GB2418684A - Platform apparatus for an intervention frame - Google Patents

Abstract

A platform apparatus 30 adapted for connection with an intervention frame 10, the platform apparatus comprising a supporting member, such that in use, the platform apparatus is connected to the intervention frame and the supporting member is shaped or otherwise adapted to support an intervention tool 60. Thus it is possible to stow an intervention tool 60, such as a coiled tubing injector head, on the intervention frame during use of the frame for other purposes. This significantly reduces the amount of time required for changeover from, for example, coiled tubing intervention, to wireline intervention. In preferred embodiments, the platform apparatus is rotatably connected to the frame and also comprises a turntable. Preferably the platform apparatus can rotate around the frame in a first direction whilst the turntable apparatus rotates in the opposite direction thus maintaining the direction of any coiled tubing towards a V-door provided on a derrick, regardless of the rotational position of the platform apparatus.

Description

24 1 8684 ma. 1 1 Apparatus 3 This invention relates to an apparatus such

as a 4 platform for an intervention frame or an intervention frame for inserting or removing 6 equipments from wells. The invention particularly 7 but not exclusively relates to an intervention frame 8 suitable for use on a semi-submersible offshore rig.

It is know to provide an intervention frame which 11 can run, for example coiled tubing or wireline, into 12 the well. A known intervention frame comprises a 13 top section with a main connector or nubbin for 14 attachment to the rig. The nubbin allows the rig to move with respect to the frame so that the amount of 16 heave caused by weather conditions applied to the 17 frame is minimized.

19 Below the top section are two parallel legs which extend towards and are rigidly connected to a bottom 21 section. A fixed winch is provided in order to pick 22 up various components, such as an injector head 1 which deploys and retrieves coiled tubing into the 2 well. A surface tree is connected to the lower end 3 of the bottom sections.

The known frames are capable of running coiled 6 tubing or alternatively running wireline into the 7 well, depending on the requirements at the 8 particular time. However when it is required to 9 change from coiled tubing to running in wireline (or vice versa) a considerable delay ensues.

12 Known frames can only accommodate a single service 13 to be rigged up within the intervention frame - that 14 is either coiled tubing or wireline services. If on completion of coiled tubing services and if it is 16 required to conduct wireline services, the coiled 17 tubing injector head would need to be removed from 18 the intervention frame and placed on the rig floor 19 or other location. Once the injector head was clear of the intervention frame, the wireline equipment 21 could then be rigged up on the intervention frame 22 for wireline services to commence. If wireline 23 services are conducted first, the injector head is 24 not rigged up on the intervention frame until after these are complete - this also necessitates the 26 time-consuming and dangerous winching of the 27 injector head onto the intervention frame.

29 The process of removal of such equipment presents many safety risks and also uses considerable rig 31 time and cost. In some instances this process can 32 be further delayed due to weather conditions as it 1 may be unsafe to pick up or lower equipment with 2 excessive rig heave, pitch & roll and mount it on 3 the intervention frame, which generally does not 4 move with the rig.

6 Moreover the fixed winches provided on known 7 intervention frames provide a limited operating area 8 thus requiring additional leverage from rig tuggers.

9 The relative movement of the rig with respect to the frame makes the rig tuggers difficult to use.

12 Therefore known intervention frames tend only to 13 lend themselves to a single service being performed 14 and hence imposes many safety, operational and commercial disadvantages.

17 Existing frames also tend to use either bails or 18 elevators on the bottom section to suspend the 19 surface tree or riser. Alternatively the surface tree or riser can be positioned through a hole in 21 the bottom section and then secured with a large nut 22 or other device. The nut is unwieldy and dangerous 23 to handle.

The bottom section of the intervention frame on 26 other conventional frames are also rigid or hinged 27 in one direction and thus takes considerable time to 28 connect the surface tree thereto.

Thus it would also be preferable to reduce the time 31 taken to secure such frames to rigs and a surface 1 tree to the frame and reduce the safety hazards 2 associated with this.

4 According to a first aspect of the invention there is provided a platform apparatus adapted for 6 connection with an intervention frame, the platform 7 apparatus comprising a supporting member, such that 8 in use, the platform apparatus is connected to the 9 intervention frame and the supporting member is shaped or otherwise adapted to support an 11 intervention tool.

