PORTABLE WORKING DECK

Abstract

A working deck configured to access offshore well heads, comprising: a barge, transverse beams fixed to an upper surface of the barge, wherein the working deck comprises cantilever beams attachable to the transverse beams, and a work platform positioned on the cantilever beams and movable in a lateral direction of the cantilever beams wherein the transverse beams are oriented perpendicular to a forward direction of the barge and comprise at least one of a track beam and one of a hold-down beam for receiving the cantilever beams, wherein the cantilever beams can be moved along the at least one track beam and the hold down beam to change the position of the cantilever beams relative to the barge, wherein the working deck comprises stiffening elements for stiffening the hold-down beam and to prevent or limit deformation of the hold-down beam.

Claims

1. A working deck configured to access offshore well heads, the working deck comprising: a barge; and transverse beams fixed to an upper surface of the barge; wherein: the working deck comprises at least two cantilever beams attachable on to the transverse beams; and a work platform positioned on the at least two cantilever beams and being movable in a lateral direction of the cantilever beams wherein the transverse beams are oriented perpendicular to a forward direction of the barge and comprise at least one of a track beam and one of a hold-down beam for receiving the at least two cantilever beams, wherein the at least two cantilever beams are able to be moved along the at least one track beam and the hold down beam to change the position of the at least two cantilever beams relative to the barge, wherein the working deck comprises a plurality of stiffening elements for stiffening the hold-down beam and to prevent or limit deformation of the hold-down beam.

2. The working deck of claim 1, wherein at least two track beams are in the form of a rail and/or the at least two track beams and one hold-down beam are fixed to the upper surface of the barge and/or the at least two track beams and one hold-down beam are structurally designed to have tracks or rails that allow the cantilever beams to move on them in a lateral direction.

3. The working deck of claim 1, wherein the hold-down beam is oriented perpendicular to a forward direction of the barge and/or is designed to limit a length of penetration of the cantilever beams on the barge.

4. The working deck of claim 1, wherein the stiffening elements are configured to prevent deformation of the hold-down beam to pending moment and shear forces that act on the hold down beam by providing an opposing moment reaction as well a vertical reaction force to counter the shear forces.

5. The working deck of claim 1, wherein: the at least two cantilever beams are connected with a link beam mounted therebetween.

6. The working deck of claim 5, wherein the link beam is configured to define a rigid position of the two cantilever beams relative to each other and/or is configured to ensure that the cantilever beams are oriented parallel to each other.

7. The working deck of claim 1, wherein: the at least two cantilever beams further comprise rollers for rolling on the at least one track beam of the transverse beams.

8. The working deck of claim 7, wherein the rollers enable the cantilever beams to roll on the track beams and/or the rollers are configured to withstand high forces and loads.

9. The working deck of claim 1, wherein: the at least two cantilever beams further comprise sliders, for sliding along the hold-down beam of the transverse beams.

10. The working deck of claim 9 wherein the sliders are made of the same material as the hold-down beam.

11. The working deck of claim 1, wherein: the at least one track beam further comprise C-clamps for holding a position of the at least two cantilever beams on the at least one track beam.

12. The working deck of claim 1, wherein the at least two cantilever beams further comprise rails, wherein the work platform can be moved along the rails.

13. The working deck of claim 1, wherein: the work platform further comprises removable floor panels for accessing the well heads.

14. The working deck of claim 13, wherein: the work platform further comprises at least one wheel driven by at least one electromotor for moving the work platform on rails of the at least two cantilever beams.

15. The working deck according to claim 14, wherein the wheel is positioned on the rails of the cantilever beams for moving the work platform along the cantilever beams in the lateral direction.

16. The working deck of claim 1, further comprising: a gangway positioned on the at least two cantilever beams, comprising a stair member and a length-adjustable platform member.

17. The working deck of claim 16, wherein length-adjustable platform member can be adjusted in length in the lateral direction and/or the stair member helps to overcome a height difference between the upper surface of the barge and the work platform.

18. The working deck of claim 16, wherein the gangway is positioned onto at least one of the two cantilever beams between the barge and the work platform.

19. The working deck of claim 1, wherein: the barge further comprises a jack-up mechanism for jacking-up the barge above the well heads and for jacking-down the barge to a desired vertical working position.

20. A method for accessing offshore well heads with a working deck, the method comprising: positioning a barge next to the offshore well heads; jacking-up the barge to a height above the offshore well heads; mounting a link beam between at least two cantilever beams; attaching the at least two cantilever beams to transverse beams fixed to the barge; positioning a work platform with floor panels on the at least two cantilever beams; electrically connecting at least one electromotor of the work platform; moving the work platform in a lateral direction to the at least two cantilever beams to a desired horizontal working position by using the at least one electromotor; positioning a gangway on the at least two cantilever beams between the barge and the work platform; removing of ones of the floor panels at the work platform for accessing the offshore well heads; and jacking-down the barge over the offshore well heads to a desired vertical working position.

