WO2012074391A1

WO2012074391A1 - Jacking system

Info

Publication number: WO2012074391A1
Application number: PCT/NL2011/050814
Authority: WO
Inventors: Henry Charles Van Der Pol; Alexander Johannes Theodorus Bot
Original assignee: Ihc Holland Ie B.V.
Priority date: 2010-11-30
Filing date: 2011-11-29
Publication date: 2012-06-07
Also published as: NL2005785C2

Abstract

The invention relates to a jacking system for jacking a structure like an offshore platform, the jacking system comprising; - a pile for engaging the seabed, - a rack and pinion drive for driving the structure along the pile, wherein, the rack is moveably coupled with the pile, and wherein the jacking system comprises; - coupling means for temporarily coupling the rack with the pile for driving the structure along the pile for providing a, - double acting system by moving the structure along the pile ( or vice versa ) via the engaged racks while, with the same rotation the idle racks are brought back to their initial position to become the active racks.

Description

Jacking System

Background

The present invention relates to a jacking system for jacking a structure like an offshore platform, the jacking system comprising a rack and pinion drive for driving the structure along a pile.

Such a jacking system is known from US 3014346 wherein a slideable elongated member is mounted for slideable movement along the leg. In US 3014346 it is required that each respective slideable elongate member is coupled with its own respective pinion.

It is also known to apply hydraulic cylinders for jacking a structure, see for example WO 2009/017399 Al, however in that case the cylinder speed limits the speed of lowering and lifting of the structure. Also, in general the jacking power depends on the working direction of the cylinder, which is undesirable. If the cylinder is pushing it can use its full piston area to develop a force, however if the cylinder is pulling, the effective area is reduced because of the cylinder rod. Working as a pulling cylinder it can therefore develop less force. In general, there is always a mode of operation in which the cylinder is in the pulling mode. Also, the stroke of the hydraulic cylinder is limited in connection with buckling of the cylinder rod. The limited stroke limits the jacking speed of the structure.

Summary of the invention

The invention aims to provide a jacking system which at least partly solves a problem associated with known jacking systems.

Yet another object of the invention is to provide an alternative jacking system.

According to a first aspect of the invention this is realized with a jacking system for jacking a structure like an offshore platform, the jacking system comprising;

- a pile for engaging the seabed, the pile having a longitudinal axis,

- a first rack system with a first rack portion for a rack and pinion drive for driving the structure along the pile, - a second rack system with a second rack portion for a rack and pinion drive for driving the structure along the pile,

wherein both the first and second rack systems are moveably coupled with the pile and moveably along the longitudinal axis of the pile,

- coupling means for alternately coupling the first or second rack system with the pile for driving the structure along the pile via that rack system coupled with the pile,

- a mainframe for coupling the jacking system with the structure, and, - provided with the mainframe a pinion drive system for a rack and pinion drive,

wherein both the first and second rack system are coupled with the same pinion drive system for driving the structure along the pile.

The rack being moveably coupled with the pile enables to use a pile without a fixed tooth rack welded onto the pile which is a considerable cost saving and prevents introduction of stresses in the pipe caused by the welding process. The jacking system with the rack being moveably coupled with the pile also enables more easy up scaling of the jacking system in terms of stroke and maximum load.

The jacking system comprising a first rack portion and second rack portion enables a faster jacking of the structure since the first rack portion and second rack portion are alternately coupled by their respective coupling means with the pile for driving the structure along the pile.

Providing the coupling means for alternately coupling the first or second rack system with the pile for driving the structure along the pile enables a double acting system by moving the structure along the pile, or the pile along the structure, via the coupled rack system while, with the same pinion drive system the so called idle rack system, that is the rack system not coupled with the pile, is brought back to its initial position to subsequently become the active rack system, that means the rack system coupled with the pile.

Coupling both the first and second rack system are with the same pinion drive system for driving the structure along the pile, renders the jacking system a more affordable and simple jacking system. Moreover, it enables continuous jacking of the structure. In an embodiment of the jacking system according to the invention, the pinion drive system engages alternately one of the first and second rack system for driving that one rack system along the pile in a first direction, and the other of the first and second rack system for driving that other rack system opposite the first direction towards an initial position of that other rack system. This way, jacking speed is even more fast and efficient.

