Truss system for offshore platform and method of use thereof

Abstract

The truss system may include multiple beams, each of which may have a different cross-sectional size in the same plane, and the multiple beams may have a geometry that may reduce the structural weight at a required strength level to achieve an optimal design.

Description

[Technical Field]

[0001] FIELD OF THE INVENTION The embodiments disclosed herein relate generally to truss systems for offshore platforms, and more particularly to the geometry of the truss systems for optimally distributing structural materials to balance structural weight and strength. [Background technology]

[0002] In oil field operations, offshore vessels such as platform supply vessels (PSVs), offshore barges, anchor handling vessels, construction support vessels (CSVs), drillships, well intervention vessels, icebreakers, crane vessels, cable laying vessels, seismic survey vessels, and firefighting vessels are commonly used for a variety of operations, including, but not limited to, hydrocarbon exploration, hydrocarbon drilling and production, hydrocarbon retention and transportation, safety platforms, and heavy lift cranes.

[0003] Typically, an offshore vessel may have a topside structure for carrying equipment payloads and environmental loads. Furthermore, stabilizing columns, such as pencil columns or rocket columns, may be attached to the offshore vessel to stabilize it in the water. The topside structure may be a truss system for forming a deck. To maximize the payload, the structural weight of the truss system must be reduced, while still meeting the structural strength criteria for the truss system in harsh environments. In an offshore environment, efficient distribution of structural materials is essential to meet both weight and strength requirements. Summary of the Invention [Means for solving the problem]

[0004] This Summary is provided to introduce some concepts that are further described below in the Detailed Description. This Summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claimed subject matter.

[0005] In one aspect, embodiments disclosed herein relate to a truss system. The truss system may include a plurality of beams. Each beam of the plurality of beams may have a different cross-sectional size in the same plane. Additionally, the plurality of beams may have a geometry that may reduce the structural weight and achieve an optimal design at a required strength level.

[0006] In another aspect, embodiments disclosed herein relate to a lower deck for a topside truss system of an offshore vessel. The lower deck can include a plurality of beams distributed into four quadrants. The beams can extend in a direction parallel to an X-axis of the plane of the lower deck, a direction parallel to a Y-axis of the plane, and directions at acute or obtuse angles from the X-axis and Y-axis. Each quadrant includes a first set of beams with a constant or varying cross-section, a second set of beams with a constant or varying cross-section, a third set of beams with a constant or varying cross-section, and a fourth set of beams with a constant or varying cross-section.

[0007] In yet another aspect, embodiments disclosed herein relate to an offshore vessel. The offshore vessel includes a base with one or more support columns disposed thereon and a deck formed by a topside truss system supported by the support of the one or more columns. The topside truss system includes an upper deck, a lower deck, and tubular members interconnecting the upper deck to the lower deck. The lower deck may have one or more quadrants including a first set of beams with a constant or varying cross-section, a second set of beams with a constant or varying cross-section, a third set of beams with a constant or varying cross-section, and a fourth set of beams with a constant or varying cross-section. Additionally, corresponding corner beam members of the topside truss system are secured to the tops of the one or more columns.

[0008] Other aspects and advantages of the present disclosure will become apparent from the following description and appended claims. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a side view of an offshore vessel in a typical offshore environment in accordance with one or more embodiments of the present disclosure. [Figure 2A] FIG. 2 is a perspective view of the offshore vessel of FIG. 1 in accordance with one or more embodiments of the present disclosure. [Figure 2B] FIG. 2B is a top view of the offshore vessel of FIG. 2A in accordance with one or more embodiments of the present disclosure. [Figure 2C] 1A-1D are various top views of a support post according to one or more embodiments of the present disclosure. [Figure 2D] 1A-1D are various top views of a support post according to one or more embodiments of the present disclosure. [Figure 2E] 1A-1D are various top views of a support post according to one or more embodiments of the present disclosure. [Figure 2F] 1A-1D are various top views of a support post according to one or more embodiments of the present disclosure. [Figure 2G] 1A-1D are various top views of a support post according to one or more embodiments of the present disclosure. [Figure 2H] 1A-1D are various top views of a support post according to one or more embodiments of the present disclosure. [Figure 3] FIG. 2B is a perspective view of the truss system of FIG. 2A in accordance with one or more embodiments of the present disclosure. [Figure 4] FIG. 1 is a top view of a truss system according to one or more embodiments of the present disclosure. [Figure 5] FIG. 1 is a top view of a truss system according to one or more embodiments of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0010] Specific embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. Similar elements in various figures may be labeled with similar reference numerals for consistency. Furthermore, in the following detailed description of embodiments of the present disclosure, numerous specific details are set forth to provide a more thorough understanding of the invention. However, it will be apparent to those skilled in the art that the embodiments disclosed herein may be practiced without such specific details. In other instances, well-known features have not been described in detail to avoid unnecessarily complicating the description.

