The present invention relates to a rig assembly for use in the oil and gas exploration and production industry. In particular, but not exclusively, the present invention relates to a rig assembly with an improved rig floor, as well as to an improved rig floor, a transporter and a method of providing a rig floor of a rig assembly.
In the oil and gas exploration and production industry, access to subterranean oil and gas reserves is typically achieved by drilling a well from surface and installing and cementing a series of concentric casing strings in the drilled borehole, extending from a wellhead. The borehole is then extended to a desired depth and a liner installed in the extended section, the liner extending from the bottom or ‘shoe’ of the lowermost casing string. Following cleaning and testing of the lined borehole, production tubing is installed extending from surface down through the casing and liner to a producing formation. Well fluids flow into the production tubing from the formation and are thereby recovered to surface.
In an offshore environment, it is necessary to install a large diameter tubing, known as a riser, extending from the wellhead to a surface facility such as a drillship, floating production storage and offloading vessel (FPSO), drilling rig or the like. Tubing strings including liner, drill strings, production tubing and other intervention or tool strings are all run into the borehole through the riser. A blow-out preventer (BOP) is also provided as part of the riser string, and is either located at seabed level on the wellhead, or is located nearer to surface, if prevailing weather conditions permit. As is well known in the art, the BOP permits safe shut-down of the well in the event of an emergency situation arising.
Other types of procedures have been proposed for gaining access to well fluids, including the method proposed by one of the present co-inventors in International Patent Application No. PCT/GB2005/002885, whereby a subsea shut-off device including a ball gripping mechanism is latched to a template at surface, and drilled in casing is suspended from the device at any position using the gripping mechanism so that the device is run to the sea floor on a casing string. The casing string is drilled into place and converted into a riser, and this is all done on a single trip to speed up the operation and reduce risk. The casing string is captured and sealed within the subsea shut-off device after installing and spacing out a surface BOP.
A vast array of equipment is required in order to bring a well into production, whether following conventional techniques, or alternatives such as that proposed in PCT/GB2005/002885. Much of the equipment utilised must be brought to a location adjacent a rig floor of the surface facility, for subsequent deployment, or is deployed from a level below the rig floor. Conventionally, this has been achieved utilising handling equipment including cranes, elevators and the like. In more recent years, dedicated equipment has been developed specifically for handling apparatus to be deployed from the rig, particularly large, heavy apparatus such as BOPs, which may weigh several hundred tonnes.
The handling of equipment utilising cranes and elevators is generally undesired, and can lead to accidents, particularly on vessels which are subject to relatively large movements under applied wind, wave and tidal loading. Additionally, the handling of apparatus using such equipment is typically time-consuming and laborious. It will be appreciated that, in view of the high rental costs involved in leasing offshore equipment such as floating rigs and drillships, it is generally desired to minimise the time taken to carry out all types of procedure in the industry.
Where dedicated equipment has been provided for handling apparatus to be deployed, this equipment has conventionally been very large, which presents a particular problem in the offshore environment, where space is severely restricted. Additionally, the handling equipment is suited only for a single use or purpose; is typically slow moving; and is not capable of being used to handle other types of apparatus.
Whilst space restrictions are less pronounced in onshore facilities, it will be understood that many of the above problems are of equal concern.
It is amongst the objects of embodiments of the present invention to obviate or mitigate at least one of the foregoing disadvantages.
According to a first aspect of the present invention, there is provided a rig assembly comprising:
It will be understood that the transporter may also be for transporting a rig floor unit from the rig floor receiving area to the storage area, when it is desired to locate an alternative selected rig floor unit in the rig floor receiving area. The transporter may therefore serve for transporting rig floor units between the two areas.
It will also be understood that a rig floor of a rig assembly is generally defined as the work area in which a rig crew conducts operations.
Providing a rig assembly with a plurality of movable rig floor units, a rig floor receiving area, and a transporter for transporting a selected rig floor unit from a storage area to the rig floor receiving area, facilitates a rapid changeover at the rig floor area when different tasks or operations are to be performed, when compared with prior practice in the industry.
Each rig floor unit may be adapted for performing a different task or operation or a step in a task or operation. Thus switching of equipment necessary to carry out the desired task, operation or step may be rapidly achieved simply by switching around the rig floor units. To facilitate this, each rig floor unit may be adapted to carry different equipment suited to the particular task, operation or step.
