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(11) | EP 3 450 676 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | CRANE, MARINE VESSEL OR RIG, AND METHOD |
| (57) There is described a crane for running equipment into or out of a well slot in a
deck of a marine vessel or rig, a related marine rig or vessel that includes the crane,
and related methods. The crane may have a boom configured for conveying a travel unit
along the boom on a track, the travel unit may include a top drive to which a drill
string may be attached.
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[0001] The present invention relates in particular to the handling of equipment on an offshore vessel or rig, in particular for performing operations relating to wells. Particular embodiments relate to a crane for running equipment into or out of a well slot in a deck of a marine vessel or rig, a rig or vessel provided with the crane, and a method of running equipment into or out of the well slot. The equipment in such embodiments may typically be a string of tubing such as drill tubing, casing, and/or lining.
[0002] In the exploration and production of oil and gas offshore, a marine vessel or rig is conventionally employed at the sea surface for constructing, servicing, and/or accessing a well beneath the seabed. The marine vessel or platform may be used in a number of different operations. A riser pipe extending from a wellhead at the seabed may for instance extend between the wellhead and the vessel, and fluid being circulated in or produced from the wellbore of the well may travel through the riser pipes and onto the vessel and then be processed. Equipment may be delivered from the vessel into the well bore, e.g. inside a riser pipe. The equipment can often include elongate tubing strings including end-to-end connected sections of drill pipe or casing. Typical vessels include floating production storage and offloading (FPSO) vessels, or drilling vessels, such as drilling ships or platforms.
[0003] On a drilling vessel, equipment may be provided for drilling a wellbore below the seabed. This can require equipment to be put in place on the seabed or handled on the vessel depending on the stage reached within the drilling process, and heavy-lift cranes are often required to allow such equipment to be deployed or installed. Dedicated crane barges fitted with heavy-lift cranes may then typically be commissioned. Heavy-lift cranes may also be provided on the drilling vessel, such as for instance BOP handling cranes. These heavy-lift cranes have high load capacities, for instance in the region of 500 metric tonnes or more. The use of a crane barge can be expensive and time consuming, and can result in increased costs and time associated with commissioning the drilling vessel and constructing the well.
[0004] On a drilling ship, drilling is conventionally performed with the assistance of a derrick which is a fixed structure towering high above deck on the ship. The derrick provides height for connecting together long sections of tubing and lowering or hoisting the connected sections through a well slot in the deck of the vessel in order for instance to insert the tubing sections into or extract the tubing sections from a well. Hoisting equipment, e.g. a top drive connected to a winch on cables passed over a crown block near the top of the derrick, may then be utilised and connected to a tubing string in order to deploy the tubing string through the well slot and into the wellbore. The hoisting equipment is typically arranged inside the derrick. Derricks of this type have been in wide use to provide a stable and capable structure suited for the handling of drill strings in drilling operations where the loads exerted on the derrick can be in the magnitude of a thousand tonnes. An example of a prior art drilling ship fitted with a derrick of this kind is illustrated in Figure 1.
[0005] The present inventors recognise that the structure of a derrick can be very substantial in size, costly to construct, and can occupy large amounts of deck space. The inventors have also identified a need for reducing the time associated with drilling and commissioning drill ships and/or other vessels in connection with drilling operations. In particular, the inventors have recognised limitations in traditional drill ship design in that scaling up the derrick beyond a certain point in size can increase costs dramatically and can be cost prohibitive and/or not realistically feasible when measured against any benefits of the increase in size. As a result, derricks on drilling ships today may only be able to accommodate stands of two or perhaps three end-to-end connected standard drill pipe sections within the derrick when performing drilling.
[0006] An aim of the invention is to obviate or at least mitigate drawbacks and difficulties as may be experienced in prior art techniques such as described above.
[0007] According to a first aspect of the invention there is provided a crane for running equipment into or out of at least one well slot in a deck of a marine vessel or rig, the crane comprising a boom configured for conveying a travel unit along the boom on a track.
