GB2599935A

GB2599935A - Deluge system

Info

Publication number: GB2599935A
Application number: GB2016371.3A
Authority: GB
Inventors: Berry Scott; Bell Richard
Original assignee: SCANTECH OFFSHORE Ltd
Current assignee: SCANTECH OFFSHORE Ltd
Priority date: 2020-10-15
Filing date: 2020-10-15
Publication date: 2022-04-20
Also published as: GB202016371D0; WO2022079422A1

Abstract

A deluge system 12 for mounting over a walkway on a boom arm of an oil or gas drilling or extraction rig, the walkway having first and second sides, wherein the deluge system 12 comprises a pipework arch, a stanchion 26 extending therefrom to a deluge nozzle 28, and mounting brackets 24 to mount legs of the arch to handrails 16 or pipework 42 situated to the sides of the walkway. The pipework arch comprises two of the legs 52, 54, a top piece 62 with two opposing ends, and two union fittings (68, figure 6), one at each of the two opposing ends for connecting the two legs 52, 54, respectively, to the two opposing ends of the top piece 62, one leg for each end. The deluge system 12 further comprises an actuator 58 for powered rotation of the top piece 62 relative to the legs 52, 54, when the union fittings (68) are not tightened, for rotation of the stanchion 26 between stowed and deployed configurations. A control unit can be provided for the actuator 58, the control unit being remote from the boom arm.

Description

Deluge System The present invention relates to a deluge system for creating a water barrier between an oil well flare and personnel or equipment on a boom or walkway on an oil rig.

It is common practice to use a flare -burning of oil or gas -on an oil rig. To distance that flare from personnel and the main structure of the oil rig, that flare is usually provided at the end of a boom arm, and a walkway is provided on that boom arm to allow personnel to service the flare nozzle and any pipework connecting the flare nozzle, along the boom arm, to the oil (or gas) well. On many oil rigs, the boom arm can be swung between a deployed and retracted state. This allows the boom arm to be selectively deployed as and when required. However, some boom arms are fixed.

A flare when operating produces a significant amount of heat, which can severely injure personnel if they are not protected therefrom. On the walkway of the boom arm this is a significant issue. To protect the personnel, a deluge system is commonly provided on the boom arm, which deluge system generates a screen or wall of water between the flare and the personnel, or between the flare and the main structure of the rig.

Many forms of deluge system have been provided in the art, including fixed arch deluge systems with multiple nozzles, which may span over the walkway. One issue with these is that the nozzle is necessarily at a low level as it needs to be serviced, which makes the wall of water often less tall than might otherwise be desirable. Other designs use a stand pipe or stanchion with a nozzle on the free end of the stand pipe or stanchion. These typically extend vertically to a higher height, thus creating a higher wall or water, but they commonly obstruct the walkway, or are positioned on the outside of the walkway, thus making servicing of them more difficult or dangerous as the personnel would need to hang over the side of the walkway.

Multi-armed stanchion arrangements are also known where each arm has a nozzle.

Usually two arms extend horizontally to either side of a vertical stanchion. The wall of water can thus be both wide and tall, offering a broader wall of protection for the boom arm or main structure of the rig. However, again these may obstruct the walkway, or they are positioned on the outside of the walkway, thus making servicing of them more difficult or dangerous as the personnel would need to hang over the side of the walkway.

To better assist servicing of the nozzles and pipework, in some stanchion systems, the stanchions are provided to be swung between stowed and deployed states. This is also so that when the boom arm is in its retracted state the deluge system can likewise be stowed. Often the hinge point is located at or near the ground or at or around waist height as this facilitate the operation of the pivot mechanism by the operator -he can reach the stanchion to swing it upwards or outwards. However, again this tends to create an obstruction of the walkway, or they are positioned on the outside of the walkway, thus making servicing of them more difficult or dangerous as the personnel would need to hang over the side of the walkway.

Various problems therefore occur with prior art deluge systems, including inconvenience with servicing, blockage of the walkway, and difficulties with deployment or retraction of the deluge system to or from a deployed state. Some of these problems occur due to access restrictions, or safety or access issues arising from the location of the installation, and these can be made worse by the bulky equipment commonly worn by personnel when working on the boom arm, or the other necessary equipment or pipes along that walkway or boom arm. For the most part the presence of inconvenience has been accepted. However, the present inventors realise that safe and minimally obstructed access is important along the walkway to allow safe servicing of the deluge system, the flare or other equipment and pipes along the boom arm, especially as these pieces of equipment are commonly used out at sea, the salt water and stormy environment making the need for servicing a regular occurrence, especially to the nozzles and the water feed pipes and pumps.

