Field of the Invention

The present invention relates to a tool servicing apparatus and in particular to a well-head service tool, for example for use in servicing blow out preventer stacks.

Background of the Invention

Blow-out preventer stacks, also known as blow out preventers and blow out prevention systems are used in oil and gas drilling rigs to seal, control and monitor oil and gas wells. Blowout preventers were developed to cope with extreme erratic pressures and uncontrolled flow (formation kick) emanating from a well reservoir during drilling. Kicks can lead to a potentially catastrophic event known as a blowout. In addition to controlling the downhole (occurring in the drilled hole) pressure and the flow of oil and gas, blowout preventers are intended to prevent tubing (e.g. drill pipe and well casing), tools and drilling fluid from being blown out of the well bore (also known as the bore hole, or the hole leading to the reservoir) when a blowout threatens. Blowout preventers are critical to the safety of crew, rig (the equipment system used to drill a well bore) and environment, and to the monitoring and maintenance of well integrity.

Blow-out preventers are important for the safety of rig crews and the natural environment, as well as the drilling rig and the well bore itseif. Authorities recommend, and regulations require, that BOPs be regularly inspected, tested and refurbished. Tests vary from daily test of functions on critical wells to monthly or less frequent testing on wells with low likelihood of control problems.

As a result of incidents involving the failure of blow-out preventers, in many parts of the world there is now a requirement that blow-out prevention stacks are removed from the rig and stripped down regularly. Oil and gas rigs tend to operate in harsh environments. As a result of this there is often significant difficulty in dismantling blow-off prevention stacks.

The biow-out prevention stack is usually made up of a number of components that are circular in cross-section and mounted concentrically one within the other. The stack usually presents a number of flanges that might be engaged to release other components of the stack. Disassembly of the stack usually involves the use of chain wrenches, long levers and numbers of men. This is unsatisfactory for a number of reasons. The chain wrenches fend to compress the flange and also to damage the flange surface. Using large numbers of men for such tasks is not an efficient use of labour.

It would therefore be desirable to provide a well-head service tool specifically adapted for disassembling biow-out prevention stacks.

Summary of the invention

According to a first aspect of the invention there is provide a tool servicing apparatus comprising a tool support frame assembly, at least two brace members for attachment to the serviced tool, the apparatus further comprising fastening means attachable to at least one of the brace members and the tool support frame assembly and configured to resist rotation of the brace member with respect to the tool support and wherein at least one of the brace members is adapted to attach to a drive member, the drive member being adapted to connect to a rotary drive so that the rotary drive may cause rotation of components of the serviced tool situated between the brace member fastened against rotation and the brace member having the drive member attached thereto.

The tool servicing apparatus may include the rotary drive. However, various hydraulic torque tools may be used as a source of rotary power, particularly when used in conjunction with rotary drive mount of the fourth aspect of the invention.

St is preferred that the tool support frame assembly comprises a frame and wherein the fastening means are removably mounted on the frame. Preferably, the frame is provided with a plurality of positions for attachment of the fastening means to the frame.

The frame may include a plurality o! holes and the fastening means include a corresponding hole and a pin is removably mounted in the hole of the fastening means and a selected one of the holes of the frame.

The fastening means may comprise jaws, or elongate rails, which may include a plurality of hoes therein.

Advantageously, the tool servicing apparatus comprises a base plate having an opening therein for receiving the serviced tool.

Preferably, the opening is substantially U-shaped,

The base plate may be provided with at least one indicia for alignment therewith of a part of the serviced tool.

The base plate may be mounted in the tool support frame assembly for movement with respect thereto in the vertical direction.

Advantageously, the tool servicing apparatus further comprises at least one actuator configured to effect said movement in the vertical direction.

At least one of the brace members may be a collar.

The tool servicing apparatus wherein at least one collar may have mounted on an inner surface thereof at least one friction element.

Preferably, the inner surface is provided with at least one recess and the friction element is aligned with the recess.

The friction element is mounted in a mounting member may be mounted in the recess.

The tool servicing apparatus may comprise a plurality of recesses and a corresponding plurality of friction elements.

It is preferred that the friction element is formed of a composite material. The friction element may be metallic.

The friction element may have a roughened surface for engaging the serviced tool.

The at least one collar may comprises a plurality of parts attachable one to another.

The drive member may comprise two spaced apart elements and at least one of the collars comprises two corresponding elements, which are adapted to transfer torque there between when aligned.

The said elements are male and female elements.

The at least one brace member may include a flange or a block for engaging with the fastening means.

The flange or block may have free ends and wherein when the collar is mounted on the serviced tool and the serviced tool is positioned in the support frame the free ends are proximate the frame.

Preferably, at least one of the brace members may be provided with lifting elements.

The lifting elements may be lifting hooks.

Preferably, at least one of the collars comprises a part of an inner surface that is formed by a protrusion and wherein the protrusion or a friction element associated therewith is adapted engage an outer surface of the serviced tool.

