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US3793840A - Mobile, arctic drilling and production platform - Google Patents

Mobile, arctic drilling and production platform Download PDF

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Publication number
US3793840A
US3793840A US00189972A US3793840DA US3793840A US 3793840 A US3793840 A US 3793840A US 00189972 A US00189972 A US 00189972A US 3793840D A US3793840D A US 3793840DA US 3793840 A US3793840 A US 3793840A
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US
United States
Prior art keywords
platform
base
caisson
water
guide column
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.)
Expired - Lifetime
Application number
US00189972A
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English (en)
Inventor
G Mott
J Wilbourn
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Texaco Inc
Original Assignee
Texaco Inc
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Filing date
Publication date
Application filed by Texaco Inc filed Critical Texaco Inc
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Publication of US3793840A publication Critical patent/US3793840A/en
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    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
    • E02D27/00—Foundations as substructures
    • E02D27/32—Foundations for special purposes
    • E02D27/42—Foundations for poles, masts or chimneys
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02B—HYDRAULIC ENGINEERING
    • E02B17/00—Artificial islands mounted on piles or like supports, e.g. platforms on raisable legs or offshore constructions; Construction methods therefor
    • E02B17/02—Artificial islands mounted on piles or like supports, e.g. platforms on raisable legs or offshore constructions; Construction methods therefor placed by lowering the supporting construction to the bottom, e.g. with subsequent fixing thereto
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
    • E02D27/00—Foundations as substructures
    • E02D27/32—Foundations for special purposes
    • E02D27/42—Foundations for poles, masts or chimneys
    • E02D27/425—Foundations for poles, masts or chimneys specially adapted for wind motors masts