13 Thus the intervention tool may be provided on the 14 supporting member attached to the frame and not have to be removed from the frame when not in use. For 16 example an injector head may be provided on the 17 supporting member when it is not in use, or 18 preferably whether in use or not.

The intervention frame can be any temporary frame, 21 such as a supporting frame, a lift frame, a coiled 22 thing lift frame, a workover frame or a wireline 23 frame.

Thus the apparatus also preferably includes a 26 connection means to allow connection, preferably 27 rotatable connection between the platform apparatus 28 and the frame.

Preferably the platform apparatus further comprises 31 a turntable apparatus, rotatably mounted on the 32 supporting member.

1 Preferably the turntable apparatus and supporting 2 member each have an aperture, typically to allow a 3 conduit to extend therethrough.

The intervention tool may be an injector head 6 typically of a coiled tubing apparatus, optionally 7 associated with a Blow-Out Preventor (BOP) assembly.

8 Alternatively the intervention tool may be a 9 wireline lubricator, optionally associated with a BOP assembly.

12 Preferably the platform apparatus comprises a first 13 motor adapted to rotate the platform apparatus with 14 respect to the frame.

16 Preferably the platform apparatus comprises a second 17 motor adapted to rotate the turntable apparatus with 18 respect to the supporting member.

Preferably the platform apparatus comprises movement 21 means adapted to allow the turntable apparatus to 22 move towards and away from the connection means.

23 The movement means may be wheels or skids.

Preferably the platform apparatus comprises a 26 further movement means which is adapted to engage 27 with the frame and move the platform apparatus with 28 respect to the frame, typically in a vertical 29 direction in use.

1 The invention also provides an intervention frame 2 comprising a platform apparatus in accordance with 3 the first aspect of the invention.

Preferably the intervention frame has tracks for 6 engagement with the movement means of the platform 7 apparatus. The movement means of the platform 8 apparatus may comprise a toothed wheel for 9 engagement with the tracks.

11 Typically the frame comprises a top section, a rig 12 connector (such as a nubbin) connected above the top 13 section, a winch, at least two legs connected to the 14 top section and extending to and connecting with a bottom section.

17 Preferably the bottom section can move with respect 18 to the legs.

Thus the invention provides an intervention frame 21 apparatus comprising a top section, a rig connector, 22 a bottom section and at least two legs; 23 wherein the bottom section can move with 24 respect to the legs.

26 More preferably a hinge is provided to allow the 27 bottom section to move with respect to the legs.

28 Even more preferably a securing mechanism is 29 provided which can releasably secure the hinge to allow or prevent movement of the bottom section with 31 respect to the legs around the hinge. The securing 32 mechanism may be a sleeve and the sleeve may be 1 hydraulically actuated to allow or prevent movement 2 of said hinge and correspondingly allow or prevent 3 movement of the bottom section with respect to the 4 legs.

6 Preferably the frame is an intervention frame.

7 Typically the frame is shaped to fit within a 8 derrick and typically can attach to a rig.

Preferably at least one (more preferably both) of 11 the legs comprise a plurality of smaller legs 12 adjoined to form the leg. Thus for certain 13 embodiments of the invention the most suitable leg 14 length required may be chosen by including or excluding some of the smaller legs.

17 Thus the invention provides an intervention frame 18 apparatus comprising a top section, a rig connector, 19 a bottom section and at least two legs; wherein at least one of the legs is provided as a 21 plurality of smaller legs which are interconnectable 22 to form said leg. Depending on the particular 23 application, not all of the smaller legs may need to 24 be used to form said leg.

26 Preferably the bottom section is adapted to connect 27 with a surface tree. Preferably the bottom section 28 has an aperture to receive the surface tree and the 29 aperture is defined, in part, by a door.

31 Thus the invention also provides an intervention 32 frame apparatus comprising a top section, a rig 1 connector, a bottom section and at least two legs; 2 wherein the bottom section has an aperture to 3 receive a member, such as a surface tree, and a 4 portion of the aperture is defined by a door.