In an embodiment of the jacking system according to the invention, one of the first and second rack system engages at a first half of a pinion of the pinion drive system for driving the structure along the pile when the pinion turns in a first pinion direction, and the other of the first and second rack system engages at the other half of the pinion for driving the structure along the pile when the pinion turns opposite the first pinion direction. This way, a single pinion can be applied, while the turning direction of the pinion also determines which rack system is used for driving the structure along the pile.

In an embodiment of the jacking system according to the invention, the first and second rack system simultaneously engage the pinion, one of the first and second rack system for driving the structure along the pile, and the other rack system for moving the second rack towards its initial position. This way, jacking speed is even more fast, continuous and efficient.

In an embodiment of the jacking system according to the invention, teeth of the first rack portion face away from the pile and teeth of the second rack portion face towards the pile.

The second rack portion with its teeth facing the pile, enables an arrangement wherein the pile itself handles lines of force caused by the driving of the structure along the pile. The embodiment assures a proper support and enclosure of the rack portions in order to avoid buckling of the rack portions.

In an embodiment of the jacking system according to the invention, the first rack system comprises a first frame and a plurality of rack portions provided with the first frame. Applying the first frame opens the possibility to couple and decouple all the first rack portions of the plurality of rack portions at once, which is beneficial in connection with considerable jacking loads.

In an embodiment of the jacking system according to the invention, the second rack system comprises a second frame and a plurality of rack portions provided with the second frame.

Providing the first frame and/or the second frame beneficially enables distribution of the plurality of rack portions along the circumference of the pile and enables easy scaling of the jacking system with respect to the load of the structure.

In an embodiment of the jacking system according to the invention, the coupling means comprise a first coupling means provided with the first frame.

In an embodiment of the jacking system according to the invention, the coupling means comprise a second coupling means provided with the second frame.

Providing the respective first and second coupling means with the first frame and second frame ensures all rack portions of the plurality of rack portions are coupled and decoupled simultaneously which is beneficially since this improves the safety during operation of the jacking system.

In an embodiment, the jacking system according to the invention comprises a plurality of pinion drive systems each having a pinion coupled with a rack portion of the plurality of rack portions of the first rack system and coupled with a rack portion of the plurality of rack portions of the second rack system for driving the structure.

In an embodiment of the jacking system according to the invention, the jacking system comprises a structure coupling means for temporarily coupling the structure with the pile. Providing structure coupling means, enables sliding of the first rack portion and/or the second rack portion relative to the pile for subsequently further advancing the structure along the pile. Moreover, the structure coupling means enable a coupling for performing operations on the structure like drilling etc.

In an embodiment, the jacking system according to the invention, the structure coupling means is provided with the main frame.

In an embodiment, the jacking system according to the invention comprises a housing fixedly coupled with the main frame, wherein the housing comprises housing coupling means for coupling the jacking system with a barge.

Applying a housing enables support of second rack portions for preventing buckling of these rack portions. The housing coupling means enable a modular use of the jacking system, which jacking system in that case can easily be coupled with a barge, a platform or anything that needs to be jacked.

The invention further relates to a method for a jacking system for jacking a structure, like an offshore platform, along a pile, the method comprising the steps;

- providing a pinion drive system with a pinion for a rack and pinion drive, - providing a first and a second rack portion for a rack and pinion drive for driving the structure along the pile,

- coupling one of the first and second rack portion with the pile,

- simultaneously engaging the first and second rack portion with the pinion, the one coupled rack portion for driving the structure in a first direction along the pile, the other portion for sliding opposite the first direction along the pile.

Simultaneously engaging both rack portions for sliding the first rack portion along the pile and the second rack portion for moving the structure along the pile enables use of a pile without a fixed tooth rack welded onto the pile which is a considerable cost saving. Sliding the rack along the pile also enables more easy up scaling of the jacking system in terms of stroke and maximum load. Moreover, jacking speed is improved. The invention further relates to a device comprising one or more of the characterising features described in the description and/or shown in the attached drawings.

The invention further relates to a method comprising one or more of the characterising features described in the description and/or shown in the attached drawings.

The various aspects discussed in this patent can be combined in order to provide additional advantageous advantages.

Description of the drawings

The invention will be further elucidated referring to an preferred embodiment shown in the schematic drawings wherein shown in:

Fig. 1 a side view of a structure with jacking systems according to the invention; fig 2, a side view of a jacking system according to the invention;

fig. 3a-e, in side view consecutive steps during lowering of a pile;

fig. 4a-e, in side view consecutive steps during lifting of a pile;

fig. 5a-e, in side view consecutive steps during lifting of a structure;

fig. 6a-e, in side view consecutive steps during lowering of a structure;

fig. 7, a side view of a coupling means.

