US20190389543A1 - Buoyancy assembly - Google Patents

Buoyancy assembly Download PDF

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US20190389543A1
US20190389543A1 US16/447,257 US201916447257A US2019389543A1 US 20190389543 A1 US20190389543 A1 US 20190389543A1 US 201916447257 A US201916447257 A US 201916447257A US 2019389543 A1 US2019389543 A1 US 2019389543A1
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United States
Prior art keywords
self
elevating unit
enclosure
buoyancy
connector
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Pending
Application number
US16/447,257
Inventor
James Charles Cain
Richard Robert Roper
Mason Corey Melkowits
Steve Brady
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Ensco International Inc
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Ensco International Inc
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Publication date
Priority to US201862687698P priority Critical
Application filed by Ensco International Inc filed Critical Ensco International Inc
Priority to US16/447,257 priority patent/US20190389543A1/en
Publication of US20190389543A1 publication Critical patent/US20190389543A1/en
Pending legal-status Critical Current

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    • BPERFORMING OPERATIONS; TRANSPORTING
    • B63SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
    • B63BSHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING 
    • B63B35/00Vessels or similar floating structures specially adapted for specific purposes and not otherwise provided for
    • B63B35/44Floating buildings, stores, drilling platforms, or workshops, e.g. carrying water-oil separating devices
    • EFIXED CONSTRUCTIONS
    • E02HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02BHYDRAULIC ENGINEERING
    • E02B17/00Artificial islands mounted on piles or like supports, e.g. platforms on raisable legs or offshore constructions; Construction methods therefor
    • E02B17/02Artificial 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
    • E02B17/021Artificial 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 with relative movement between supporting construction and platform
    • EFIXED CONSTRUCTIONS
    • E02HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02BHYDRAULIC ENGINEERING
    • E02B17/00Artificial islands mounted on piles or like supports, e.g. platforms on raisable legs or offshore constructions; Construction methods therefor
    • E02B17/04Equipment specially adapted for raising, lowering, or immobilising the working platform relative to the supporting construction
    • E02B17/08Equipment specially adapted for raising, lowering, or immobilising the working platform relative to the supporting construction for raising or lowering
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B63SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
    • B63BSHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING 
    • B63B35/00Vessels or similar floating structures specially adapted for specific purposes and not otherwise provided for
    • B63B35/44Floating buildings, stores, drilling platforms, or workshops, e.g. carrying water-oil separating devices
    • B63B2035/448Floating hydrocarbon production vessels, e.g. Floating Production Storage and Offloading vessels [FPSO]
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B63SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
    • B63BSHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING 
    • B63B43/00Improving safety of vessels, e.g. damage control, not otherwise provided for
    • B63B43/02Improving safety of vessels, e.g. damage control, not otherwise provided for reducing risk of capsizing or sinking
    • B63B43/10Improving safety of vessels, e.g. damage control, not otherwise provided for reducing risk of capsizing or sinking by improving buoyancy
    • B63B43/14Improving safety of vessels, e.g. damage control, not otherwise provided for reducing risk of capsizing or sinking by improving buoyancy using outboard floating members
    • B63B2043/145Improving safety of vessels, e.g. damage control, not otherwise provided for reducing risk of capsizing or sinking by improving buoyancy using outboard floating members pneumatic, e.g. inflatable on demand
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B63SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
    • B63BSHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING 
    • B63B2207/00Buoyancy or ballast means
    • B63B2207/02Variable ballast or buoyancy
    • EFIXED CONSTRUCTIONS
    • E02HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02BHYDRAULIC ENGINEERING
    • E02B17/00Artificial islands mounted on piles or like supports, e.g. platforms on raisable legs or offshore constructions; Construction methods therefor
    • E02B2017/0039Methods for placing the offshore structure
    • EFIXED CONSTRUCTIONS
    • E02HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02BHYDRAULIC ENGINEERING
    • E02B17/00Artificial islands mounted on piles or like supports, e.g. platforms on raisable legs or offshore constructions; Construction methods therefor
    • E02B2017/0056Platforms with supporting legs
    • EFIXED CONSTRUCTIONS
    • E02HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02BHYDRAULIC ENGINEERING
    • E02B17/00Artificial islands mounted on piles or like supports, e.g. platforms on raisable legs or offshore constructions; Construction methods therefor
    • E02B2017/0056Platforms with supporting legs
    • E02B2017/006Platforms with supporting legs with lattice style supporting legs
    • EFIXED CONSTRUCTIONS
    • E02HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02BHYDRAULIC ENGINEERING
    • E02B17/00Artificial islands mounted on piles or like supports, e.g. platforms on raisable legs or offshore constructions; Construction methods therefor
    • E02B2017/0056Platforms with supporting legs
    • E02B2017/0073Details of sea bottom engaging footing
    • E02B2017/0082Spudcans, skirts or extended feet
    • EFIXED CONSTRUCTIONS
    • E02HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02BHYDRAULIC ENGINEERING
    • E02B3/00Engineering works in connection with control or use of streams, rivers, coasts, or other marine sites; Sealings or joints for engineering works in general
    • E02B3/20Equipment for shipping on coasts, in harbours or on other fixed marine structures, e.g. bollards
    • E02B3/26Fenders

Abstract

A device includes at least one float. The at least one float is configured to provide a buoyancy force away from a seabed when placed in water. The device also includes an enclosure configured to house the at least one float. The enclosure comprises at least one connection configured to couple the enclosure to a self-elevating unit used in offshore oil operations or offshore gas operations.