Preferably, one of the brace members comprises a plate for mounting of the serviced tool thereon and wherein the plate is configured such that the serviced fool is attachable thereto by elongate fasteners.

The plate may include holes and the fasteners are pins or bolts passing through the holes in the plate and holes in a part of the serviced tool.

The uprights may extend from the plate and wherein said fastening means may attach to the uprights.

The piate may include a hole configured such that a part of the serviced tool may pass through the hole and another part of the serviced tool may rest on the piate. A second aspect of the invention provides a method of servicing a tool using an apparatus according to the first aspect of the invention.

The servicing may comprise assembling or disassembling a tool.

The tool may be a BOP or an actuator for example.

When reassembling a well-head the rotary drive must rotate in the opposite direction to the direction of rotation for separating the parts of the well-head. This may be achieved either by inverting the the rotary drive, by reversing the drive, or by providing a bi-directional drive.

A third aspect of the invention relates to a bi-directional rotary drive which comprises a first linear actuator and a second linear actuator attached respectively to a first arm and a second arm, the first and second arms both mounted for rotation about a common axis, and wherein extension and retraction of the first linear actuator rotates the first arm clockwise and counter clockwise and wherein extension and retraction of the first and second linear actuators rotates the second arm counter clockwise and clockwise respectively.

Preferably, one of the first and second arms is attached to a shaft centred on the common axis and the other of the first and second arms is attached to a sleeve centred on the common axis and mounted rotatably on the shaft. More preferably, the attachment of the first and second arms to the shaft and sleeve respectively is by means of a ratchet drive situated between the arms and the shaft and sleeve, the ratchet drive providing that rotation of the first and second arms resulting from one of extension and retraction of the first and second linear actuators transfers torque to the shaft and sleeve respectively, and the other of extension and retraction of the first and second linear actuators does not transfer torque to the shaft and sleeve.

The rotary drive preferably includes first and second mounting members for mounting the first and second linear actuators therein, and wherein the the first and second linear actuators are mounted for rotation with respect to the first and second mounting members respectively. The first and second linear actuators may each be mounted in a gimbal, the gimbals mounted for rotation in the first and second mounting members.

The rotary drive may comprise a housing, including a base plate and a beam, the first and second arms situated between the base plate and the beam. Preferably, the first and second mounting members are situated between the base plate and the beam.

Advantageously, the first and second linear actuators are hydraulically powered.

According to a fourth aspect of the invention there is provided a rotary drive mount, the rotary drive mount configured for mounting on the frame assembly and including at least one reaction member configured to transfer a reaction force from the rotary drive to the frame assembly.

It is preferred that the rotary drive mount is adapted to receive a plurality of different rotary drives, the providing a plurality of positions for the at least one reaction member.

Brief Description of the Drawings in the Drawings, which illustrate preferred embodiments of an apparatus according to the invention:

Figure 1 is a schematic representation of components of a well-head service tool according to a first aspect of the invention;

Figure 2 is a exploded view of a lift frame assembly of the well-head service tool illustrated in Figure 1 ;

Figure 3 is an exploded view of a frame of the well-head service tool illustrated in Figure 1 ;

Figure 4 is a schematic representation of collars of the well-head service tool illustrated in Figure 1 ;

Figure 5 is a schematic representation of the well-head service tool of the invention with a BOP mounted therein; Figure 6 illustrates an alternative configuration of a collar of the well-head service tool of the invention;

Figure 7 is a schematic representation of a part of the collar illustrated in Figure 6;

Figure 8 is a schematic representation of the part illustrated in Figure 7 with an alternative gripping element;

Figure 9 is a schematic representation of the collar illustrated in Figure 6 in assembled form;

Figure 10 is a cross-section through a service tool with an actuator mounted therein;

Figure 11 is a schematic representation of the components of the service tool illustrated in Figure 10;

Figure 12 illustrates an alternative form of clamp;

Figure 13 is an exploded schematic representation of an alternative embodiment of a well-head service tool of the invention;

Figure 14 is a front view of the well-head service tool illustrated in Figure 13;

Figure 15 is an exploded schematic representation of a drive collar of the well-head service tool illustrated in Figures 13 and 14;

Figure 16 is a schematic representation of the drive collar illustrated in Figure 5 in assembled form;

Figure 17 is a rear view of a lift of the well-head service tool illustrated in Figures 13 and 4; Figure 18 is a front view of the lift illustrated in Figure 17;

Figure 19 is an exploded schematic representation of a securing collar of the well-head service tool illustrated in Figures 3 and 14;

Figure 20 is schematic representation of the securing collar show in Figure 19 in assembled form;

Figure 21 is an exploded schematic representation of a rotary tool receiving plate, drive and reaction members of the well-head service tool illustrated in Figures 3 and 4; Figure 22 is a schematic representation of the rotary tool receiving piate, drive and reaction members illustrated in Figure 21 in assembled form;