6 Preferably the door is adapted to move from a first 7 closed position to a second open position.

8 Preferably the aperture is generally O-shaped when 9 the door is in the first closed position and preferably generally C- shaped when the door is in 11 the second open position.

13 Preferably the nubbin is adapted for connection and 14 disconnection with the top section such that a variety of different sizes may be used.

17 Thus the invention provides an intervention frame 18 apparatus comprising a top section, a rig connector, 19 a bottom section and at least two legal wherein the rig connector is releasably connected to 21 the intervention frame.

23 Preferably the winch means is rotatably connected to 24 the frame.

26 Thus the invention provides an intervention frame 27 comprising a winch means, the winch means having 28 connection means, wherein the winch means is 29 rotatably connected to the invention frame via said connection means.

32 Preferably the winch means is a winch.

1 Preterably there is more than one winch. Preferably 2 the or each winch is connected to a leg. More 3 preferably one winch is connected to the first leg 4 and the second winch to the second leg.

6 Preferably the winch has a movement mechanism 7 adapted to allow movement of the winch towards and 8 away from its connection means.

Typically the legs of the frame have lifting 11 connection means such as padeyes to allow them to be 12 connected to a rig tugger and lifted and preferably 13 at least one of the padeyes is rotatably mounted on 14 the legs.

16 According to a further aspect of the invention there 17 is provided an intervention frame apparatus 18 comprising a top section, a rig connector, a bottom 19 section and at least two legs; and at least one connector rotatably mounted on 21 one of the legs.

23 Preferably the connector is a pad-eye. Preferably 24 there are two such connectors on one of the legs.

26 Preferably the connector comprises a sleeve.

27 Optionally a stop may be provided to limit rotation 28 of the connector.

Any feature of any aspect of any invention or 31 embodiment described herein may be combined with any 1 feature of any aspect of any other invention or 2 embodiment described herein mutatis mutandis.

4 An embodiment of the present invention will now be described by way of example only, with reference to 6 the accompanying drawings, in which: 8 Fig. la is a front view of a derrick of an 9 offshore drilling intervention/workover rig used in connection with hydrocarbon wellboresi 11 Fig. lb is a front view of a frame in 12 accordance with one aspect of the present 13 invention connected to a surface tree and riser 14 string; Fig. 2a is an enlarged view of the Fig. lb 16 frame without the surface tree and riser 17 string; 18 Fig. 2b is a plan view of a bottom section of 19 the Fig. 2a frame; Figs. 3a and 3b are sectional views of the Fig. 21 lb frame with an attached platform apparatus in 22 differing positions; 23 Fig. 4a is perspective view of the Fig. lb 24 frame and attached injector head, gooseneck and a portion of coiled tubing; 26 Fig. 4b is a perspective view of the Fig. 4a 27 frame and attached injector head, gooseneck and 28 a portion of coiled tubing, provided within a 29 derrick; Fig. 5 is a side view of a platform apparatus 31 in accordance with one aspect of the present 32 invention; 1 Fig. 6 is a second simplified side view of the 2 Fig. 5 platform apparatus with an attached 3 stripper and blow-out preventor(BOP) and with a 4 turntable channel removed; Fig. 7 is a plan view of the Fig. 5 platform 6 apparatus; 7 Fig. 8 is a second plan view of the Fig. 5 8 platform apparatus in its rotated, stowed 9 position along with a bottom section of the Fig. lb frame and injector head but omitting 11 the top section of the frame; 12 Fig. 9 is an exploded perspective view of part 13 of the Fig. 5 platform apparatus, without a 14 base unit; Figs. 10a-lOf are a series of plan views of the 16 frame and platform apparatus showing the 17 platform apparatus is a variety of rotational 18 positions; 19 Fig. 11 is a side, perspective view of an upper end of the Fig. lb frame; 21 Fig. 12 is a second side, perspective view of 22 an upper end of the Fig. lb frame; 23 Fig. 13 is a side, perspective view of a 24 rotatable drive for a winch, with the winch omitted for clarity; 26 Fig. 14 is a side, perspective view of a lower 27 end of the Fig. lb frame; 28 Fig. 15a is a front view of a hinge lock which 29 forms part of the Fig. lb frame; and, Fig. 15b is also a front view of the Fig. lb 31 hinge, with the hinge in a different 32 orientation; 1 Fig. 16a is a top view of a sleeve which forms 2 part of a swivel pad-eye in accordance with one 3 aspect of the present invention, mounted on a 4 portion of a leg; Fig. 16b is a sectional view of the Fig. 16a 6 sleeve mounted on the leg; and, 7 Fig. 16c is an end view of the Fig. 16a sleeve 8 and leg.