Detailed description of embodiments

Fig. 1 depicts a side view of a structure 2, in this case a barge, with jacking systems 1 coupled with the barge at opposite sides of the barge. The jacking system 1 is provided with a pile 3 for engaging the seabed. The pile 3 extends vertically along its vertical axis 7. One end of the pile 3 faces the seabed. The one end is provided with a feet 5 for engaging the seabed. The jacking system 1 is capable of lifting the barge above the water line or lifting a pile 3 away from the seabed.

Fig. 2 depicts a side view of a jacking system 1. The jacking system comprises a pinion drive system 11, 19, in this case two drives, which is known per se. The pinion drive system 11, 19 is suitable for driving the structure 2 along the pile 3, that is lowering or lifting the structure 2. On the other hand the pinion drive system 11, 19 is suitable for lowering or lifting the pile 3. According to the invention, the first and second rack systems 12, 21 are moveably coupled with the pile 3, along the longitudinal axis 7 of the pile 3. Here, the first rack system 12 is, specifically slideably coupled with the pile 3 along the longitudinal axis 7 of the pile 3. The second rack system 21 is moveably coupled with the pile 3 in a geared manner via the pinion drive systems 11, 19, specifically via the pinions 32, 33 of the pinion drive systems 11, 19. It is conceivable that a first and/or second rack system 12, 21 is coupled with the pile 3 in a rolling manner. Here, the pile 3 is suitable for sliding the first rack system 12 with the respective rack portions 14, 23, thereof, along the pile 3, specifically the outer circumference of the pile 3. The pile 3 supports the first rack portions 14, 23 in a sliding manner and such that buckling of the first rack portions 14, 23 is prevented. The first rack portions 14, 23 are provided with teeth for toothed engagement with the structure 2, here by means of the pinions 32, 33, any other suitable means for toothed engagement of the first rack portions 14, 23 with the structure 2 are conceivable. The jacking system 1 is provided with coupling means 6, 16 for temporarily coupling the first 12 and/or 21 second rack system with the pile 3 for driving the structure 2 along the pile 3. In this embodiment the first rack system 12 is provided with a first frame 17 for arranging the first rack portions 23, 14 with respect to the pile 3, specifically the circumference of the pile 3. In this case a plurality of rack portions 23, 14 are provided, arranged along the first frame 17, here a circumferential first frame 17. The first frame 17 aligns the first rack portions 23, 14, in this case two first rack portions 23, 14 with the longitudinal axis of the pile 3. The first frame 17 distributes the first rack portions 23, 14 along the circumference of the pile 3, here in a evenly spaced manner. Here, the first coupling means 16 are provided with the first frame 17. Therefore, the plurality of first rack portions 23, 14 are simultaneously coupled or decoupled with the pile 3.

The jacking system 1 comprises a second rack system 21 with second rack portions 13, 18 wherein the second rack system 21 is moveably coupled with the pile 3 as well. The second rack portions 13, 18 are coupled with the pile 3 in a geared manner and are moveable along the longitudinal axis 7 of the pile 3. The jacking system 1 comprises a second coupling means 6 for temporarily coupling the second rack system 21 with the second rack portions 13, 18 thereof with the pile 3 for driving the structure 2 along the pile 3. Here, the first rack portions 14, 23 engage with a first half of the pinion 32, 33 for driving the structure 2 along the pile 3. The second rack portions 13, 18 engage with the other half of the pinion 32, 33 for driving the structure 2 along the pile 3. In this case, the second rack portions 13, 18 face towards the pile 3 with the teeth of the second rack portions 13, 18. The first rack portions 14, 23 faces away from the pile 3 with its teeth. This way the second rack portions 13, 18 retain the first rack portions 14, 23 against the pile 3. This arrangement enables the pile 3 itself to handles lines of force caused by the driving of the structure 2 along the pile 3 which is useful in terms of use of material. Different arrangements are conceivable however it is useful that each set of a first rack portions 14, 23 and a second rack portions 13, 18 pair for engagement with a pinion 32, 33, each pair with its own respective single pinion 32, 33.

