WO2009111845A1

WO2009111845A1 - Collapsible drilling rig

Info

Publication number: WO2009111845A1
Application number: PCT/AU2009/000311
Authority: WO
Inventors: Guido Stangherlin; Stan Westcott
Original assignee: Easternwell Group Holdings Pty Ltd
Priority date: 2008-03-14
Filing date: 2009-03-16
Publication date: 2009-09-17
Also published as: AU2009225260A1; CA2716937A1

Abstract

A collapsible drilling rig (1) configured for transport on a vehicle trailer (2). The drilling rig (1) comprises a ground-bearing substructure (3) and a derrick (4) pivotally mounted to the substructure (3) and pivotable relative to the substructure (3) between a working erect position and a nonworking collapsed position for transport. The derrick (4) has a vertical attitude when in the working position and a generally horizontal attitude when in the nonworking position

Description

COLLAPSIBLE DRILLING RIG Field of the Invention

One aspect of the present invention relates to a collapsible drilling rig comprising a ground-bearing substructure and a derrick pivotally mounted to the substructure and pivotable relative to the substructure between an erect working position and a nonworking collapsed position. Another aspect of the present invention relates to a drilling rig that is collapsible for transport on a vehicle trailer. Yet another aspect of the present invention relates to a traveling slips frame assembly that is mountable to a substructure of a drilling rig, for supporting the slips as well as for handling a blow-off preventer (BOP). Background of the Invention

Erecting a conventional on-shore drilling rig is an arduous task. First, components of the drilling rig must be loaded onto vehicles and transported over long distances, usually as grossly oversized loads, to a site of interest. Second, components of the drilling rig must be assembled and the rig must be rendered operational. Loading and transporting the components of the drilling rig, assembling the many components of the drilling rig and rendering the rig operational can take much time, skill and manpower, and is wrought with danger.

The present inventors have now developed a collapsible drilling rig that minimises at least one of the disadvantages referred to above. Conventional slips assemblies, for holding pipes, are utilised at a work floor level of the rig. Such assemblies can only be used in the one position and cannot be used for other purposes.

BOPs, which are attached to a well head of a well, are required to be transported between working and nonworking locations during the operation of a drilling rig. Since BOPs can weigh 10,000 kg, specialised BOP-handling systems, such as a winch-type system, need to be installed between the drilling rig sub-base and work floor. Consequently, additional height clearance is usually required between the sub-base and the work floor. Also, conventional specialised BOP-handling systems cannot be used for other purposes. The present inventors have now developed a traveling slips frame assembly mountable to a substructure of a drilling rig, for supporting the slips as well as for handling a BOP.

Detailed Description of the Invention According to a first aspect of the present invention, there is provided a collapsible drilling rig comprising: a ground-bearing substructure; and a derrick pivotally mounted to the substructure and pivotable relative to the substructure between an erect working position and a nonworking collapsed position, wherein in the working position the derrick has a vertical attitude and in the nonworking position the derrick has a generally horizontal attitude.

The derrick may be of any suitable size, shape and construction, and may be made of any suitable material or materials. The derrick preferably comprises a framework comprising an inner mast and an outer mast, and the inner mast is extendable and retractable (telescopic) relative to the outer mast. In the working position, preferably the inner mast is extended relative to the outer mast and lockable in that position. The inner mast may be locked to the outer mast in any suitable way, e.g. a locking pin arrangement.

The inner mast may be extended and retracted relative to the outer mast in any suitable way. Preferably, one or more mast extending hydraulic cylinders extending between the inner and outer masts carry out this function. One end of the hydraulic cylinder may be mounted to the inner mast and the other end of the hydraulic cylinder may be mounted to the outer mast.

The derrick may have an upper end and a lower end. The upper end will typically have a crown and support a top drive. Preferably, a lower end of the outer mast is generally rectangular and comprises two upper corner posts and two lower corner posts.

The two upper corner posts may have apertures for receiving locking pins when in the erect working position.

The ground-bearing substructure may be of any suitable size, shape and construction, and may be made of any suitable material or materials. The substructure may comprise a derrick-mounting frame to which is pivotally mounted the derrick.

The derrick-mounting frame may comprise a pair of upright assemblies spaced from one another. Each upright assembly may comprise a vertically extending tubular beam. Each upright assembly may further comprise a pivot pin mounted to the tubular beam and extending upwardly of the tubular beam.