The storage area may comprise a plurality of rig floor storage locations, each configured to receive a respective rig floor unit. Accordingly, each rig floor unit may be adapted to be located in a respective storage location in the storage area. The selected rig floor unit may be adapted to be transferred from its storage location on to the transporter, which may then transport the rig floor unit to the rig floor receiving area.
The transporter may be movable along a path extending between the storage area and the rig floor receiving area, for transporting the rig floor units between the storage area and the rig floor receiving area. The transporter may therefore be movable to a position where it can access any one of the rig floor units, such that the selected rig floor unit may be transferred on to the transporter, and such that a rig floor unit returned from the rig floor receiving area to the storage area by the transporter may be transferred off the transporter. The rig floor units may each be configured to be releasably secured, locked or located relative to or within the transporter. This may permit safe transportation of the rig floor units between the storage area and the receiving area, as well as safe operation in use of the rig floor defined by the rig floor unit. One or both of the rig floor units and the transporter may comprise a locking assembly for securing the rig floor units relative to the transporter. The transporter may be configured to be releasably secured, locked or located relative to or within the rig floor receiving area. In this fashion, the transporter, carrying the selected rig floor, may be secured within the rig floor receiving area and may thereby locate the rig floor unit in the receiving area, to define the rig floor. It will therefore be understood that the transporter may remain within the receiving area during the time when the selected rig floor unit is in the receiving area.
The transporter may be configured to be secured to a support structure provided in the rig floor receiving area. One or both of the transporter and the support structure may comprise a locking assembly for securing the transporter in the receiving area. The locking assembly may comprise at least one, and preferably a plurality of locking dogs, pins, latches or the like. The locking assembly may be hydraulically actuated, or in alternative embodiments, may be electro-mechanically or electrically actuated or a combination thereof.
In alternative embodiments, the rig floor units may each be configured to be releasably secured, locked or located relative to or within the rig floor receiving area. In this fashion, the transporter may be removed from the receiving area, if desired, following location of the rig floor unit within the rig floor receiving area.
The rig floor units may be configured to be secured to a support structure provided in the rig floor receiving area. One or both of the rig floor units and the support structure may comprise a locking assembly for securing the rig floor units in the receiving area. The locking assembly may comprise at least one, and preferably a plurality of locking dogs, pins, latches or the like. The locking assembly may be hydraulically actuated, or in alternative embodiments, may be electro-mechanically or electrically actuated or a combination thereof.
The rig assembly may comprise a transfer system for transferring the rig floor units between a storage location within the storage area and the transporter. The transfer system may comprise a translation device for translating the rig floor units between their storage locations and the transporter. The translation device may be adapted to transfer the rig floor units directly between their respective storage locations and the transporter. However, in embodiments of the invention, the transfer system may comprise a lift, elevator or the like for raising and/or lowering the rig floor units between a level of the storage locations and a level of the transporter. In use, a rig floor unit may be translated on to the lift and the lift may then raise or lower the rig floor unit into a position where the unit may be received within the transporter. The transporter may be shaped to define a space in which the rig floor units are received, to facilitate transfer of the units from the lift into the transporter. In particular, the transporter may be shaped to straddle the rig floor units, and may comprise first and second sides spaced and connected by a connecting structure, with a space defined between the sides in which the rig floor units are received. In a variation, the transporter may be height adjustable for raising and lowering to a level of the unit storage locations.
The rig assembly may be modular and may therefore be adaptable for various different types of rig, according to the space available. Accordingly, the rig assembly may be configured as required to suit a particular rig.
The rig assembly may comprise handling equipment which may be coupled to and movable with the transporter, or which may be independently movable relative to the transporter. The handling equipment may comprise a tubing handling device for picking up and/or supporting a length of tubing, and which may serve for transferring tubing on to the transporter. This may facilitate subsequent deployment of the tubing on to and/or through the rig floor defined by the selected rig floor unit. It will be understood that the tubing may be a length of casing, liner, riser, drill tubing, production tubing or any other tubing utilised in the industry. The handling device may comprise one or more electromagnetic supports for selectively picking up and/or supporting the tubing. The handling device may be adapted to incline the tubing to assist in transfer on to the rig floor, and may comprise a support for supporting an end of the tubing during transfer.