[0011] Furthermore, as will be appreciated by those skilled in the art, when describing a second element disposed above a first element, it is understood that the disposition can refer to either directly disposing the first element on the second element or indirectly disposing the first element on the second element. For example, the first element may be directly disposed on the second element, such as by directly contacting the first and second elements with each other, or the first element may be indirectly disposed on the second element, such as by disposing a third and / or additional element between the first and second elements. As used herein, the terms “attached to” or “coupled” or “coupled to” or “connected” or “connected to” can refer to the establishment of either a direct or indirect connection, but are not limited to either unless expressly stated as such. Furthermore, although the embodiments disclosed herein are described using terms referring to offshore vessels in relation to floating vessels, any terms referring to offshore structures (i.e., any platform or semi-submersible) should not be considered as limiting the scope of the present disclosure. Wherever possible, similar or identical reference numbers are used in the drawings to identify common or identical elements. The drawings are not necessarily to scale, and certain features and views of the drawings may be shown exaggerated in scale for clarity.

[0012] In one aspect, embodiments disclosed herein generally relate to a truss system for the topside structure of an offshore vessel. The truss system may be formed by a plurality of interconnected beams. More specifically, the beam geometry may be configured to optimize the structural weight and strength of the truss system. In one or more embodiments, the truss system may be disposed on columns of the offshore vessel. In other embodiments, the truss system may be designed for use with onshore structures such as oil derricks. Furthermore, the truss system may be designed for use in any offshore or onshore environment without departing from the scope of the present disclosure. Furthermore, it should be understood that the various embodiments described herein may be used in various stages of offshore oil and gas operations, such as rig site preparation, drilling, completion, and abandonment, as well as in other environments, such as workover rigs, fracking rigs, well testing rigs, and oil and gas production facilities, without departing from the scope of the present disclosure. The embodiments are described merely as useful applications and are not limited to any specific details of the embodiments described herein.

[0013] Referring to FIG. 1, a side view of an offshore vessel 113 in a typical offshore environment is shown. For example, the offshore vessel 113 may be a semi-submersible structure for oil and gas operations. A deck 101 is located above the water surface 111. The deck 101 is typically used for drilling, production, or other operations, and therefore, operational equipment, personnel, and operational gear may be located thereon. Due to ocean wave loads, platform motion, and topside loads, typical design load conditions for the offshore vessel 113 may be vertical bending moment, lateral shear, pry-squeeze, pitch connect moment, and lateral acceleration. The deck 101 is formed by a topside truss system 100. The topside truss system 100 includes two or more deck levels (100A, 100B). For example, the upper deck 100B is interconnected to the lower deck 100A by tubular members 100C.

[0014] In one or more embodiments, the topside truss system 100 may be supported by one or more columns. As shown in this example, the topside truss system 100 is positioned on columns 106A and 106B, thereby keeping it away from large waves on the water surface 111. The columns 106A and 106B are used to support the topside truss system 100 and may also function as storage. Additionally, the columns 106A and 106B may be ballasted. A base, such as a pontoon base 105, has the columns 106A and 106B positioned thereon. The pontoon base 105 may have a substantially rectangular shape when viewed from the side, from a top view, or both. In some embodiments, the topside truss system 100, the one or more columns, and the pontoon base 105 may be an integrated system forming the offshore vessel 113.

[0015] The offshore vessel 113 obtains buoyancy from ballasted pontoons or ballasted pillars. As such, the ballasted structures (ballasted pontoons or ballasted pillars, or both) may be filled with water or any other ballast material (ballast) or may be discharged with water or any other ballast material (de-ballast) to stabilize the offshore vessel 113. As shown, the semi-submersible 113 is moored to the seabed 109 by anchor lines 107A and 107B. The anchor lines 107A and 107B may be wires, chains, or any other mooring devices known in the art that will keep the semi-submersible in position relative to the seabed 109. Furthermore, the anchor lines need not be limited to only two lines as shown in this example. The offshore vessel 113 may be moored by any number of anchor lines.

[0016] In some embodiments, when used in a shallow water offshore environment, the offshore vessel 113 may be adapted to be placed on the seabed 109 without the use of anchor lines 107A and 107B. In this case, the pontoon base 105 may be placed on the seabed 109 and secured to the seabed 109 using anchors (not shown) to secure the pontoon base 105, and ultimately the offshore vessel 113, to the seabed 109.