The present invention therefore seeks to provide a new arrangement for a deluge system which alleviates one or more of these issues.

Where the present invention refers to an oil rig, each of oil and gas drilling or extraction rigs are intended. Such rigs include floating rigs, such as a drill or extraction ships. It can also be a fixed rig, such as a fixed production platform. It may be at sea or on land.

According to the present invention there is provided a deluge system for mounting over a walkway on a boom arm of an oil or gas drilling or extraction rig, the walkway having first and second sides, wherein the deluge system comprises a pipework arch, a stanchion extending therefrom to a deluge nozzle, and mounting brackets to mount legs of the arch to handrails or pipework situated to the sides of the walkway, wherein: the pipework arch comprises two of the legs, a top piece with two opposing ends, and two union fittings, one at each of the two opposing ends for connecting the two legs, respectively, to the two opposing ends of the top piece, one leg for each end; and the deluge system further comprises an actuator for powered rotation of the top piece relative to the legs, when the union fittings are not tightened, for rotation of the stanchion between stowed and deployed configurations.

In some embodiments, the union fittings are hammer unions with radial flanges for hitting with a lump hammer for loosening or tightening thereof. Such unions are commonly used for pipework connections on rigs, and are thus familiar to the personnel on the rig.

By the provision of an actuator, the rotation of the stanchion between stowed and deployed configurations is made more straightforward as less effort is required by the personnel operating the deluge system. Operation of the actuator can be remote from the deluge system -for example from the safety of the main structure of the rig, rather than from on the boom arm. For this purpose, the control unit for the actuator may be provided way from the boom arm, with a wireless connection therebetween, or a control cable therebetween.

In some configurations the actuator is a hydraulic or pneumatic actuator. In others it may be a motor or screw-drive/geared arrangement. Electric power, or hydraulic or pneumatic supply lines, can be provided as appropriate.

With normal hammer union fittings, personnel will still need to manually tighten and loosen the unions prior to and after use of the actuator (for raising or lowering the stanchion). However, motorised or hydraulic or pneumatic-operated unions can be provided instead, thus allowing them also to be remotely operated. Again suitable electric power, or hydraulic or pneumatic supply lines, can be provided as appropriate, along with suitable wired or wireless control systems, which may also connect to the remote control unit.

As it is preferred that the raised stanchion will be tethered or restrained by guy ropes or other stabilising cables, these too may require personnel to apply or tighten them once the actuator has raised the stanchion, and likewise to loosen or unclip them when the stanchion is to be lowered. However, for a fully remote operated solution, powered stabilising cables -on spools or pulley blocks -can be utilised.

The stanchion can also be secured in a lowered position by one or more a strap or bracket, for example connected to the or each of the handrails. This also may require manual intervention for applying and removal. However, in a fully remote operated solution, powered brackets or latches can be used instead.

As it is desirable to maintain access past the deluge system, it is preferred that the underside of the top piece, measured at its vertical centreline, extending parallel to the length of the walkway, is at least 1.7 m above a top (or walked on) surface of the walkway, measured vertically. More preferably it is at least 1.9 m above the top surface of the walkway. This allows personnel to reach the union fittings for undoing them and retightening them, while still being able to travel along the walkway under the top piece without ducking or crouching under the arch/deluge system. The arch could be higher if desired as well as the actuator allows rotation of the stanchion even when it cannot be reached by personnel on the walkway.

As the actuator typically extends across into the area underneath the top piece, it can hinder access to the handrail. Preferably, therefore, in some embodiments the bottom of the actuator is at least 10 cm above a top surface of the handrails, measured vertically. This puts the actuator in a position less likely to prevent an operator from being able to hold onto the handrail, making the pathway underneath the deluge system, along the walkway, even more easy to pass.

In some embodiments the actuator is a piston, for example a hydraulic or pneumatic piston In some embodiments the actuator has a first end attached to one of the legs via a first actuator bracket and a second end attached to the top piece via a second actuator bracket. Preferably the first actuator bracket is a lower actuator bracket and the second actuator bracket is an upper actuator bracket.

In some embodiments the second actuator bracket extends outward -preferably generally radially -from an outer wall of the top piece. The second actuator bracket thus forms a pivot arm for rotating the top piece.

In some embodiments each opposing end of the top piece defines an end plane, the two end planes being parallel. Preferably the union fittings encompass or fit over those opposing ends.

In some embodiments the legs each have an upright section and a bend piece or elbow (preferably a 90 degree elbow) at the top thereof to turn the tops to face the opposing ends of the top piece. The rotation of the top piece relative to the legs thus can be about an axis perpendicular to the end planes of the top piece, and likewise perpendicular to correspondingly parallel planes defined by the upper ends of the legs (or left and right branches).