21. The method of claim 20, wherein: the positioning of the at least two cantilever beams on the transverse beams is carried out in such a way that rollers of the at least two cantilever beams roll on at least one track beam of the transverse beams and a slider of the at least two cantilever beams slides along a hold-down beam of the transverse beams.

22. The method of claim 20, further comprising: fixing the at least two cantilever beams attached to the transverse beams with C-clamps.

23. The method according to claim 20, wherein the cantilever beams are dissembled and/or stored in a 40 ft ISO container.

24. The method according to claim 20, wherein when the working deck is not used, the transverse beams are oriented and fixed perpendicular to a forward direction of the barge, the cantilever beams, the link beam and the gangway are disposed and secured on an upper surface of the barge in a location reachable with a crane when the barge is moving to the offshore well heads.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0040] FIG. 1 shows a working deck at an offshore working location seen from above.

[0041] FIG. 2 shows the part of the working deck of FIG. 1 in a perspective view.

[0042] FIG. 3 shows transverse beams of the working deck fixed to the barge.

[0043] FIG. 4 shows at least two cantilever beams with a link beam mounted therebetween.

[0044] FIG. 5 shows a work platform of the working deck with removed removable floor panels.

[0045] FIG. 6 shows the work platform of FIG. 5 with attached removable floor panels.

[0046] FIG. 7 shows a stair member.

[0047] FIG. 8 shows a length-adjustable platform member.

[0048] FIG. 9 shows an example of how components of the working deck are stored on the barge.

[0049] FIG. 10 shows how the link beam is mounted between the at least two cantilever beams.

[0050] FIG. 11 shows a first assembly step of the at least two cantilever beams with link beam at the transverse beams.

[0051] FIG. 12 shows a second assembly step of the at least two cantilever beams with link beam at the transverse beams.

[0052] FIG. 13 shows an assembly of a work platform.

[0053] FIG. 14 shows the working deck in an assembled state at a first working position from above.

[0054] FIG. 15 shows a flowchart of a method for accessing an offshore well heads with a working deck.

DETAILED DESCRIPTION OF THE INVENTION

[0055] The invention will now be described on the basis of the drawings. It will be understood that the embodiments and aspects of the invention described herein are only examples and do not limit the protective scope of the claims in any way. The invention is defined by the claims and their equivalents. It will be understood that features of one aspect or embodiment of the invention can be combined with a feature of a different aspect or aspects and/or embodiments of the invention.

[0056] FIG. 1 shows a working deck 100 at an offshore working location as seen from above. A barge 10 comprises jack-up mechanisms 80 for jacking-up the barge 10 after the barge 10 was moved to the offshore working location. The jacking-up mechanism 80 is one of a known art and will be not described in detail hereinafter. A maintenance area 5 is located in a rear end relative to a forward direction D2 of the barge 10. The barge 10 can be any of a floating vessel comprising a platform or a deck with and without its own drive. With other words, the barge 10 can drive on its own or be drawn by another vessel, for example a boat, to the offshore working location.

[0057] FIG. 2 shows the working deck 100 in operation in a perspective view. The working deck 100 is configured to access offshore well heads 70 of an offshore well head platform. It can be seen that the working deck 100 comprises in addition to the barge 10, further components, such as transverse beams 20 with at least one of a track beam 20a and one of a hold-down beam 20b, a plurality of stiffening elements 25, at least two cantilever beams 30, a link beam 60, and a work platform 40. The work platform 40 has removable floor panels 40a and is positioned on the cantilever beams 30. The work platform 40 is movable in a lateral direction D1 of the cantilever beams 30. The working deck 100 further comprises a gangway 50 comprising a stair member 50a and a length-adjustable platform member 50b.

[0058] As seen in FIG. 3, the transverse beams 20 are fixed to an upper surface 11 of the barge 10. The transverse beams 20 are made of a weldable metal such as for a non-limiting example steel. The upper surface 11 of the barge 10 is a surface in general parallel to the surface of the water on which the barge 10 is floating. The two track beams 20a and the hold-down beam 20b are fixed to the upper surface 11 of the barge 10 by, for example, welding.

