PIPELINE HOISTING STRUCTURE AND METHOD

Abstract

The present invention relates to a structure and method of hoisting pipelines for subsea connection assisted by a remotely operated vehicle, ROV. Particularly, the present invention describes a pipeline hoisting structure comprising three beams joined together in a U-shape, and two hoisting systems, each being coupled to one of the vertical beams of the hoisting structure.

Claims

1. A pipeline hoisting structure, comprising three vertical beams joined together in a U-shape, and two hoisting systems, each being coupled to one of the vertical beams of the hoisting structure.

2. The structure according to claim 1, comprising a horizontal beam arranged in the upper portion of the structure and connecting with two of the three vertical beams.

3. The structure according to claim 2, wherein each of the three vertical beams is connected, at its lower end, to a fixing shoe that provides support and stability to the metallic structure on a seabed.

4. The structure according to claim 3, wherein each hoisting system of the two hoisting systems acts independently in relation to each other, wherein a first hoisting system of the two hoisting systems acts as the main hoisting system and a second system acts as a secondary hoisting system.

5. The structure according to claim 4, wherein each hoisting system comprises: a hydraulic cylinder; a hoisting steel cable; a set of cable steering pulleys; a hoisting hook); and a belt.

6. The structure according to claim 5, further comprising two drive receptacles, each associated with one of the hoisting systems, and mounted on the upper portion of each vertical beam and configured to actuate a movement of the cylinder through connection of a hot stab in at least one drive receptacle by a remotely operated vehicle (ROV).

7. The structure according to claim 6, wherein one end of the steel cable is attached to a fixing element mounted on the hydraulic cylinder.

8. The structure according to claim 7, wherein the hydraulic cylinder is configured to extend a first vertical section of the steel cable when the hydraulic cylinder advances

9. The structure according to claim 8, wherein the set of steering pulleys comprises a first steering pulley fixedly disposed at the lower end of the hydraulic cylinder and on the fixing shoe, with the function of transmitting load and movement between two vertical paths of the first vertical section of the steel cable.

10. The structure according to claim 9, wherein the set of steering pulleys further comprises a second steering pulley fixedly mounted on the horizontal beam, closer to its end, and configured to transmit load and movement between a vertical path of the first vertical section of the steel cable and a horizontal path of a horizontal section of the hoisting steel cable.

11. The structure according to claim 10, wherein the set of steering pulleys further comprises a third steering pulley fixedly mounted on the horizontal beam, centered in relation to the same, and horizontally spaced in relation to the second steering pulley, wherein the third steering pulley is configured to transmit load and movement between the horizontal path of the horizontal section of the steel cable and a vertical path of a second vertical section of the steel cable.

12. The structure according to claim 11, wherein the hoisting hook is mounted at the other end of the two ends of the hoisting steel cable, the hoisting hook being configured to receive and suspend the belt wrapped around a connection region of the pipeline.

13. The structure according to claim 6, wherein the ROV is configured to actuate on the hydraulic cylinder to tension or relax the steel cable.

14. The structure according to claim 1, further comprising an additional containment system to support the hoisting structure.

15. The structure according to claim 11, wherein an axis of rotation of the third steering pulley of a main hoisting system is not coincident with the axis of rotation of a third steering pulley of a secondary hoisting system.

16. A pipeline hoisting method, comprising: driving a drive receptacle associated with a main hoisting system to vertically move a hydraulic cylinder; transmitting a load and movement through a hoisting steel cable attached to an end of the cylinder and passing through a set of steering pulleys; and hoisting a pipeline by a belt wrapped around the pipeline and connected to a winch arranged at the end of the steel cable.

17. The method according to claim 16, further comprising driving a drive receptacle associated with a secondary hoisting system to vertically move a hydraulic cylinder of the secondary hoisting system in case of failure of the main drive system.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0023] The brief description above, as well as the detailed description below, of the preferred embodiments of the invention in question, will be better understood when read together with the attached drawings. For the purpose of illustrating the present invention, embodiments thereof are shown in the drawings. It must be understood, however, that the invention in question is not limited only to the precise arrangements and instruments as shown.

[0024] Thus, the present invention will be described below with reference to typical embodiments thereof and also with reference to the attached drawings, in which:

[0025] FIG. 1 shows a perspective view of a pipeline hoisting structure, according to an exemplary configuration of the present invention.

[0026] FIG. 2 presents a perspective view of a pipeline hoisting structure, according to another exemplary configuration of the present invention.

[0027] FIG. 3 presents in detail a connection region between an end of a hoisting steel cable and a hydraulic cylinder fixing element, according to an exemplary configuration of the present invention.