Fig. 1 show a typical derrick 1 provided above oil 11 wells, for example on offshore rigs (not shown).

12 The derrick 1 includes a plurality of pylons 2 which 13 support the structure. A front V-door 3 is provided 14 at one side of the derrick 1 to allow for access to install components within the derrick or to allow 16 for continuous in use connection of, for example, 17 coiled tubing. A smaller access point 4 is provided 18 at the back of the derrick for the same reason.

19 Other derricks can have a diamond-shaped access, known simply as a diamond, above the V-door 3.

21 However, diamonds are also limited to access on a 22 single face of the derrick 1.

24 A frame 10 in accordance with one aspect of the present invention is shown in Fig. lb and in more 26 detail in Figs. 2a, 3a, 3b. Referring to Fig. 2a, 27 the frame 10 comprises a top section 12 with a 28 connector or nubbin 14, legs 16 & 18, a primary 29 winch 24, a secondary winch 26 a platform apparatus 30, and a bottom section 22.

1 In use, the frame 10 is provided within a derrick, 2 as shown in Fig. 4b. The nubbin 14 (not shwon in 3 Fig. 4b) connects to the rig (not shown) in the 4 conventional manner. Semi-submersible rigs on which the present invention is often used, are allowed to 6 move in response to the prevailing weather 7 conditions. This movement would cause problems with 8 aligning tools and the like into the wellbore, but 9 the moveable connection between the nubbin 14 and the rig allows for such movement and keeps the frame 11 10 generally stationary with respect to the 12 wellbore.

14 As shown in Fig. lb, a tree 4 with attached riser string 5 is connected to the bottom section 22 of 16 the frame 10 as described further below.

18 An injector head 60 for coiled tubing 62 (shown in 19 Fig. 4a) is provided on the platform apparatus 30.

This receives coiled tubing 62 from a reel (not 21 shown) and deploys it downhole. The coiled tubing 22 62 extends from the reel through the V-door 3 of the 23 derrick 1 to the injector head 40, as shown in Fig. 24 4b. It is noted that the V-door 3 for the coiled tubing 62 is only provided on one face of the 26 derrick 1 and that a generally planar path (defined 27 by the arcuate shape of the coiled tubing) through 28 the V-door 3 or diamond must be provided between the 29 coiled tubing reel and the injector head 60 to prevent the coiled tubing 62 from buckling.

31 Therefore the injector head 60 must remain oriented 32 in generally the same direction (that is, so that 1 the coiled tubing 62 is directed towards the V-door 2 3 of the derrick 1 at all times.) 4 The platform apparatus 30, which mounts the injector head 60, can rotate around the leg 16 of the frame 6 10 from a central position where it can deploy its 7 tubing downhole, to a side position where it can be 8 conveniently stored whilst wireline or other 9 services are being deployed downhole. Fig. 4b shows the injector head 60 in the stowed position, to 11 allow access to the well below for other services.

12 In this position the coiled tubing 62 still extends 13 out of the V-door 3 of the derrick 1, as it does 14 when the injector head 60 is postitioned between the legs 16, 18.

17 To maintain the orientation of the coiled tubing 62 18 extending from the reel to the injector head 60, a 19 turntable 34 is provided on the platform apparatus 30 which counter-rotates with respect to the 21 rotation of the platform apparatus 30 around the leg 22 16 of the frame 10 as described in more detail, with 23 reference to figs. 5-9.

Referring to Fig. 5 in the first instance, the 26 platform apparatus 30 comprises a base unit 32, a 27 carriage 46 mounted on the base unit 32, a turntable 28 34 mounted on the carriage 46, and a platform 29 29 mounted on the turntable 34.