Definitions

  • the invention relates to a marine platform adapted to be removably positioned at an offshore body of water, the surface of which is periodically subjected to sheet ice and floating ice masses.
  • the platform includes a controllably buoyant foundation-like base at its lower end, which normally rests on the ocean floor.
  • a shelllike body extends upwardly from said base and is defined on its external surface by a progressively decreasing cross sectional area from the body lower end, to a point adjacent the upper end.
  • a work deck disposed at, and operably carried at the body upper end includes equipment necessary to function at said offshore site.
  • a caisson extending uprightly through the platform is partially embedded into the substratum beneath the platform, firmly anchoring the latter and protecting wells during and after a drilling operation.
  • One method found to be suitable for opposing the lateral thrust of a moving ice mass, whether in the form of floes or an entire ice field, is by fabricating a platform with sufficient mass and with an adequate degree of stability to physically resist the displacing forces exerted on the structure.
  • Such platforms however as a rule are of a relatively permanent nature in that once they are installed at a particular site they are not amenable to be subsequently readily removed or to be reused in different water depths. Thus, if the site proves to be nonproductive, the use of an expensive nonsalvageable platform would result in excessive operating expense.
  • Ice floes are known to reach to the ocean floor and be of such a magnitude as to scour and dig out the latter. This results in the subjecting to bending, breaking off or otherwise damaging, any sea floor equipment installed in such an environment. Even though the said equipment be buried to a desired depth beneath the ocean floor, it may still be susceptible to physical damage when extraordinary size icebergs or the like are in the area.
  • Said structure comprises in effect a platform adapted for drilling, producing or exploratory work in an offshore body of water in which moving ice is prevalent.
  • the platform is provided with a relatively widespread foundation-like base to afford a firm footing. Further, it is made salvageable such that the platform can be removed from a particular spot and subsequently reset at an alternate drilling or producing location.
  • the platform embodies a downwardly extending heavy walled caisson through which the respective wells are drilled. Said caisson is of sufficient strength and rigidity to resist installation forces and to protect the wells during the drilling operation. When the platform is removed, the caisson may be left in place and thus serves as a well protector.
  • the platform is physically contoured along its exterior particularly along the level at which ice would be concentrated, such as to expose a minimum area thereof to contact with moving ice.
  • FIG. 1 is a vertical elevation in partial cross section of the instant marine structure shown submerged and anchored at an underwater site.
  • FIG. 2 is similar to FIG. 1 illustrating the platform when buoyed to a floating position.
  • FIG. 3 is a segmentary view in cross section showing a portion of the structure shown in FIG. 1.
  • FIG. 4 is an enlarged segmentary view showing a well head installation subsequent to removal of the anchoring caisson.
  • a platform 10 of the type contemplated is shown installed at the floor of an offshore body of water.
  • Base 11 comprises in general a circular, octagonal or other multisided barge-like unit disposed at the lower end of the platform, which member ordinarily assumes a horizontal disposition.
  • Base 11 supports an upstanding, conically shaped shell or body 12 having a contoured external surface which connects a relatively broad lower section to a relatively constricted narrow portion at the upper end.
  • Body 12 is further provided with an upwardly extending column 13 along which an equipment deck 14 is operably received.
  • deck 14 can be raised or lowered to a desired height beyond the waters surface.
  • either the upper end of said shell 12 or column 13 is disposed adjacent to the waters surface whereby to meet, break up and deflect moving ice at the waters surface.
  • Base member 11 comprises in effect a barge-like vessel formed of a plurality of closed, individually controlled tanks. By regulation of the buoyancy of the respective tanks, the attitude and disposition of the base can be readily regulated between the ocean floor and the waters surface.
  • Base 11 is preferably formed with welded steel or reinforced concrete sections of sufficient strength and so reinforced, as to resist external forces and pressures expected in the depths of water where the platform would normally be positioned.
  • the respective compartments such as 16 and 17 within base 11 are individually separated by discretely placed bulkheads and panels. Thus, selective adjustment of the buoyancy of said compartments results in the platform being raised or lowered to a desired depth or positioned at a desired attitude.
  • each compartment 16 and 17 is connected with a buoyancy system regulated from the water's surface and adapted to urge a fluid medium such as water or drilling mud through the respective compartments as required.
  • Said system of course includes means for regulating the flow of said fluids to achieve the purpose of raising or adjusting the level of the barge.
  • An opening 18 extends transversely and centrally of barge l1, communicating the upper and lower surfaces thereof in a generally vertical disposition.
  • Elongated, conically shaped shell 12 is disposed with its center axis normal to base 11, extending into and being rigidly connected to the latter.
  • Column 13 also connects to and extends axially through conical shell 12 and base 11.
  • the respective members are thus secured one to the other in a manner to form a rigid, upright structure.
  • the relationship between said members not only assembles the respective parts into a unitary component, but transfers or applies sheer stress and overturning loads applied to column shell exterior, to the widespread base 11.
  • a suitable fastening means between base 11 and shell 12 may be provided by fabri eating the shell 12 of reinforced concrete whereby to achieve a satisfactory bonded engagement between the body peripheral lower edge, and the base.
  • Base 11 is further provided with means to assure its fixed positioning at a desired offshore working site.
  • said base includes not only center transverse opening 18, but optionally may include openings adapted to receive a plurality of relatively short spud piles 27 which can be driven through the base to engage or be embedded into the substratum after the platform comes to rest on the latter.
  • conical shell 12 The lower edge of conical shell 12 is secured to base 1 l and maintains the shell in a substantially upright disposition.
  • One embodiment of said shell comprises a hollow, heavy walled unit formed of reinforced concrete, steel, or a combination of said materials.
  • the shell is made in the form of a geometrically conical member characterized by an outer wall surface having a horizontal cross section which decreases as the distance from base 11 increases.