[0008] The track may typically be provided on the boom. The track may comprise at least one rail, channel, or slot disposed on the boom.
[0009] The crane may include the travel unit, and the travel unit may be positioned in at least one location along the boom and be arranged to travel upward or downward along the boom on the track.
[0010] The travel unit may be arranged to suspend the equipment from the boom. The travel unit may include a fitting for attaching the equipment to the travel unit.
[0011] By way of the travel unit, the fitting may be positioned in an exit/entry aligned with, and preferably substantially vertically above, the well slot on an outside of the boom.
[0012] The equipment may comprise at least one section of a wellbore string. The travel unit may include a top drive for rotating the wellbore string or said section thereof. The wellbore string may comprise end-to-end connected tubular sections. The string may comprise sections of drill pipe, casing, or liner tubing.
[0013] By way of the track, the travel unit may be arranged to be guided between first and second locations along the boom. The track may preferably be provided on an exterior of the boom.
[0014] The track may comprise at least one guider for guiding the travel unit along the boom. The guider may comprise at least one slot, channel, rail, engager, or guide wheel. The guider may be mounted on an exterior of the boom.
[0015] The travel unit may typically be configured to be coupled to the boom such that rotation or lateral movement therebetween may be restricted or substantially prevented or blocked.
[0016] The travel unit may be coupled to the boom via a first member and a complementary second member in an interference relationship whereby either or both of the first and second members may cooperate to restrict or block movement of the travel unit laterally with respect to the boom.
[0018] The travel unit may typically comprise a dolly arranged to run along at least one slot, channel, or rail extending along the boom. The dolly may comprise an engager or guide wheel for engaging with the slot, channel, or rail.
[0019] The boom may typically comprise a lattice frame. The boom and/or lattice frame may extend between a base at a lower end of the boom and a neck at an upper end of the boom.
[0020] The crane may further comprise at least one cable for supporting the travel unit, or the travel unit and the equipment when connected thereto. The crane may further comprise draw works, which may include at least one winch, for controlling the cable for either or both of moving and supporting the travel unit via the cable, optionally with or without equipment attached thereto. Thus, the travel unit may be lowered or raised along the track by operation of the cable, once the boom is in position.
[0021] The crane typically has a rotary coupling through which the boom can be rotatably connected to a base. This may be for allowing the boom and/or crane to rotate or "swivel" about a vertical axis of rotation with respect to the base.
[0022] The boom may typically be rotatable relative to a base. The boom typically extends from the base.
[0023] The elongate boom may be arranged to rotate about either or both of a horizontal and a vertical axis of rotation relative to the vessel or rig and/or the base.
[0024] The boom may be arranged to pivot, swivel, or rotate e.g. for configuring the boom in a configuration so that the boom is upright and operable for moving the equipment into or out of the well slot and/or for configuring the boom in another configuration wherein the boom is rotated and may be operable to perform lifting and handling of other equipment, e.g. with an end of the boom reaching over a side of the vessel or rig.
[0025] According to a second aspect of the invention there is provided a rig or vessel provided with the crane according to the first aspect of the invention, the rig or vessel having at least one well slot in a deck thereof, the crane being arranged with the boom upright to run the equipment into or out of the well slot.
The boom may be selectively positioned over different well slots. The crane may therefore be used for running equipment into or out of a first well slot in one configuration, and for running in equipment into or out of a second well slot in another configuration. The boom may be manipulated, e.g. by rotation about horizontal and/or vertical axes of rotation, in order to move the boom from one configuration to another. In another configuration, the boom may be positioned for performing general lifting, away from the well slots, e.g. over the side of the vessel or rig.
[0027] According to a third aspect of the invention, there is provided a method of running equipment into or out of at least one well slot on a marine vessel or rig, the method comprising the steps of:
providing the crane according to the first aspect of the invention on the marine vessel or rig;
attaching the equipment to the travel unit; and
operating the crane to run the equipment into or out of the well slot.
[0028] The method may further comprise:
lowering the travel unit and attached equipment along the boom to insert the equipment into the well slot.