The structure 2 is alternately coupled with the pile 3 by means of the first rack portions 14, 23 and the second rack portions 13, 18 by means of respectively the first 16 and second 6 coupling means. When the pile 3 is moving along the first rack portions 14, 23, also referred to as inner rack portions 14, 23, the idle second rack portions 13, 18, also referred to as outer racks, are brought back to their initial position in the same rotation movement of the pinion 32, 33. Subsequently the first coupling means 16 decouples and the second coupling means 6 couples for the second rack portions 13, 18 to become the active racks and the structure 2 is moved along the pile 3 over the second rack portions. Again in the same driving movement of the pinion 32, 33, the inner racks 23, 14 are brought back to their initial position.

Here, the second frame system 21 is provided with a second frame 22 for arranging the second rack portions 13, 18 with respect to the pile 3. In this case a plurality of second rack portions 13, 18 are provided with the second frame 22, arranged along the second frame 22, here a circumferential second frame 22. The second frame 22 aligns the second rack portions 13, 18 in this case two second rack portions 13, 18 with the longitudinal axis of the pile 3 as well as with the first rack portions 14, 23 such that the first rack portions and second rack portions may pair for each pair to engage with a single pinion 32, 33. The second frame 22 distributes the second rack portions 13, 18 along the circumference of the pile 3, here in a evenly spaced manner. Here, the second coupling means 6 are provided with the second frame 22. Therefore, the plurality of second rack portions 13, 18 are simultaneously coupled or decoupled with the pile 3. The jacking system 1 is provided with a structure coupling means 15 for temporarily coupling the structure 2 with the pile 3, during operations on the structure

2, like drilling. Here, the structure coupling means 15 is fixedly coupled with the structure 2 by a structure frame 20, also referred to as main frame 20. In this case, the pinion drive system 11, 19 is provided with the structure frame 20.

The pinion drive system 11, 19 comprises a pinion 32, 33 or conceivably several pinions, driven by an electric or hydraulic motor via a planetary gearbox. The pinion drive system 11, 19 is a bi-directional drive which is able to apply a similar load for each direction. The pinion drive system 11, 19 is coupled with the structure 2, allowing the structure 2 to be lifted or lowered. The forces that are needed to lift the structure 2 are transferred from the rotational movement of the pinions 32, 33 over the first and second rack portions to the structure 2 via the pinion drive foundation 20, also referred to as main frame 20. As an option, additional auxiliary coupling means 15, also referred to as structure coupling means 15, can be provided at the foundation to couple the structure 2 with the pile 3 once the structure 2 is at its elevated position. This auxiliary means of coupling 15 can also be used when the system changes between the upper coupling means 6, also referred to as second coupling means 6, and the lower coupling means 16, also referred to as first coupling means 16. This offers an extra safety during operation of the jacket system 1. Obviously, during the lifting or lowering operation auxiliary means of coupling 15 can not be engaged with the pile 3.

During operation of the jacket system 1 of the invention, the first rack portions 14, 23 and/or second rack portions 13, 18 move along the longitudinal axis of the pile

3. The first rack portions 14, 23 and second rack portions 13, 18 are consecutively coupled with the pile 3 for moving the structure 2 along the longitudinal axis of the pile 3.

The operation of the jacking system 1 is explained referring to fig. 3a-e to fig. 6a- e wherein in side view consecutive steps are shown successively during lowering of a pile 3, lifting of pile 3, lifting of a structure 2 and lowering of a structure 2. The lowering of a pile 3 will be explained in detail, the other operational modes are similar and will be clear from the figures alone. In the figures 3a-e to fig. 6a-e, the single half filled triangle indicates which one of the first 16 and second 6 coupling means is coupled with the pile 3 Firstly (a) the second coupling means 6 is couples the second rack system 21 with the pile 3. The first coupling means 15, 16 is decoupled and the structure frame 20 and the first frame 17 may move with respect to the pile 3, in geared engagement with the pile 3 by means of the pinions 32, 33. The pinion 32, 33 is operated such that the pinion 33 runs clockwise and the pile 3 with the second frame 22 and second rack portions 13, 18 is lowered (b). The first rack system 12 with the first rack portions 14, 23 are simultaneously driven in the opposite direction. Subsequently, the first coupling means 16 is coupled with the pile 3 and the second coupling means 6 is decoupled. The pinion 33 is now operated in the counter clockwise direction for lowering the pile 3 with the first frame 17 and the first rack portions 14, 23. The second rack portions 13, 18 are moved in the opposite direction, ending in the initial position (d), (a). The second coupling means 6 is coupled with the pile 3 and the first coupling means 16 is decoupled (e). The steps are repeated to lower the pile 3 as desired.