The rig floor receiving area may be adapted to be provided on or in a deck of a surface facility on which the rig assembly is provided. The rig floor receiving area may be provided around or adjacent to a moonpool in the facility. It will be understood that the moonpool is the opening in the hull or structure of the surface facility through which equipment/apparatus passes. The transporter may be for transporting the selected rig floor unit to a location above the moonpool, for the deployment of equipment into the moonpool. It will be understood that the surface facility may be a vessel such as a drillship, FPSO or FSO, or a rig such as a semi-submersible, submersible or jack-up rig. Alternatively, the rig floor receiving area may be adapted to be provided on or in a frame or support which may extend overboard.
The rig floor units may each comprise handling apparatus for handling equipment to be deployed from the rig floor. The rig floor units may be selected from a group comprising: a drill unit having a rotary drive for driving and rotating a string of tubing; a BOP unit for supporting a BOP; a coiled tubing injector unit for supporting a coiled tubing injector to be used for running coiled tubing; and a subsea shut-off device unit, for running a subsea shut-off device such as that disclosed in International Patent Application No. PCT/GB2005/002885. However, it will be understood that, in principle, any desired rig floor unit may be provided. At least one of the rig floor units may be adapted for deploying equipment from the rig assembly. For example, in embodiments of the invention, at least one of the rig floor units may comprise an aperture through which equipment may be deployed.
At least one of the rig floor units may be adapted to selectively support a tubing string and may therefore serve for suspending at least part of the load of a tubing string from the rig. The rig assembly may comprise a support for supporting a load of a tubing string during changeover of rig floor units.
If desired, the transporter may be configured to receive a plurality of selected rig floor units. Thus, for example, where the rig assembly comprises three or more rig floor units, the transporter may be configured to receive two units, for faster changeover.
The transporter may be self-driven, and may therefore comprise a drive system for moving the transporter between the storage area and the rig floor receiving area. The drive system preferably comprises a plurality of drive wheels which are adapted to run on guide rails, but may alternatively comprise wheels, tracks or the like.
According to a second aspect of the present invention, there is provided a movable rig floor unit, the rig floor unit configured for location in a rig floor receiving area of a rig assembly to thereby define a rig floor of the rig assembly, the rig floor unit further configured to be received in a transporter for transportation from a storage area to the rig floor receiving area.
According to a third aspect of the present invention, there is provided a rig floor transporter, the transporter configured to receive any one of a plurality of rig floor units, for transporting a selected one of the rig floor units from a storage area to a rig floor receiving area of a rig assembly.
Further features of the rig floor unit and the transporter of the second and third aspects of the invention, respectively, are defined above in relation to the first aspect of the invention.
According to a fourth aspect of the present invention, there is provided a rig comprising a rig assembly according to the first aspect of the present invention.
According to a fifth aspect of the present invention, there is provided a vessel comprising a rig, the rig comprising a rig assembly according to the first aspect of the present invention.
According to a sixth aspect of the present invention, there is provided a method of providing a rig floor of a rig assembly, the method comprising the steps of:
Preferably, the method further comprises the steps of:
The method may comprise securing the selected rig floor unit relative to the transporter, transporting the selected rig floor unit to the receiving area and securing the transporter within the receiving area. An operation or step in an operation may then be carried out from the rig floor. Alternatively, the selected rig floor unit may be secured within the receiving area and the transporter moved away from the receiving area.
The rig floor units may be stored in respective rig floor unit storage locations within the storage area, and may be transferred on to the transporter by a transfer system. The storage locations may be at a level above or below that of the transporter, therefore the method may comprise lowering or raising the units from their respective storage locations to the level of the transporter, for transferring the units on to the transporter.
According to a seventh aspect of the present invention, there is provided a rig assembly comprising:
Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:
Turning firstly to
The rig assembly 12 is shown in the Figures with all of the rig floor units 18, 20, 22 and 24 in respective storage locations 30, 32, 34 and 36 in the storage area 28 and thus prior to transportation of a selected one of the rig floor units from the storage area 28 to the rig floor receiving area 14.
A ram rig 38 is provided in the rig floor receiving area 14 above a moonpool 40 (
As will be described in more detail below, each of the rig floor units 18, 20, 22 and 24 are designed for carrying out different operations, or different steps in an operation, and carry various different types of equipment suited to the particular operation to be carried out. By providing rig floor units 18, 20, 22 and 24 suited for such different operations, the different operations or steps can be carried out by transporting the desired rig floor unit from the storage area 28 to the rig floor receiving area 14 to a position above the moonpool 40, to thereby define a rig floor of the rig assembly 12. Once located in the receiving area 14, the desired operation or steps are carried out and, following completion of the operation, the selected rig floor unit 18, 20, 22 or 24 may then be returned from the rig floor receiving area 14 to the storage area 28 and an alternative rig floor unit selected and transported to the rig floor receiving area 14. This alternative rig floor unit 18, 20, 22 or 24 is then located above the moonpool 40 to define a different rig floor, and permits an alternative operation, or a further step in an operation, to be carried out.