[0017] Referring to FIG. 2A, a perspective view of an offshore vessel 113 is shown. The offshore vessel 113 may include four columns 106A-106D extending upward from a pontoon base 105. The topside truss system 100 is disposed on the four columns 106A-106D via corresponding corner beam members 108 of the topside truss system 100 for each of the four columns 106A-106D. For example, tubular members of the corresponding corner beam members 108 may be fixed to the tops of the four columns 106A-106D. The corresponding corner beam members 108 may be made of tubular members similar to the tubular member 100C interconnecting the upper deck 100B with the lower deck 100A. In some embodiments, the corresponding corner beam ends 100AB of the lower deck 100A are also fixed to the tops of the four posts 106A-106D at a fixed distance from the corresponding corner beam members 108.

[0018] In one or more embodiments, the columns 106A-106D and the pontoon base 105 form the hull of the offshore vessel 113. As shown in FIG. 1 , the columns 106A-106D are disposed on the pontoon base 105. Further, in this case, the pontoon base 105 may be generally rectangular, triangular, and / or polygonal in shape, and the columns 106A-106D may be disposed near the corners of the pontoon base 105 or at any location along the pontoon base 105. One skilled in the art will appreciate that the locations of the columns 106A-106D are not limited to the corners of the pontoon base 105, as the columns 106A-106D may be disposed in any other location relative to the pontoon base 105. Additionally, one skilled in the art will appreciate that the number of columns is not limited to four columns 106A-106D as shown, as any number of columns may be present. Non-limiting examples of offshore vessels 113 may be described in U.S. Patent No. 9,145,190, the entire teachings of which are incorporated herein by reference. It is further contemplated that the offshore vessels 113 disclosed herein may be any semi-submersible vessel in the art.

[0019] 2A , in one or more embodiments, each of the columns 106A-106D includes a line 114 to illustrate the vertical position along the column 106A-106D, where the sides of the columns 106A-106D may join over rounded edges but gradually transition to join over squared edges. Additionally, region 115 represents a transition region of the columns 106A-106D where the rounded corners may gradually transition to squared corners. In this example, the transition region extends along a portion of the column 106A-106D and terminates at the connection between the column 106A-106D and the pontoon base 105.

[0020] Referring to FIG. 2B , a top view of the offshore vessel 113 is shown. As shown in FIG. 2B , the pontoon base 105 may be generally rectangular, triangular, and / or polygonal in shape. Additionally, one or more corners 209 of the pontoon base 105 may be chamfered (as shown). Alternatively, the pontoon base 105 may have one or more square corners, one or more rounded corners, or any combination or alternative thereof (not shown). Additionally and similarly, the interior 211 of the pontoon base 105 may have one or more chamfered corners 213 that may or may not correspond to the interior chamfered corners 209. Alternatively, the interior 211 of the pontoon base 105 may have one or more square corners, one or more rounded corners, or any combination or alternative thereof (not shown).

[0021] In one or more embodiments, cross section 215 of posts 106A-106D may have five sides. One or more corners 217A, 217B, and 217C of posts 106A-106D may be squared, as shown. Additionally, one or more edges 219A, 219B, and 219C of posts 106A-106D may be rounded, as shown. In this particular example, one or more edges 219A, 219B, and 219C of posts 106A-106D are rounded at one vertical end of the post and squared at the opposite end of posts 106A-106D. Additionally, one or more sides 221A, 221B, 221C, 221D, and 221E corresponding to cross section 223 each represent a side of the post. Alternatively, the corners or edges may be chamfered, rounded, squared, or any combination or alternative thereof.

[0022] 2B, topside truss system 100 is shown in outline form for illustrative purposes only to better illustrate how topside truss system 100 is supported by columns 106A-106D on pontoon base 105. As shown in FIG. 2B, corner beam members 108 of topside truss system 100 are supported on columns 106A-106D.