31 As shown in Fig. 6, the base unit 32 includes a 32 connection means 36 for connection with the leg 16 1 of the frame 10, a slew motor 40 and a hydraulic 2 crawling mechanism 42. The slew motor 40 drives the 3 platform apparatus 30 around the leg 16 of the frame 4 10. The hydraulic crawling mechanism 42 comprises toothed wheels 45 (shown in Fig. 2a) which are 6 adapted to engage with tracks 43 (shown in Figs. 2a 7 and 14) on the leg 16 of the frame 10 and can move 8 the platform apparatus 30 up and down the leg 16.

9 Below the base unit 32, various tools can be connected, depending on the particular operation 11 being performed. In Fig. 6, for example, a surface 12 stripper 6 to seal the coiled tubing into the well 13 and a blow-out preventor 7 are shown. A channel 44, 14 shown in Fig. 5, is provided on an upper face of the base unit 32 to receive the carriage 46.

17 The carriage 46 has hydraulically activated wheels 18 48 and can move transversely within the channel 44 19 of the base unit 32 towards and away from the leg 16 in order to align the platform apparatus 30 with the 21 wellbore in use (or an off-centre tool). Also this 22 can be used to prevent collision of the leg 16 with 23 the injector head 60 when stowing the platform 24 apparatus 30 away from the centre of the frame 10, as described in more detail further below.

27 The carriage 46 also comprises a turntable motor 38 28 (shown in Fig. 6) to rotate the turntable 34 mounted 29 thereon. The platform 29 is secured on the turntable 34. Pins 35 are provided on the platform 31 29 in order to form a secure connection with an 32 injector head of a coiled tubing apparatus.

1 An aperture extends generally through the centre of 2 the platform apparatus 30 to allow coiled tubing to 3 extend therethrough. For example, an oval central 4 aperture 33 (shown in Fig. 7) is provided within the base unit 32. Circular apertures are provided 6 through the carriage 46, platform 29 and turntable 7 34 since these all move with the injector head 60 8 and the coiled tubing which extends therethrough.

Fig. 9 shows the carriage 46 and turntable 11 connected via a slew ring 37.

13 Thus, in use, the platform apparatus 30 is rotated 14 such that it is aligned with the central bore 23 of the bottom section 22. The injector head 60 is 16 winched onto the platform apparatus 30 and secured 17 via the pins 35. Coiled tubing 62 is fed from the 18 coiled tubing reel via a gooseneck 64 into the 19 injector head 60. The tubing 62 extends through the injector head 60, through the central aperture of 21 the platform apparatus 30, through the aperture 23 22 in the bottom section and through the tree 4 and 23 riser string 5 to the well. Fig. lOa shows a plan 24 view of the coiled tubing injector 60, directly above the bottom section 22. The coiled tubing 62 26 is fed into the injector head 60 via a gooseneck 64.

27 The coiled tubing 62 can extend out of the derrick 1 28 via the V-door 3.

When it is required to run wireline into the well 31 rather than coiled tubing, the coiled tubing 62 is 32 retrieved in the conventional manner. However, the 1 coiled tubing injector head 60 does not need to be 2 removed from the frame 10 as is conventional for 3 other frames but can be stowed. The platform 4 apparatus 30 rotates around the leg 16 away from the central axis of the frame 10 allowing for access for 6 wireline. See angle A is Figs. lOb-lOf. At the same 7 time, the turntable 34 of the platform apparatus 30 8 counter-rotates in order to maintain the orientation 9 of the coiled tubing 62 towards V-door 3 of the derrick 1 and towards the coiled tubing reel. The 11 rotation of the turntable 34 is shown as angle B in 12 Figs. lOb-lOf. Fig. 8 is a more detailed view of 13 the platform apparatus towards its stowed position.

14 Fig. lOf shows the injector head clear of the aperture 23 in the base section 22. Thus the coiled 16 tubing injection head 60 can be positioned clear of 17 the central axis of the frame 10 allowing clear rig 18 up of wireline service from either direction.

