GB2150962A - Riser joints handling system on drilling rig structures - Google Patents

Abstract

A system for storing and handling drill tubulars such as for example riser joints on a drilling rig comprises storing the tubulars (10), in horizontal array in a tween deck of the rig and more especially below the rig drill deck (3), with each tubular (10) extending vertically. The bottom of the tubulars (10) can be located by fixed cones (20) while each tubular (10) supports a spacer member (19) at the upper end thereof, each spacer member (9) being of rectangular form and including means to link with adjoining spacers so that a platform is formed spacing the tubulars and enabling access to the tops of the tubulars (10). A peripheral support (23) is provided for the edge of the spacer platform. An overhead travelling crane (11) serves to transport each tubular and its spacer from the storage zone (9) to a riser forming zone (8) for tubular link up, and includes a hoisting device (15) which additionally operates to remove a spacer from its tubular at the riser forming zone (8). A stacker (60) is provided for the spacers (19) removed from the tubulars (10). <IMAGE>

Description

SPECIFICATION Handling system for riser joints or other elongate cylindrical items on drilling rig structures The present invention relates to a handling system for riser joints and other cylindrical items such as drilling tubulars including heavy wall drill pipes and the like on a drilling rig structure, particularly an offshore rig or unit.

Such cylindrical items are hereinafter generally referred to as tubulars.

In an offshore drilling rig structure, the upper deck supports a drill floor which supports the drill derrick serving to raise and lower the marine riser or other tubular elongate structure. The deck immediately below the drill floor usually defines a moon pool area, i.e. a rig area having an aperture for vertical through passage of items, e.g. diving bells, drilling equipment. The marine riser can be very many hundreds of feet in overall length and consequently the item is made up of a plurality of sections (known as riser joints): the riser joints are fitted with suitable connection pieces to enable joining up of the joints. It has been normal practice to store the riser joints horizontally adjacent to the drilling area on the drill deck, and transfer of the joints to the drill derrick has involved substantial manual operations.Since a very considerable number of riser joints will be used in the formation of the marine riser, the linking up of the riser (and also the dismantling thereof) generally has been a laborious and indeed even dangerous task.

It is an object of the present invention to provide an improved system of handling the marine riser on an offshore drilling rig or unit.

The present invention broadly provides a method of handling tubulars on drilling rig structures as aforesaid, the method comprising storing the tubulars vertically in a storage area below the drill deck, moving the tubulars successively to the moon pool area of the rig by mechanical handling means, joining each tubular to the preceding tubular at the moon pool area for the formation of a joined tubular structure, and connecting the joined tubular structure to the hook of the drill derrick.

The mechanical handling means preferably comprises an overhead travelling crane.

According to a more specific aspect of the present invention, a method of handling tubulars in a drilling rig structure as aforesaid comprises storing the tubulars vertically in a storage zone, fitting a spacer member at an upper end of each tubular to enable the tubulars to be stored in spaced relationship in the storage zone, lifting and carrying each tubular with its spacer member attached thereto to a tubular joining zone by carrying means, joining the tubular to a preceding tubular at said joining zone for the formation of a joined tubular structure, causing said carrying means to remove the spacer member from its tubular, and connecting the joined tubular structure to the derrick hook of the rig.

According to another aspect of the present invention there is provided apparatus for handling tubulars in a drilling rig structure as aforesaid, said apparatus comprising, means for storing the tubulars vertically in spaced relationship in a tubular storage zone located below the drill deck of the rig, mechanical handling means for lifting and carrying each tubular from said storage zone to the moon pool area of the rig whereat each tubular is joined to a preceding tubular for the formation of a joined tubular structure, and means for connecting the joined tubular structure to the derrick hook of the rig.

Preferably spacer means are attached to the upper end of each tubular to enable the tubulars to be stored in spaced relationship; and the mechanical handling means preferably comprise an overhead travelling crane, adapted both to lift the combination of tubular and spacer and to remove the spacer from its tubular at said tubular joining zone.

Preferably stacking apparatus is provided for the spacer elements removed from tubulars by the crane means.

The present invention also provides a hoisting device usuable in conjunction with crane means for the handling of tubulars provided with removable spacing elements, said hoisting device including lifting means which are settable in a first position for lifting of a tubular with a spacing element thereon by the crane means, and in a second position for removal of the spacer element from the tubular by the crane means.

Preferably the lifting means comprises pivotal plate means swingable by an actuating device into either of said first and second positions.

