periphery of said pad to form said cavity.
  • said pad includes; seating means on said upper surface adapted to register a corresponding surface of said buoyant casing whereby to fixedly position the latter with respect to said pad.
  • buoyant casing includes; a plurality of discrete buoyancy tanks, and said pumping system being separably communicated with the respective tanks and operable to regulate the buoyant capabilities thereof.
  • said pumping system includes; pumping means communicated with said respective buoyancy tanks and means to remotely actuate said pumping means for regulating the tank buoyancy.
  • said guide means includes; a flexible line communicated with the respective casing and base member, said flexible line being extendable to maintain said connection between said base member as the latter is lowered to the ocean floor.
  • said flexible line includes; a wind-up carried on said casing being operable to regulate the flexible line length as said base member is separated from said casing and means on the latter adapted to slidably engage said flexible line whereby to direct said easing into engagement with said base member as said casing is controllably lowered to the ocean floor.
  • conduit means communicating said buoyancy tanks with a source of a fluidized material.
  • conduit means communicating said buoyancy tanks with a source of a fluidized material and agitating means in said buoyancy means being operable to fluidize said material for passage thereof through said conduit means.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • Ocean & Marine Engineering (AREA)
  • Earth Drilling (AREA)
  • Foundations (AREA)
US11998A 1970-02-17 1970-02-17 Foundation anchor for floating marine platform Expired - Lifetime US3611734A (en)

Applications Claiming Priority (1)

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US1199870A 1970-02-17 1970-02-17

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US3611734A true US3611734A (en) 1971-10-12

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US (1) US3611734A (de)
JP (1) JPS516961B1 (de)
DE (1) DE2106985A1 (de)
GB (1) GB1303594A (de)
NL (1) NL7102015A (de)
NO (1) NO134979C (de)

Cited By (21)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3880105A (en) * 1973-10-01 1975-04-29 Offshore Co Drilling vessel and drilling vessel mooring system and method
US4018057A (en) * 1973-06-01 1977-04-19 King-Wilkinson, Limited Off shore structures
US4102147A (en) * 1975-10-13 1978-07-25 Hollandsche Beton Groep Nv Submersible positioning and guiding apparatus for pile driving
DE2742459A1 (de) * 1977-09-21 1979-03-29 Babcock Ag Offshore-konstruktion
US4181453A (en) * 1977-08-24 1980-01-01 Sea Tank Co. Apparatus for positioning an off-shore weight structure on a previously positioned sea bed unit
US4222682A (en) * 1976-06-30 1980-09-16 Enterprise D'equipments Mechaniques Et Hydrauliques, E.M.H. Platforms for sea-bottom exploitation
US4344721A (en) * 1980-08-04 1982-08-17 Conoco Inc. Multiple anchors for a tension leg platform
US4352599A (en) * 1980-08-04 1982-10-05 Conoco Inc. Permanent mooring of tension leg platforms
US4354446A (en) * 1980-08-22 1982-10-19 Conoco Inc. Temporary mooring of tension leg platforms
US4445805A (en) * 1982-11-17 1984-05-01 Sonat Offshore Drilling Inc. Jack-up platform variable bearing assembly
US4620820A (en) * 1985-03-27 1986-11-04 Shell Oil Company Tension leg platform anchoring method and apparatus
US4624645A (en) * 1984-02-09 1986-11-25 Sofec, Inc. Rapid deployment mooring and discharge system and method
US4776140A (en) * 1986-08-06 1988-10-11 San Diego Gas And Electric Modular block anchor
US4808040A (en) * 1987-10-20 1989-02-28 Itt Corporation Submersible mixer support system with removable guide bars
US4934872A (en) * 1986-09-30 1990-06-19 Aker Engineering A/S Arrangement in an offshore platform, and method for the mounting thereof
GB2245923A (en) * 1990-06-15 1992-01-15 Norwegian Contractors Sea bed frame for oil wells
US20080112759A1 (en) * 2006-11-10 2008-05-15 Stewart Hardison Artificial reef anchor structure
US20090304453A1 (en) * 2007-11-08 2009-12-10 Stewart Hardison Mooring habitat structure
US8869746B2 (en) 2009-08-06 2014-10-28 Stewart Hardison Mooring structure with habitat features for marine animals
US10400414B2 (en) * 2015-04-22 2019-09-03 Ihc Iqip Uk Ltd Method of installing a pile by means of a pile guide
CN113883013A (zh) * 2021-11-24 2022-01-04 岭南师范学院 一种方便拆装的海上风力发电设备基座