[0028] FIG. 4 shows in detail a connection region between a steering pulley and a horizontal beam of a pipeline hoisting structure, according to an exemplary configuration of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0029] There follows a reference made in detail to the preferred embodiments of the present invention illustrated in the attached drawings. Whenever possible, the same or similar reference numbers will be used throughout the drawings to refer to the same or similar features. It should be noted that the drawings are in simplified form and are not drawn at a precise scale, so slight variations are anticipated.

[0030] The present invention relates to a structure for hoisting pipelines in subsea connections of the diverless type and its associated method of operation. Furthermore, according to the embodiments of the present invention, the hoisting structure was developed with the objective of meeting any demand in which it is necessary to hoist subsea pipelines, such as, for example, to improve the alignment of flanges and allow the assembly of spikes and/or definitive cases in connection operations between pipelines.

[0031] Furthermore, the hoisting structure of the present invention can be used regardless of sea conditions, as it is previously launched over the pipeline to be connected and, when necessary and regardless of sea conditions, a remotely operated vehicle, ROV, through a hydraulic connection system, hot stab, installed in the structure, can act in a controlled manner and precisely hoist the pipeline to continue the assembly of the spikes and/or definitive cases.

[0032] Therefore, the present invention can be applied in operations requiring controlled pipeline hoisting, mainly, but not limited to subsea connection activities with ROV.

[0033] It is worth to highlight that the pipeline hoisting operation provided with the structure that the present invention discloses optimizes waiting time for good sea conditions, as it is necessary, for example, for the use of vessel cranes in alignment operations of flanges for pipeline connection. Thus, the present invention also provides optimization of the vessel costs in this maneuver.

[0034] In addition, there is a risk of disarming or failure of the vessel crane during the maneuver of hoisting the pipeline for connection, as it is subject to the influence of the relative movements of the vessel, which could cause the pipelines being interconnected to be dragged, and, consequently, possible damage to the same. With the hoisting structure disclosed by the present invention, this risk of dragging or damage to the pipelines is non-existent, since the structure is not connected to the vessel and acts independently, with the operation being completely controlled by the ROV, precisely, via hot stab system of the hoisting structure itself.

[0035] Thus, reference is made to FIG. 1, which provides a representation of the pipeline hoisting structure according to an embodiment of the present invention.

[0036] The hoisting structure 100 comprises three metal beams joined together in a U shape, wherein two beams 10 extend vertically upwards and connect to the ends of a beam 11 horizontally arranged in the upper portion of the hoisting structure 100. Furthermore, according to an embodiment of the present invention, each of the vertical beams 10 is connected, at its lower end, to a fixing shoe 20 that provides support and stability to the metallic structure 100 on the seabed.

[0037] In addition, according to embodiments of the present invention, the hoisting structure 100 has two hoisting systems 90, each being coupled to one of the vertical beams 10 of the structure 100 and acting independently in relation to each other. In this configuration, one of the hoisting systems 90 coupled to a vertical beam 10 acts as the main, or titular, hoisting system, whereas the other hoisting system 90, coupled to the opposite vertical beam, acts as the secondary, or backup, hoisting system. It is worth to highlight that both hoisting systems 90 have the same components and operate according to the same operating principle.

[0038] For ease of description, the hoisting system 90 coupled to the right vertical beam 10 will be referred to as the main hoisting system, while the hoisting system 90 coupled to the left vertical beam 10 will be referred to as the secondary hoisting system. However, as it should be noted, this configuration is not limiting, so that the main hoisting system can be considered as the system coupled to the left vertical beam 10, and the secondary hoisting system can be considered as the system coupled to the right vertical beam 10, without deviating from the objectives of the present invention and in accordance with the convenience of the operation.

[0039] In addition, as detailed in FIGS. 1 and 2, each hoisting system 90 comprises a hydraulic cylinder 30, preferably double-acting, capable of using hydraulic energy to both retract and extend; a hoisting steel cable 40; a set of cable steering pulleys 50a, 50b, 50c; a hoisting hook 60 and a belt 70. Further, in accordance with embodiments of the present invention, the hoisting structure 100 comprises two drive receptacles 80, each associated with one of the hoisting systems 90, and mounted on the upper portion of each vertical beam 10.

[0040] In this way, each hydraulic cylinder 30 is driven by means of an ROV (not shown) that connects a hot stab to the interface of the drive receptacle 80 to actuate the movement of the cylinder 30 in a controlled manner. According to embodiments of the present invention, as seen exemplarily in FIGS. 1 and 2, and in detail G of FIG. 3, one of the two ends of the hoisting steel cable 40 is attached to a fixing element 31 mounted on the hydraulic cylinder 30.