Further, the present invention provides a spacer member for use with a tubular, which spacer member is of plate form and includes linking elements to enable linking up of a horizontal array of similar such spacer members, the arrangement being such that the linked plate-form spacer members constitute a horizontal floor structure to facilitate access to the upper ends of vertical tubulars carrying the spacer members and stored in horizontal array.

Preferably the linking elements for the spacer member comprises tongues on the spacer member which tongues are received in slots in another spacer member.

Whereas the above specified methods and apparatus according to the present invention specifically relate to the assembly of a joined tubular structure, especially a marine riser, it will be understood that these methods and apparatus could function in reverse for disas sembly and storage of the tubular structure, and the present invention covers the said methods and apparatus operating in this way.

An embodiment of the present invention will now be described by way of example with reference to the accompanying drawings wherein: Fig. 1 shows a pictorial view of an upper part of an offshore drilling rig structure including a riser handling system according to the present invention; Fig. 2 shows a pictorial view of the upper ends of stored riser joints in the arrangement of Fig. 1 in greater detail; Fig. 3 shows a plan view of a top spacer plate for a riser joint; Fig. 4 shows an end view of the top plate looking in direction of arrows A-A of Fig. 3; Fig. 5 shows the section B-B of Fig. 3; Fig. 6 shows a cross-sectional side elevation of the top plate with a riser joint in position; Fig. 7 shows a pictorial view of the bottom location of the stored riser joints; Fig. 8 shows a side elevation of a bottom fixing cone of Fig. 7;; Fig. 9 shows a sectional elevation of a hoisting carriage for lifting a riser joint and its associated top spacer plate; Fig. 10 shows a sectional side view of the lifting pin of the carriage of Fig. 9 set for lifting both the riser joint and its top plate; Fig. 11 shows the same view as Fig. 10 but with the lifting pin set for lifting the top plate alone; Fig. 12 shows a plan view of Fig. 11; Fig. 1 3 shows a sectional plan view of the lifting pin with the pin set in an intermediate position; Fig. 14 shows a side elevation of a storage stacker for the top spacer plates; and Fig. 1 5 shows a plan view of the stacker of Fig. 14.

Referring to the drawings and particularly to Fig. 1, a floating drilling rig 1 (only part shown) has an upper deck 2 supporting an elevated drill floor 3 by means of upstanding box structures 4, and the drill floor 3 includes the usual rotary table 5 for the drill tubulars(marine riser) and additionally supports a drill derrick 6. Below the upper deck 2 there is located a lower deck 7 providing a moon pool 8 situated below the rotary table 5. The deck 7 also provides an area or areas 9 to the side of the moon pool 8 for the vertical storage of tubular riser joints 10 and these joints 10 are carried individually by mechanical handling means (later described) from area 9 to the moon pool 8 whereat the riser joints 10 are connected for the formation of the full marine riser.

Movement of the riser joints 10 to the moon pool 8 is achieved by an overhead travelling crane 11 which has opposed sup port trolleys 1 2 running in girders 1 3 extend ing transversely to the for-and-aft direction of the rig and suitably supported in the rig. The .trolleys 12 are linked by a pair of longitudi nally extending rails 14, which support a hoisting carriage 1 5 the trolleys 1 2 and the rails 14 forming a gantry and the crane gir ders 1 3 are suitably located in the rig at a level to enable the hoisting carriage 1 5 to be appropriately located over the upper ends of the riser joints 10 for the lifting operation. 1 6 is the crane operator's cabin.

The ends of the riser joints 10 are provided with suitable connection pieces 17, to enable joining up of the riser joints 10 and the connection pieces 1 7 used include radial flanges 18. More specifically the pieces 1 7 shown are those sold under the trade name Vetco.The upper ends of the riser joints 10 are held in spaced relationship by means of top spacer plates 1 9 (see Figs. 1 and 2) whilst the bottom of the joints 10 are located by means of cones 20 (see Fig. 7) arranged in appropriate array on the lower deck 7 and each inserted into the bore of a connection piece 1 7. Each top plate 1 9 is a steel box type fabrication (see Figs. 3 to 6) having a central circular aperture 20 enabling the plate 1 9 to be placed over a riser connection piece 17, a flanged top 21 of the plate 1 9 being supported by the connector flange 1 8 (Fig. 6) when the plate 1 9 is in position.The riser joint 10 can include choke and kill lines 22 (see Fig. 6), and the top plate 1 9 when located on the joint 10 will allow clearance for these lines and additionally for connector seals and other hydraulic lines. Each plate 1 9 includes an internal circular wall 28 including a frusto conical portion 28A to assist centring of the plate and also a cylindrical portion 28B to closely surround the flange 1 8.