[0023] 2C-2H, top views of a single support pillar are shown. In FIG. 2C, one or more side surfaces 303A, 303B, 303C, and 303D of support pillar 301 may be disposed relative to one another as shown. Specifically, first side surface 303A may be disposed at a first angle relative to second side surface 303B. The second side surface may be disposed at a second angle relative to third side surface 303C. The third side surface 303C may be disposed at a third angle relative to fourth side surface 303D. In this example, the first and second angles may be substantially right angles. Furthermore, the third angle may be substantially obtuse. An example of an obtuse angle may be substantially 135 degrees, as shown. However, an obtuse angle may be any angle between greater than 90 degrees and less than 180 degrees. Additionally, the obtuse angle may be any angle between 91 degrees and 179 degrees, between 100 degrees and 170 degrees, between 110 degrees and 160 degrees, between 120 degrees and 150 degrees, or between 130 degrees and 140 degrees. The fourth side 303D may be disposed at a fourth angle relative to the fifth side 303E. The fifth side 303E may be disposed at a fifth angle relative to the first side 303A. In this example, the fourth angle may be a substantially obtuse angle, and the fifth angle may be a substantially right angle. In this example, one or more sides 303A, 303B, 303C, and 303D of the support 301 may be joined by rounded corners. Alternatively, one or more sides 303A, 303B, 303C, and 303D of the support 301 may be joined by chamfered corners, square corners, or any alternative thereof. However, those skilled in the art will appreciate that the corners and corresponding sides of the support posts are not limited to the above arrangement.

[0024] 2D, one or more sides 403A, 403B, and 403C may extend outwardly along at least a portion of the post 401. As shown, the outward extensions or "flares" may be provided for additional support at the base of the post 401. Additionally, one skilled in the art will appreciate that the extensions may be inward (not shown).

[0025] In FIG. 2E, one or more sides 503A, 503B, and 503C may start at one end of the strut 501 and extend outward (or inward) to the other end. In this example, there is no tapered location along a portion of the length of the strut 501, as in FIG. 2D. Notably, the flare runs the entire length of the strut 501. Thus, the tapered location may be at one or both ends of the strut, and the flare may extend along the entire length of the strut 501. Furthermore, in this example, side 503B does not have to be flared. Thus, a flare may be present on any number of sides, or none at all.

[0026] 2F, one or more sides 603A, 603B, and 603C of post 601 may be flared at the base. In this example, side 603B is also flared. One skilled in the art will appreciate that the taper location may be anywhere along the length of post 601.

[0027] In Figure 2G, one or more sides 703A, 703B, and 703C of post 701 may be flared at the base. In this example, there is no tapered location similar to that described above in Figure 2F along any portion of the length of post 701. Notably, the flare runs the entire length of post 701. Thus, the tapered location may be at one or both ends of the post, and the flare may extend along the entire length of post 701. Furthermore, in this example, side 703B may or may not be flared. Thus, a flare may be present on any number of sides, or none at all.

[0028] In FIG. 2H , strut 801 has one or more chamfered sides 803A and 803B. The one or more chamfered sides 803A and 803B of strut 801 may not be limited to being inward or outward relative to the pontoon structure. Additionally, and as shown in FIG. 2H , a cross section of strut 801 may include one or more edges 805A, 805B, 805C, 805D, 805E, and 805F corresponding to one or more sides of strut 801. Edges 805A, 805B, 805C, 805D, 805E, and 805F may be positioned as shown in FIG. 2H . In particular, first edge 805A may be positioned at a first angle relative to edge 805B. Edge 805B may be positioned at a second angle relative to edge 805C. Edge 805C may be disposed at a third angle relative to edge 805D. Edge 805D may be disposed at a fourth angle relative to edge 805E. Edge 805E may be disposed at a fifth angle relative to edge 805F. Edge 805F may be disposed at a sixth angle relative to edge 805A. Additionally, edges 805C and 805F may be chamfered to correspond to chamfered sides 803A and 803B of post 801. In this example, the second and fifth angles may be substantially right angles, and the first, third, fourth, and sixth angles may be substantially obtuse angles. An example of an obtuse angle may be substantially 135 degrees, as shown. However, an obtuse angle may be any angle between greater than 90 degrees and less than 180 degrees. Additionally, the obtuse angle can be any angle between 91 degrees and 179 degrees, between 100 degrees and 170 degrees, between 110 degrees and 160 degrees, between 120 degrees and 150 degrees, or between 130 degrees and 140 degrees. One of ordinary skill in the art will appreciate that a six-sided pillar may or may not include any or all of the features disclosed herein for any of the above-described multi-sided pillar embodiments. For example, in one or more embodiments, a six-sided pillar may include one or more of one or more transition regions, one or more taper positions, and a flare. Additionally, in one or more embodiments, a six-sided pillar may include one or more of rounded edges or corners, squared edges or corners, and chamfered edges or corners. As will be appreciated by one of ordinary skill in the art, the above-described features are provided as examples, and the embodiments herein should not be limited to the above-described features.