Figure 23 is a schematic representation of a rotary drive suitable for use with the well-head service tool illustrated in Figures 13 and 14;

Figure 2.4 is a schematic representation of a rotary drive suitable for use with the well-head service tool illustrated in Figures 13 and 14 with a drive member attached thereto;

Figure 25 is an exploded view of the rotary drive illustrated in Figures 23 and 24;

Figure 26 is an exploded view of the rotary drive illustrated in Figure 25 from above and the front;

Figure 27 is an exploded view of the rotary drive illustrated in Figure 25 from above and the rear;

Figure 27a illustrates two internally splined square drives;

Figure 28 is a cutaway schematic representation of the well-head service tool shown in Figures 13 to 27 with a BOP mounted therein; and

Figure 29 is a variation of the service tool shown in Figures 10 and 11 .

Detailed Description of the Invention

Referring now to Figure 1 , an apparatus according to the invention comprises a frame 1 which is configured to receive and support a well-head tool, in this case a blow out prevention stack (BOP) 101 .

The frame 1 comprises four corner posts 2 connected together by cross-members 3, 4, 5. Corner brace members 6 extend between the cross members and corner posts 2. As can be seen from Figure , the frame 1 is configured so that one side thereof is open, that is cross members 3 and 5 are provided at the top and the bottom of the corner posts 2, but not between these extremes. This open side allows the component, in this case a BOP 101 that is to be serviced to be introduced into the frame 1 . In order to provide for the frame to be moved from place to place under the lower cross members 5 situated to either side of the the open side the frame has fork receiving boxes 7 so that the frame 1 may be moved about by a forklift truck or pallet lifter.

The frame 1 is provided with a number of components that assist in the disassembly and assembly of the BOP 101 . The first of these components is the support assembly 20, which is best shown in Figure 2. The support assembly 20 comprises a base plate 21 and a wall frame 22, which is fastened to the base plate 21 . The base piate 21 includes a substantially U-shaped opening 23. The surface 21 ' of the base plate 21 is provided with a series of concentric rings 24 (note that the parts of the rings that would be situated in the U-shaped opening 23 are not present).

The concentric rings 24 provide markers and allow the BOP 101 to be positioned so that it is correctly centred in the frame 1 . The concentric rings 24 are provided on radii corresponding to the radii of circular parts of common BOP's used in the oil and gas industry. The plate 21 , the U- shaped opening 23 thereof and the concentric rings 24 may be configured for a particular BOP or range of BOP's.

The wall frame 22 and attached base piate 21 are mounted in the frame 1 so that they may be moved upwards and downwards in the frame 1 . To this end the underside of the base p!ate 21 is provided with downwardly extending bosses 2 a which engage with actuators 11 , in the form of hydraulic cylinders in the present embodiments.

The frame 1 is also configured to support a drive tool 30, which comprises reaction arms 31 , a gear set 32 attached to the reaction arms 31 and a hydraulic motor 33 arranged to drive the gear set 32. In the present example the gear set comprises a plurality of planetary drives arranged in series, which serve to reduce the speed and increase the torque at the output of the gear set 32 in comparison with the speed and torque of the hydraulic motor 33. Each reaction arm 31 includes a hole 34, which in use locates on and receives a boss 10. Each boss 10 includes a through bore 10' through which a pin (not shown) may be inserted. With the drive tool mounted on the frame 1 , two diagonally opposed bosses engaging with the holes 34 of the respective reaction arms 3 , pins are passed through the holes 10' in the engaged bosses, thereby preventing unwanted movement of the reaction arms off the frame 1 .

The drive tool 30 provides a square drive 35. The square drive is configured to engage and drive a drive plate.

The drive plate forms part of one of a number of collar assemblies that are configured to engage with certain surfaces of the BOP 101 .

Figure 4 illustrates the BOP equipped with three collar assemblies 40, 50 and 60. The function of the collar assemblies 40, 50 an 60 is two fold. First, the collars assist in mounting of the BOP in the frame and fixing the BOP in a desired position; second, the collars play a role in the transmission of torque from the drive tool to the BOP to separate elements thereof from one another.

Turning first to the collar 40, this is configured to attach to an uppermost part of the BOP 101 , The collar 40 comprises four elements 41 . These four elements 41 are joined together in pairs by bolts to form collar members 4 '. Each collar member 4 ' is presented up to one side of a flange 102 of the BOP 101 . Holes 43 in flat faces 43' of the elements 41 are aligned and bolts 44 passed therethrough. Nuts 46 are engaged on the respective bolts 45 so that the collar members 41 ' may be brought into tight engagement with the flange 102 of the BOP, suitable washers 45 being provided between the bolt head and the collar element and the nut and the collar.

In order to prevent the collar 40 from rotating with respect to the flange 102, friction material is provided on the inner surface of the curved part of the four collar elements 41 . In the present example, each collar element 41 is provided with three discrete recesses 47, each configured to receive a pad 48 formed of friction generating material 48. The friction pad may be an interference fit in the recess 47.