The derrick-mounting frame may further comprise a crosspiece extending between the tubular beams of the upright assemblies as well as one or more brace members extending between or from the tubular beams.

The derrick may be pivotally mounted to the derrick-mounting frame in any suitable way. Preferably, the lower corner posts of the derrick are pivotally mounted to the tubular beams of the upright assemblies by way of pivot pins that extend through coinciding apertures of the lower corner posts and the tubular beams. The derrick may be pivoted between the working and nonworking positions in any suitable way. Preferably, the drilling rig comprises at least one derrick lifting hydraulic cylinder extending between the substructure and the derrick. More preferably, two derrick lifting cylinders extend from the two lower corner posts to the substructure below and lift the derrick relative to the substructure. Preferably, the drilling rig comprises at least one derrick positioning hydraulic cylinder extending between the derrick-mounting frame and the derrick. More preferably, two derrick positioning cylinders extend from the derrick-mounting frame and each has a catch that engages an extension of the derrick intermediate the upper and lower corner posts, when raising or lowering the derrick above to the derrick-mounting frame. The derrick-mounting frame may be configured for both a working position and a collapsed transport position. In the working position, the derrick may extend from a top of the derrick-mounting frame and in the collapsed transport position the derrick may extend laterally of the derrick-mounting frame.

Each upright assembly may be of adjustable length. The length may be adjusted in any suitable way. Preferably, each upright assembly comprises a hydraulic jack cylinder extending from a bottom of the tubular beam, and extendable and retractable relative to the tubular beam.

The derrick-mounting frame may comprise a pair of derrick base-support members, each pivotally connected to a said upright assembly, and pivotable between a nonworking transport position whereby they extend alongside the derrick (when in the nonworking position) and a working position whereby the derrick base-support members extend directly beneath the two upper corner posts of the derrick and are lockable thereto. The derrick base-support members may be pivoted in any suitable way. Each derrick base-support member may comprise a beam and a sleeve connected to an end of the beam. Each sleeve may extend over a respective pivot pin of the upright assembly so as to allow pivoting between the working and nonworking positions. Preferably, the derrick-mounting frame comprises a base-support member positioning hydraulic cylinder and a linkage assembly extending between the crosspiece and each beam of the derrick base-support member. The linkage assembly may be connected to a piston of the base-support member positioning cylinder and may enable the beam to pivot through an angle of about 180°, such that the beam extends about 90° relative to the crosspiece when in the working position.

The two upper corner posts of the derrick may be lockable to the derrick base- support members in any suitable way. Preferably, a locking pin is extendable through coinciding apertures in the upper corner posts and the beams of the derrick base-support members. Preferably, the derrick comprises a pair of hydraulic locking cylinders each having a piston connected to a pin that extends through the coinciding apertures.

The derrick-mounting frame may comprise a ground-support leg assembly comprising a leg having an upper leg portion extending from the beam of the derrick base-support member and a lower leg portion hinged to the upper leg portion, and the lower leg portion is pivotable between an extended ground-engaging working position and a retracted transport position whereby the lower leg portion is raised relative to the ground.

Each lower leg portion may be moved in any suitable way. Preferably, each ground support leg assembly comprises a leg-extending hydraulic cylinder extending between each lower leg portion and each beam of each derrick base-support member. Each lower leg portion may be lockable in the extended ground-engaging working position and this may be achieved in any suitable way. Preferably, a locking pin is used and extends through coinciding apertures in the upper and lower leg portions.

Each ground-support leg assembly may be of adjustable length. The length may be adjusted in any suitable way. Preferably, each ground-support leg assembly comprises a hydraulic jack cylinder mounted to the lower leg portion and is extendable and retractable relative to the lower leg portion. Preferably, the drilling rig is transportable by way of a vehicle, and more preferably a vehicle trailer. In one embodiment, the substructure comprises a vehicle trailer subframe extending from the derrick-mounting frame, wherein the subframe is mountable to a wheeled chassis of the trailer. In another embodiment, the substructure comprises a wheeled chassis of a trailer, with or without a trailer subframe. In yet another embodiment, the substructure is merely transportable by way of a vehicle trailer.

Preferably, the substructure comprises a vehicle trailer subframe that is mountable to a wheeled chassis of the trailer and which extends from the derrick-mounting frame.