[0029] The method may further comprise:
elevating the travel unit and attached equipment along the boom to remove the equipment out of the well slot.
[0030] The method may further comprise any of:
arranging the boom in upright configuration;
coupling a travel unit to the boom; and
operating the travel unit to travel along the boom, e.g. on an outside of a side of the boom, between first and second locations along the boom.
[0031] According to a fourth aspect of the invention, there is provided a method of operating the crane of the first aspect of the invention, the crane being provided on a rig or vessel, the crane having a first configuration and at least one further configuration, wherein the method comprises using the crane in the first configuration to run the equipment into or out of the well slot on the rig or the vessel, the equipment being attached to the travel unit, the travel unit travelling on the track along the boom.
[0032] The method may further comprise:
using the crane in a further configuration to suspend a load from the boom with an end of the boom extending over a side of the vessel.
[0033] In the first configuration, the method may be performed to run equipment into or out of a first well slot, and may further comprise using the crane in a further configuration to run equipment into or out of a further well slot on the vessel or rig.
[0034] The method may further comprise rotating the boom about either or both of a vertical axis of rotation and a horizontal axis of rotation, to move the crane from the first configuration to the further configuration.
[0035] The method may further comprise:
locating the travel unit in a parking location;
when the travel unit is in the parking location, rotating the boom about either or both a vertical or a horizontal axis of rotation to use the crane in the second configuration.
[0036] The method may further comprise moving the travel unit along the boom into the parking location, the travel unit travelling on the track. The equipment may be attached to the travel unit when parked.
[0037] The method may further comprise, when in the further configuration, using the boom to handle other equipment.
[0038] Any of the above aspects of the invention may include further features as described in relation to any other aspect, wherever described herein. Features described in one embodiment may be combined in other embodiments. For example, a selected feature from a first embodiment that is compatible with the arrangement in a second embodiment may be employed, e.g. as an additional, alternative or optional feature, e.g. inserted or exchanged for a similar or like feature, in the second embodiment to perform (in the second embodiment) in the same or corresponding manner as it does in the first embodiment.
[0039] Various advantages of the invention and its features are described and will be apparent from the specification throughout.
[0040] There will now be described, by way of example only, embodiments of the invention with reference to the accompanying drawings, in which:
- Figure 1
- is a representation of a prior art drilling ship with a derrick;
- Figure 2
- is an end on part-sectional view of a drilling ship in accordance with an embodiment of the invention, configured for a drilling operation with a drill string connected to a top drive suspended from a crane;
- Figure 3
- is an overhead representation of the top drive on the crane of the embodiment of Figure 2 in close up;
- Figure 4
- is an end on part-sectional view of the drilling ship of Figure 2, in use in a heavy lift operation according to an embodiment of the invention;
- Figure 5
- is an overhead representation of the drilling ship of Figure 2 in accordance with an embodiment of the invention;
- Figure 6
- is an overhead plan view representation of a jack-up rig with a crane on a cantilever for performing a drilling operation, according to an embodiment of the invention; and
- Figure 7
- is a side view of the crane on the cantilever of Figure 6 during the drilling operation.
[0041] With reference to Figure 2, there is generally exemplified a drilling ship 1 which has a well slot 2 through which equipment is passed to insert or retrieve the equipment from a wellbore in the subsurface beneath the seabed. In order to run the equipment into or pull the equipment out of the well slot 2, the drilling ship 1 is fitted with a crane 3. By means of the crane 3, equipment in the form of a drill string 20 can be suspended and can be lowered into or lifted out of the well bore (below the ship) through the well slot 2.
[0042] The crane 3 has an elongate boom 4 which at a lower end is connected to a base. The base is in the form of a pedestal 5. The boom 4 consists of an elongate lattice framework and is fixed-length.