The collar 40 includes a drive plate 49. The drive plate 49 includes three sockets, a socket 49a to the centre and configured to receive the square drive 35 of the drive tool 30, and two sockets 49b, one to either side of the socket 49a. The sockets 49b are configured to engage with bosses 42 of each element 41 . If can be seen from Figure 3 that when the elements 41 are connected together in pairs the bosses 42 are situated adjacent one another. To the side of each boss 42 is a bore 42a extending into the body of the element 41 . When the sockets 49b of the drive plate 49 are presented up to the bosses 48 and placed thereon holes 49c adjacent the sockets 49b will be aligned with the bores 42a. It is preferred that the bores 42a are threaded so that a bolt or screw that passes through the hole 49c can engage therewith so as to fasten the drive plate to the collar members 41 '.

Each element 41 includes a flange 41 a that extends significantly beyond the holes 43. When the two members 41 ' are attached together, these flanges 41 a may be engaged by the jaws 16, the reaction torque being transmitted to the frame proximate thereto.

Collars 50 and 60 are provided for attachment to other flanges of the BOP 101 .

The collars 50 and 60 differ from the collar 40. Whereas the collar 40 is driven so as to rotate, the collars 50 and 60 provide for locking the BOP 101 with respect to the frame 1 so as to prevent relative rotate therebetween.

In the illustrated embodiments each of the collars 50, 60 is formed of four collar elements 51 , 61 .

Each collar element 51 includes a flange 52 at the free ends thereof. Each flange includes holes for receiving bolts 53 secured by nuts 54. One of the flanges 52 of each collar element 51 includes a boss 52'. When the collar 50 is assembled the bosses 52' can be engaged by a drive plate in the same way that the drive plate 49 engages bosses 42. Each collar element 51 is also provided with a protruding block 55. The blocks 55 provide two functions. First, as can be seen from Figure 3, a lifting hook 56 is attached to each block 55.

Typically, a hole is formed in the block 55, threaded internally and the lifting hook 56 is provided with a threaded shaft so that the lifting hook 56 may be attached releasably to the block 55. The block 55 also provides for securing of the BOP 101 in the frame 1 as will be described in greater detail below.

The collar 60 is similar to the collars 40 and 50 insofar as the collar 60 comprises four collar elements 61 , each of which has flanges 62 at the free ends thereof, and friction elements mounted on the inner surface of each collar element. The flanges 62 include holes that receive bolts 63 which, together with nuts 64 fasten the collar elements 61 together to form the collar 60. The collar 60 differs in that it is not intended to engage with a drive tool by means of a drive plate and bosses. The function of the collar 60 is to assist in supporting the BOP in the frame 1 and to resist torque applied to other parts of the BOP during assembly and disassembly. To this end, the flanges 62 extend beyond the bolts 63 to provide a block that can be received in a channel 16a. By extending the flanges 62 further towards the frame, the torque reacted when the drive too! 30 is rotated is situated close to the frame, which is advantageous.

Referring now to Figure 5, it can be seen that the BOP 101 has collars 40, 50 and 60 attached thereto and is mounted in the frame 1 . Figure 5 also illustrates the hydraulic lift for support assembly 20 and associated guide rails 13. Guide rails 13 are mounted in brackets 12 which themselves are attached to a rear wail plate 2a. Two guide rails 13 are shown in the present embodiment, although the actual number of guide rails is not critical. A collar 21 d is attached to the base plate 21 of the support assembly 20. The provision of the guide rails 13 and associated collars 21 d ensures that the support assembly 20 moves vertically and avoids unwanted lateral loads being transferred to the lift actuators 11 .

The support assembly 20 is lifted by two actuators 11 to the front of the frame 1 and two actuators 11 a to the rear of the frame. The actuators 11 , 11a are hydraulically powered by a common hydraulic supply line 11 b, the actuators 11 , 11 a being specified such that key extend and retract at the same rate.

The frame 1 includes vertically disposed side rails 14, the side rails being provided with a plurality of holes 15. The function of the side rails 14 is to provide a means of attaching jaws 16 to the frame 1 . Jaws 16 are secured on the rails 14 (two on each rail in this example) by means of removable plates 16b, and can be fixed in a particular position on the rails 14 by aligning holes in the jaws 16 with a hole 15 in the side rail and passing a pin 17 therethrough. The pin 17 is provided with a hole for receiving a retaining clip 17a, which stops the pin 17 from inadvertently being removed from the hole 15.

Each jaw 6 is provided with a channel 16a. The channels 16a are configured to receive one of the blocks 55 of the collar 50, or in the case of the lowermost jaws 16, to receive the ends of the flanges 62 of the collar 60.