Description

    CROSS REFERENCE TO RELATED APPLICATIONS
  • This application is a Non-Provisional Application of U.S. Provisional Patent Application No. 62/687,698, entitled “Buoyancy Assembly” filed Jun. 20, 2018, which is herein incorporated by reference.
  • BACKGROUND
  • This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present disclosure, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.
  • Embodiments herein relate to mobile offshore units, specifically self-elevating units. Self-elevating units are used in the offshore industry for a multitude of tasks including but not limited to drilling and production operations, general construction operations, crew accommodation, wind-turbine installation, etc. Self-elevating units can refer to jackups, liftboats, jackup barges, mobile offshore drilling units (MODUs), mobile offshore production units (MOPUs), or the like.
  • Self-elevating units are typically constructed of a hull, supported on one or more legs which extend through or on the side of the hull. A lifting system or “jacking system” is installed on the self-elevating unit for the purpose of raising or lowering the legs relative to the hull. The self-elevating unit is designed such that the hull is buoyant and can float, supporting itself and the legs and its cargo (e.g., in an “afloat” mode). Once the self-elevating unit reaches the desired location where it is to operate, the legs are lowered to the seabed and the hull is raised above the waterline (e.g., in an “elevated” mode), so that there is no longer a buoyancy force on the hull, creating a stable platform with a positive airgap. One of the first steps in the process of transitioning from afloat to elevated mode is commonly referred to as “going on location.”
  • Conversely, the process of transitioning from elevated mode to afloat mode is commonly referred to as “coming off location.” The self-elevating unit lowers its hull from positive air gap into the water, partially submerging the hull. The jacking system lowers the hull until the buoyancy of the hull is sufficient to extract and raise the legs. The legs of the self-elevating unit typically incorporate a footing that provides the bearing or contact surface between the seabed (and/or the soil beneath the seabed) and the self-elevating unit. The legs of a self-elevating unit may have an individual footing for each leg (spudcan) or the legs may share a common footing (mat). There exists environments that present difficulties for going on location by a self-elevating unit. For example, in some shallow waters, the draft of the self-elevating unit may preclude the self-elevating unit from moving into position to operate.
  • BRIEF DESCRIPTION OF DRAWINGS
  • FIG. 1 illustrates a profile view of a self-elevating unit in the afloat mode, in accordance with an embodiment;
  • FIG. 2 illustrate a profile view of the self-elevating unit of FIG. 1 in the elevated mode, in accordance with an embodiment;
  • FIG. 3 illustrates a profile view of a plurality of buoyancy assemblies, in accordance with an embodiment;
  • FIG. 4 illustrates a top view of the plurality of buoyancy units of FIG. 3 coupled to the self-elevating unit of FIG. 1, in accordance with an embodiment;
  • FIG. 5 illustrates a prospective view of the plurality of buoyancy units of FIG. 3 coupled to the self-elevating unit of FIG. 1, in accordance with an embodiment;
  • FIG. 6 illustrates a first side view of the plurality of buoyancy units of FIG. 3 coupled to the self-elevating unit of FIG. 1, in accordance with an embodiment;
  • FIG. 7 illustrates a second side view of the plurality of buoyancy units of FIG. 3 coupled to the self-elevating unit of FIG. 1, in accordance with an embodiment;
  • FIG. 8 illustrates a second prospective view of the plurality of buoyancy units of FIG. 2 coupled to the self-elevating unit of FIG. 1, in accordance with an embodiment;
  • FIGS. 9A-9D illustrate disconnection of a buoyancy assembly of FIG. 3 to the self-elevating unit of FIG. 1, in accordance with an embodiment; and
  • FIGS. 10A-10F illustrate collapsing of a buoyancy assembly of FIG. 3, in accordance with an embodiment.
  • DETAILED DESCRIPTION
  • One or more specific embodiments will be described below. In an effort to provide a concise description of these embodiments, all features of an actual implementation may not be described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.
  • When introducing elements of various embodiments, the articles “a,” “an,” “the,” and “said” are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements.
  • Self-elevating units (which may be referred to as “units”) can refer to jackups, liftboats, jackup barges, mobile offshore drilling units (MODUs) (e.g., a platform equipped with a drill rig to engage in offshore oil and gas exploration and/or equipped with maintenance or completion items to engage in work including, but not limited to, casing and tubing installation, subsea tree installations, and well capping), mobile offshore production units (MOPUs), mat rigs, or the like. The self-elevating units each include a draft, which may be representative of a vertical distance between the waterline and the bottom of the self-elevating unit. The draft of the self-elevating unit determines the minimum depth of water that the self-elevating unit may pass through.