[0043] In Figure 2, the boom 4 is upright, so that it towers substantially vertically upward from the pedestal 5 and allows for suspending the drill string 20, or drill string sections or tools, from a supporting cable 12 which passes over sheaves 31 disposed on a neck arranged high up at a top end 4x of the boom 4. The neck allows the cable 12 at the point of leaving the sheaves 31 to be positioned vertically above the well slot 2.
[0044] The pedestal 5 is mounted in fixed position on a deck of the ship 1 and comprises a rotary coupling, by means of which the boom 4 can be rotated (with respect to the pedestal and the deck) about a vertical axis of rotation in order to orient the boom 4 in different lateral rotational positions. The boom 4 is also rotatably and pivotally connected to the base 5 so as to be able to be tilted about a horizontal axis of rotation when performing other operations, into different angles of inclination for raising or lowering a far end of the boom 4. The crane 3 includes draw works including a drum 11 from which the cable 12 is spooled out. The cable 12 is secured to the drum 11 at one end while the opposite "free" end is passed over and suspended from the sheaves 31. On the end of the cable at the free end, the cable 12 has a connector 13 for connecting a load to the cable.
[0045] The crane 3 in this example is a heavy-lift crane with a lift capacity in the region of 500 to 1500 metric tonnes. The length of the boom is between 70 and 100 m but in general can be provided in other lengths.
[0046] In order to facilitate running the drill string 20 into or out of the well slot 2, the crane 3 is provided with a travel unit 7. The travel unit 7 is arranged to travel up or down along the boom 4 on a track which in this example is provided by way of guide rails 10 which extend along the boom 4.
[0047] The guide rails 3 are mounted on the outside of the boom 4, and extend from the top end 4x to a bottom end 4y of the boom 4. The travel unit 7 is coupled to the guide rails 10, such that as it travels, the travel unit 7 is guided from location to location along the boom.
[0048] In addition, the travel unit 7 is attached to the suspending end of the cable 12 via the connector 13. In this way, the cable 12 is utilised to support and suspend the travel unit 7 from the cable 12. For instance, by paying out the cable from the drum 11, the travel unit 7 [e.g. in use together with equipment attached to the travel unit] can be controllably lowered along the boom under gravity. Conversely, by spooling the cable back onto the drum 11 a lifting force can be applied by the cable and the travel unit 7 [e.g. in use together with equipment attached to the travel unit] can be pulled and lifted upward along the boom 4.
[0049] In this particular example, the travel unit 7 has a rotary fitting 17 arranged to fit onto the upper end of the drill string 20 for attaching the drill string 20 to the travel unit 7. The travel unit 7 also includes a top drive 8 which can operate to rotate the drill string 20 about its longitudinal axis for using the string to perform drilling in the wellbore. The rotary fitting 17 is thus adapted to permit the top drive 8 to apply rotation to the connected drill string 17 when it operates.
[0050] Due to being attached to the drill string 20 via the fitting 17, while drilling takes place and the drill string progresses further through the well slot 2, the travel unit 7 travels downward along the boom 4 together with the drill string 20. When pulling the string out of the wellbore, the travel unit 7 travels upward along the boom 4 together with the connected string 20.
[0051] The travel unit 7 comprises a dolly 9 for coupling the travel unit 7 to the guide rails 10. The dolly 9 follows the guide rails 10 along the boom 4. In this way, the top drive 8 is carried on the travel unit 7 downward along the boom 4 of the crane 3, guided by the guide rails 10, while the drill string 20 advances into the subsurface or in order to reconnect to the drill string 20 after a section of the drill string 20 has been removed. Conversely, the top drive 8 is carried on the travel unit 7 upward along the boom 4 to an elevated position in order to insert a new section in the drill string, or while hoisting the drill string upward to allow a section of the drill string to be removed. While travel is permitted up or down the boom, displacement of the travel unit 7 laterally is restricted. The travel unit 7 is kept in the desired lateral position and is retained with respect to the boom by way of the coupling provided by the dolly 9 between the travel unit 7 and the guide rails 10. It will be appreciated nonetheless that rotation of the drill string 20 can still take place by operating the top drive 8 and rotary fitting 17 during translation of the travel unit 7 along the boom 4.