The whole BOP 101 is supported on the base plate 21 of the support assembly 20. The support assembly is provided with three clamps which serve to orient the BOP in the frame 1 correctiy and to secure the BOP against movement in the vertical axis. One of the clamps 22a has an inward facing surface having two facets 22b, 22c, both of which lie forward of the vertical, the facet 22c lying further forward of the vertical than the facet 22b. The clamp 22a is attached to the base plate 21 by means of a slot 28 therein, with a bolt 22d that passes through the slot 28 and a bore extending into the base clamp 22a. When the clamp 22a is in the desired position with respect to the slot 28, the bolt 22d is tightened. The other two clamps are also mounted on base plate 21 and moveable in slots 28 by bolts 27. However, these clamps comprise a jaw 26 that is s!idab!e in a bracket 25. The jaw 26 includes a shaped part 26b that is configured to slide in the bracket 25, which internally is shaped to prevent rotation of the jaw 26 with respect to the bracket 25.

The bolt 27 passes through the part 26b of the jaw 26 and the slot 28 of the base plate 21 . The jaw 26 is moved in the slot 28 to the desired position and the bolt 27 is tightened by means of the nut 27a, thereby pulling the jaw onto the upper surface F of a flange of the BOP 101 . Both jaws 26 are positioned and fastened. This results in the flange F being held between three clamps arranged substantially equidistantly and being pressed down onto the upper surface of the base plate 21 ,

Hence, it will be understood by one skilled in the art thai the jaws 16 secure the BOP against rotation, while the clamps 22a, 23a prevent movement in the vertical direction. The drive tool may therefore apply torque to the BOP that causes relative rotate of the parts thereof situated between the collar that the drive tool engages with and the most proximate collar that is restrained against rotation. The tool of the invention may be used to disassemble or assemble BOP's or other devices that comprise multiple parts fastened together by rotating one part relative to another.

Figures 6 to 9 illustrate an alternative embodiment of collar 70, formed of two elements 71 rather than four elements. Each element 71 provides flanges 72 having holes 73 therein which provide for one element 71 to be attached to another by means of bolts 73a and nuts 73b. In the previously described embodiment the friction elements are mounted directly in slots formed in the inner face of the elements of the collars. In this embodiment a mounting member 76 sits in each recess 75, with a friction element 80, 81 being attached to the mounting member 76. The mounting member 76 includes a bore 77 which is threaded internaiiy. A bolt or screw is passed through one of the holes 74 provided in each recess 75 and into the bore 77. The mounting member 76 includes walls 76a. The friction element 80 fits between the wails 76a and may be an interference fit therewith. Alternatively, bolts or pins 79 passing through holes 78 may engage with hole in the friction element 80. Such holes may be threaded internaiiy or not, the bolts or pins 79 being configured to engage securely in with the friction element 80.

The friction element 80 is typically a flexible woven friction material. The friction elements 81 are metal with a knurled surface 82. The knurled surface 82 bites into the surface it engages with when subjected to sufficient pressure by the collar 70. The friction elements 81 are fastened to the mounting member 76 by bolts or pins 79, for example by an internally threaded hole in each of the friction elements 82.

The friction elements 81 are useful where the parts of the BOP require very great torques to be applied to cause rotation between said parts. Referring now to Figures 10 and 11 , in this embodiment an actuator 201 is supported in the frame 1 , The collar 40 is attached to the upper part of the actuator 201 in the same manner as it is attached to the BOP 101 , The square drive 35 of the drive tool 30 and its engagement in the drive plate 49 can also be appreciated from this figure. However, rather than the actuator 201 being provided with further collars 50, 60 and being supported by them against rotation in the frame 1 , the actuator is mounted on a plate 210 which is placed on the base plate 21 .

The actuator 201 has a flange 203 which includes holes in the corners thereof. The plate 210 is provided with corresponding holes so that the actuator can be fastened to the plate 2 0 by bolts 215 and corresponding nuts 216. The plate 210 is mounted on spacers 211 which also act as pockets for receiving the forks of a fork lift truck which may be used to lift the actuator and plate 210 into the frame or to move the combination around in the workshop. The spacer 212 serves to support the end of the plate 210 to which it is attached. Uprights 213 extend from the plate 210 and are reinforced by webs 214. When the plate 210 is placed in the frame upon the base plate 21 the jaws 16 are engaged therewith. The provision of spacers 211 , 212 provide for access to the nuts 216.

Figure 12 shows a BOP 101 having collars 40 and 50 attached thereto in the same manner as described with reference to the previous figures. The lowermost flange 80 differs to the flange 60 however, in that the inner surface comprises two parts 81 , 82, the part 81 protruding inward of the part 82. The surface 82 is typically provided with one or more friction elements so that the collar may grip the part of the BOP 101 with which it is engaged. Providing a step in the inner surface of the flange 80 allows the BOP 101 to be gripped and restrained against rotation at a point on the BOP 101 where slight surface damage is acceptable, and those parts of the BOP that must not be damaged to be avoided.