In some embodiments the second actuator bracket extends perpendicular to that rotation axis so that the pivot arm formed thereby is efficient for rotating the top piece about the rotation axis.

In some embodiments the first actuator bracket extends outward -preferably generally radially -from an outer wall of one of the legs. Preferably the outer wall is part of the upright part of the leg. In some embodiments the first actuator bracket extends underneath the top pipe. Preferably it extends so that its free end locates vertically underneath the second actuator bracket.

Each actuator bracket can have a mounting point for the actuator. Preferably the two mounting points lie substantially above and below each other.

Preferably the mounting points comprise bushings or bearings, each defining a rotation axis for the ends of the actuator. Preferably those rotation axes are parallel to one another. Preferably they are also parallel to the axis of rotation of the top piece relative to the legs.

In some embodiments the two legs are left and right hand branches of the pipework arch, and one or both of them connect to one or more water supply or feed pipe that extends along the boom arm, for example from a pump on the boom arm or rig. The water may be seawater.

In some embodiments the water supply or feed pipe runs along just one side of the walkway, and the appropriate left or right hand branch is connected thereto. Preferably the other branch is then provided with an end cap to close its lower end. In some embodiments the end cap is provided with a valve to allow venting of water from that leg, if needed. According to a further aspect of the present invention, therefore, there is also provided a deluge system for mounting over a walkway on a boom arm of an oil rig, the walkway having first and second sides, wherein the deluge system comprises a pipework arch, a stanchion extending therefrom to a deluge nozzle, and mounting brackets to mount legs of the arch to handrails or pipework situated to the sides of the walkway, wherein: the pipework arch comprises two of the legs and a top piece for connecting between the two legs, one of the legs being for connecting to a water supply or feed pipe that runs along one side of the walkway, and the other leg is provided with an end cap to close its lower end.

In some embodiments the union fittings comprise lugs to facilitate rotation thereof to loosen or tighten the fittings, and thus the connection between the legs and the top piece.

In some embodiments, the mounting brackets are formed on or are connected to a framework for the deluge system, the framework comprising a first framework member for one side of the walkway and a second framework member for the second side of the walkway, each framework member being attached to a respective handrail or pipework to the sides of the walkway, by one or more of the mounting brackets, and to a respective one of the legs.

In some embodiments the first and second framework members each have two mounting brackets, a forward one and a rearward one, for spacing along the handrail or pipework, thus offering improved stability to the deluge system.

In some embodiments the first and second framework members each have one or more pipework (or leg) clamp for attachment thereof to the respective leg -typically the upright thereof.

In some embodiments the first and second framework members each comprise an upright and a bottom brace, and a front connection member to brace the L formed by the upright and bottom brace. Preferably there are two pipework clamps on the upright -to securely attach the leg to the upright.

In some embodiments the framework has a release mechanism to allow removal of the pipework arch from the handrail without detaching the mounting brackets from the handrails or pipework to the sides of the walkway. In some embodiments the release mechanism comprises one or more upstand extending up from the mounting brackets, the upstand having holes therein, and the framework being attached to the upstands by a pin or bolt connection, undoing and removing the pin or bolt allowing the framework and pipework arch to be lifted off the upstand of the mounting bracket.

Preferably the framework has one or more slot or groove provided to accommodate the or each upstand of the mounting brackets.

In other embodiments, the framework is just welded to the mounting brackets, and is thus formed as one piece therewith for more rapid assembly of the deluge system on the handrails.

The present invention also provides a deluge system for mounting over a walkway on a boom arm that extends from a side of a main deck of an oil or gas drilling or extraction rig, wherein the deluge system comprises pipework, a stanchion extending therefrom to a deluge nozzle, and mounting brackets for mounting the pipework and stanchion to the walkway or boom arm, the stanchion being rotatable relative to the walkway between stowed and deployed configurations, the deluge system further comprising an actuator for powering the rotation of the stanchion between the stowed and deployed configurations, the deployed configuration being generally upright, wherein a control unit is provided for the actuator, the control unit being remote from the boom arm. With this system, the control unit can be located on the main deck for when controlling the actuator, rather than needing to be by the deluge system. This aspect of the present invention thus allows remote actuation of the deluge system, or control of the movement of the stanchion between raised and lowered states, from the safety of the main deck, rather than on the boom arm. This can have benefits, even if the unions and stabilising cables are used -as they can be quickly loosened, tightened or attached, whereas the stanchion, which may be multiple meters long, and thus potentially too heavy to move by hand, has generally required the use of a crane on the main deck, and thus interaction between multiple operators for coordinating the lift once appropriate connections between the crane and the stanchion have been made. As discussed above, however, this can have even greater benefits if motorised unions and motorised stabilising cables, and where provided, motorised securing brackets, are used.