The rig 1 includes a peripheral support beam 23 suitably mounted in the rig structure and serving to support the joined top plate array, the beam 23 being positioned at the level of the upper end of the vertically sup ported joints 10, and more specifically at the level of the connector flanges 18. Each top plate 1 9 is square in plan view and each side wall 24 of the plate 1 9 has a pin 25 project ing therefrom and also includes a vertical slot 26 which mates with an aperture 26A on the top wall 21. the pin and slots 25, 26 of the plates constituting tongue and groove connec tions whereby the various plates 1 9 can be linked together. Thus the pin and slots of one plate interlock with those of other plates: additionally the support beam 23 carries an interlock bar 27 having a similar pin and slot arrangement 25, 26 whereby the peripheral plates 1 9 of the plate array can interlock with the support beam 23. The shape of the pins 25 and slots 26 are such as to allow for some degree of misalignment between interlocking plates 1 9 before they are interlocked. The size of the top plates 1 9 depends upon the dia meter of the riser joint 10 with its buoyancy module 29.

When the top plates 1 9 are interlocked (as shown in Fig. 2) and supported by the riser joints 10, the plates 1 9 form a platform so enabling the riser connections, seals and other items to be inspected by personnel walking on top of the top plate platform. The lower support cones 20 are coated with rubber or synthetic plastics to prevent damage to the ends of the riser connections 1 7. The cones 20 are mounted on a support plate 20A fixed to the lower deck 7 by bolts or tack welds so that the cones 20 can be conveniently replaced in the event of damage.

The hoisting carriage 1 5 of the crane 11 is movable on gantry rails 14 by means of wheels 1 5A (Fig. 9) while the gantry is movable on girders 1 3 so that the carriage 1 5 can be positioned over any part of the riser storage area 9. Briefly the carriage 1 5 comprises pivotal plate catch elements serving to selectably grip the riser connector flange or the top plate, which elements are carried by a hydraulically operable piston-cylinder device for lifting (or lowering) a riser and/or its associated top plate. The crane 11 serves to lift a riser joint 10 (and top plate) from the storage area 9 and to transport the joint 10 to a spider device 30 at the moon pool 8.Referring particularly to Fig. 9 the piston 32 of a piston/cylinder device 31 supports an upstanding piston rod 33 having a wheel 34 at the upper end thereof, and the wheel 34 is rotatably supported on a support plate 35 of the carriage 1 5 by means of a substantial thrust bearing 36 of ball-race form. The cylinder 37 of the device 31 is closed adjacent its bottom end by a plate 38, and at its upper end by an annular sealing plate 39, and pressure fluid can be selectively supplied to either side of the piston 32 for double acting operation of the device 31. A lifting plate 40 surrounds the cylinder 37 so as to have a clearance fit therewith and the lifting plate 40 is supported from the cylinder 37 by means of lifting plate cylinders 41 so that the plate 41 is vertically movable relative to the cylinder 37.The lifting plate 40 carries four lifting pins 42 which can pass through corresponding apertures 42A in the top plate 1 9.