[0029] Referring now to FIG. 3 , a perspective view of the topside truss system 100 is shown. The upper deck 100B of the topside truss system 100 directly supports equipment used in drilling, production, or other operations, so that operational equipment, personnel, and operational gear may be placed thereon. To support the equipment, the upper deck 100B may be formed by a plurality of beams (e.g., steel I-beams) within or upon which the equipment fits. The perimeter may be generally square, rectangular, and / or polygonal in shape. The upper deck 100B includes a first set of beams 110 and a second set of beams 112. The first set of beams 110 form the main truss row. The second set of beams 112 may be oriented horizontally or laterally.

[0030] In one or more embodiments, the tubular members 100C space the upper deck 100B a fixed distance from the lower deck 100A. The tubular members 100C may be angled to support the upper deck 100B on the lower deck 100A. Additionally, corner beam members 108 connect the topside truss system 100 to the support posts (see 106A-106D in FIGS. 2A-2H). In some embodiments, the lower deck 100A does not cross through the corner beam members 108. Additionally, the lower deck 100A may include two corresponding corner beam ends 100AB for each corner beam member 108. Each corner beam end 100AB is also secured to the top of four support posts (see 106A-106D in FIGS. 2A-2H) a fixed distance from each corner beam member 108.

[0031] In one or more embodiments, during the conceptual design stage of the lower deck 100A, the dominant load case may be a simplified environmental load combined with the inertial load of the masses on the lower deck 100A and the upper deck 100B. The upper deck 100B and the lower deck 100A may be optimized to address the dominant load case by determining various shapes of voids and material distribution within the deck.

[0032] 4 and 5, the lower deck 100A may be formed by a plurality of beams (101a-1041) arranged on a plane P. The plane P may be a plane within which the lower deck 100A rests. For example, the plane P may be substantially parallel to the pontoon base (see 105 in FIGS. 1-2B). The plurality of beams (101a-1041) may utilize a variety of beams in structural support operations. Those skilled in the art will recognize how the lower deck 100A may achieve increased performance, reduced non-productive time (NPT), and improved equipment life and maintenance.

[0033] In one or more embodiments, the plurality of beams (101a-104l) of the lower deck 100A may include a first set of beams (101a-101d), a second set of beams (102a-102i), a third set of beams (103a-103m), and a fourth set of beams (104a-104l). Each set may have the same cross-section or varying cross-sections. It is understood that different sizes, numbers, and / or types of beams may be used depending on the size, shape, and configuration of the vessel (and its use). Additionally, the first set of beams (101a-101d), the second set of beams (102a-102i), the third set of beams (103a-103m), and the fourth set of beams (104a-104l) may be connected to each other at their ends, midpoints, or along any length of the beams (101a-104l). For example, the connection points between two beams can be end-to-end and / or the end of one beam to the midpoint of the other beam. Furthermore, one beam can be connected to two beams at corresponding midpoints of the two beams. It is also contemplated that one beam can be connected to two beams at a corresponding midpoint of one beam to the end of the other beam. Those skilled in the art will understand how the connection points can be adjusted to meet the load requirements for multiple beams (101a-104l).

[0034] In FIG. 4, the beams (101a-101d) may have a first geometric arrangement for optimally distributing structural materials to balance structural weight and strength. The first set of beams (101a-101d) may be arranged to have beams extending parallel to the X-axis X of the plane P, parallel to the Y-axis Y of the plane P, and at acute or obtuse angles from the X-axis and Y-axis. The second set of beams (102a-102i) may be arranged to have beams extending parallel to the X-axis X of the plane P, parallel to the Y-axis Y of the plane P, and at acute or obtuse angles from the X-axis and Y-axis. The third set of beams (103a-103m) may be arranged to have beams extending parallel to the X-axis X of the plane P, parallel to the Y-axis Y of the plane P, and at acute or obtuse angles from the X-axis and Y-axis. The fourth set of beams (104a-104d) may be arranged to have beams extending parallel to the X-axis X of the plane P and parallel to the Y-axis Y of the plane P.

[0035] In one or more embodiments, the arrangement of FIG. 4 for the lower deck 100A may include one or more quadrants of similar design. For example, the lower deck 100A may have four quadrants, as represented by the dashed boxes 500A-500D. The lower deck 100A may also be symmetrical about a line of symmetry extending diagonally from corner to corner. For example, each quadrant 500A-500D includes the same number of beams from the first beam set (101a-101d), the second beam set (102a-102i), the third beam set (103a-103m), and the fourth beam set (104a-104d) in the same geometric arrangement. Specifically, each quadrant 500A-500D has four beams from the first beam set (101a-101d), nine beams from the second beam set (102a-102i), thirteen beams from the third beam set (103a-103m), and four beams from the fourth beam set (104a-104d). It is further contemplated that the quadrants 500A-500D are symmetric about the longitudinal axis Lo and the horizontal axis LA. Alternatively, the lower deck 100A may be asymmetric in some locations.