In some embodiments, the components are made of stainless steel, rather than cast iron. They can thus be made more lightweight, which can assist with avoiding overloading the boom arm.

In some embodiments, the stanchion is mounted centrally relative to the walkway, so as to balance the load between the sides of the walkway. Having the pipework that connects to the stanchion in the form of an arch or bridge over the walkway, and attached to both sides of the walkway further assists with balancing the load on the walkway/boom arm.

The stanchion and nozzle, as discussed above, will be for forming a water curtain or water wall when in the deployed condition. That water curtain or wall is created with high pressure water through the pipework and stanchion and then the nozzle. That water, as it exits the nozzle, forms millions of water droplets, which water droplets are of sufficient quantity to refract the UV light (heat) from the flare, in addition to absorbing heat into the droplets, which creates the barrier to the heat to protect personnel on the main deck. The water wall effectively reflects or absorbs much of the heat away from the structure being protected. Due to the pressures involved, for creating the large wall of water, there are significant forces acting on the stanchion from that water. Mounting the stanchion on the central axis (longitudinal axis) of the boom arm centralises those loads, further improving the stability of the boom arm.

The present invention also provides a flare boom arm comprising a walkway with handrails, and a deluge system as defined above mounted on or above the handrails.

In preferred embodiments, the stanchion of the deluge system vertically aligns with a central longitudinal axis (or a central vertical longitudinal plane) of the boom arm. It also preferably rotates in that plane when rotating between stowed and deployed conditions.

The present invention also provides a method of deploying or retracting a deluge system to or from a deployed state, the deluge system being as defined above, and the method comprising operating the actuator to rotate the top piece and stanchion.

The present invention also provides a method of deploying a flare boom arm to or from a deployed state, the flare boom arm being as defined above, the method comprising swinging the boom arm and operating the actuator to rotate the top piece and stanchion.

According to a further aspect of the present invention, there is also provided a deluge system for mounting over a walkway on a boom arm of an oil rig, the walkway having first and second sides, wherein the deluge system comprises a pipework arch, a stanchion extending therefrom to a deluge nozzle, and mounting brackets to mount legs of the arch to handrails or pipework situated to the sides of the walkway, wherein: the pipework arch comprises two of the legs and a top piece for connecting between the two legs, one of the legs being for connecting to a water supply or feed pipe that runs along one side of the walkway, and the other leg is provided with an end cap to close its lower end. This deluge system can also have any of the features of the preceding aspects.

According to a further aspect of the present invention, there is also provided a deluge system for mounting over a walkway on a boom arm of an oil rig, the walkway having first and second sides, wherein the deluge system comprises a pipework arch, a stanchion extending therefrom to a deluge nozzle, and mounting brackets to mount legs of the arch to handrails or pipework situated to the sides of the walkway, wherein: the pipework arch comprises two of the legs and a top piece for connecting between the two legs, the two legs being attached to a framework that has a release mechanism to allow removal of the pipework arch from the handrails or pipework without detaching the mounting brackets from the handrails or pipework to the sides of the walkway. In some embodiments the release mechanism comprises one or more upstand extending up from the mounting brackets, the upstand having holes therein, and the framework being attached to the upstands by a pin or bolt connection, undoing and removing the pin or bolt allowing the framework and pipework arch to be lifted off the upstand of the mounting bracket. . This deluge system can also have any of the features of the preceding aspects.

With the present invention, the deluge system is easy to attach to and remove from the boom arm, as access to the handrails is simple to achieve. The deluge system assembly can be preassembled in a factory and simply attached to the handrails and water supply on the boom arm, or it can be assemble on the main deck and craned onto the handrails. Alternatively it can be fully or part assembled onto the boom arm. The flexibility of the present invention's design is an important advantage.