  • There exist locations in which it would be desirable to utilize a self-elevating unit in oil and/or gas operations (e.g., drilling and/or workover operations). However, some of these locations may be shallow water locations (or may include shelves or other seabed impediments) that reduce the depth of the water to less than the draft of the self-elevating unit. This normally would prohibit access to the location by the self-elevating unit. However, embodiments herein allow for adding buoyancy (e.g., provide a buoyancy force away from a seabed) to the self-elevating unit to reduce the draft of the self-elevating unit, thus allowing the self-elevating unit to access locations that would otherwise be inaccessible. In some embodiments, one or more buoyancy assemblies may be coupled to the self-elevating unit to reduce the draft of the self-elevating unit. These buoyancy assemblies may be of various sizes, may be coupled to the self-elevating unit at various locations (e.g., predetermined locations), may be collapsible, may be releasable from the self-elevating unit, and/or may include one or more buoyancy members that may, for example, be inflated and deflated. Embodiments for the connection of the buoyancy assemblies are also described herein. Using the one or more buoyancy assemblies in conjunction with a self-elevating unit, the draft of a self-elevating unit can be adjusted to a desired level to allow for access to offshore locations having particular depths that otherwise would be inaccessible to the self-elevating unit.
  • With the foregoing in mind, FIG. 1 illustrates an offshore platform comprising a self-elevating unit 2. Although the presently illustrated embodiment of an offshore platform is of a particular offshore self-elevating unit 2, other offshore platforms may be substituted for the self-elevating unit 2. The techniques and systems described below are described in conjunction with self-elevating unit 2 and are intended to cover at least jackups, liftboats, jackup barges, mobile offshore drilling units (MODUs), mobile offshore production units (MOPUs), mat rigs, or the like.
  • The present self-elevating unit 2 includes one or more legs 4 and the self-elevating unit 2 is capable of floating on a hull 6 (e.g., a buoyant hull), which may also operate to support the legs 4 of the self-elevating unit 2. As illustrated in FIG. 1, the self-elevating unit 2 is operating in an afloat mode as its mode of operation, whereby the self-elevating unit 2 has its legs 4 fully raised relative to the waterline 8 above a seabed 10.
  • FIG. 1 shows the self-elevating unit 2 in the afloat mode with its legs 4 fully raised, which may allow for a transit of the self-elevating unit 2 (e.g., since the draft of the self-elevating unit 2 is the bottom 9 (or keel) of the hull 6 and not any portion of the legs 4 extending therefrom. This is is represented as the draft 11 of the self-elevating unit 2 (i.e., the vertical distance between the waterline 8 and the bottom 9 of the hull 6 of the self-elevating unit 2).
  • FIG. 2 illustrates the self-elevating unit 2 operating in an elevated mode. As illustrated, the legs 4 of the self-elevating unit 2 are lowered onto the seabed 10 so that the self-elevating unit 2 (e.g., the hull 6) may be raised above the waterline 8. This may allow the self-elevating unit 2 to operate as a stable platform. While in the elevated mode, footings 12 (e.g., spudcans or the like) at the bottom of the legs 4, provide a bearing surface for transmitting loads between the self-elevating unit 2 and the seabed 10.
  • Returning to FIG. 1, in some embodiments, the bottom 9 of the hull 6 may be too close to the seabed 10 such that the draft 11 of the self-elevating unit 2 is insufficient to access a particular location to perform oil and/or gas operations. To alleviate this problem, additional buoyancy (e.g., a buoyancy force away from the seabed 10) may be provided to the self-elevating unit 2. In some embodiments, one manner to introduce or provide additional buoyancy to the self-elevating unit 2 may include affixing otherwise attaching one or more buoyancy assemblies to the self-elevating unit 2.
  • FIG. 3 illustrates buoyancy assemblies 14, 16, 18, and 20. Each of buoyancy assemblies 14, 16, 18, and 20 are illustrated as including one or more floats 22 that provide a desired amount of buoyancy). In some embodiments, the one or more floats 22 may have a predetermined (e.g., fixed) amount of buoyancy associated therewith, which may corresponds to the size and/or dimensions of the float 22 and/or the material used in manufacturing the float 22. In other embodiments, the one or more floats 22 may be bags (such as airbags), sacs, bladders, or similar elements that may be inflated and/or deflated so as to generate a desired amount of buoyancy per float 22 or as a group of floats 22.