[0036] In each quadrant 500A-500D, from the corner beam member 108, the four beams of the first beam set (101a-101d) have a geometry such that the first beam 101a extends along the X-axis X and the second beam 101b forms an acute angle from the first beam 101a, and the third beam 101c extends along the Y-axis Y and the fourth beam 101d forms an acute angle from the third beam 101c. From the first beam 101a of the first beam set extending along the X-axis X, two beams 102a-102b of the second beam set (102a-102i) further extend along the X-axis X, and four beams 103a-103d of the third beam set (103a-103m) further extend along the Y-axis Y. From the third beam 101c of the first beam set (101a-101d) extending along the Y-axis Y, two beams 102c-102d of the second beam set (102a-102i) extend further along the Y-axis Y, and four beams 103e-103h of the third beam set (103a-103m) extend further along the X-axis X. From the distal end of the second beam 101b, which forms an acute angle from the first beam 101a, beam 102e of the second beam set (102a-102i) extends perpendicular to the distal end of the fourth beam 101d, which forms an acute angle from the third beam 101c. Furthermore, from the distal ends of the second beam 101b and the fourth beam 101d, beams 102f-102g from the second beam set (102a-102i) extend further in the angled direction with beams 103i-103j from the third beam set (103a-103m) at the distal ends of beams 102f-102g. In addition, beam 103k from the third beam set (103a-103m) extends in a perpendicular direction from beam 103i at the distal end of beam 102e to beam 103j.

[0037] In some embodiments, each quadrant 500A-500D shares a first set consisting of beam 104a from the fourth beam set (104a-104d), beam 103l from the third beam set (103a-103m), beam 102h from the second beam set (102a-102i), and beam 104b from the fourth beam set 104, which extend in a straight line along the Y-axis Y, and a second set consisting of beam 104c from the fourth beam set (104a-104d), beam 103m from the third beam set (103a-103m), beam 102i from the second beam set (102a-102i), and beam 104d from the fourth beam set (104a-104d), which extend in a straight line along the X-axis X.

[0038] In FIG. 5, the beams (101a-104l) may have a second geometric arrangement for optimally distributing structural materials to balance structural weight and strength. The first set of beams (101a-101d) may be arranged to have beams extending parallel to the X-axis X of the plane P, parallel to the Y-axis Y of the plane P, and at acute or obtuse angles from the X-axis and Y-axis. The second set of beams (102a-102h) may be arranged to have beams extending parallel to the X-axis X of the plane P, parallel to the Y-axis Y of the plane P, and at acute or obtuse angles from the X-axis and Y-axis. The third set of beams (103a-103g) may be arranged to have beams extending parallel to the X-axis X of the plane P, parallel to the Y-axis Y of the plane P, and at acute or obtuse angles from the X-axis and Y-axis. The fourth set of beams (104a-104l) may be arranged to have beams extending parallel to the X-axis X of the plane P and parallel to the Y-axis Y of the plane P.

[0039] 5 of the lower deck 100A may include four symmetrical quadrants, as represented by the dashed boxes 600A-600D. For example, each quadrant 600A-600D includes the same number of beams from the first beam set (101a-101d), the second beam set (102a-102h), the third beam set (103a-103g), and the fourth beam set (104a-104l) in the same geometric arrangement. Specifically, each quadrant 600A-600D has four beams from the first beam set (101a-101d), eight beams from the second beam set (102a-102h), seven beams from the third beam set (103a-103g), and twelve beams from the fourth beam set (104a-104l). It is further contemplated that quadrants 600A-600D are symmetrical about longitudinal axis Lo and transverse axis LA. Alternatively, lower deck 100A may be asymmetrical in some localized areas.