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2551019B1 (fr) * 1983-08-26 1989-09-01 Inst Francais Du Petrole Perfectionnements aux plates-formes marines, en vue d'ameliorer leur equilibrage dynamique
DE10223314A1 (de) * 2002-05-24 2003-12-11 Peter Kelemen Windkraftanlage und Verfahren zur Festlegung einer Windkraftanlage in einem Gewässer
CN111374079B (zh) * 2020-03-18 2021-09-21 吴常文 一种坐底式柱状深远海牧场可移动管理平台
CN115217151B (zh) * 2022-07-19 2024-02-06 中铁第五勘察设计院集团有限公司 一种明挖隧道长距离下穿施工方法

Cited By (24)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4018057A (en) * 1973-06-01 1977-04-19 King-Wilkinson, Limited Off shore structures
US3880105A (en) * 1973-10-01 1975-04-29 Offshore Co Drilling vessel and drilling vessel mooring system and method
US4102147A (en) * 1975-10-13 1978-07-25 Hollandsche Beton Groep Nv Submersible positioning and guiding apparatus for pile driving
US4222682A (en) * 1976-06-30 1980-09-16 Enterprise D'equipments Mechaniques Et Hydrauliques, E.M.H. Platforms for sea-bottom exploitation
US4181453A (en) * 1977-08-24 1980-01-01 Sea Tank Co. Apparatus for positioning an off-shore weight structure on a previously positioned sea bed unit
DE2742459A1 (de) * 1977-09-21 1979-03-29 Babcock Ag Offshore-konstruktion
US4344721A (en) * 1980-08-04 1982-08-17 Conoco Inc. Multiple anchors for a tension leg platform
US4352599A (en) * 1980-08-04 1982-10-05 Conoco Inc. Permanent mooring of tension leg platforms
US4354446A (en) * 1980-08-22 1982-10-19 Conoco Inc. Temporary mooring of tension leg platforms
US4445805A (en) * 1982-11-17 1984-05-01 Sonat Offshore Drilling Inc. Jack-up platform variable bearing assembly
US4624645A (en) * 1984-02-09 1986-11-25 Sofec, Inc. Rapid deployment mooring and discharge system and method
US4620820A (en) * 1985-03-27 1986-11-04 Shell Oil Company Tension leg platform anchoring method and apparatus
US4776140A (en) * 1986-08-06 1988-10-11 San Diego Gas And Electric Modular block anchor
US4934872A (en) * 1986-09-30 1990-06-19 Aker Engineering A/S Arrangement in an offshore platform, and method for the mounting thereof
US4808040A (en) * 1987-10-20 1989-02-28 Itt Corporation Submersible mixer support system with removable guide bars
GB2245923A (en) * 1990-06-15 1992-01-15 Norwegian Contractors Sea bed frame for oil wells
GB2245923B (en) * 1990-06-15 1994-12-07 Norwegian Contractors Bottom frame foundation structure for support and protection of drilling equipment
US20080112759A1 (en) * 2006-11-10 2008-05-15 Stewart Hardison Artificial reef anchor structure
US20090304453A1 (en) * 2007-11-08 2009-12-10 Stewart Hardison Mooring habitat structure
US8869746B2 (en) 2009-08-06 2014-10-28 Stewart Hardison Mooring structure with habitat features for marine animals
US9464413B2 (en) 2009-08-06 2016-10-11 Stewart Hardison Mooring structure with habitat features for marine animals
US10400414B2 (en) * 2015-04-22 2019-09-03 Ihc Iqip Uk Ltd Method of installing a pile by means of a pile guide
CN113883013A (zh) * 2021-11-24 2022-01-04 岭南师范学院 一种方便拆装的海上风力发电设备基座
CN113883013B (zh) * 2021-11-24 2023-10-03 岭南师范学院 一种方便拆装的海上风力发电设备基座

Also Published As

Publication number Publication date
JPS516961B1 (de) 1976-03-03
NO134979B (de) 1976-10-11
NL7102015A (de) 1971-08-19
DE2106985A1 (de) 1971-08-26
NO134979C (de) 1977-01-19
GB1303594A (de) 1973-01-17

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