  • conical shell or body 12 The primary function of conical shell or body 12 is to provide a relatively widespread footing for the platform in conjunction with base 11. Further, said body is provided with a sloping outer contour or surface to best encounter moving sheet ice whereby to deflect the latter upwardly, causing it to break into smaller pieces due to induced bending stresses. While not presently shown in detail, compartments built into the interior of shell 12 are vented to the atmosphere to better control the internal and external pressures while the platform is being submerged.
  • Elongated, cylindrical column 13 extends coaxially of shell 12 from the point adjacent to base 11 to which it is fastened, to a point beyond the shell 12 upper end.
  • column 13 projects upwardly for a substantial distance beyond the shell upper end when platform is resting on the floor of an offshore drilling site.
  • the primary function of said column is to operably support work deck 14 during the transportation of the platform as well as to provide a means of elevating the work deck 14 a desired distance beyond the waters surface during actual drilling operations.
  • Column 13 thus comprises an elongated cylindical member formed of relatively heavy walled steel or reinforced concrete.
  • the column lower end is received in receptacle means forming opening 18 in base 11 and is fastened to the latter by cementing, welding, or other appropriate means.
  • the upper end of shell 12 is further fastened to the outer wall of column 13 to fixedly join the entire assembly into a unitary structure.
  • Intermediate support means such as struts, braces 22 and 23 or bulkheads are further disposed within body 12 and radiate outwardly from the column wall to reinforce both the shell and the column, and to permit ballasting of the conical shell 12 as needed.
  • the column can be provided with the necessary slots, indentations, protrusions or the like.
  • Said means facilitate gripping of the column wall by a plurality of climbing jacks and claps carried within deck 14.
  • Such jacks are clamps known in the art and are frequently utilized on mobile offshore structures for regulating the disposition of retractable legs carried on the marine platform or structure.
  • a caisson 26 which has previously been secured inside column 13 and extends longitudinally thereof, is released and jetted into the sea bottom.
  • Base 1 l is thus firmly embedded in the substratum beneath the platform quickly and easily without the use of either piles or anchor.
  • a sufficient embedment of said caisson 26 will assist platform 10 in absorbing and transmitting to the ocean bottom, lateral forces imposed on the structure, thus further insuring against the possibility of lateral displacement of the platform.
  • caisson 26 extends preferably in a downward direction through the center of the platform to achieve the desired anchoring function.
  • F urther in connection with a drilling or producing operation, and as shown in FIG. 4, when it is deemed feasible to move the platform, column 13 is free to slide along the embedded portion of caisson 26 as the platform is raised by ballasting.
  • the lower remaining end of the caisson serves as a protector or enclosure for both wells and well head equipment at the floor of the drilling site.
  • caisson 26 In the event that icebergs of other relatively deep ice masses tend to scour the floor of the ocean in the vicinity of submerged wells 28, the protruding portion of caisson 26 will form a barrier about said wells. Should caisson 26 nonetheless be contacted by a floating iceberg in a manner to bend or deform the caisson walls, the internal wells 28 would still be protected due to their position within the caisson which will tend to bend rather than fracture as they are displaced by the ice mass.
  • Caisson 26 is initially assembled with platform 10 during fabrication of the latter. Thus, it can be floated to the drill site by the buoyant platform. It is appreciated that since caisson 26 will be lowered or driven into the substratum, it will be necessary to add additional caisson sections if the platform is moved to other locations. A number of caisson sections would thus be carried, ancillary to the platform placing operation.
  • caisson 26 when in the installed position, the lower end of caisson 26 is disposed contiguous with walls of the column 13 extending through the shell lower surface. If it is desired to permanently place a platform at a desired location, means may also be provided for cementing or otherwise rigidly fastening the shell 12 upper and lower ends to the casing to rigidize the disposition thereof and to avoid movement in response to pressure exerted against the platform.
  • deck 14 is elevated along column l3 outer surface, beyond the waters surface a predetermined height to facilitate drilling operation and to maintain deck carried equipment beyond the reach of the anticipated waves and ice.
  • wells 28 may be completed with subsea well heads 31 or extended to the deck elevation for conventional surface cntrols, or may be capped for future use. In the latter event, such equipment may be embedded below the surface of the substratum as a form of protection. In such instance, the remaining, protruding portion of caisson 26 will serveto enclose said well head and equipment until such time as the wells are connected to the surface for producing petroleum fluids.
  • platform is separated from caisson 26 by ballasting the latter to raise it a predetermined distance beyond the ocean floor.
  • the platform will then slide upwardly along caisson 26 in an orderly, controlled manner.
  • the platform can be entirely raised from its position and refloated to an alternate working site.
  • a marine platform adapted to be removably positioned at an offshore body of water, the latter being in an environment subject to floating ice, which platform includes;
  • a submergible base including buoyancy means incorporated therein for controllably regulating the disposition of said base between the floating position at the waters surface, and a resting position at the floor of said body of water, said base having means forming a vertical transverse opening therethrough, a guide column having upper and lower ends, the latter being fixed to and extending upwardly from said base in alignment with said vertical transverse opening, the column upper end being of sufficient length to extend beyond the waters surface when said base is positioned at said a caisson disposed internally of and contiguous with said guide column, extending longitudinally thereof and having the lower end embedded into the substrate beneath said platform whereby to anchor the latter during a drilling operation, and to subsequently permit upward guided movement of said platform along the caisson when the platform is raised from a submerged position,
  • an elongated shell characterized by a generally conical external surface, having the broad end connected to said base and having the upper constricted end in engagement with said guide column adjacent the upper end thereof, and
  • a deck operably carried on said guide column upper end being longitudinally movable therealong for positioning a desired distance beyond the waters surface.
  • a marine platform as defined in claim 1 including a caisson operably received in said guide column and longitudinally movable through the latter whereby to permit lowering of said caisson downwardly through said base to permit embedment thereof into the floor of said body of water.
  • said conical shell is of sufficient height to position at least a portion thereof beyond the waters surface when said base is resting at said floor.