Due to the space constraints the turntable 34 can 21 also be moved transversely during this operation of 22 moving the platform apparatus 30 away from above the 23 aperture 23. This prevents collision of the mounted 24 injector head 60 with the leg 16 and is achieved by using the wheels 48 in the channel 44 to move the 26 carriage 46 and attached turntable 34, platform 29 27 and injector head 60.

29 Embodiments of the present invention benefit in that the wireline services may be conducted from varying 31 directions with a coiled tubing injector head 32 remaining supported by the intervention frame. Thus 1 the coiled tubing injector head can remain rigged up 2 for multiple bottom hole assembly deployments using 3 coiled tubing or wireline services.

This saves considerable time when changing from 6 coiled tubing work to wireline work or vice versa.

7 Moreover, where inclement weather renders mounting 8 and Remounting of an injector head from the rig to 9 an intervention frame too dangerous due to the relative movement of the frame and the rig, 11 considerable delays can ensue. However, embodiments 12 of the present invention benefit in that the 13 injector head remains on the frame at all times.

Embodiments of the present invention also benefit in 16 that the full weight of the injector head is 17 supported by, not only a winch, but also the 18 platform whether in use or not and thus is far safer 19 than conventional frames which support the injector head using only a winch when in use.

22 A further benefit of certain embodiments of the 23 invention is that the transverse movement of the 24 platform apparatus and/or winches allow the injector head to be easily aligned with items which do not 26 have a central bore but rather have an off-centre 27 bore, such as a dual completion string.

29 A particular benefit of the present invention is that the platform apparatus with the injector head 31 can move up and down the leg whilst supporting the 1 injector head and hence can vary the position or 2 height as required.

4 Some more specific features of the frame 10 will now be described. The primary 24 and secondary 26 6 winches are shown in Figs. 11-12. Preferably the 7 primary winch is connected to the leg 16 with the 8 platform apparatus and the secondary winch is 9 connected to the other leg, in this case leg 18.

Figs. lb, and 2a reflect this preferred 11 configuration whilst Figs. 3a, 3b are of the 12 opposite configuration. The winches 24, 26 are 13 mounted on stewing Davot_ arms 25, 27 respectively.

14 The arms are in turn rotatably connected to the legs 16, 18 respectively. Moreover the winches 25, 27 16 are mounted on carriages to allow them to move 17 transversely on their respective arms 26, 28 in 18 order to move the winch 25/27 closer to or away from 19 the attached frame 10. This allows the arms 26, 28 to slew external of the frame 10, and for the 21 winches 25, 27 to move transversely to provide an 22 unobstructed and straight line lift of components 23 between the rig floor and the frame 10.

An advantage of such embodiments of the invention is 26 that an additional winch fixed to the rig (not the 27 frame 10), known as a rig tugger, may not be 28 required to restrain and guide the lifted item past 29 obstructions to the position required (typically over the well bore). Such rig tuggers are often 31 difficult to use in such applications because of the 32 movement/heaving of the rig.

1 The legs 16, 18 may be provided as a number of 2 smaller, varying leg lengths joined in a bolt type 3 clamp hub. Sections of the smaller legs can be 4 removed in order that the frame can be of appropriate size for particular applications.

7 The nubbin 14 may be removed and replaced in order 8 to cater for a variety of different connections to 9 rigs and to alternate types or in the event of danger/wear occurring. The nubbin 14 is used to 11 allow for derrick travelling block elevators (not 12 shown) of the rig to attach thereto.

14 The hinges 80, shown in Fig. 15a and 15b, are enclosed by a sleeve 82 which prevents the pivoting 16 action of the hinges 80. The sleeve can be 17 retracted by pistons 84 (not shown in Figs. 15a, 18 15b) to allow the hinges 80 to pivot.

Fig. 14 shows a simplified version of the bottom 21 section 22 of the frame 10. The legs 16, 18 are 22 connected to the bottom section 22 via the hinges 80 23 in order to allow the bottom section 22 to pivot 24 around the hinges 80 and for the plane of the bottom section 22 to be disposed at right angles to the 26 plane defined by the legs 16, 18. This allows the 27 frame 10 to be used in a variety of positions in 28 relation to obstructions on the derrick, such as 29 derrick dolly tracks (not shown) and is used in particular when attaching the surface tree 4 to the 31 frame 10, as described below.