[0052] Figure 2 shows the crane 3 positioned so that the guide rails 10 are vertical providing a vertical path for the top drive 8 along the boom 4 during use. The drill string 20 is aligned and extends longitudinally vertically through the well slot 2. As can be seen, the travel unit 7 with the fitting 17 operates in an exit/entry corridor aligned with the well slot 2 for extracting and inserting sections of the drill string. The fitting 17 is arranged vertically above the well slot 2. Thus, sections of the drill string 20 can enter or be retrieved from the well slot in vertical orientation held at the top end by the fitting 17 [and travel unit 7 and/or cable 12]. Sections can then be connected or disconnected accordingly. Thus, by arrangement of the crane 3 in this manner, essential functions in allowing sections to be removed and added to a drill string can be obtained, but without requiring the extensive derrick structure traditionally applied. Moreover, the boom can readily be made higher so at more reasonable cost, and may accommodate for instance stand lengths consisting of 3 or more, e.g. 4, 5, 6, 7 or more joints of standard 10 m drill pipe lengths. It will be appreciated that each such stand could be arranged with long axis vertically above the well slot 2, be held on the travel unit (using the fitting 17), and be connected or disconnected from the string 20 as a unit. This can make drilling operations more efficient, as the number of connections needed to be made up or broken during the run in or pull out of the string 20 may be reduced. By way of implementation with a crane, other lifting or handling operations for instance at either end of a drilling trip may be conveniently performed with the crane, as will be described further below, which can facilitate time efficiency and reduced costs in completing drilling and other drilling ship operations offshore.
[0053] With further reference to Figure 3, the travel unit 7 and the manner in which it is coupled to the outside of the boom 4 of the crane 3 can be seen in further detail. First it can be noted that the travel unit 7 with the top drive 8 is arranged over the well centre 2, the projection of the well centre position being indicated in the figure.
[0054] A track is provided by two guide rails 10 extending in parallel along the boom 4 each having a slot or channel 21 in which a roller wheel 33 of the dolly 9 is received. The roller wheel 33 of the dolly 9 interlocks with the guide rail 10, providing a coupling between the travel unit 7 and the guide rail 10. With the wheel 33 in the track 21, the travel unit 7 travels up or down the boom 4. The wheel 33 is retained in the channel 21 by a side surface of the channel 21. This keeps the dolly 9 engaged with the rail 10 while allowing the travel unit 2 to travel along the track. Thus, the travel unit 7 and connected drill string 20 can be advantageously kept in correct lateral orientation with respect to the boom 4. The dolly 9 in this case has struts 24 on which the roller wheels 33 are mounted. The struts 24 extend to maintain a certain lateral distance between the fitting 17 and the outside of boom 4, such that the fitting 17 and top drive 8 of the travel unit 7 is positioned in the exit/entry corridor vertically above the well slot. The lateral distance between the fitting 17 and the outside of the boom 4 is maintained to be substantially constant between locations as the travel unit 7 travels along the boom 4 in the exit/entry corridor.
[0055] It can also be noted that the travel unit 7 can include circulating equipment for circulating drilling fluid into and out of the wellbore during drilling and/or during disconnection of the top drive 8 for insertion or removal of sections of the drill string. Such circulating equipment may be mounted to the travel unit 7 in the region 41 in Figure 3. It can also be seen in Figure 3 that the guide rails 10 are mounted and affixed to the outside of the crane boom 4 via rigid support members 22a-d and bracing 23.
[0056] The crane 3 is positioned eccentrically to one side of the well centre 2, with the exit/entry corridor on the outside of the boom 4. On an opposite side of the well slot 2 the drilling ship 1 is equipped with a setback tower 14 in which stands 16 of end-to-end connected drill string sections 15a-15f are stored ready to be accessed and incorporated into the drill string 20. Although typically the setback tower is positioned opposite to the top-drive guide tracks (i.e. the crane boom) as explained above, any other position can also be utilized.