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Civil Engineering (AREA)
  • Structural Engineering (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Mining & Mineral Resources (AREA)
  • Paleontology (AREA)
  • Mechanical Engineering (AREA)
  • Earth Drilling (AREA)
  • Foundations (AREA)
US00189972A 1971-10-18 1971-10-18 Mobile, arctic drilling and production platform Expired - Lifetime US3793840A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US18997271A 1971-10-18 1971-10-18

Publications (1)

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US3793840A true US3793840A (en) 1974-02-26

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US00189972A Expired - Lifetime US3793840A (en) 1971-10-18 1971-10-18 Mobile, arctic drilling and production platform

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US (1) US3793840A (da)
CA (1) CA970579A (da)
DK (1) DK140438B (da)
NO (1) NO137511C (da)

Cited By (21)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3996754A (en) * 1973-12-14 1976-12-14 Engineering Technology Analysts, Inc. Mobile marine drilling unit
US4193455A (en) * 1978-04-14 1980-03-18 Chevron Research Company Split stack blowout prevention system
US4325655A (en) * 1980-01-16 1982-04-20 Exxon Production Research Company Multiple slope structure
US4470725A (en) * 1982-03-01 1984-09-11 Ingenior Thor Furuholmen A/S Offshore platform structure intended to be installed in arctic waters, subjected to drifting icebergs
US4484841A (en) * 1980-09-02 1984-11-27 Ingenior Thor Furuholmen A/S Offshore platform structure for artic waters
US4511288A (en) * 1981-11-30 1985-04-16 Global Marine Inc. Modular island drilling system
US4558973A (en) * 1984-06-21 1985-12-17 Seahorse Equipment Corporation Subsea wellhead protector
US4579481A (en) * 1983-04-29 1986-04-01 Standard Oil Company Mobile offshore drilling structure for the arctic
US4679964A (en) * 1984-06-21 1987-07-14 Seahorse Equipment Corporation Offshore well support miniplatform
WO1993003230A1 (en) * 1991-08-02 1993-02-18 The Broken Hill Proprietary Company Limited Submerged shielded pile foundation
US6371695B1 (en) 1998-11-06 2002-04-16 Exxonmobil Upstream Research Company Offshore caisson having upper and lower sections separated by a structural diaphragm and method of installing the same
WO2003080939A1 (en) * 2002-03-20 2003-10-02 Boreas Consultants Limited Foundation structure
US20100221069A1 (en) * 2006-03-30 2010-09-02 Carl Rhys Brinkmann Mobile, Year-Round Arctic Drilling System
US20100329796A1 (en) * 2009-05-11 2010-12-30 American Global Maritime, Inc. Drilling rig ice protector apparatus and methods
US20110188945A1 (en) * 2010-02-02 2011-08-04 Rune Hartkopf Support structure for supporting an offshore wind turbine
US20110305523A1 (en) * 2008-06-20 2011-12-15 Seatower As Support structure for use in the offshore wind farm industry
WO2012067749A1 (en) * 2010-11-18 2012-05-24 Conocophillips Company Conical piled monopod
NL2007257C2 (en) * 2011-08-11 2013-02-12 Bos & Kalis Baggermaatsch Method for installation of an off-shore mast or pile.
US8568063B2 (en) 2009-04-30 2013-10-29 Exxonmobil Upstream Research Company Mooring system for floating arctic vessel
US9487944B2 (en) * 2014-12-22 2016-11-08 Muhammad Amzad Ali Jack-up conical structure
US10443574B2 (en) * 2015-03-27 2019-10-15 Drace Infraestructuras, S.A. Gravity foundation for the installation of offshore wind turbines

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4576518A (en) * 1984-02-22 1986-03-18 Epi Resources Ltd. Fixed/movable marine structure system

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2574140A (en) * 1947-07-18 1951-11-06 Raymond Concrete Pile Co Marine oil well derrick foundation
US2622404A (en) * 1949-03-24 1952-12-23 George P Rice Offshore drilling apparatus and method of installing the same
US2661600A (en) * 1947-12-31 1953-12-08 George R Hopkins Underwater drilling derrick
US3165898A (en) * 1962-06-11 1965-01-19 Continental Oil Co Off-shore oil drilling apparatus
US3408821A (en) * 1965-08-10 1968-11-05 Vickers Ltd Waterborne vessel
US3486343A (en) * 1966-09-15 1969-12-30 Brown & Root Platform for drilling wells at water locations
US3645104A (en) * 1969-12-29 1972-02-29 Phillips Petroleum Co Tower structure