[0040] In each quadrant 600A-600D, from the corner beam member 108, the four beams of the first beam set (101a-101d) have a geometry such that the first beam 101a extends along the X-axis X with the second beam 101b forming an acute angle from the first beam 101a, and the third beam 101c extends along the Y-axis Y with the fourth beam 101d forming an acute angle from the third beam 101c. From the first beam 101a of the first beam set (101a to 101d) extending along the X-axis X, the beam 103a of the third beam set (103a to 103g) and the beam 102a of the second beam set (102a to 102h) extend further along the X-axis X, and the beam 104a of the fourth beam set (104a to 104l), the beam 103b of the third beam set (103a to 103g), the beam 102b of the second beam set (102a to 102h), and the beam 104b of the fourth beam set (104a to 104l) extend further along the Y-axis Y. From the third beam 101c of the first beam set (101a to 101d) extending in the Y-axis Y, the beam 103c of the third beam set (103a to 103g) and the beam 102c of the second beam set (102a to 102h) further extend in the X-axis X, and the beam 104c of the fourth beam set (104a to 104l), the beam 103d of the third beam set (103a to 103g), the beam 102d of the second beam set (102a to 102h), and the beam 104d of the fourth beam set (104a to 104l) further extend in the Y-axis Y. From the distal end of second beam 101b, which forms an acute angle from first beam 101a, beam 103e of the third beam set (103a-103g) extends perpendicular to the distal end of fourth beam 101d, which forms an acute angle from third beam 101c. Furthermore, from the distal ends of second beam 101b and fourth beam 101d, beams 102e-102h of the second beam set (102a-102h) extend in a direction angled from second beam 101b and fourth beam 101d. Additionally, beams 103f-103g of the third beam set (103a-103g) extend from beam 102f to beam 102h so as to be parallel to beam 103e.

[0041] In some embodiments, each quadrant 600A-600D shares a first set of four beams 104e-104h from the fourth beam set (104a-104l) that extend in a straight line along the Y-axis Y, and a second set of four beams 104i-104l from the fourth beam set (104a-104l) that extend in a straight line along the X-axis X.

[0042] 5 and 6, in one or more embodiments, the various pieces of equipment used on lower deck 100A can be connected anywhere along the first set of beams (101a-101d), the second set of beams (102a-102h), the third set of beams (103a-103g), and the fourth set of beams (104a-104l). The various pieces of equipment can be any equipment used to conduct oil and gas operations.

[0043] In addition to the benefits described above, an optimized lower deck layout may improve the overall efficiency and performance of an offshore vessel, along with reduced costs, minimized product engineering, reduced assembly time, reduced hardware costs, reduced weight and enclosure, and many other benefits. Furthermore, an optimized lower deck layout may provide additional benefits, such as maintaining or increasing operational availability, improving equipment life and maintenance, improving site safety, and reducing the structural weight of the lower deck. It should be noted that an optimized lower deck layout may be used in any onshore and offshore oil and gas operation.

[0044] While the present disclosure has been described with respect to a limited number of embodiments, it will be appreciated that those skilled in the art, having the benefit of this disclosure, may devise other embodiments without departing from the scope of the present disclosure as set forth herein. Accordingly, the scope of the present disclosure should be limited only by the appended claims.

Claims

1. 1. A lower deck for a topside truss system of an offshore vessel, the lower deck comprising: a plurality of beams distributed into four quadrants, the plurality of beams extending in a direction parallel to an X-axis of the plane of the lower deck, a direction parallel to a Y-axis of the plane, and directions at acute or obtuse angles from the X-axis and the Y-axis, each quadrant comprising: a first beam set having at least four beams of constant or varying cross-section; a second beam set having at least eight beams of constant or varying cross section; a third beam set having at least seven beams of constant or varying cross-section; and A lower deck including a fourth beam set having at least four beams of constant or varying cross section.

2. The lower deck of claim 1 , wherein the four quadrants are symmetrical about a longitudinal axis of the lower deck and a horizontal axis of the lower deck.

3. a first beam of the first beam set extends in the X-axis and a second beam of the first beam set extends at an acute angle from the first beam from a corresponding quadrant corner, a third beam of the first beam set extends in the Y-axis and a fourth beam of the first beam set extends at an acute angle from the third beam; From the first beam of the first beam set extending in the X-axis, two beams of the second beam set further extend in the X-axis, and four beams of the third beam set further extend in the Y-axis; from the third beam of the first beam set extending in the Y-axis, two beams of the second beam set further extending in the Y-axis, and four beams of the third beam set further extending in the X-axis; a beam of the second set of beams extends perpendicularly from a distal end of the second beam at an acute angle from the first beam to a distal end of the fourth beam at an acute angle from the third beam; a beam from the second set of beams further extends from each distal end of the second beam and the fourth beam in the angled direction with a beam from the third set of beams at its distal end; 2. The lower deck of claim 1, wherein a beam from the third set of beams extends in a direction perpendicular to the beam from the third set of beams at the distal end of the beam from the second set of beams that further extends in the angled direction.