Each pin 42 houses a catch plate 43 (best seen in Figs. 10 and 11) which is pivotal on pivot pin 44, and the plate 43 pivots from one position (Fig. 10) where a first catch surface 45 projects from the pin so as to engage a connector flange 18 (Fig. 9) to a second position (Fig. 11) where a second catch surface 46 projects from the pin 42 to engage the bottom surface of the top 21 of a plate 19. The pins 42 include axial slots 47 to permit pivoting of the plates 43. Pivoting is achieved by means of an acutating spindle 48 which is reciprocal in a bore of the pin 42 and which carries a pin 49 engagable in a slot 50 of the plate 43 to form a cam-and-follower arrangement, and each spindle 48 is driven by a fluid piston/cylinder actuator 51. Fig. 13 shows the plate 43 in an intermediate position.The circular wall 28 of the top plate 1 9 includes slots 52 to permit through passage of the plate 43 for engagement of the connector flange 1 8 by the surface 45. The wheel 34 is rotatable by means of a fluid motor 53 for slewing of the piston rod 33, the motor 53 including a pinion 58 drivingly engaging peripheral teeth 59 on the wheel 34. Guide bar 54 is rigidly fixed to the wheel 34 and engages with brackets (not shown) on the cylinder 37, which brackets can slide over the guide bar 54 and prevent the cylinder 37 from rotating relative to the wheel 34.Consequently, the guide bar 54 serves to transmit the slewing action of the wheel 34 to the cylinder 37 and thus to the riser joint 1 0. The wheel 34 can be rotated through any suitable angle by the motor for example through 270 . Control of fluid to either side of the piston 32 is achieved by a control block 55 mounted on the wheel 34 and supplying fluid appropriately to the cylinder via conduits 56 and 57 in the piston rod 33. Operation of the fluid control block 55 can be controlled irrespective of the slewed position of the wheel 34. Appropriate control means (not shown) are also provided for the piston/cylinders 41 51.The following vertical movements are therefore possible in the hoisting carriage 15: 1) a) Lowering of the cylinder 37 by supplying pressure fluid to the outer side of the piston 32 via conduit 57, or b) Raising of the cylinder 37 by supplying pressure fluid to the other side of the piston 32 via conduit 56. This serves for raising or lowering of a riser joint 10. It will be noted that when the carriage 1 5 supports a riser joint 10, the thrust bearing 36 must absorb the dynamic loads imposed by the riser joint 10 hanging below the hoisting carriage 1 5.

11) Movement of the lifting plate 40 relative to the cylinder 37 by actuation of piston/cylinders 41. This serves to securely clamp a riser joint for lifting.

111) Movement of the spindle 48 by actuator 51 for pivoting of plate 43 so as to position catch surfaces 45, 46 appropriately.

When a riser joint 10 has been joined to the prior formed riser portion at the moon pool 8, it is necessary to remove and store the top plate 1 9 from the joint 10, and to this end plate stackers 60 are provided on the lower deck 7 between the storage area 9 and the moon pool 8. Referring particularly to Figs. 14 and 15, each stacker 60 comprises a base 61 carrying four upstanding U-bar columns 62, and these U-bars 62 constitute rails for a top-plate support trolley 63 which includes runner wheels 64 located in the rails 62. The columns 62 also include corner angle pieces 65 for location of the top plates 1 9.

Upward movement of the trolley 63 is achieved by a pulley cable 66 wound on winch drum 67 driven by motor 68. The cable 66 extends from the drum 67 to a pulley wheel 69 at the top of one column (A) then down the column (A) to a pulley wheel 70 on the trolley 63, across to another pulley wheel 71 on the same one side of the trolley, then passes up a second column (b) to a pulley wheel 72, across to another column (C) whence the cable passes down and around further pulley wheels 70, 71 on the other side of the trolley 63, and finally the cable 66 passes up to an anchor point at the top of the fourth column (D). Consequently driving of the drum 67 causes smooth upward movement of the support trolley 63: downward movement of the trolley is achieved by gravity effect.The vertical position of the trolley 63 is controlled by limit switches (not shown) so that a top plate 1 9 is flush with the upper end of columns 62 (as shown in Fig. 14) in readiness to be picked up by the hoisting carriage 1 5. When the riser joints 10 are returned to the storage area 9 they are again fitted with top plates 1 9 supplied from the stackers 60.

The spider 30 is of conventional form but is mounted on beams 72 placed across the moon pool 8. The beams 72 constitute a bifurcated formation which is hinged at its forward end and which can be raised clear of the moon pool 8 once the riser has been run.

Further, a main hook lifting tool (not shown) of pneumatic operation is provided to grip the top of the riser joint 10 once the bottom connection has been made up at the spider 30. This tool is connected by drill pipe to the derrick main hook which is above the drill floor 3. The drill pipe is guided by a bushing in the rotary table 5.

Operation of the Riser Handling system The lower marine riser portion and ball joint is positioned, on a trolley, over the moon pool 8. The hoisting carriage 1 5 is positioned over a riser joint 10 in the storage area 9, and the hoist cylinder 37 is lowered over the riser connection piece 1 7 and the lifting pins 42 pass through the apertures 42A in the top plate 1 9. The lifting plate 40 is lowered by the piston/cylinders 41, and the actuating cylinders 51 then pivot the catch plates 43 to move catch surfaces 45 outwards to grip below the riser flange 18.The lifting plate 40 is then raised to securely clamp the riser flange 1 8 between the end of the hoist cylinder 37 and the catches 45: this enables the riser joint 10 to be held in a substantially nonswayable condition, and end of the connection piece 1 7 being located in an end portion of the cylinder 37. The hoist cylinder 37 is then raised to lift the riser joint 10 clear of the bottom cone 20.