  • As illustrated, the buoyancy assemblies 14, 16, 18, and 20 may be modular (e.g., composed of standardized units or sections for easy construction or flexible arrangement). As illustrated, buoyancy assembly 20 has the least area, buoyancy assembly 14 has the second least area, buoyancy assembly 18 has the third least area, and buoyancy assembly 16 has the greatest area. Each of the illustrated buoyancy assemblies 14, 16, 18, and 20 may have differing lengths (as measured along direction 24). Likewise, in some embodiments, each of the buoyancy assemblies 14, 16, 18, and 20 may have the same width (as measured along direction 26) and/or depth (as measured along direction 28) or differing widths and/or depths. For example, the length, width, and depth of the buoyancy assemblies 14, 16, 18, and 20 may be based upon the sizes (length, width, diameter, etc.) of the floats 22 used in each buoyancy assembly 14, 16, 18, and 20. Selection of the sizes of the floats 22 may be selected based upon, for example, maximum buoyancy per float 22, size, or another characteristic. Additionally, each buoyancy assembly 14, 16, 18, and 20 may be self-propelled (e.g., via a motor) and control of the movement can be done locally (e.g., onboard the buoyancy assembly 14, 16, 18, and 20) or remotely (e.g., from the buoyancy assembly 14, 16, 18, and 20 or an adjacent vessel). Alternatively and/or additionally, there may be a hitch disposed on each buoyancy assembly 14, 16, 18, and 20 that allows for a connection to another vessel to tow or to winch each buoyancy assembly 14, 16, 18, and 20 into position.
  • Buoyancy assembly 16 is additionally illustrated as having an enclosure 30 disposed on a top 32 of the buoyancy assembly 16 (e.g., on a side furthest away from the seabed 10). While buoyancy assembly 16 and enclosure 30 are described below, it should be appreciated that an enclosure similar to enclosure 30 and sized for each of buoyancy assembly 14, 18, and 20 also may be utilized. However, for simplicity, only enclosure 30 and buoyancy assembly 16 are discussed below. In some embodiments, the enclosure 30 may include a fixed frame disposed on the top 32 of the buoyancy assembly 16. Additionally, the enclosure 30 may include one or more latches, tethers, straps, or the like that may be affixed along each of the sides 34, 36, 38, and 40 of the buoyancy assembly 16 to keep the one or more floats 22 positioned relative to the enclosure 30 along directions 24 and 26. The enclosure 30 may also include one or more additional latches, tethers, straps, or the like that additionally may be affixed along the bottom 42 of the buoyancy assembly 16 (e.g., on a side closest to the seabed 10) to keep the one or more floats 22 positioned relative to the enclosure 30 along direction 28. The one or more latches, tethers, straps, or the like along each of the sides 34, 36, 38, and 40 and the bottom 42 may be, in some embodiments, affixed to the enclosure 30.
  • In other embodiments, the enclosure 30 may include a fixed frame disposed on the top 32 of the buoyancy assembly 16 and along each of the sides 34, 36, 38, and 40 of the buoyancy assembly 16 to keep the one or more floats 22 positioned relative to the enclosure 30 along directions 24 and 26. One or more additional latches, tethers, straps, or the like additionally may be affixed along the bottom 42 of the buoyancy assembly 16 (e.g., on a side closest to the seabed 10) to keep the one or more floats 22 positioned relative to the enclosure 30 along direction 28. The one or more latches, tethers, straps, or the like along the bottom 42 may be, in some embodiments, affixed to the enclosure 30.
  • In other embodiments, the enclosure 30 may include a fixed frame disposed on the top 32 of the buoyancy assembly 16, along each of the sides 34, 36, 38, and 40 of the buoyancy assembly 16, and along the bottom 42 of the buoyancy assembly 16. This may allow the enclosure 30 to keep the one or more floats 22 positioned along directions 24, 26, and 28. One or more faces of the enclosure 30 (when the enclosure 30 fully includes a fixed frame on the top 32, the sides 34, 36, 38, 40, and on the bottom 42) may be removable or may rotate to create an opening in the enclosure 30 of sufficient size to accept one or more floats 22. For example, the one or more faces may open and/or rotate via one or more hinges to allow for an opening in the enclosure 30 through which the one or more floats 22 may be placed into (disposed in) the interior of the enclosure 30.
  • The enclosure 30 may operate to rigidly couple (e.g., prevent independent movement the floats 22 along directions 24, 26, and 28) when more than one float 22 is disposed in the enclosure 30. In some embodiments, a number of floats 22 may be placed into the enclosure 30 that substantially fills at least the surface area of the top 32 of the enclosure and/or the volume of the enclosure 30 (e.g., the floats 22 may be stacked along direction 28 to fill the volume of the enclosure 30).
  • Also illustrated in FIG. 3 is a compressor 44. In some embodiments, the compressor 44 may be disposed on the enclosure 30 and may operate to provide or remove a fluid (e.g., air or another gas) to and from one or more floats 22. As illustrated, the compressor 44 may be coupled to an aperture 46 in one or more of the floats 22 via respective lines 48 (e.g., hoses). In other embodiments, a manifold or another plenum may be provided between the compressor 44 and the lines 48. The compressor 44 may be coupled to floats 22 in a top row of floats 22 of the enclosure 30. Alternatively, the compressor 44 may be coupled to floats 22 in a top row and at least one row beneath the top row of floats 22 of the enclosure 30. In other embodiments, the compressor may be coupled to floats 22 in at least one row beneath the top row of floats 22 of the enclosure 30 but not the top row of floats 22. In other embodiments, the compressor 44 may be coupled to each float 22 in the enclosure 30.