4. 4. The lower deck of claim 3, wherein each quadrant shares a first set of beams from the fourth beam set, a beam from the third beam set, a beam from the second beam set, and a beam from the fourth beam set that extend in a straight line along the Y axis, and a second set of beams from the fourth beam set, a beam from the third beam set, a beam from the second beam set, and a beam from the fourth beam set that extend in a straight line along the X axis.

5. a first beam of the first beam set extends in the X-axis and a second beam of the first beam set extends at an acute angle from the first beam from a corresponding quadrant corner, a third beam of the first beam set extends in the Y-axis and a fourth beam of the first beam set extends at an acute angle from the third beam; From the first beam of the first beam set extending in the X-axis, a beam of the third beam set and a beam of the second beam set further extend in the X-axis, and a beam of the fourth beam set, a beam of the third beam set, a beam of the second beam set, and a beam of the fourth beam set further extend in the Y-axis; From the third beam of the first beam set extending in the Y-axis, a beam of the third beam set and a beam of the second beam set further extend in the Y-axis, and a beam of the fourth beam set, a beam of the third beam set, a beam of the second beam set, and another beam of the fourth beam set further extend in the X-axis; a third set of beams extends perpendicularly from a distal end of the second beam at an acute angle from the first beam to a distal end of the fourth beam at an acute angle from the third beam; four beams from the second beam set extend from each distal end of the second beam and the fourth beam in directions angled from the second beam and the fourth beam; 2. The lower deck of claim 1, wherein two beams from the third set of beams extend from the beam from the second set of beams that extend in the angled direction from the second beam and the fourth beam.

6. 6. The lower deck of claim 5, wherein each quadrant shares a first set of four beams from the fourth beam set that extend aligned with the Y axis and a second set of four beams from the fourth beam set that extend aligned with the X axis.

7. a base having one or more posts disposed thereon; a deck formed by a topside truss system supported by the one or more columns, the topside truss system comprising: The upper deck and The lower deck and a tubular member interconnecting the upper deck to the lower deck; The lower deck is a first beam set having at least four beams of constant or varying cross-section; a second beam set having at least eight beams of constant or varying cross section; a third beam set having at least seven beams of constant or varying cross-section; and a fourth beam set having at least four beams of constant or varying cross section; and having one or more quadrants including Corresponding corner beam members of the topside truss system are secured to the top of the one or more struts of the offshore vessel.

8. The offshore vessel of claim 7 , wherein the offshore vessel is semi-submersible.

9. The offshore vessel of claim 8 , wherein the base is a pontoon base.

10. The support of the one or more columns may further comprise: a six-sided pillar; the first side of the post and the second side of the post are disposed at a first angle relative to one another; the second side of the post and the third side of the post are disposed at a second angle relative to one another; the third side of the post and the fourth side of the post are disposed at a third angle relative to one another; the fourth side of the post and the fifth side of the post are disposed at a fourth angle relative to one another; the fifth side of the post and the sixth side of the post are disposed at a fifth angle relative to each other; the sixth side of the post and the first side of the post are disposed at a sixth angle relative to one another; The offshore vessel of claim 9 , wherein the pontoon base is disposed at a lower end of the pillar.

11. The support of the one or more columns may further comprise: a five-sided pillar; the first side of the post and the second side of the post are disposed at a first angle relative to one another; the second side of the post and the third side of the post are disposed at a second angle relative to one another; the third side of the post and the fourth side of the post are disposed at a third angle relative to one another; the fourth side of the post and the fifth side of the post are disposed at a fourth angle relative to one another; the fifth side of the post and the first side of the post are disposed at a fifth angle relative to one another; the pontoon base is disposed at a lower end of the pillar; The offshore vessel of claim 9 , wherein at least one side of the pillar includes a tapered portion such that the at least one side flares outwardly or inwardly along at least a portion of a length of the pillar.

12. 8. The offshore vessel of claim 7, wherein the upper deck includes a perimeter having a fifth set of beams and a sixth set of beams, the fifth set of beams forming a main truss row, and the sixth set of beams being oriented horizontally or laterally.

13. The offshore vessel of claim 7 , wherein the tubular members are angled to space the upper deck a fixed distance above the lower deck.

14. The offshore vessel of claim 7 , wherein the lower deck does not cross into the corresponding corner beam members of the topside truss system.

15. The offshore vessel of claim 14 , wherein corresponding corner beam ends of the lower deck are secured to the upper portions of four of the struts at a fixed distance from the corresponding corner beam members.

16. The offshore vessel of claim 7 , wherein the lower deck is symmetrical about a diagonal axis.

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