The present invention therefore offers significant advantages over conventional procedures where apparatus required for conducting different operations must be separately transported to the rig floor receiving area using handling equipment such as cranes and elevators and, in certain-circumstances, specialised handling equipment suited only for the particular apparatus to be transported. As described above, such procedures are time-consuming and laborious. In contrast, it is anticipated that changeover of a rig floor unit 18, 20, 22 or 24 in place above the moonpool 40 with an alternative rig floor unit will take around 15 minutes to complete, and the operation will offer significant advantages in terms of safety when compared to conventional handling methods using cranes, elevators and the like.
The rig assembly 12 and method of providing a rig floor of the rig assembly 12 will now be described in more detail.
The rig floor units 18, 20, 22 and 24 are shown in more detail in the views of
As shown in
As shown particularly in
The rig assembly 12 also includes a transfer system, best shown in
Further, similar translation assemblies 90, 92 and 94 are provided which include bow-stern drives 96, 98 and 100, respectively. It will therefore be understood that the rig floor units 18, 20, 22 and 24 may be moved around the storage locations 30, 32, 34 and 36 in the storage area 28, for positioning a desired rig floor unit adjacent the lift 74 and thus for transferring the selected unit onto the lift 74.
Returning now to
Returning to
With the BOP 44 suspended below the support frame 104, the BOP 44 is lowered through the moonpool 40 and from the drillship 10 towards a seabed. Successive tubing sections are coupled together to end-to-end in a fashion known in the art, to progressively extend the tubing string. This is achieved by lowering the frame 104 out of the moonpool 40; suspending the tubing string and BOP 44 from the deck 50b using slips or the like (not shown); releasing the gripping device on the frame 104 from the tubing; and stripping the frame 104 back along the tubing up the moonpool 40. The tubing string/BOP 44 is then once again supported from the frame 104 using the gripping device, the slips released and the tubing/BOP 44 lowered a further distance. Additional tubing, suspended from the ramrig 38, is then coupled to the tubing section extending up through the moonpool 40, and the tubing string/BOP 44 lowered a further distance. This process is repeated until the BOP 44 has been deployed down to the seabed and connected to a wellhead.
In accordance with the teachings of PCT/GB2006/001822, the support frame 104 forms part of a compensating system for compensating movement of the drillship 10 relative to the seabed, and can be operated in both active and passive compensation modes.
Returning now to
Returning once more to
The rig assembly 12 is operated to bring a selected rig floor unit 18, 20, 22 or 24 to the rig floor receiving area 14 as follows. Initially, each of the units 18, 20, 22 and 24 are located in their respective storage locations 30, 32, 34 or 36 and the transporter is in the position shown in
With the drill deck 20 in position, the lock-down pins 62 are actuated, engaging in the tubes 64, and the drill deck 20 is then locked and secured relative to the transporter 26. The transporter 26 is then returned along the guide rails 116, and moves to a position where the drill deck 20 is above the moonpool 40, with the transporter lock-down pins 108 aligned with the transporter lock-down tubes 110. The pins 108 are then actuated, to lock and secure the transporter 26 within the rig floor receiving area 14. This therefore secures the drill deck 20 within the receiving area 14, and the drill deck 20 now forms the rig floor.
Following completion of a drilling procedure utilising the drill deck 20, it is desired to return the drill deck 20 to the storage area 28 and to select an alternative rig floor unit from the injector deck 18, BOP deck 22 and shut-off device deck 24. To achieve this, the transporter lock-down pins 108 are disengaged, and the transporter returned to a position where the drill deck 20 is above the lift 74. The lift 74 is then raised to bear the load of the drill deck 20, and the lock-down pins 62 disengaged. The transporter 26 is then translated back along the guide rails 116, and the drill deck 20 returned to the storage location 32, utilising the lift drives 120 and the lateral drives 82. If it is now desired to transfer the injector deck 18 from its storage location 30 to the receiving area 14, the drill deck 20 is firstly transferred to a holding storage location 122 by the bow-stern drives 86 on the translation assembly 78, and the injector deck 18 is then transferred on to the lateral translation assembly 78 by the bow-stern drives 96 on the assembly 90. The injector deck 18 is then transferred on to the lift 74, and secured to the transporter 26 before being carried to the receiving area 14 and secured as described above. Following completion of a procedure utilising the injector deck 18, the injector deck 18 is returned to the storage location 30 in a similar fashion to the drill deck 20, and the BOP deck 22 or shut-off device deck 24 may then be carried to the receiving area 14 in the fashion described.