  • In operation, the compressor 44 may be controlled and/or operated to inflate or deflate the one or more floats 22 that it is coupled to so as to increase (or decrease) the total buoyancy of the buoyancy assembly 16. The compressor 44, lines 48, and manifold (if used) may be portable, such that they can be moved from buoyancy assembly 16 to another of the buoyancy assemblies 14, 18, or 20. Alternatively, a dedicated compressor 44, lines 48, and manifold (if used) may be included (e.g., affixed to and remain with) with one or more of each of the buoyancy assemblies 14, 16, 18, or 20.
  • FIG. 4 illustrates a top view of the self-elevating unit 2. As illustrated, the self-elevating unit 2 includes buoyancy assemblies 16, 18, and 20 disposed around the perimeter of the self-elevating unit 2 as well as apertures 50 through which respective legs 4 may pass. While not illustrated, it may be appreciated that the configuration of buoyancy assemblies 16, 18, and 20 is illustrative only and that other configurations, which may alternatively include buoyancy assembly 14 are contemplated. Choice of the location and number of buoyancy assemblies 16, 18, and 20 about the perimeter of the self-elevating unit 2 may be design choices, for example, made based upon desired buoyancy to be provided to the self-elevating unit 2, available locations along the perimeter of the self-elevating unit 2, or additional design and/or operational concerns. As illustrated, six buoyancy assemblies 16 may be disposed along an end section 52 of the self-elevating unit 2. Likewise, two buoyancy assemblies 16 and two buoyancy assemblies 18 may be disposed along a middle section 54 of the self-elevating unit 2. Furthermore, two buoyancy assemblies 20 and a buoyancy assembly 16 may be disposed along a front section 56 of the self-elevating unit 2. Thus, in total, thirteen modular buoyancy assemblies 16, 18, and 20 may be disposed about the perimeter of the self-elevating unit 2.
  • Additionally, some or all of the buoyancy assemblies 16, 18, and 20 may be coupled to the self-elevating unit 2 via a releasable coupling that allows the buoyancy assemblies 16, 18, and 20 to decouple and disperse from (e.g., float away from, be towed from, or be propelled from) the self-elevating unit 2 when the releasable coupling is actuated. In this manner, the releasable connection of buoyancy assemblies 16, 18, and 20 (as well as buoyancy assembly 14) to the self-elevating unit 2 may differ from welded or other non-releasable connections that would otherwise affix the buoyancy assemblies 14, 16, 18, and 20 to the unit self-elevating unit 2. Indeed, it is envisioned that through the use of modular and releasable buoyancy assemblies 14, 16, 18, and 20, draft 11 reduction may accomplished for a self-elevating unit 2 when desired (e.g., in conjunction with particular shallow water operations). Likewise, use buoyancy assemblies 14, 16, 18, and 20 may be excluded from the self-elevating unit 2 when reduced draft 11 is not desired (e.g., in conjunction with less shallow water operations). Thus, the present buoyancy assemblies 14, 16, 18, and 20 allow for greater configurability of the self-elevating unit 2 as well as allow the self-elevating unit 2 to operate in more environments without incurring any penalties associated with permanent or semi-permanent affixing of buoyancy assemblies 14, 16, 18, and 20 to the self-elevating unit 2 (e.g., increased drag on the self-elevating unit 2 when being moved to locations that would not benefit from reduced draft 11).
  • FIG. 5 illustrates a prospective view of the self-elevating unit 2. As illustrated, the buoyancy assemblies 16, 18, and 20 are coupled to the self-elevating unit disposed around the perimeter of the self-elevating unit 2 such that the at least a portion of the one or more floats 22 for each of buoyancy assemblies 16, 18, and 20 is partially submerged. However, in other embodiments, all of the one or more floats 22 for each of buoyancy assemblies 16, 18, and 20 may be fully submerged (i.e., fully below the waterline 8) or all of the one or more floats 22 for each of buoyancy assemblies 16, 18, and 20 may be fully disposed above the waterline 8. Location of the buoyancy assemblies 16, 18, and 20 and, thus, the floats 22 may be determined by the vertical location of the coupling of the buoyancy assemblies 16, 18, and 20 and the self-elevating unit 2.
  • FIG. 6 illustrates a side view along the middle section 54 of the self-elevating unit 2. As illustrated, at least a portion of the one or more floats 22 for each of buoyancy assemblies 16, 18, and 20 is partially submerged. Additionally illustrated is the draft 58 of the self-elevating unit 2, which is reduced relative to the draft 11 of the self-elevating unit 2, illustrated in FIGS. 1 and 2. The draft 58 may be, for example, between approximately 5 meters and 20 meters or, for example, may be approximately 5 meters, 6 meters, 7 meters, 8 meters, 9 meters, 10 meters, 11 meters, 12 meters, 13 meters, 14 meters, 15 meters, 16 meters, 17 meters, 18 meters, 19 meters, 20 meters, or another value in depth along the direction 26. FIG. 7 illustrates an additional side view of the self-elevating unit 2 along the end section 52 of the self-elevating unit 2.