These and other features of the present invention will now be described in further detail, purely by way of example, with reference to the accompanying drawings, in which: Figure 1 shows a side view of a boom arm for a flare on an oil rig with a deluge system in accordance with the present invention constructed thereon, and shown in a stowed configuration; Figure la is a similar arrangement to Figure 1, but showing an alternative stowed configuration, in which the stanchion is retained in its stowed configuration by a strap or bracket; Figure 2 shows part of the boom arm of figure 1 with the deluge system rotated into its deployed configuration; Figure 3 is a top-down view of the arrangement in figure 2; Figure 4 is an elevational view of the arrangement in figure 2, showing in more detail the deluge system of the present invention; Figure 5 is a front perspective view of the arrangement in figure 2, again showing the deployed deluge system; Figure 6 shows a more detailed view of area B -a pivoting region -of the deluge system of figure 4; Figure 7 shows a more detailed view of area C -a rear handrail clamp -of the deluge system of figure 4; Figure 8 shows a more detailed side view of a mounting bracket of the deluge system of figure 4; Figure 9 shows a more detailed view of area D -a front handrail clamp -of the deluge system as identified in figure 8; and Figure 10 shows a more detailed view of area E -an actuator and bracket -of the deluge system as identified in figure 8.

Referring first to figure 1, there is shown a boom arm 10 that can be swung via a pivot point 22 between a deployed and retracted position relative to an oil rig's central structure. In the deployed condition it extends away from that structure. In the retracted position it may be brought alongside the structure. For supporting the cantilever of the boom arm, one or more support cable 20 can be provided. It will be appreciated that in some booms, a fixed arm is provided, rather than a swingable arm 10.

At the free end of the boom arm 10 the flare 18 is provided. This flare 18 is for flaring excess oil or gas on the oil rig.

Along the boom arm 10, a deluge system 12 is provided. As can be seen in figures 5 and 7, this deluge system 12 is mounted on top of handrails 16 using mounting brackets 24. Further, the deluge system is connected to a water supply from the oil rig's central structure by a feed pipe 14.

In figure 1, the deluge system 12 is shown in a stowed configuration. In this stowed configuration a stanchion 26 thereof is rotated down towards the handrails 16. As the stanchion is central to the walkway in this embodiment, it won't rotate onto the handrail, but simply locates to a position between the two handrails.

Referring next to Figure la, an alternative stowed configuration is shown. In this configuration a strap or bracket 90 is provided to securing the stanchion down in its stowed configuration. This may be useful at times when the boom arm is swung back to its own stowed state -against the side of the rig. It can also prevent undesirable flexure of the stanchion during extreme weather events, as commonly experienced in at sea -for example storms or freezing conditions. There may be a strap or bracket attaching the stanchion to one hand rail, both hand rails, or to the feed pipe or pipes 14.

Referring next to figure 2, which shows in more detail the deluge system of the present invention, rather than the whole boom arm 10, the deluge system 12 can now instead be seen to have been reconfigured into its deployed configuration. In this configuration the stanchion 26 is now rotated upwardly so as to be arranged in a generally vertical orientation. This points a nozzle 28, as fitted to the free end of the stanchion 26, in a forward direction towards the flare 18. However, as the nozzle 28 is designed to generate a generally radial wall of spray, rather than a mono-directional spray, it is not important whether the nozzle faces forwards or backwards, only that the wall of spray is generally in a vertical plane to create a barrier to radiant heat from the flames from the flare 18 when the flare 18 and deluge system 12 are operational. After all, even if pointing rearwardly, that radial wall of spray would still provide effectively the same barrier, albeit with the stanchion 26 and rear of the nozzle 28 closer to the flare's heat For generating that wall of spray, it can be seen that the nozzle has a spreader plate 30 near its end against which water can be ejected through the nozzle so as to fan outwardly, radially, from the sides of the nozzle. Many forms of similar deluge nozzle are known in the art and thus further description thereof is not necessary herein, as the present invention can accommodate most forms of deluge nozzle at the end of it stanchion 26.

Referring next to figure 3, a top-down view of figure 2 is provided. As can be seen, two support cables 20 are provided, one on each side of a walkway 32. These extend from a manifold 34, which connects to a crane cable (not shown), down to the boom arm -to attachment points to the sides thereof. Such support cables 20 are well known in the art. There are many different forms for such support cables, so the invention is not limited to this particular arrangement.

From the top-down view it can also be seen that the mounting brackets 24 are located on handrails extending either side of the walkway 32. This arrangement is more clearly visible in figure 4 and figure 5. As can be seen in figures 3, 4 and 5, the walkway 32 is a walking surface by which personnel can gain access along the boom arm 10 for servicing or installation of the deluge, the flare 18, and other fluid pipes 34 that extend along the walkway 32 or boom arm 10. Some of the other fluid pipes 34 are shown in section in figure 4.

Figure 4 also has two highlighted areas B, C which will be described in more detail below with reference to figure 6 and 7.