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2574140A (en) * 1947-07-18 1951-11-06 Raymond Concrete Pile Co Marine oil well derrick foundation
US2661600A (en) * 1947-12-31 1953-12-08 George R Hopkins Underwater drilling derrick
US2622404A (en) * 1949-03-24 1952-12-23 George P Rice Offshore drilling apparatus and method of installing the same
US3165898A (en) * 1962-06-11 1965-01-19 Continental Oil Co Off-shore oil drilling apparatus
US3408821A (en) * 1965-08-10 1968-11-05 Vickers Ltd Waterborne vessel
US3486343A (en) * 1966-09-15 1969-12-30 Brown & Root Platform for drilling wells at water locations
US3645104A (en) * 1969-12-29 1972-02-29 Phillips Petroleum Co Tower structure

Cited By (29)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3996754A (en) * 1973-12-14 1976-12-14 Engineering Technology Analysts, Inc. Mobile marine drilling unit
US4193455A (en) * 1978-04-14 1980-03-18 Chevron Research Company Split stack blowout prevention system
US4325655A (en) * 1980-01-16 1982-04-20 Exxon Production Research Company Multiple slope structure
US4484841A (en) * 1980-09-02 1984-11-27 Ingenior Thor Furuholmen A/S Offshore platform structure for artic waters
US4511288A (en) * 1981-11-30 1985-04-16 Global Marine Inc. Modular island drilling system
US4470725A (en) * 1982-03-01 1984-09-11 Ingenior Thor Furuholmen A/S Offshore platform structure intended to be installed in arctic waters, subjected to drifting icebergs
US4579481A (en) * 1983-04-29 1986-04-01 Standard Oil Company Mobile offshore drilling structure for the arctic
US4558973A (en) * 1984-06-21 1985-12-17 Seahorse Equipment Corporation Subsea wellhead protector
US4679964A (en) * 1984-06-21 1987-07-14 Seahorse Equipment Corporation Offshore well support miniplatform
WO1993003230A1 (en) * 1991-08-02 1993-02-18 The Broken Hill Proprietary Company Limited Submerged shielded pile foundation
US6371695B1 (en) 1998-11-06 2002-04-16 Exxonmobil Upstream Research Company Offshore caisson having upper and lower sections separated by a structural diaphragm and method of installing the same
WO2003080939A1 (en) * 2002-03-20 2003-10-02 Boreas Consultants Limited Foundation structure
GB2402695A (en) * 2002-03-20 2004-12-15 Boreas Consultants Ltd Foundation structure
US8523491B2 (en) 2006-03-30 2013-09-03 Exxonmobil Upstream Research Company Mobile, year-round arctic drilling system
US20100221069A1 (en) * 2006-03-30 2010-09-02 Carl Rhys Brinkmann Mobile, Year-Round Arctic Drilling System
US20110305523A1 (en) * 2008-06-20 2011-12-15 Seatower As Support structure for use in the offshore wind farm industry
US9233739B2 (en) 2009-04-30 2016-01-12 Exxonmobil Upstream Research Company Mooring system for floating arctic vessel
US8568063B2 (en) 2009-04-30 2013-10-29 Exxonmobil Upstream Research Company Mooring system for floating arctic vessel
US9011044B2 (en) * 2009-05-11 2015-04-21 American Global Maritime, Inc. Drilling rig ice protector apparatus and methods
US20100329796A1 (en) * 2009-05-11 2010-12-30 American Global Maritime, Inc. Drilling rig ice protector apparatus and methods
US20110188945A1 (en) * 2010-02-02 2011-08-04 Rune Hartkopf Support structure for supporting an offshore wind turbine
CN103221613A (zh) * 2010-11-18 2013-07-24 科诺科菲利浦公司 锥形打桩单脚架
US8821071B2 (en) 2010-11-18 2014-09-02 Conocophillips Company Conical piled monopod
WO2012067749A1 (en) * 2010-11-18 2012-05-24 Conocophillips Company Conical piled monopod
CN103221613B (zh) * 2010-11-18 2016-01-20 科诺科菲利浦公司 锥形打桩单脚架
WO2013022338A1 (en) * 2011-08-11 2013-02-14 Baggermaatschappij Boskalis B.V. Method for installation of an off-shore mast or pile
NL2007257C2 (en) * 2011-08-11 2013-02-12 Bos & Kalis Baggermaatsch Method for installation of an off-shore mast or pile.
US9487944B2 (en) * 2014-12-22 2016-11-08 Muhammad Amzad Ali Jack-up conical structure
US10443574B2 (en) * 2015-03-27 2019-10-15 Drace Infraestructuras, S.A. Gravity foundation for the installation of offshore wind turbines

Also Published As

Publication number Publication date
CA970579A (en) 1975-07-08
DK140438B (da) 1979-08-27
DK140438C (da) 1980-01-21
NO137511C (no) 1978-03-08
NO137511B (no) 1977-11-28

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