[0041] Thus, the activation of the hydraulic cylinder 30 by means of the ROV via hot stab of the hoisting structure 100 causes the cylinder 30 to advance, extending a first vertical run section 40a of the steel cable 40. A first steering pulley 50a is fixedly disposed at the lower end of the hydraulic cylinder 30 and on the fixing shoe 20, with the function of transmitting load and movement between two vertical paths of the first vertical run section 40a of the steel cable 40.

[0042] Additionally, the set of steering pulleys 50a, 50b, 50c of each hoisting system 90 further comprises a second steering pulley 50b fixedly mounted on the horizontal beam 11, closer to its end, and configured to transmit load and movement between a vertical path of the first vertical run section 40a of the steel cable and a horizontal path of a horizontal run section 40b of the hoisting steel cable.

[0043] Furthermore, according to some embodiments of the present invention, each hoisting system 90 further comprises a third steering pulley 50c of the set of pulleys 50a, 50b, 50c fixedly mounted on the horizontal beam 11, substantially centered in relation thereto and spaced horizontally relative to the second steering pulley 50b, wherein the third pulley 50c is configured to transmit load and movement between the horizontal path of the horizontal run section 40b of the steel cable and a vertical path of a second vertical run section 40c of the steel cable.

[0044] In accordance with embodiments of the present invention, a hoisting hook 60 is mounted at the other end of the two ends of the hoisting steel cable 40, the hook 60 being configured to receive and suspend a belt 70 wrapped around a region pipeline connection. Particularly, in relation to this process, in some embodiments of the present invention, an ROV or diver can be used to connect the belt 70, previously passed around the pipeline, to the hook 60 and, thus, perform the controlled hoisting of the pipeline by actuating the hydraulic cylinder 30. In this way, the pipeline is hoisted from the seabed and remains at an appropriate height from the ground to continue the connection or opening operation of lines.

[0045] After carrying out the operation and the pipeline hoisting maneuver, the ROV actuates the hydraulic cylinder 30 through a hot stab connected to the receptacle 80, so that the cylinder 30 moves in the opposite direction to the direction to pull the steel cable 40, thus relaxing the tension on the cable and loosening the same to release the belt 70 from the pipeline that was hoisted.

[0046] The present invention further provides a method for hoisting pipelines. Using the method of the present invention, it is possible to enable the complete operation of hoisting the pipeline for subsea connection or opening lines, depending on the application and design convenience.

[0047] Accordingly, according to an embodiment of the present invention, the pipeline hoisting method comprises: driving a drive receptacle 80 associated with a main hoisting system to vertically move a hydraulic cylinder 30; transmitting the load and movement through a hoisting steel cable 40 attached to the cylinder 30 at one of its ends and passing through a set of steering pulleys 50a, 50b, 50c; and hoisting the pipeline by means of a belt 70 wrapped around the pipeline and connected to a winch 60 arranged at the end of the steel cable. Additionally, according to an embodiment of the present invention, the method further comprises, in the event of failure of the main drive system, driving a drive receptacle associated with a secondary hoisting system to vertically move a hydraulic cylinder of the secondary hoisting system.

[0048] According to the method of the present invention, the driving of the drive receptacle is carried out by means of an ROV that connects a hot stab to the receptacle interface, pressurizing the hydraulic system of the ROV and allowing the cylinder to move.

[0049] As provided for by the present invention, one of its advantages lies in the redundancy of the hoisting systems that act independently of each other, allowing, in the event of failure in the drive cylinder or any other component on one side of the hoisting structure during the pipeline hoisting maneuver, an ROV can operate the structure through a secondary, or backup, hoisting system available on the opposite side of the structure, without the need of bringing the entire structure to the surface to perform the maintenance.

[0050] Still, as previously mentioned, another advantage of the present invention is the compact constructive form of the structure, which allows connecting or opening services of lines in a controlled manner by using, in some configurations, an additional containment system 200 (such as hoods) to support the hoisting structure 100, as shown exemplarily in FIG. 2.

[0051] Furthermore, FIG. 4 shows in detail a detail H of the third steering pulley 50c and the change from a horizontal path of the horizontal section 40b of the steel cable to a vertical path of the second vertical section 40c of the steel cable, according to an embodiment of the present invention. In this FIG. 4, there is shown, according to one of the embodiments of the present invention, a configuration wherein the axis of rotation of the third steering pulley 50c of a main hoisting system is not coincident with the axis of rotation of a third steering pulley 50c of a secondary hoisting system, positioned in the rear region of the horizontal beam 11. This configuration allows the second vertical sections 40c of the hoisting cables 40 to be parallel to each other, as well as the hooks 60 respectively associated with them, in order to facilitate the replacement of one system for another, if necessary.

[0052] Those skilled in the art will value the knowledge presented herein and will be able to reproduce the invention in the presented embodiments and in other variants, encompassed by the scope of the attached claims.