Figure 4 also shows a sling clamp 36 mounted towards the top of the stanchion 26, below the nozzle 28, which sling clamp 36 can be used to attach further stabilising cables 40 (see for example figure 5) to the stanchion 26 so that the stanchion 26 can be more securely supported in its upright position. More than one such sling clamp or an alternative mounting of an attachment eye for a cable, can be provided if needed. The cables can be just for securing it in the operational position, and may extend forwards and backwards as guy ropes. Alternatively, one or more of the cables can additionally be for locking it down when in the stowed condition. This may supplement or replace the strap or bracket 90 shown in Figure la, although usually they are not used for this purpose.

The other ends of the stabilising cables may be attached, for example, to further boom sling clamps 38, or other eyes, on the handrails 16, as shown in figure 5, or on the pipework or elsewhere on the boom arm.

Referring further to figure 5, the deluge is mounted on the handrails 16 at the tops thereof. Also on the top of one of the handrails 16 is the feed pipe 14, which in this embodiment is a multicomponent feed pipe having various uniform length sections 42 joined at supply pipe brackets 44. In this embodiment, the supply pipe brackets also comprise pipe bracket clamps 46 for clamping the brackets to the top of the handrail 16. Being on top of the handrail gives easy access to these components for servicing.

Figure 5 also shows that the deluge system 12 is arranged with pipework 50 to allow it to be mounted on either handrail 16, with a branched feed supply 52, 54, 62 extending both to the left and right handrails 16. In this embodiment, the left hand branch 54, as identified when facing towards the flare 18, is connected to the feed pipe 14. However, there is also a right hand branch 52, which could be connected instead (or as well) if the feed pipe 14 was instead (or as well) extending along the right-hand handrail 16. As that right hand branch 52 is not being used in this embodiment, the free end thereof is closed with an end cap 48, which may feature a valve within it to allow draining of water therefrom, e.g. during servicing.

Figure 5 also shows a lower actuator bracket 56 and an actuator 58 which can be used to deploy the stanchion 26 from a stowed condition into its deployed condition, and vice versa, through an extension of the actuator 58 (a hydraulic or pneumatic piston in this embodiment). As shown in figure 6, there is also an upper actuator bracket 60 positioned on a top piece 62 of the branched feed supply 52, 54, 62.

Still referring to figure 6, the branched feed supply 52, 54, 62 can be seen to have the three main pipe components -the left-hand branch 54, the right hand branch 52, and the top piece 62. Each of the left hand branch 54 and the right hand branch 52 are in fixed orientations relative to the handrails 16 as they are each mounted thereto via a framework member 64, pipework clamps 66 and handrail clamps 24-i.e. the mounting brackets 24. The top piece 62, however, is arranged for pivotal rotation relative to the left and right-hand branches 52, 54. For this purpose, union fittings 68 are provided at either end of the top piece 62 for threaded connection with the ends of the left and right-hand branches 52, 54. Thus, to change the configuration of the deluge system, the union fittings 68 are undone, the actuator 58 is powered to raise (or lower) the stanchion 26 and the union fittings 68 are then tightened to lock the stanchion in its adjusted position. By using the actuator 58, the difficulty in lifting or lowering the stanchion is avoided as the actuator can do the lifting or lowering. Bearing in mind that the pipework is relatively long and has a wide diameter, it is relatively heavy and thus difficult or impossible for a single user to operate without the actuator. With the actuator, however, the operator simply has to loosen and re-tighten the union fittings 68.

In this embodiment, the top piece 62 is a T connector with a central upper opening in the deployed condition. The stanchion 26 is connected thereto via a flanged fitting 70. This fixed connection ensures that the stanchion 26 rotates with the top piece 62 as the top piece 62 is driven by the actuator 58.

Referring next to figure 7, an elevational view along the right-hand handrail 16 is shown, as per details see in figure 4. This shows the boom sling clamp 38 in front of the mounting brackets 24 with a cable mounting eye 74 for the connection to the further stabilising cable 40 (not shown). Part of the end cap 48 is also shown, as is a lower of two securing pins 76 which will be further described with reference to figure 9.

Referring next to figure 8, a side elevation of the mounting brackets 24 and the base of the deluge system 12 is shown, with two areas highlighted D, E, which correspond to figures 9 and 10. In this drawing, the actuator 58 can be seen to be extending between the upper actuator bracket 60 and the lower actuator bracket 56. The lower actuator bracket 56 is mounted on the framework member 64 -on an upright 80 thereof. The framework member 64 also has a bottom brace 82 which extends between the two mounting brackets 24 that are attached to the handrail 16. The framework member additionally has an arched front 84 connecting the ends of the L formed by the upright 80 and the bottom brace 82. The framework member 64 is fixed relative to the handrail 16 by the two mounting brackets 24 and therefore provides a fixed mounting position for the actuator 58.