The rig assembly 12 additionally includes tubing handling equipment in the form of a casing car, which is shown in the enlarged plan and side views of
The casing car 124 includes a lifting arm 126 which is pivotally mounted to a beam 128, the beam 128 being driven and rotatable about an axis 132 relative to the frame 130. Additionally, the beam 128 can be driven along the length of a cross-frame arm 133. The lifting arm 126 carries a pair of electromagnets 134 which, when actuated, collect a casing section 136 from a store 138 on the deck 16. Lifting of the casing section 136, deployment onto the transporter 26 and thus onto the rig floor is shown in the schematic views of
To assist in deployment of the casing section 136, a tail loader 146 is provided in the transporter 26 and is shown in more detail in the plan, side and end views, respectively, of
Considering now the support frame 104 in more detail, the support frame 104 includes a leader frame 156 which is supported on a tension frame 158. The leader frame 156 is movable within the moonpool 40 and locks out towards a lower end 160 of the moonpool, whilst the tension frame 158 can be deployed into the water below the drillship 10, following the teachings of PCT/GB2006/001822. Four arms 162, best shown in
Turning now to
The gripper device 170 includes a pair of hinged gripper arms 180, each of which carries a half-cylindrical slip or tubing grip 182. The arms 180 are pivotally mounted to the hub 174 by pins 181, and are moved between disengaged and engaged positions by hydraulic pistons 184. The arms 180 are shown in
Movement of the tension frames 158, 158′ is controlled using winches and tensioner devices according to the teachings of PCT/GB2006/001822. In an active compensation mode, movement of the tension frame 158 or 158′ is controlled such that the location of equipment relative to a seabed is precisely controlled during deployment of the equipment from the drillship 10. This is particularly important, for example, during lowering of a tubing string carrying the BOP 44 where the drillship 10 is pitching, rolling and heaving under applied wind, wave and tidal loads. In a passive compensation mode, movement of the tension frame 158 or 158′ relative to the drillship 10, due to movement of the drillship 10, is damped out using the winches and tensioner devices.
The rig assembly described herein, including the rig floor units 18-24, transporter 26 and support frame 104 offers particular advantages in that the load of tubing/equipment can be transferred between the frame 104 and the drillship 10 deck, facilitating changeout of the deck units.
Various modifications may be made to the foregoing without departing from the spirit and scope of the present invention.
For example, the locking assemblies may comprise locking dogs, latches or the like. The locking assemblies may be hydraulically actuated, electro-mechanically or electrically actuated, or indeed a combination thereof.
The rig floor units may each be configured to be releasably secured, locked or located relative to or within the rig floor receiving area. In this fashion, the transporter may be removed from the receiving area, if desired, following location of the rig floor unit within the rig floor receiving area.
The translation devices may be adapted to transfer the rig floor units directly between their respective storage locations and the transporter.
The transporter may be height adjustable for raising and lowering to a level of the unit storage locations.
The tubing handling device may serve for picking up and/or supporting any desired type of tubing, which may be a length of casing, liner, riser, drill tubing, production tubing or any other tubing utilised in the industry. In place of electromagnets, any other suitable support may be provided.
Where the rig assembly is for a surface facility, the surface facility may be an alternative vessel such as an FPSO or FSO, or a rig such as a semi-submersible, submersible or jack-up rig.
The rig floor receiving area may be provided on or in a frame or support which may extend overboard.
Any desired rig floor unit may be provided, including suitable support/deployment apparatus or equipment.
The transporter may be configured to receive a plurality of selected rig floor units. Thus, for example, where the rig assembly comprises three or more rig floor units, the transporter may be configured to receive two units, for faster changeover.
Instead of being self-driven, a separate drive system may be provided for moving the transporter/handling equipment.
Number | Date | Country | Kind |
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0602946.6 | Feb 2006 | GB | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/GB2007/000509 | 2/14/2007 | WO | 00 | 12/2/2008 |