Referring now to Figures 13 and 14, an apparatus according to another embodiment of the invention comprises a frame 300 which is configured to receive and support a well-head tool, in this case a blow out prevention stack (BOP) 01 . The frame 300 comprises four corner posts 302 connected together by cross-members 303, 305. Corner brace members 306 extend between the cross members 303, 305 and corner posts 302. As can be seen from Figure 13, the frame 300 is configured so that one side thereof is open, that is cross members 303 and 305 are provided at the top and the bottom of the corner posts 302, but not between these extremes. The cross member 303a is removably mounted in correspondingly shaped tubes 303b, and is held in place by bolts 303c. A plate 311 , which is described in greater detail below is fitted to the back of the frame 300. The open side allows the component, in this case a BOP 101 that is to be serviced to be introduced into the frame 300. it may be necessary to remove the cross member 303a to permit the BOP 101 to be introduced through the open side.

In order to provide tor the frame to be moved from place to place under the lower cross members 305 situated to either side of the the open side the frame has fork receiving boxes 307 so that the frame 300 may be moved about by a forklift truck or pallet lifter.

The frame 300 is provided with a number of components that assist in the disassembly and assembly of the BOP 101 . The first of these components is the support assembly 320, which is best shown in Figures 13, 14, 17 and 18. The support assembly 320 comprises a base plate 321 mounted on a frame which comprises a back plate 322 and frame members 322' extending from the back plate 322. The back plate 322 has brackets 324 attached thereto which engage with vertically oriented rails 313. The frame and base plate 321 may therefore slide up and down on the rails 313. Such sliding is controlled by an actuator, which is typically a hydraulic ram. The base plate 321 includes a substantially U-shaped opening 323. The upward facing surface of the base plate 321 may be provided with a series of concentric rings (note that the parts of the rings that would be situated in the U-shaped opening 323 would not be present) to assist in positioning the BOP 101 centrally on the base plate 321 .

Concentric rings provide markers and allow the BOP 101 to be positioned so that it is correctly centred in the frame 300. Concentric rings may be provided on radii corresponding to the radii of circular parts of common BOP's used in the oil and gas industry. The plate 321 , the U-shaped opening 323 thereof and the concentric rings may be configured for a particular BOP or range of BOP's,

The frame 300 is configured to support a drive tool and to this end includes a top plate 330 which is configured to receive and support a rotary drive. A collar 331 is provided at each corner of the top plate 330, the collars 331 for receiving legs of a rotary drive 330 or rotary drive mount 430,

The frame 300 includes vertically disposed side rails 314, the side rails being provided with a first plurality of holes 314a which provide for attachment of the side rails 314 to spaced apart upright frame members 304 by means of bolts 310, and a second plurality of hoies 315. The function of the side rails 314 is to provide a means of attaching collars mounted on the BOP 01 to the frame 300. When the side rails 314 are attached to the frame members 304 by bolts 310, the side rails 314 extend into notches 325 formed in the base plate 321 of the support assembly 320.

Figures 17 and 18 illustrate the actuator 350 (a hydraulic actuator in the illustrated embodiment) which raises and lowers the support 320. The actuator 350 includes an attachment part 351 having a hole 352 extending therethrough. A pin 343 passes through bushes 342 mounted in plates 340 which are attached to the rear of plate 322. The actuator 350 is attached at its other end to the plate 31 1 by means of a pin or bolt passing through a hole 353. The brackets 324 are provided with bushes 324a, which provide for better sliding of the support 320 on rails 313,

Referring now also to Figures 15, 16, 19 and 20, the whole BOP 101 is supported on the base plate 321 of the support assembly 320. In the illustrated embodiment two collar assemblies are provided, one (that illustrated in Figures 19 and 20) serving to orient the BOP 101 in the frame 300 correctly and to secure the BOP 101 against movement in the vertical axis, the other (that illustrated in Figures 15 and 16) to transmit torque from the rotary drive to a part of the BOP that is to be released and/or removed. The collar 600 shown in Figures 15 and 1 6 connects to the rotary drive to transmit torque therefrom to a part of the BOP 10 , typically to an uppermost part of the BOP. The collar 600 comprises two collar members 641 . Each collar member 641 is presented up to one side of a flange 102 of the BOP 101 . Holes 643 in flat faces 641 a of the members 641 are aligned and bolts 644 passed therethrough. Nuts 645 are engaged on the respective bolts 644 so that the collar members 641 may be brought into tight engagement with the flange 102 of the BOP, suitable washers may be provided between the bolt head and the collar element and the nut and the collar.

in order to prevent the collar 600 from rotating with respect to the flange 102, friction material is provided on the inner surface of the curved part of the two collar members 641 . !n the present example, each collar member 641 is provided with eight discrete recesses 647, each configured to receive a friction element assembly comprising a pocket 648 which is seated in a recess 647 and attached to the collar member by a screw 650 which passes through a hole 647a, the pocket receiving two elements 649 of friction generating material.