  • FIG. 8 illustrates a second a prospective view of the self-elevating unit 2. In the illustrated embodiment, the self-elevating unit 2 includes buoyancy assemblies 16 and 20 disposed around the perimeter of the self-elevating unit 2. As illustrated, six buoyancy assemblies 16 may be disposed along an end section 52 of the self-elevating unit 2. Likewise, two buoyancy assemblies 16 may be disposed along a middle section 54 of the self-elevating unit 2. Furthermore, two buoyancy assemblies 20 and a buoyancy assembly 16 may be disposed along a front section 56 of the self-elevating unit 2. Thus, in total, eleven modular buoyancy assemblies 16, 18, and 20 may be disposed about the perimeter of the self-elevating unit 2. The region 60 of the perimeter along the middle section 54 of the self-elevating unit 2 may not have any buoyancy assembly (e.g., buoyancy assembly 18) attached thereto so that, for example, lifeboats may be launched in region 60 without interference. Moreover, some or all of the buoyancy assemblies 16, 18, and 20 may be coupled to the self-elevating unit 2 via a releasable coupling that allows the buoyancy assemblies 16, 18, and 20 to decouple and disperse from (e.g., float away from, be towed from, or be propelled from) the self-elevating unit 2 when the releasable coupling is actuated. Accordingly, FIG. 8 may illustrate the self-elevating unit 2 subsequent to buoyancy assemblies being removed from the self-elevating unit 2.
  • FIGS. 9A-9D illustrate disconnection of one of the buoyancy assemblies 14, 16, 18, or 20 (e.g., buoyancy assembly 14) from the hull 6 of the self-elevating unit 2. As illustrated in FIG. 9A, the buoyancy assembly 14 is coupled to the hull 6 via a first connector 62 and a second connector 64. In some embodiments, either of the first connector 62 or the second connector 64 and the resulting connection with the buoyancy assembly 14 may be omitted. The first connector 62 may be a receptacle that receives a projection of the enclosure 30 and may lock onto the projection. Examples of the connection made may be a mechanical joint, such as a ball and socket joint or the like. Likewise, the first connector 62 may be a slot that narrows as it moves vertically away from the waterline with gating elements, pins, steps, or the like that may affix the projection of the enclosure 30 at a particular location. These gating elements, pins, steps, or the like may be releasable to allow the projection of the enclosure 30 to be removed from the first connector 62, for example, to release the buoyancy assembly 14 from the self-elevating unit 2.
  • The second connector 64 may be a receptacle that receives a beam 66 of the buoyancy assembly 14 and may lock onto the beam 66. It should be noted that more than one beam 66 may be utilized and may be disposed, for example, at predetermined locations along the enclosure 30. The additional beams 66 may be coupled to additional respective second connectors 64. Examples of the connection between a beam and a second connector 64 made may be a mechanical joint, such as a ball and socket joint or the like. In some embodiments, the connection made between the second connector 62 and the beam 66 may likewise be releasable so that the buoyancy assembly 14 may be released from the self-elevating unit 2. Release of the connection may be accomplished via removal of a pin or other locking member coupling the beam to the second connector 64 or via other techniques. Also illustrated in FIG. 9A is a strut 68 that may operate to resist compression and or provide support to the beam 66.
  • As illustrated in FIG. 9B, release of the beam 66 from the second connector 64 may be effected. This may cause the beam 66 to move towards the enclosure 30 while strut 68 aids in supporting the beam during its movement. FIG. 9C, shows the beam 66 in a further lowered position, whereby the beam 66 is approaching a storage position. FIG. 9D illustrates the beam 66 and the strut 68 in a storage position. If the buoyancy assembly 14 is still connected via the first connector 62, this connection may be released to allow the buoyancy assembly 14 to disperse from (e.g., float away from, be towed from, or be propelled from) the self-elevating unit 2. Moreover, connection of the buoyancy assembly 14 may be completed by reversing the steps illustrated in FIGS. 9A-9D.
  • FIGS. 10A-10F illustrate movement of one of the buoyancy assemblies 14, 16, 18, or 20 (e.g., buoyancy assembly 14) relative to the hull 6 of the self-elevating unit 2, while still allowing the buoyancy assembly 14 to be tethered to the hull 6. This movement may allow for the buoyancy assembly 14 to be positioned along the side of the hull 6 (or, in some embodiments, below the hull 6) so that operations (e.g., placing a lifeboat in the water, operating a crane on the deck of the hull 6, or other operations) may be accomplished without interference from the buoyancy assembly 14.