[0059] The two track beams 20a are in the form of a rail, but this is not limiting of the invention. The two cantilever beams 30 are affixed at a desired position on the track beams 20a using C-clamps 20c which position the two cantilever beams 30 onto the track beams 20a. FIG. 3 shows a total of eight C-clamps 20c, but this is not limiting of the invention. The eight C-clamps 20c are in four pairs of two C-clamps 20c. A first two pairs are arranged on a first one of the track beams 20a and a second two pairs are arranged on a second one of the track beams 20a. The cantilever beams 30 can then be disposed and affixed between the pairs of the C-claims 20c. In this manner, the relative position of the cantilever beams 30 to the barge 10 can be chosen and fixed before placing the two cantilever beams 30. Alternatively, the C-clamps 20c can also be affixed onto the track beams 20a after the cantilever beams 30 are assembled to the transverse beams 20. The C-clamps 20c are made, for example, of a metal such as steel and have the form of a letter C to cover the track beam 20a. The hold-down beam 20b comprises the plurality of stiffening elements 25 which have the function of stiffening the hold-down beam 20b and to prevent or limit deformation of the hold-down beam 20b. The stiffening elements 25 are made of a weldable metal such as steel (but this is not limiting of the invention) and are welded to the hold-down beam 20b and to the upper surface 11 of the barge 10. Due to the pending moment and shear forces that act on hold down beam by providing an opposing moment reaction as well a vertical reaction force to counter the shear forces.

[0060] The hold down beams 20b is very essential and unique part of the transverse beams structural design and its main advantages are, working as anchoring and supporting structure for the whole cantilever structure weight and stability of the whole system. The hold-down beam 20b comprises the plurality of stiffening elements 25 which have the function of stiffening the hold-down beam 20b and to prevent or limit deformation of the hold-down beam 20b. The hold down beam 20b is oriented perpendicular to a forward direction of the barge. This orientation of the hold-down beam supports the stability of the whole construction while moved to the working location. Limiting the length of penetration of the cantilever beams on the barge/vessel main deck. Which makes most of the working space of the barge/vessel main deck available for other scopes of work to be carried out in parallel or for facilitating other equipment allocations.

[0061] As seen in FIG. 4, two cantilever beams 30 are connected with a link beam 60 mounted between the two cantilever beams 30. The link beam 60 is for example a welded structure of metal beams which define a rigid position of the two cantilever beams 30 relative to each other. The two cantilever beams 30 have rollers 30a. The rollers 30a are designed in such a way to be able to withstand high forces and loads. It will be apparent that the rollers 30a are connected to the cantilever beams 30 with bearings. The rollers 30a enable the cantilever beams 30 to roll on the track beams 20a. The cantilever beams 30 further have sliders 30b. The sliders 30b enable the two cantilever beams 30 to slide along the hold-down beam 20b. The sliders 30b is a unique feature of the structural design for the cantilever beams 30 as they have the function to enable the two cantilever beams 30 to slide along the hold-down beam 20b. As highlighted as well in FIG. 11 indicating the engagement points between the sliders 30b and hold down beam 20b facilitating the movement of the cantilever beam 30 laterally. The sliders 30b are made for example of the same material as the hold-down beam 20b in order to reduce friction between the sliders 30b and the hold-down beam 20b when moved relative to each other. The two cantilever beams 30 further include rails 30c. As will be described later, the work platform 40 can be moved along the rails 30c.

[0062] FIGS. 5 and 6 show the work platform 40 with (FIG. 5) and without (FIG. 6) the plurality of removable floor panels 40a. When the work platform 40 is moved to the desired working position above the well heads 70, all or a few of the removable floor panels 40a can be removed from the work platform 40 to access one or more of the offshore well heads 70.

[0063] The overboard work platform 40 is made up of removable floor panels 40a for ease of operation. Depending on the location of wellhead, and/or certain orientation for accessing such wellheads, then the floor panels 40a can be added and removed accordingly, which brings good flexibility to the working deck/platform for the well operations.

[0064] Unlike other conventional platforms or Texas Decks which relying on the changing position of the whole cantilever structure by retracting or extending one end of the platform over the perimeter by a piston arrangement, a hydraulic cylinders or rotating lifting screw.

[0065] The work platform 40 further comprises at least one wheel 40b driven by at least one electromotor 40c. In FIGS. 5 and 6 two wheels 40b are shown, but this is not limiting of the invention. The wheel/s 40b will be positioned on the rails 30c of the cantilever beams 30 for moving the work platform 40 along the cantilever beams 30 in the lateral direction D1, as can be seen in FIG. 1.

[0066] In order to access the work platform 40 in a safe way the gangway 50 (see FIG. 2) is positioned onto at least one of the two cantilever beams 30 between the barge 10 and the work platform 40. FIG. 7 shows the stair member 50a which helps to overcome a height difference between the upper surface 11 of the barge 10 and the work platform 40 (see FIG. 2). The stair member 50a is, for example, a welded steel construction.

[0067] FIG. 8 shows the length-adjustable platform member 50b. The length-adjustable platform member 50b can be adjusted in length in the lateral direction D1 for accessing the movable work platform 40 in a safe way.