[0057] In use, when extending the wellbore by drilling, a penetrating end of the drill string 20 is advanced into the well bore whilst being connected to the top drive 8 and the crane 3. The drill string 20 extends through the well slot 2 in the deck of the drilling ship. The travel unit 7 travels along the boom 4 following the guide rails 10, downward until eventually it arrives close to the aperture of the well slot 2 in the drill deck. In order to advance further into the subsurface, the drill string 20 is temporarily secured in position using for example slips arranged near the well slot, the top drive 8 is disconnected from the drill string 20, and is then moved back up to the top of the boom 4 of the crane 3, along the guide rails 10, e.g. by operating the draw works to spool in the cable 12 onto the drum 11 (e.g. a winch drum) and pull the travel unit 7 upward along the boom 4. When near the top of the boom 4, a new stand 16 of drill pipe from the setback tower 14 is presented, in the exit/entry corridor, to the top drive 8 by a racking machine. The new stand 16 is attached at its top end to the fitting 17 on the travel unit so as to connect it to the top drive 8, and is attached at its bottom end to the top of the drill string 20 which is held and supported in the slips. Once attached, the slips are disengaged, pumps are operated to pump drilling fluid through the drill string, and the top drive 8 is restarted once again to rotate the drill string 20. Drilling then progresses and results in extending the wellbore into the subsurface. The top drive 8 travels correspondingly downward along the boom 4, guided by the guide rails 10, with the cable 12 supporting the connected top drive 8 and drill string 20.
[0058] In order to pull out the string from the wellbore, the above process is performed in reverse. With the drill string 20 attached to the travel unit 7, the travel unit 7 runs upward along the boom until near the top of the boom at which point movement it is halted. This can be carried out by operating the draw works to pull and hoist the travel unit 7 with drill string attached upward (spooling in on the drum 11). The drill string 20 extends through the well slot 2 in the drill deck, and slips are activated to hold onto the drill string near the foot of the boom. A stand of drill pipe is disconnected by breaking the connection in the exit /entry corridor above and adjacent to the slips. The racking machine is used to hold onto the stand to be removed, and the top of the stand of drill pipe is detached from the fitting 17 and the top drive 8. The racking machine is then operated to place the stand in the setback tower 14. The travel unit 7 travels back downward along the boom [e.g. by controlled lowering by the draw works] and is connected to the top of the drill string being held by the slips. The slips are then disengaged, and the travel unit with the drill string attached is once again hosted upward along the boom for disconnection and removal of the next section of drill pipe.
[0059] When not engaged in operations over the well centre 2, the crane 3 can conveniently be employed for other purposes such as for general handling such as lifting, lowering, and/or suspending an item.
[0060] Figure 4 illustrates the use of the crane 3 in connection with a heavy lifting operation where the boom 4 is rotated with respect to the pedestal 5 about a vertical axis and tilted (about a horizontal axis) to bring the boom 4 over the side of the ship 1 to lift and manoeuvre a module 50 for installation of the module 50 on a nearby rig 60. The module 50 exemplified here is a plug and abandonment module including a BOP for installation over a well slot 52 on the rig 60.
[0061] Figure 5 illustrates the ship 1 where the boom 4 of the crane 3 is being rotated so as to extend over the side of the hull of the ship for use in the configuration of Figure 4.
[0062] In order to change the mode of configuration of the crane between a first, well centre configuration as illustrated in Figures 2 and 3 and a second, general lifting configuration as illustrated by Figures 4 and 5, the top unit 7 for the drill string 20 is run to the base of the crane and is parked. In Figure 4, the drill string 20 remains connected to the travel unit 7 while it is parked, and the crane 3 is used to suspend the module 50 with an inclined boom 4. For this purpose, it can be seen in Figure 4 that the guide rails 10 each have first and second sections 10a, 10b with the first section 10a provided on the boom 4 and the second section 10b provided on an outside of the pedestal 5. In the configuration of Figures 2 and 3, the two guide rail sections 10a, 10b are fully aligned to provide a continuous track along the boom and across any join between the two sections 10a, 10b. In the configuration of Figures 4 and 5, the boom 4 is pivoted to the other side of the pedestal 5 which brings the first guide rail section 10a out of alignment with the other as the boom 4 is utilised for the lifting operation, while the travel unit is parked on the second guide rail section 10b. The travel unit 7 may be secured to the pedestal 5 on the second section 10b, for instance by clamping the travel unit 7 onto the second guide rail section 10b.