The crane 11 moves the riser joint 10 to the moon pool 8 and locates the joint over the lower marine riser ball joint, and the hoist cylinder 37 is lowered to place the joint 10 in position. The connection of the joint to the preformed riser portion is made up using power tools. The slewing provision in the hoist carriage 1 5 (through wheel 34) enables the riser joint 10 and the top plate 1 9 to be rotated to line up the choke, kill and hydraulic connections when connection is being made between riser joints at the spider 30. Also, when the riser joints 10 are being stowed in the storage position it may be necessary for slewing of the hoist carriage to occur to provide slight rotation of the top plate 1 9 for engagement of the tongue and groove interlocking mechanism.

The lifting plate 40 of the carriage 1 5 is then lowered to take the weight off the catch surfaces 45, and the actuating cylinders 51 pivot plates 43 so that catch surfaces 45 now engage under the top 21 of plate 19. The hoist cylinder 37 is then raised to lift the top plate 1 9 clear of the riser joint 10, and hoist carriage 1 5 can be moved to a stacker 60 to place the top plate 1 9 therein. The crane 11 can then return to the storage area 9 to uplift the next riser joint 10.

While the hoist carriage 1 5 is collecting the next riser joint 10 the formed riser is handled by the main hook in the derrick 6. In particular, the lifting tool connects the top of the riser to the main hook, and the hook lifts the riser (and the lower marine riber package) clear of the trolley which is then returned to its storage position. The beams 72 with the spider 30 are then lowered across the moon pool, and the formed riser is lowered by the main derrick hook onto the spider. The lifting tool is disconnected and the main hook raised to a position in readiness to handle the next riser joint.

The hoisting carriage 1 5 places the next riser joint 10 onto the spider 30, and the sequence is repeated with the main hook lowering the preformed riser portion through the spider while the hoisting carriage 1 5 brings the riser joints 10 successively from the storage area 9.

The marine riser is retrieved and dismantled by reversing the order of the above operations.

The above described marine riser handling system of the present invention enables formation and also retrieval of the riser considerably more quickly than with previous systems and also with a greater degree of safety.

Modifications are of course possible in the arrangement. In particular, adjustments to the handling system may be required depending on the precise constructional nature of the tubular (riser joint) and its appendages; and this particularly applies where some other form of connection piece is used than the Vetco (RTM) connector. Thus the top spacer plate 19 in particular may be of modified form, and this may require alteration to the hoisting carriage 1 5. During the period when the connection is being made up between riser joints at the moonpool, the connection supports the upper riser joint while the hoist carriage removes the top plate:. the upper riser joint is thus in a substantially freestanding condition. It would be possible to provide an additional support for the riser joint during this period. For example this additional support may take the form of a support arm mounted on a bulkhead at the forward end of the moonpo̲l and serving to grasp the riser joint just below the top riser connector. Additionally, the means for interlocking the top plates could differ: for example instead of alternating pins and slots on each plate side wall, the side walls may include in alternating manner either only interlocking pins or interlocking slots so that the pins of the side wall of one plate interlock with the slots of the side wall of another plate.

Claims (26)

1. A method of handling tubulars on drilling rig structures as aforesaid, the method comprising storing the tubulars vertically in a storage area below the drill deck, moving the tubulars successively to the moon pool area of the rig by mechanical handling means joining each tubular to the preceding tubular at the moon pool area for the formation of a joined tubular structure, and connecting the joined tubular structure to the hook of the drill derrick.

2. A method of handling tubulars in a drilling rig structure as claimed in claim 1, including fitting a spacer member at an upper end of each tubular to enable the tubulars to be stored in spaced relationship in the storage area, lifting and carrying each tubular with its spacer member attached thereto to the tubular joining zone at the moon pool by carrying means, joining the tubular to a preceding tubular at said joining zone for the formation of a joined tubular structure, and causing said carrying means to remove the spacer member from its tubular.