  • As illustrated in FIG. 10A, the buoyancy assembly 14 is coupled to the hull 6 via a first connector 62 and a second connector 64. In FIG. 10B, release of the connection between the first connector 62 and the enclosure 30 (e.g., a protrusion of the enclosure 30) may allow for the buoyancy assembly 14 to begin to rotate. This rotation may occur with the beam 66 being coupled to the second connector 64. As part of the rotation, the strut 68 may be released from its connection to the enclosure 30. As illustrated in FIGS. 10C-10E, the rotation of the buoyancy assembly 14 may continue towards a storage position for the buoyancy assembly 14. FIG. 10F illustrates a storage position of the buoyancy assembly 14 with the buoyancy assembly 14 disposed along the side of the hull 6. The buoyancy assembly 14 may be locked into the storage position to minimize movement from the storage position. Additionally, connection of the buoyancy assembly 14 may be completed by reversing the steps illustrated in FIGS. 10A-10F. In some embodiments, the steps illustrated in FIGS. 10A and 10F may be facilitated by a winch or a crane (e.g., disposed on a deck of the hull 6) that may be coupled to the buoyancy assemblies 14, 16, 18, and 20 to aid in the raising and/or lowering of the buoyancy assemblies 14, 16, 18, and 20. The winch or crane may additionally be utilized in other connection and decoupling operations relating to the buoyancy assemblies 14, 16, 18, and 20 relative to the self-elevating unit 2.
  • In some embodiments, the size of the floats 22 utilized may be between approximately 10 meters and 20 meters in length along the direction 24 or for example, approximately 10 meters, 11 meters, 12 meters, 13 meters, 14 meters, 15 meters, 16 meters, 17 meters, 18 meters, 19 meters, 20 meters, or another value in length along the direction 24. The diameter of the floats 22 utilized may be approximately between 1 meter and 5 meters or, for example, approximately 1 meter, 2 meters, 3 meters, 4 meters, 5 meters, or another value in diameter length. The widths of the buoyancy assemblies 14, 16, 18, and 20 may be approximately between 5 meters and 15 meters in width along the direction 26 or for example, approximately 5 meters, 6 meters, 7 meters, 8 meters, 9 meters, 10 meters, 11 meters, 12 meters, 13 meters, 14 meters, 15 meters, or another value in width along the direction 26.
  • Attachment of buoyancy assemblies (e.g., buoyancy assemblies 14, 16, 18, and 20) to the self-elevating unit 2, may accomplished via, for example, partial sinking of the buoyancy assemblies 14, 16, 18, and 20. This partial sinking of the buoyancy assemblies 14, 16, 18, and 20 may be accomplished, for example, through reduction of the buoyancy of the buoyancy assemblies 14, 16, 18, and 20. For example, the buoyancy of the buoyancy assemblies 14, 16, 18, and 20 may be reduced, the buoyancy assemblies 14, 16, 18, and 20 then may be coupled to the self-elevating unit 2, and the buoyancy of the buoyancy assemblies 14, 16, 18, and 20 subsequently may be increased, for example, to a predetermined amount. The modification of the buoyancy of the buoyancy assemblies 14, 16, 18, and 20 may be accomplished via, for example, use of the compressor 44 (operating alone or in conjunction with a manifold or plenum) to alter the buoyancy of one of more of the floats 22. The partial sinking of the buoyancy assemblies 14, 16, 18, and 20 may be accomplished additionally and/or alternatively, for example, through addition of weight on the buoyancy assemblies 14, 16, 18, and 20. For example, one or more weights may be placed on the enclosures 30 of the buoyancy assemblies 14, 16, 18, and 20, the buoyancy assemblies 14, 16, 18, and 20 then may be coupled to the self-elevating unit 2, and the one or more weights subsequently may be removed from the buoyancy assemblies 14, 16, 18, and 20.
  • In other embodiments, attachment of buoyancy assemblies (e.g., buoyancy assemblies 14, 16, 18, and 20) to the self-elevating unit 2, may accomplished via, for example, jacking of the self-elevating unit 2. For example, the self-elevating unit 2 may be jacked down relative to an afloat mode to a predetermined connection height (lower to the seabed 10 than a height of the self-elevating unit 2 in the afloat mode). The buoyancy assemblies 14, 16, 18, and 20 may be coupled to the self-elevating unit 2 and subsequently, the self-elevating unit 2 may be returned to its afloat mode. In other embodiments, the self-elevating unit 2 may be jacked down into a pre-positioned buoyancy assembly 14, 16, 18, and 20 to attach the buoyancy assembly 14, 16, 18, and 20 to the self-elevating unit 2. For example, the first connector 62 may be a gap or notch into which a protrusion of the buoyancy assembly 14, 16, 18, and 20 may interface and, subsequently, the protrusion and first connector 62 connection may be locked to couple the buoyancy assembly 14, 16, 18, and 20 with the self-elevating unit 2. Release of the connection therebetween and subsequent jacking up of the self-elevating unit 2 may allow the buoyancy assemblies 14, 16, 18, and 20 to be decoupled and disperse from (e.g., float away from, be towed from, or be propelled from) the self-elevating unit 2.
  • Likewise, the self-elevating unit 2 may include an adjustable attachment point as the first connector 62 such that the buoyancy assemblies 14, 16, 18, and 20 may be moved into position to connect to the first connector 62. A connection therebetween may be formed and a ratchet or other system alone or in conjunction with a winch, crane or the like may be used to raise or lower the buoyancy assemblies 14, 16, 18, and 20 into an operational position in which they may remain until released.