[0063] When the travel unit 7 arrives and is positioned at the pedestal 5 on the second guide rail section 10b, it is disconnected from the end of the cable 12, e.g. by disconnecting from the connector 13. Another connector, e.g. a hook or the like, configured for the general lifting application, may then be provided on the end of cable 12 in place of the connector 13. The crane 3 can then be operated to rotate the boom 4 with respect to the pedestal 5 and manoeuvre the module 50 as in Figure 4.
[0064] Referring to Figures 6 and 7, an example of use of the crane 3 on a jack-up rig 101 is described. The jack-up rig has legs 103a-c which support a hull 102 of the jack-up rig 101 on the seabed. This provides a stable platform for supporting the crane 3 upon the hull 102. The jack-up rig 101 has a cantilever 104 which reaches over the side of the rig 101 and is movable horizontally in x and y directions with respect to the hull 102, to allow alignment with a particular well slot in a well pattern. The crane 3 is mounted on the cantilever 104 and in this example supports the drill string 20 via the top unit 7 on the cable 12 in a corresponding manner to that described in relation to Figures 2 and 3. In this case however, the drill string 20 passes through a slot 162 in the cantilever 104. In Figure 7, the cantilever 104 of the jack-up rig 101 is applied to the nearby platform 60 and is positioned over the well slot 62 of the platform 60 such that the suspended drill string 20 on the crane 3 penetrates through the well slot 62. It will be appreciated that the crane 3 when in use on the jack-up rig 101 could be employed in other configurations with the boom 4 tilted and rotated into suitable orientations for general lifting, e.g. when not engaged for an operation via the well slot 162 in the cantilever.
[0065] The solutions described in embodiments of the invention herein can be advantageous in that lifting barges may not be required since heavy lifts can be performed from the drilling ship. In addition, through the use of the crane, considerably longer stands, e.g. 2 to 3 times longer than normal, can be handled without the need of a derrick as may be used in the prior art. Furthermore, some heavy lift equipment on the vessel (such as BOP or Xmas tree handling cranes) might be omitted. In addition, a more efficient use of deck space may also result. Access to equipment such as winches and the deck space in and around the well centre can be relatively open for facilitating ease of access, service and maintenance.
[0066] Various modifications and improvements may be made without departing from the scope of the invention herein described. For example, although the above embodiments have been described with reference to using cable 12 to suspend and lift the travel unit, with or without the drill string 20 attached thereto where applicable, it should be appreciated that the travel unit 7 can take other forms in other variants. For instance, the travel unit 7 may have a motorized coupling with the outside of the boom 4 to operate to move up and down on the boom. For instance the boom may be fitted with a track comprising a tooth rack extending along the boom, and the travel unit 7 may have motor which drives a pinion up or down along the tooth rack, so as to allow the travel unit 7 to be moved up or down the boom and lower or lift the attached drill string 20 as appropriate.
[0067] The travel unit may also in other variants be utilised with other types of equipment such as one or more tubulars including any of coiled tubing, lining, or casing. The equipment may also be in the form of elongate tool strings, or tools arranged to be incorporated with such tubulars or tool string. Such equipment may be conveniently deployed or retrieved by passage through the well slot to access and/or perform operations in a wellbore or well head on the seabed.
1. A crane for running equipment into or out of at least one well slot in a deck of a
marine vessel or rig, the crane comprising a boom configured for conveying a travel
unit along the boom on a track.
2. A crane as claimed in claim 1, wherein the track is provided on the boom and comprises
at least one rail, channel, or slot.