Referring next to figure 9, the mounting of the framework member 64 to the handrail 16 will be shown and described in more detail. As can be seen, the handrail 16 extends horizontally along the walkway and has bolted thereto a base plate 78. The bolts 86 tighten handrail clamps similar to that shown in figure 7 for the boom sling clamps 38. Due to the viewing angle of figure 7, the base plate 78 can be seen, as can a lower securing pin 76. Referring to figure 9, that lower securing pins 76 is matched with an upper securing pin 76 above it, which securing pins can connect the framework member 76 to the base plate 78 by pushing through holes in an upstand 88 that extends up from the base plate 78, and then through holes in the arched front 84 of the framework member 64. The section of the arched front 84 is as shown to be a C or H section so that there is a groove into which the upstand 88 can fit. This allows the framework member 64 to be removed for servicing if needed by removing the pins 76.

Instead of C or H sections, a box section, or circular section can be provided with a hollow or aperture for receiving the upstand.

This structure for the framework members 64 is convenient as it allows a quick disassembly of the framework members off the handrails. It also makes each component less bulky, facilitating the installation -fewer heavy parts. However, it is not essential to the invention as the framework members can instead be simply welded to the brackets that secure them to the handrails, or otherwise joined thereto, such as with bolts or screws. Pre-assembly in this manner can likewise have advantages over the assembly on the boom ark, in that there are fewer parts to join, whereby any irregularities in the components or inconveniences arising from the location of installation (the environment on the boom arm is commonly quite harsh) cause less difficulties -such as from adjoining members not pulling square, or pins not fitting due to ice ingress.

Referring finally to figure 10, an enlarged view of area E is shown. From this view, the flanged fitting 70 can be seen connecting the stanchion 26 to the top piece 62. Furthermore, the pipework clamp 66, which is attached at one half thereof to the upright 80 of the framework member 64, can be seen to be connected to the left hand branch 54 of the deluge system's pipework. Furthermore, the actuator 58 can be seen to be connected at its top end -the free end of its piston rod -to the upper actuator bracket 60. Yet further the union fitting 68 can be seen to have outwardly extending lugs 94 enabling a tool such as a wrench to be used for rotating it for releasing the top piece 62 from the fixed connection to the left and right-hand branches 52, 54, thus allowing rotation of the stanchion 26 upon activation of the actuator 58, which pushes and pulls the upper actuator bracket 60 away from and towards the lower actuator bracket, which due to the lever arm effect of the upper actuator bracket on the top piece 62 rotates the top piece 62 relative to the left hand branch 54.

Referring back to figure 4, it can be seen that the left and right-hand branches are elongated to extend upwardly from the handrails 16. They then have elbows at their free ends at the tops, which elbows and then end in vertical faces within the union fittings 68. The two elbows thus define two vertical planes that are parallel to one another. The vertical planes within the union fittings 68 define the planes of rotation about which the ends of the top piece 62 rotates during rotation of the stanchion 26 into its raised or stowed conditions. The elongated left and right-hand branches, along with the top piece 62, define an arch over the walkway 32. As personnel will walk along the walkway, the elongated left and right-hand branches are desirably long enough to present a free walking space underneath the top piece 62 so that the personnel can freely walk along the walkway without having to duck underneath the top piece 62. It is preferred, therefore, that the underside of the top piece is at least 2 m above the top surface of the walkway 32. This still allows personnel to reach the union fittings 68 for undoing them. The arch could be higher if desired. For example, as the lower actuator bracket 56 extends across into the area underneath the top piece 62, in some embodiments the height of the bottom of the actuator could be at 2 m. This puts the actuator in a position less likely to be hit by a person's head.

The actuator can even be angled differently. In this embodiment it extends substantially vertically: for example it extends vertically in a parallel plane to the centreline of the walkway, although as shown in figure 8 it need not be vertical in the plane perpendicular to that centreline. In a different embodiment, however, the actuator might be angled relative to that parallel plane so that the lower actuator bracket extends this far underneath the arch formed by the top piece 62. A more complicated connection to the upper and lower bracket then becomes necessary, however, as there will be more axes of rotation at the connections between the actuator and the brackets as the stanchion is raised and lowered. It is preferred, therefore, that a vertical arrangement is present for the actuator in at least one plane to allow a simple pivotal connection of the actuator to the brackets.

An embodiment of the present invention has therefore been described above purely by way of example. Modifications in detail may be made to the invention within the scope of the claims as appended hereto.