[0068] FIG. 9 shows an example of how the components of the working deck 100 are stored on the upper surface 11 of the barge 10 when the components are not in use. The transverse beams 20 are oriented and fixed perpendicular to the forward direction D2 of the barge 10. The work platform 40 equipped with the removable floor panels 40a as well as the cantilever beams 30, the link beam 60 and the gangway 50 are disposed and secured on the upper surface 11 of the barge 10 in a location reachable with a crane 90 when the barge 10 is moving to the offshore well heads 70.

[0069] With reference to FIGS. 10 to 14 in conjunction with FIG. 15, a method 200 for accessing one or a plurality of offshore well heads 70 with the working deck 100 will be described.

[0070] In step S1 the barge 10 is positioned next to the offshore well heads 70 of the offshore well head platform and jacked-up to a height above the offshore well heads 70 in step S2 of the method 200 of FIG. 15. Following step S2 the link beam 60 is mounted between the two cantilever beams 30 in step S3 (see also FIG. 10).

[0071] In step S4 of the method 200 of FIG. 15 and as seen in FIGS. 11 and 12, the cantilever beams 30 with the link beam 60 are assembled at the transverse beams 20 using the crane 90. FIG. 11 shows a first part of step S4 at which the cantilever beams 30, mounted with the link beam 60 in between, are hooked and raised by the crane 90 to a position close to the transverse beams 20. The crane 90 can position and/or move the cantilever beams 30 with the link beam 60 along the track beams 20a and the hold-down beam 20b to change the position of the cantilever beams 30 relative to the barge 10. Thus, the cantilever beams 30 can be moved to a position above the well heads 70, as seen in FIG. 2.

[0072] In a second part of step S4, as seen in FIG. 12, the cantilever beams 30 with the link beam 60 are attached to the transverse beams 20. For the attachment of the cantilever beams 30, the sliders 30b are hooked to the hold-down beam 20b while the opposite side of the cantilever beams 30 is lifted. After the sliders 30b are attached to the hold-down beam 20b, the opposite side of the two cantilever beams 30 is lowered and the rollers 30a are attached onto the track beam 20a. After the cantilever beams 30 are positioned at the desired location, the cantilever beams 30 are secured with C-clamps 20c (not shown in FIG. 12). Alternatively, if the desired position is determined before the attachment of the cantilever beams 30 to the transverse beams 20, the C-clamps 20c can be affixed to the track beams 20a upfront.

[0073] In step S5 of the method 200 of FIG. 15, as seen in FIG. 13, the work platform 40 comprising the removable floor panels 40a is positioned by the crane 90 onto the two cantilever beams 30 in such a way, that the wheels 40b of the work platform 40 are positioned on the rails 30c of the cantilever beams 30. The wheels 40b are driven by the electromotors 40c of the work platform 40 which are electrically connected in step S6 of the method 200 of FIG. 15 to a power supply (not shown). The wheels 40b are driven by at least one electromotor 40c and the work platform 40 is moved in step S7 in a lateral direction D1 to a desired horizontal working position, as shown in FIGS. 2 and 14.

[0074] After the work platform 40 arrives at the desired horizontal position, the gangway 50 can be assembled. In step S8 of the method 200 of FIG. 15, the gangway 50 is positioned on the two cantilever beams 30 between the barge 10 and the work platform 40 (see FIG. 2).

[0075] For accessing at least one of the offshore well heads 70, one or more of the removable floor panels 40a are removed in step S9 before the barge 10 is jacked-down to the desired vertical working position in step S10 of the method of FIG. 15. It will be apparent that steps S9 and S10 can be also changed, such that step S10 is performed before step S9.

[0076] To access others of the offshore well heads 70 the work platform 40 can be moved in the lateral direction D1 which also causes an adjustment of the length-adjustable platform member 50b. If needed, the barge 10 can be jacked-up/jacked-down between different work positions during operation and or maintenance work.

[0077] When the work is finished, the barge 10 is jacked-up above the well heads 70 and the components are disassembled and stored again on the upper surface 11 of the barge 10. After all components are secured the barge 10 is jacked-down and able to continue work at another offshore working location.

REFERENCE SIGNS

[0078] 10 barge [0079] 11 upper surface [0080] 20 transverse beams [0081] 20a track beam [0082] 20b hold-down beam [0083] 20c C-clamps [0084] 25 stiffening element [0085] 30 cantilever beams [0086] 30a rollers [0087] 30b sliders [0088] 30c rails [0089] 40 work platform [0090] 40a removable floor panels [0091] 40b at least one wheel [0092] 40c at least one electromotor [0093] 50 gangway [0094] 50a stair member [0095] 50b length-adjustable platform member [0096] 60 link beam [0097] 70 well head [0098] 80 jack-up mechanism [0099] 90 crane [0100] 100 working deck [0101] D1 lateral direction [0102] D2 forward direction