The collar 640 includes a drive plate 651 . The drive plate 651 includes three sockets, a socket 654 to the centre and configured to receive a square drive 537 of the drive tool 530, and two sockets 655, one to either side of the socket 654. The sockets 655 are configured to engage with bosses 642 of each collar member 641 . To the side of each boss 642 is a bore 646 extending into the body of the collar member 641 . When the sockets 655 of the drive plate 651 are presented up to the bosses 642 and placed thereon slots 652 adjacent the sockets 655 will be aligned with the bores 646. It is preferred that the bores 646 are threaded so that a bolt or screw that passes through the slot 652 can engage therewith so as to fasten the drive plate 651 to the collar members 641 .

Figures 19 and 20 illustrate a collar 700 for attachment to other flanges of the BOP 101 .

The collar 700 differs from the collar 600. Whereas the collar 600 is driven so as to rotate, the collar 700 provides for locking the BOP 101 with respect to the frame 300 to prevent relative rotate therebetween. The collar 700 comprises two collar members 741 . Each collar member 741 is presented up to one side of a flange 103 of the BOP 01 . Holes 743 in flat faces 741 a of the members 741 are aligned and bolts 744 passed therethrough. Nuts 745 are engaged on the respective bolts 744 so that the collar members 741 may be brought into tight engagement with the flange 103 of the BOP. Each of the flat faces 741 a of one of the coliar members 741 has attached thereto a spacer 741 b which includes a hole 743a that is aligned with hole 743. The other of the collar member 741 is also has a spacer 751 attached to the fiat faces 741 a. However, the spacer 751 extends upwardly from the flat face 741 a and has a hole 752 therein. A block 753 is attached to the part of the spacer 751 that extends above the fiat face 741 a. The hole 752 extends through the block 753. The spacers 751 allow the coliar 700 to be attached to the side rails 314 by aligning the holes 752 with holes 314a of the side rails 314 and passing a pin or bolt 760 through the aligned holes.

In the illustrated embodiment the collar members 741 include holes 755 which are threaded.

Lifting eyes may be attached to the threaded holes 755 to facilitate handling of the collar members.

Figure 21 illustrates an adapter 430 which allows different torque tools to be used as the rotary drive. The adapter 430 includes a base plate 431 having legs 432 depending from each corner of the base plate 431 . The legs 432 are arranged such that each leg 432 engages with one of the collars 331 of the frame 300. A second plate 433 is attached to the upper surface of the plate 431 . The function of the second plate 433 is to strengthen the adapter 430 so that more powerful torque tools may be used. A central hole 434 extends through the both the base piate 431 and the second piate 433.

The adapter 430 includes a plurality of holes 435a to 435d. Each hole 435a to 435d is sized to receive a reaction member 436, and is positioned so that a reaction arm of one of a number of different torque tools will engage the reaction member 436 when situated in a selected one of the holes 435a to 435d. Two of the holes 435a and 435b extend through both the base piate 431 and the second plate 433, the double thickness of piate being more capable of resisting twisting forces that the single thickness of plate present at holes 435c an 435d. The drive plate 651 is configured such that torque is transferred to it by a square drive. The adapter 430 is configured to receive a square drive 437, The square drive socket 437 sits in a bearing 438, which itself sits in a collar 439, the collar 439 mounted in the hole 434. Hence, when a torque tool (not shown) attached to the square drive socket 437 can rotate the square drive socket 437 relative to the adapter 430 and farm 300.

Figures 23 to 27 illustrate a bi-directional rotary drive 530. The drive 530 comprises a base plate 531 with a leg 532 at each corner thereof. The legs 532 are arranged such that each leg 532 engages with one of the collars 331 of the frame 300. A wall 533 extends from the base piate 531 .

The bi-directional drive 530 comprises two externally spiined drives 535, 536, the drive 535 being an externally spiined shaft and the drive 536 an externally spiined sleeve that is arranged around the shaft 535. One of the drives is driven to rotate clockwise and the other to rotate counter clockwise, as will be described in greater detail below.

In Figure 24 a square drive 537 is attached to the external splines 536. The square drive 537 comprises an internally spiined 537a collar 538 from which a square drive head 539 extends, which is shown in greater detail in Figure 27a. !n order to change the direction of rotation of drive, the square drive 537 is removed and replaced with a simiiar square drive 537' that is driven by the engagement of spiined shaft 535 with internal splines 537b.