3. A method as claimed in claim 1 or 2, wherein the mechanical handling means comprises an overhead travelling crane.

4. Apparatus for handling tubulars in a drilling rig structure as aforesaid, said apparatus comprising, means for storing the tubulars vertically in spaced relationship in a tubular storage zone located below the drill deck of the rig, mechanical handling means for lifting and carrying each tubular from said storage zone to the moon pool area of the rig whereat each tubular is joined to a preceding tubular for the formation of a joined tubular structure, and means for connecting the joined tubular structure to the derrick hook of the rig.

5. Apparatus as claimed in claim 4, wherein spacer means are attached to the upper end of each tubular to enable the tubulars to be stored in spaced relationship.

6. Apparatus as claimed in claim 4 or 5, wherein there is provided a hoisting device usable in conjunction with the crane means for the handling of tubulars provided with said removable spacing means, said hoisting device including lifting means which are settable in a first position for lifting of a tubular with a spacing means thereon by the crane means, and in a second position for removal of the spacer means from the tubular by the crane means.

7. Apparatus as claimed in claim 5 or 6, wherein each spacer means comprises a box form construction provided with a central aperture for through passage of a top end of a tubular.

8. Apparatus as claimed in claim 7, wherein the central aperture includes a frusto-conical part to facilitate centring of the tubular.

9. Apparatus as claimed in claims 6 and 7, wherein the hoisting device includes catch rods penetrating through-bores in each spacer means for uplifting of a tubular with its associated spacer means.

10. Apparatus as claimed in any one of claims 6 to 9, wherein the hoisting device comprises a fluid operable piston-and-cylinder device for uplifting of a tubular.

11. Apparatus as claimed in any one of claims 6 to 10, wherein the hoisting device includes fluid operable clamping means to secure a tubular prior to uplifting by the hoisting device.

12. Apparatus as claimed in claim 11, wherein the clamping means engage a flange portion of the tubular and clamps said flange portion against an annular lip of the hoisting device.

1 3. Apparatus as claimed in claim 11 or 12, wherein the clamping means are controlled by selective control means to permit selective setting of said lifting means in said first position for uplifting of a tubular and in said second position for removal of a spacer means from a tubular.

1 4. Apparatus as claimed in any one of claims 6 to 13, wherein the lifting means comprises pivotal plate means swingable by an actuating device into either of said first and second setting positions.

1 5. Apparatus as claimed in claim 14, wherein the actuating device is a fluid operable device.

1 6. Apparatus as claimed in claims 1 2 and 14, wherein said pivotal plate means includes first and second operating surfaces, the first operating surface engaging said flange portion in said first setting position while said second operating surface engages the associated spacer means in said second setting position.

1 7. Apparatus as claimed in any one of claims 6 to 16, wherein said hoisting device is carried by rotary means for angular posi tioning of a tubular and its associated spacer means.

1 8. Apparatus as claimed in any one of claims 4 to 17, wherein the mechanical handling means comprise an overhead travelling crane, adapted both to lift the combination of tubular and spacer means and to remove the spacer means from its tubular at said tubular joining zone.

1 9. Apparatus as claimed in any one of claims 5 to 18, wherein stacking apparatus is provided for the spacer means removed from tubulars by the crane means.

20. Apparatus as claimed in claim 19, wherein the stacking apparatus comprises (a) a vertical frame structure, (b) a platform supported in said frame structure for vertical movement and carrying said spacer means, and (c) means for selective vertical movement of said platform.

21. Apparatus as claimed in claim 20, wherein the selective movement means (c) comprises an endless cable trained around pulley wheels on the frame structure (a) and coupled to said platform (b) motion of the cable being achieved by a winch drum drive and switch means are provided operatively connected to the winch drum drive for controlled movements of the platform (b).

22. Apparatus as claimed in any one of claims 5 to 21, wherein each spacer means is of plate form and rectangular in plan and includes linking elements to enable linking up of a horizontal array of similar such spacer means, the arrangement being such that the linked platform spacer means constitute a horizontal floor structure to facilitate access to the upper ends of vertical tubulars carrying the spacer means and stored in horizontal array.

23. Apparatus as claimed in claim 22, wherein the linking elements for the spacer means comprises tongues on the spacer means which tongues are received in slots in another spacer means.

24. Apparatus as claimed in claim 22 or 23, wherein edge receiving means are provided to hold peripheral parts of said floor structure formed from the spacer means.

25. A method of handling tubulars on a drilling rig structure as claimed in claim 1 and substantially as hereinbefore described.

26. Apparatus for handling tubulars in a drilling rig structure substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.