  • In some embodiments, the order in which the buoyancy assemblies 14, 16, 18, and 20 are coupled to and/or decoupled from the self-elevating unit 2 may be random. Alternatively, the order in which the buoyancy assemblies 14, 16, 18, and 20 are coupled to and/or decoupled from the self-elevating unit 2 may correspond to a pattern, for example, a pattern about the perimeter of the self-elevating unit 2 or a star pattern about the self-elevating unit 2. In some embodiments, the order in which the buoyancy assemblies 14, 16, 18, and 20 are coupled to and/or decoupled from the self-elevating unit 2 may be random.
  • This written description uses examples to disclose the above description to enable any person skilled in the art to practice the disclosure, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the disclosure is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims. Accordingly, while the above disclosed embodiments may be susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and have been described in detail herein. However, it should be understood that the embodiments are not intended to be limited to the particular forms disclosed. Rather, the disclosed embodiment are to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the embodiments as defined by the following appended claims.

Claims (20)

What is claimed is:
1. A device, comprising:
at least one float configured to provide a buoyancy force away from a seabed when placed in water; and
an enclosure configured to house the at least one float, wherein the enclosure comprises at least one connector configured to couple the enclosure to a self-elevating unit used in offshore oil operations or offshore gas operations.
2. The device of claim 1, wherein the enclosure comprises a fixed frame as a top portion of the enclosure.
3. The device of claim 2, wherein the enclosure comprises a second fixed frame as a side portion of the enclosure.
4. The device of claim 3, wherein the enclosure comprises a third fixed frame as a bottom portion of the enclosure.
5. The device of claim 1, wherein the enclosure comprises an affixable support as a side portion of the enclosure.
6. The device of claim 1, wherein the enclosure comprises an affixable support as a bottom portion of the enclosure.
7. The device of claim 1, comprising a propulsion mechanism configured to propel the device.
8. The device of claim 1, comprising a compressor configured to be coupled to the at least one float to adjust the buoyancy force.
9. A system, comprising:
a first connector configured to be attached to a self-elevating unit used in offshore oil operations or offshore gas operations; and
a buoyancy assembly, comprising:
at least one float configured to provide a buoyancy force away from a seabed when placed in water;
an enclosure configured to house to the at least one float; and
a second connector coupled to the enclosure and configured to couple with the first connector.
10. The system of claim 9, wherein the first connector comprises a receptacle configured to receive the second connector.
11. The system of claim 9, wherein the first connector comprises a slot with a releasable latch that affixes the second connector at a particular location when engaged.
12. The system of claim 9, wherein the second connector comprises a protrusion extending from the enclosure.
13. The system of claim 9, comprising a third connector configured to be attached to the self-elevating unit.
14. The system of claim 13, wherein the buoyancy assembly comprises a beam coupled to the enclosure.
15. The system of claim 14, comprising a locking mechanism configured to couple the beam to the third connector wherein the locking mechanism is engaged.
16. The system of claim 13, comprising a strut coupled to the beam and the enclosure.
17. A method, comprising:
coupling a buoyancy assembly to a self-elevating unit used in offshore oil operations or offshore gas operations, wherein the buoyancy assembly comprises at least one float configured to provide a buoyancy force away from a seabed to reduce a draft of the a self-elevating unit and an enclosure configured to house to the at least one float.
18. The method of claim 17, wherein the coupling of the buoyancy assembly to the self-elevating unit comprises:
reducing the buoyance force provided by the at least one float;
moving the buoyancy assembly to a first position adjacent to the self-elevating unit; and
increasing the buoyance force provided by the at least one float to move the to a second position adjacent to the self-elevating unit, wherein the second position is above the first position relative to the seafloor.
19. The method of claim 17, wherein the coupling of the buoyancy assembly to the self-elevating unit comprises:
jacking down the self-elevating unit from a first height relative to the seafloor to cause a first connector of the self-elevating unit to interact with a second connector of the buoyancy assembly; and
engaging latch to lock the first connector to the second connector.
20. The method of claim 17, wherein the coupling of the buoyancy assembly to the self-elevating unit comprises:
moving the buoyancy assembly into position to connect to a connector of the self-elevating unit;
forming a connection between the connector and the buoyancy assembly; and
moving the buoyancy assembly into an operational position.
US16/447,257 2018-06-20 2019-06-20 Buoyancy assembly Pending US20190389543A1 (en)

Priority Applications (2)

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EG23940A (en) * 2004-12-21 2008-01-16 Gamal Ali Mohamed Fala El Manzalawy Multipurpose hydraulic life jacket for ship safety
ITMI20060823A1 (en) * 2006-04-24 2007-10-25 Isea S P A modular floating structure
JP5750537B1 (en) * 2014-07-17 2015-07-22 三井海洋開発株式会社 Offshore structure construction method
CN104627335B (en) * 2014-12-29 2017-01-04 宁波市镇海捷登应用技术研究所 A kind of wave resistance formula sea mobile platform
NL2017637B1 (en) * 2016-10-18 2018-04-26 Ulstein Design & Solutions B V Self-propelled jack-up vessel

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