Claims

CLAIMS: 1. A deluge system for mounting over a walkway on a boom arm of an oil or gas drilling or extraction rig, the walkway having first and second sides, wherein the deluge system comprises a pipework arch, a stanchion extending therefrom to a deluge nozzle, and mounting brackets to mount legs of the arch to handrails or pipework situated to the sides of the walkway, wherein: the pipework arch comprises two of the legs, a top piece with two opposing ends, and two union fittings, one at each of the two opposing ends for connecting the two legs, respectively, to the two opposing ends of the top piece, one leg for each end; and the deluge system further comprises an actuator for powered rotation of the top piece relative to the legs, when the union fittings are not tightened, for rotation of the stanchion between stowed and deployed configurations.
The deluge system of claim 1, wherein the actuator is a piston.
3. The deluge system of claim 1 or claim 2, wherein the actuator has a first end attached to one of the legs via a first actuator bracket and a second end attached to the top piece via a second actuator bracket.
4. The deluge system of claim 3, wherein the second actuator bracket extends outward from an outer wall of the top piece.
5. The deluge system of claim 3 or claim 4, wherein the first actuator bracket extends underneath the top pipe
6. The deluge system of any one of the preceding claims, wherein each opposing end of the top piece defines an end plane, the two end planes being parallel.
7. The deluge system of any one of the preceding claims, wherein the legs each have an upright section and a bend piece or elbow at the top thereof to turn the tops to face the opposing ends of the top piece.
8. The deluge system of any one of the preceding claims, wherein the second actuator bracket extends perpendicular to the rotation axis of the top piece.
9. The deluge system of any one of the preceding claims, wherein the two legs are left and right hand branches of the pipework arch, and one or both of them connect to one or more water supply or feed pipe that extends along the boom arm.
10. The deluge system of claim 9, wherein the water supply or feed pipe runs along just one side of the walkway, and the appropriate left or right hand branch is connected thereto.
11. The deluge system of claim 10, wherein the other branch is provided with an end cap to close its lower end.
12. The deluge system of claim 11, wherein the end cap is provided with a valve to allow venting of water from that leg, if needed.
13. The deluge system of any one of the preceding claims, wherein the underside of the top piece, measured at the vertical centreline, extending parallel to a length of the walkway, is at least 1.7 m above a top surface of the walkway, measured vertically, and more preferably at least 1.9m.
14. The deluge system of any one of the preceding claims, wherein the bottom of the actuator is at least 10cm above a top surface of the handrails, measured vertically. 25
15. The deluge system of any one of the preceding claims, wherein the mounting brackets are formed on or are connected to a framework for the deluge system, the framework comprising a first framework member for one side of the walkway and a second framework member for the second side of the walkway, each framework member being attached to a respective handrail or pipework to the sides of the walkway, by one or more of the mounting brackets, and to a respective one of the legs.
16. The deluge system of claim 15, wherein the first and second framework members each have two mounting brackets, a forward one and a rearward one, for spacing along the handrail or pipework.
17. The deluge system of claim 15 or claim 16, wherein the framework has a release mechanism to allow removal of the pipework arch from the handrail without detaching the mounting brackets from the handrails or pipework to the sides of the walkway.
18. The deluge system of claim 17, wherein the release mechanism comprises one or more upstand extending up from the mounting brackets, the upstand having holes therein, and the framework being attached to the upstands by a pin or bolt connection, undoing and removing the pin or bolt allowing the framework and pipework arch to be lifted off the upstand of the mounting bracket.
19. A deluge system for mounting over a walkway on a boom arm that extends from a side of a main deck of an oil or gas drilling or extraction rig, wherein the deluge system comprises pipework, a stanchion extending therefrom to a deluge nozzle, and mounting brackets for mounting the pipework and stanchion to the walkway or boom arm, the stanchion being rotatable relative to the walkway between stowed and deployed configurations, the deluge system further comprising an actuator for powering the rotation of the stanchion between the stowed and deployed configurations, the deployed configuration being generally upright, wherein a control unit is provided for the actuator, the control unit being remote from the boom arm.
20. The deluge system of claim 19, wherein the control unit is located on the main deck when controlling the actuator.
21. The deluge system of claim 19 or claim 20, when also in accordance with any one of claims 1 to 18.
22. A flare boom arm comprising a walkway with handrails, and a deluge system according to any one of claims 1 to 21, mounted on or above the handrails.
23. A method of deploying or retracting a deluge system to or from a deployed state, the deluge system being in accordance with any one of claims 1 to 21, and the method comprising operating the actuator to rotate the top piece and stanchion.
24. A method of deploying a flare boom arm to or from a deployed state, the flare boom arm being as defined in claim 22, the method comprising swinging the boom arm and operating the actuator to rotate the top piece and stanchion.