Figures 25 to 27 illustrate the internal parts of the bi-directionai drive 530. A beam 540 is attached to the base piate 531 by spaced apart bosses 541 , 542. The boss 541 comprises shaped end portions 541a that extend through correspondingly shaped holes 543 in the base plate 531 and the beam 540 respectively. The end portions 541 a are shaped to resist rotation between the boss 541 , base plate 531 and beam 540. The boss 542, in addition to securing the beam 540 with respect to the base plate 531 , also attaches actuator mounting members 550 with respect to the beam 540 and base platte 531 . The actuator mounting members 550 include a central opening 553 through which a block 552 passes. Correspondingly shaped openings are provided in the beam 540 and a spacer 555. A recess 554 having a cross-section corresponding to the cross-section of biock 552 is formed in the boss 542. The actuator mounting members 550 are secured to the boss 542 by screws 557 which pass through holes 556 in the actuator mounting members, through aligned holes in the beam 540, the spacer 555 and boss 542 and into aligned holes 531 a in the base plate 531 , The beam 540 is also provided with holes 558 that are aligned with hoies in the boss 541 and holes 53 a in the base plate for receiving screws 557. The beam 540 and actuator mounting members 550 are therefore secured to the base plate 531.

The actuator mounting members 550 each include a hole 551 in which a part of actuator mount in the form of a gimbal is received. The gimbal 560 comprises a circular part 561 and extending from opposite sides thereof, stub shafts 561 . One of the stub shafts 561 is are received in the hole 551 , the other being received in a hole 569a of a spacer 569. A portion 569b of the spacer 569 sits in a hole formed in the base plate 531 , the spacer being attached thereto by screws, 531a.

An actuator in the form of a hydraulic ram 565 is mounted in the gimbal. The hydraulic ram 565 includes a piston 566 which has a bracket 567 mounted on the free end thereof. The bracket includes a hole for receiving a pin 568 which passes through hoies 571 a first arm 570.

The spline shaft 535 is supported between the beam 540 and the base plate 541. The spiined shaft 535 is best seen in Figure 25 and comprises a lower spiined portion 535a, which engages a square drive, and an upper spiined portion 535b, which engages with a ratchet drive 573. The shaft 535 also includes an upper portion 535c which sits in a hole 540a in the beam 540. A bush 540b is mounted in the hole 540a and spacer rings 540b and 540c. The ratchet drive 573 sits inside a hole 572 in first arm 570 and is driven by a pawl 575 which is mounted in a recess 575a the first arm 570. The pawl 575 is biased towards the spiined outer surface of ratchet drive 573 so that teeth of the pawl are pushed into engagement with said spiined outer surface. However the surfaces of the splines of the ratchet drive 573 and the teeth of pawl 575 are angled such that when the first arm 570 rotates in one direction the teeth of pawl 575 engage with the splines of the ratchet drive 573 and cause the shaft 535 to rotate and when the first arm 570 rotates in the opposite direction the teeth of the pawl 575 slide over the splines of ratchet drive 573.

A bearing 576 is situated between the ratchet drive 573 associated with the first arm 570 and a ratchet drive 573 with a second arm 570'. A further bearing 577 is situated between the underside of the ratchet drive 573 associated with the second arm 570' and a bearing seat 580 which is mounted in a hoie 531 b in the base plate 531 . The bearing seat 580 is held in the hole 531 b by a ring 581 ,

A lever 590 adjusts a valve (not shown) which controls the flow of fluid to and from the hydraulic actuators 565. It will be appreciated that extending the actuators 565 causes the spiined shaft 535 to rotate in one direction and the spiined sleeve 536 to rotate in the opposite direction. To change the direction of drive transmitted to the collar 600, all that is required is for the square head 537 to be changed so that it is engaged with the splines of the other of the spiined shaft and spiined sleeve.

Figure 28 illustrates the BOP 101 mounted in the tool illustrated in Figures 13 to 27.

Figure 29 illustrates a similar construction to that shown in Figure 11 . An actuator 201 ' is supported on a plate 210' in the frame 300. The collar 600 is attached to the upper part of the actuator 201 in the same manner as it is attached to the BOP 101. However, rather than the actuator 201 being provided with further collars and being supported by them against rotation in the frame 300, the actuator is mounted on a plate 210' which is placed on the base plate 321 .

The actuator 201 ' has a flange 203' which includes holes 204' in the corners thereof. The plate 210' is provided with a slot 217' so that the actuator can be fastened to the plate 210' by bolts 215' and corresponding nuts 2 6'. The slot 2 7' allows flanges 203' of different size to be attached to the plate 210'. The plate 210' is mounted on spacers 211 ' which also act as pockets for receiving the forks of a fork lift truck which may be used to lift the actuator and plate 210' into the frame 300 or to move the combination around in the workshop. Uprights 213' extend from the plate 210' and are reinforced by webs 214'. When the plate 210' is placed in the frame upon the base plate 321 , the position of the base plate is adjusted until the slots 218 align with holes 3 5 of side rails 314. Bolts 219 are passed through the slots 218', through holes 315 and secured with a nut (not shown).

The tool servicing apparatus of the present invention is particularly useful in relation to the servicing of blow out preventer stacks. However, the apparatus may be useful in other situations where tools comprising a number of parts that are designed to rotate relative to one another need to be disassembled or assembled. The torque applied during assembly can be controlled to a desired level through the rotary drive.