Fig. 7, depicts a side view of a coupling means 6, 16 applied with the jacking system 1. The pile 3 is provided with recesses 8 for receiving the coupling means 6, 16. These recesses 8 are provided in a row along the entire length of the pile 3. Each single recess 8 is able to withstand the payload of the structure 2 by means of the coupling means 6, 16 coupled with that single recess 8. The coupling means 6, 16 is coupled with the recess 8 such that limited rotation of the pile 3 around a central axis 24 of the recess 8 is allowed. Here , the coupling means 6, 16 is a pin 29. The pin 29 is provided with a conical section 26 for relieving contact area more quickly which is beneficial with respect to wear during coupling and decoupling of the pin 29 with the recess 8 of the pile 3.

It will also be obvious after the above description and drawings are included to illustrate some embodiments of the invention, and not to limit the scope of protection. Starting from this disclosure, many more embodiments will be evident to a skilled person which are within the scope of protection and the essence of this invention and which are obvious combinations of prior art techniques and the disclosure of this patent.

Claims

1. Jacking system (1) for jacking a structure (2) like an offshore platform, the jacking system comprising;

- a pile (3) for engaging the seabed, the pile having a longitudinal axis (7),

- a first rack system (12) with a first rack portion (14, 23) for a rack and pinion drive for driving the structure along the pile,

- a second rack system (21) with a second rack portion (13, 18) for a rack and pinion drive for driving the structure along the pile,

- coupling means (16, 6) for alternately coupling the first or second rack system with the pile for driving the structure along the pile via that rack system coupled with the pile,

- a mainframe (20) for coupling the jacking system with the structure, and, - provided with the mainframe a pinion drive system (11, 19) for a rack and pinion drive,

2. Jacking system according to claim 1, wherein the pinion drive system engages alternately one of the first and second rack system for driving that one rack system along the pile in a first direction, and the other of the first and second rack system for driving that other rack system opposite the first direction towards an initial position of that other rack system.

3. Jacking system according to claim 2, wherein one of the first and second rack

system engages at a first half of a pinion (32, 33) of the pinion drive system for driving the structure along the pile when the pinion turns in a first pinion direction, and the other of the first and second rack system engages at the other half of the pinion for driving the structure along the pile when the pinion turns opposite the first pinion direction.

4. Jacking system according to a preceding claim, wherein the first and second rack system simultaneously engage the pinion, one of the first and second rack system for driving the structure along the pile, and the other rack system for moving the second rack towards its initial position.

5. Jacking system according to a preceding claim, wherein teeth of the first rack

portion face away from the pile and teeth of the second rack portion face towards the pile.

6. Jacking system according to a preceding claim, wherein the first rack system

comprises a first frame (17) and a plurality of rack portions (14, 23) provided with the first frame.

7. Jacking system according to a preceding claim, wherein the second rack system comprises a second frame (22) and a plurality of rack portions (13, 18) provided with the second frame.

8. Jacking system according to a preceding claim, wherein the coupling means

comprise a first coupling means (16) provided with the first frame.

9. Jacking system according to a preceding claim, wherein the coupling means

comprise a second coupling means (6) provided with the second frame.

10. Jacking system according to a preceding claim 6-9, comprising a plurality of pinion drive systems (11, 19) each having a pinion (32, 33) coupled with a rack portion of the plurality of rack portions of the first rack system and coupled with a rack portion of the plurality of rack portions of the second rack system for driving the structure.

11. Jacking system according to a preceding claim, wherein the jacking system

comprises a structure coupling means (15) for temporarily coupling the structure with the pile.

12. Jacking system according to a preceding claim, wherein the structure coupling means is provided with the main frame.

13. Jacking system according to a preceding claim, comprising a housing (31) fixedly coupled with the main frame, wherein the housing comprises housing coupling means (30) for coupling the jacking system with a barge.

14. Method for a jacking system (1) for jacking a structure, like an offshore platform, along a pile (3),the method comprising the steps;

- providing a pinion drive system with a pinion for a rack and pinion drive,

- providing a first and a second rack portion for a rack and pinion drive for driving the structure along the pile,

- coupling one of the first and second rack portion with the pile,