1 The aperture 23 of the bottom section 22 of the 2 frame 10 is manufactured as a "C" section as opposed 3 to an open hole and has a door 76 to complete the 4 aperture 23. A hydraulic arm 78 operates the door 76 from a closed to an open position. This allows 6 the surface tree or riser (not shown) to have its 7 securing nut in position and there is no need to 8 completely remove the nut in order for the surface 9 tree 4 to engage be received within the aperture 23 of the bottom section 22 because the door 76 can be 11 opened to allow access and then close to secure them 12 together.

14 The legs 16, 18 extend from screw connections 13 into the top section 12 to remotely operated hinge 16 locks 80 for connection to the bottom section 22.

17 The legs 16, 18 may be provided in a number of 18 different sections which are adjoined by quick 19 disconnect connections 21.

21 Swivel padeyes 17 are provided at either end of the 22 leg 16 and fixed padeyes 15 are provided at either 23 end of the leg 18. These are used when lifting the 24 frame 10 into the derrick 1.

26 The swivel pad-eyes 18 are shown in more detail in 27 Figs. 16a - 16c and comprise a sleeve 70 with an 28 attached padoye portion 72. The sleeve 70 is 29 provided around the leg 16 of the frame 10. A step 74 is provided on the edge of the sleeve and stops 31 75 on the leg 16 engage with the steps 74. The size 32 of the steps 74 and the stops 75 thus determines the 1 allowable rotation of the sleeve 70 and attached 2 padoye 72 with respect to the leg 16. Preferably the 3 step extends for 180 around the sleeve 70 thus 4 allowing the padoye 72 to rotate by 90 with respect tothe leg 16 in either direction. In certain 6 embodiments the stops 75 may not be necessary and 7 the sleeve is thus allowed to rotate around the leg 8 16 freely.

Bail connectors 54 are provided for an alternative, 11 less preferred, connection means and can allow the 12 surface tree 4 to be hung-off from the bottom 13 section 22 of the frame 10.

The operation to secure the frame 10 to the rig will 16 now be described. Before lifting the frame 10 onto 17 the derrick 1, the frame 10 is placed on a platform 18 of the rig (not shown) and all padeyes 15, 17 are 19 orientated upwards. A crane (not shown) connects to each padeye and lifts the frame 10 towards the 21 derrick 1. The connection with the fixed padoyes 15 22 are then released and the frame 10 rotates around 23 the leg 16 under its own weight. The swivel padeyes 24 17 allow for such rotation. Elevators (not shown) of the rig connect to the nubbin 14 and the frame 10 26 is brought inside the derrick 1 and rotates into a 27 vertical position.

29 The crane releases the padoyes 17 and the frame 10 is lowered onto the rig platform by the rig 31 elevators.

1 The sleeve 82 on the hinges 80 is then retracted by 2 the pistons 84 to allow the bottom section 22 to 3 pivot with respect to the main part of the legs 16, 4 18. One of the winches 24, 26 then connects to the bottom section 22 and winches it up slightly so that 6 the bottom section 22 is at right angles to the rest 7 of the frame 10.

9 Then the integral door 76 within the bottom section 22 is opened to allow access for the surface tree 4 11 to the aperture 23. The surface tree 4 is 12 positioned within the aperture 23 and the door 76 13 closed. The surface tree 4 or riser securing nut can 14 be tightened if necessary.

16 The frame 10 is then raised by the elevators into 17 the final position. Raising the frame 10 allows the 18 bottom section 22 to pivot back under its own weight 19 such that its plane is parallel with the plane defined by the legs 16, 18. This allows the surface 21 tree or riser to be lifted safely from the 22 horizontal to the vertical position. The sleeves 82 23 are returned over the hinges 80 in order to prevent 24 any further pivoting of the bottom section 22 with respect to the legs 16, 18.

27 Thus embodiments of the present invention benefit in 28 that there is reduced manual intervention and risk 29 in handling surface tree securing nut. The frame 10 can also be more secured to the rig more quickly 31 than certain known frames.