3. A crane as claimed in claim 1 or 2, including the travel unit, the travel unit being
positioned in at least one location along the boom and arranged to travel upward or
downward along the boom on the track.
4. A crane as claimed in any preceding claim, the travel unit arranged to suspend the
equipment from the boom.
5. A crane as claimed in any preceding claim, wherein the travel unit includes a fitting
for attaching the equipment to the travel unit.
6. A crane as claimed in any preceding claim, wherein the equipment comprises at least
one section of a wellbore string.
7. A crane as claimed in any preceding claim wherein the travel unit includes a top drive
for rotating the well bore string or said section thereof.
8. A crane as claimed in any preceding claim, further comprising at least one cable for
supporting the travel unit, or the travel unit and the equipment when connected thereto.
9. A crane as claimed in claim 8, further comprising at least one winch for controlling
the cable for either or both of moving and supporting the travel unit via the cable,
optionally with or without the equipment attached thereto.
10. A crane as claimed in any preceding claim, wherein by way of the track, the travel
unit is arranged to be guided between first and second locations along the boom.
11. A crane as claimed in any preceding claim wherein the track is provided on an exterior
of the boom.
12. A crane as claimed in any preceding claim, wherein the travel unit is configured to
be coupled to the boom such that lateral displacement therebetween is restricted or
substantially prevented or blocked.
13. A crane as claimed any preceding claim 12, wherein the travel unit is coupled to the
boom via a first member and a complementary second member in an interference relationship
whereby either or both of the first and second members cooperate to restrict or block
movement of the travel unit laterally with respect to the boom.
14. A crane as claimed in any preceding claim, wherein the boom extends from a base and
is rotatable relative to the base, for configuring the boom so that the boom is upright
and operable for moving the equipment into or out of the well slot.
15. A crane as claimed in any claim 20, wherein the elongate boom is rotatable about either
or both of a horizontal axis of rotation and a vertical axis of rotation.
16. A rig or vessel or drilling ship provided with the crane as claimed in any preceding
claim, the rig or vessel having at least one well slot in a deck thereof, the crane
being arranged with the boom upright to run the equipment into or out of the well
slot.
17. A method of running equipment into or out of at least one well slot on a marine vessel
or rig, the method comprising the steps of:
providing the crane as claimed in any of claims 1 to 16 on the marine vessel or rig;
attaching the equipment to the travel unit; and
operating the crane to run the equipment into or out of the well slot.
18. A method as claimed in claim 17, which further comprises:
lowering the travel unit and attached equipment along the boom to insert the equipment into the well slot, the travel unit travelling on the track.
19. A method as claimed in claim 17 or 18, which further comprises:
elevating the travel unit and attached equipment along the boom to remove the equipment out of the well slot, the travel unit travelling on the track.
20. A method of operating a crane as claimed in any of claims 1 to 16, the crane being
provided on a rig or vessel, the crane having a first configuration and at least one
further configuration, wherein the method comprises using the crane in the first configuration
to run the equipment into or out of the well slot on the rig or the vessel, the equipment
being attached to the travel unit, the travel unit travelling on the track along the
boom.
21. A method as claimed in claim 20, which further comprises:
using the crane in a further configuration to suspend a load from the boom with an end of the boom extending over a side of the vessel.
22. A method as claimed in claim 20 or 21, which in the first configuration is performed
to run equipment into or out of a first well slot, and which further comprises using
the crane in a further configuration to run equipment into or out of a further well
slot on the vessel or rig.
23. A method as claimed in any of claims 20 to 22, which further comprises rotating the
boom about a vertical axis of rotation and/or a horizontal axis of rotation to move
the crane from the first configuration to the further configuration.
24. A method as claimed in any of claims 21 to 23, which further comprises:
locating the travel unit in a parking location;
when the travel unit is in the parking location, rotating the boom about either or both a vertical or a horizontal axis of rotation to use the crane in the further configuration.
25. A method as claimed in claim 24, which further comprises moving the travel unit along
the boom into the parking location, the travel unit travelling on the track.