1 Improvements and modifications may be made without 2 departing from the scope of the invention.

Claims (1)

1 Claims 3 1. A platform apparatus adapted for connection 4 with an

intervention frame, the platform apparatus comprising a supporting member, such that in use, 6 the platform apparatus is connected to the 7 intervention frame and the supporting member is 8 shaped or otherwise adapted to support an 9 intervention tool.

11 2. A platform apparatus as claimed in claim 1, 12 also including a connection means which in use 13 allows the platform apparatus to rotate with respect 14 to the frame.

16 3. A platform apparatus as claimed in claim 2, 17 comprising a first motor operable to rotate the 18 platform apparatus with respect to the frame.

4. A platform apparatus as claimed in any 21 preceding claim, further comprising a turntable 22 apparatus, rotatably mounted on the supporting 23 member.

5. A platform apparatus as claimed in claim 4 when 26 dependent upon any one of claims 2 or 3, wherein the 27 connection means and turntable apparatus are adapted 28 to counter-rotate with respect to each other.

6. A platform apparatus as claimed in claim 4 or 31 claim 5, comprising a second motor adapted to rotate 1 the turntable apparatus with respect to the 2 supporting member.

4 7. A platform apparatus as claimed in any one of claim 4 to 6, wherein the turntable apparatus and 6 supporting member each have an aperture to allow a 7 conduit to extend therethrough.

9 8. A platform apparatus as claimed in any one of claim 4 to 7, comprising movement means adapted to 11 allow the turntable apparatus to move towards and 12 away from the connection means.

14 9. A platform apparatus as claimed in any preceding claim, comprising vertical movement means 16 which, in use, are adapted to engage with the frame 17 and move the platform apparatus with respect to the 18 frame in a generally vertical direction.

10. An intervention frame comprising a platform 21 apparatus as claimed in any preceding claim.

23 11. An intervention frame as claimed in claim 10, 24 comprising tracks for engagement with movement means of the platform apparatus so that in use, the 26 platform apparatus is moveable in a vertical 27 direction with respect to the intervention frame.

29 12. An intervention frame as claimed in claim 10 or claim 11, comprising a winch means rotatably 31 connected to the frame.

1 13. An intervention frame as claimed in claim 12, 2 the winch means comprising a winch and a movement 3 mechanism adapted to allow movement of the winch 4 towards and away from its connection with the frame.

6 14. An intervention frame comprising a top section, 7 a rig connector, a winch means, at least two legs 8 connected to the top section and extending to and 9 connecting with a bottom section.

11 15. An intervention frame as claimed in claim 14, 12 wherein the bottom section can move with respect to 13 the legs.

16. An intervention frame as claimed in claim 15, 16 wherein a hinge is provided to allow the bottom 17 section to move with respect to the legs.

19 17. An intervention frame as claimed in claim 16, comprising a securing mechanism operable to 21 releasably secure the hinge to allow or prevent 22 movement of the bottom section with respect to the 23 legs.

18. An intervention frame as claimed in any one of 26 claims 14 to 17, wherein at least one of the legs 27 comprises a plurality of smaller legs adjoined to 28 form the leg.

19. An intervention frame as claimed in any one of 31 claims 14 to 18, wherein the bottom section has an 32 aperture shaped to receive a portion of a surface 1 tree and the aperture is defined, in part, by a 2 door.

4 20. An intervention frame as claimed in claim 19, wherein the door is adapted to move from a first 6 closed position to a second open position.

8 21. An intervention frame as claimed in claim 19 or 9 claim 20, wherein the aperture is generally O-shaped when the door is in the first closed position and 11 generally C-shaped when the door is in the second 12 open position.

14 22. An intervention frame as claimed in any one of claims 14 to 21, wherein the rig connector is 16 releasably connected to the intervention frame.

18 23. An intervention frame as claimed in any one of 19 claims 13 to 22, comprising at least one connector rotatably mounted on one of the legs for use in 21 mounting the intervention frame within a derrick.

23 24. An intervention frame as claimed in claim 23, 24 wherein a stop is provided to limit rotation of the connector.