Optimally, the substructure is no wider than about 3.5 m and no longer than about 25 m (when combined with the length of the prime mover and helper dolly), such that it is not considered an oversized load.

The subframe may have a front end and a rear end. Preferably, the derrick- mounting frame extends from the rear end. The subframe will typically comprise an outer frame, and inner frame members comprising crosspieces and gussets extending within the outer frame. The inner frame members may provide a structure to which may be mounted service winches, a drawworks, one or more hydraulic power units and other standard components of drilling rigs. The subframe may have locating lugs that engage the chassis of the trailer.

The substructure may have a rack located at the front end of the subframe for supporting the upper end of the derrick when in the nonworking collapsed position.

The substructure may comprise an outrigger assembly extending from each longitudinal side of the subframe and/or derrick-mounting frame and pivotable between working and transport positions relative to the subframe, whereby in the working position the outrigger assembly extends perpendicularly from the longitudinal side of the subframe and in the transport position the outrigger assembly extends substantially parallel with the rear end of the subframe.

Any suitable type of outrigger assembly may be used. Such an assembly will typically comprise a hydraulic jack cylinder, a framework comprising a first end pivotally mounted to the longitudinal side of the subframe or derrick-mounting frame and a second end to which is mounted the jack cylinder, and one or more locking pins for locking the framework in the working and transport positions. As mentioned, the drilling rig may comprise components of known drill rigs, including a crown, top drive, drawworks, rough neck, service winch, hydraulic power unit, and slip and traveling blocks.

The drilling rig may comprise one or more pipe positioners to help manoeuvre pipes between the derrick and an elevated trough assembly of a tubular load handler that is located on the opposite side of the work floor. The tubular load handler may be as described in the specification of Australian Patent Application No. 2008202799, the entire contents of which are hereby incorporated by way of cross reference.

Preferably, the pipe positioner comprises a guide roller for receiving a pipe and the guide roller can be moved horizontally as well as vertically relative to the derrick mounting frame. The pipe positioner may be of any suitable size, shape and construction, and may be made of any suitable material or materials.

The pipe positioner may further comprise a mounting bracket assembly, a base, a boom, an arm assembly, a hydraulic base cylinder, a hydraulic boom cylinder, a hydraulic arm cylinder and a hydraulic arm elevating cylinder.

The mounting bracket assembly may be connected to a main beam of a derrick base-support member. The base may be pivotally connected to the mounting bracket assembly such that the base may pivot in a parallel plane to the main beam. The boom may be pivotally connected to the base such that the boom may pivot in a parallel plane to the base. The arm assembly may comprise a swivel base and an L-shaped arm having a lower end pivotally connected to the swivel base and an upper end connected to the guide roller. The swivel base may be pivotally connected to the boom such that the swivel base may pivot in a parallel plane to the boom, and the L-shaped arm may be pivotally connected such that the guide roller may be raised and lowered relative to the swivel base. The hydraulic base cylinder may be pinned to both the mounting bracket and the base. The hydraulic boom cylinder may be pinned to both the base and the boom. The hydraulic arm cylinder may be pinned to both the boom and the swivel base. The hydraulic arm elevating cylinder may be pinned to both the swivel base and the L-shaped arm. The drilling rig may further comprise a traveling slips frame assembly mounted to the substructure. The slips frame assembly may be of any suitable size, shape and construction. Preferably, the slips frame assembly is adjustably mounted between the beams of the derrick base-support members, and the slips frame assembly is movable between pipe-engaging and resting positions. This may be achieved in any suitable way.

Preferably, the slips frame assembly comprises a frame for holding the slips and roller assemblies comprising rollers mounted to opposing ends of the frame. Preferably, each beam of the derrick base-support member has a channel that extends along a longitudinal axis of the beam and which receives the rollers such that the frame may move there along.

The rollers may be movable between raised and lowered positions relative to the frame, wherein in the raised position the frame rests on a base of the channel and in the lowered position the frame does not rest on the base and the rollers enable the frame to be moved along the channel between the pipe-engaging and resting positions.

Preferably, a roller assembly is located at each end of the frame of the slips frame assembly and comprises a first roller, a second roller, a first forked roller frame connected to the first roller, a second fork roller frame connected to the second roller, and a roller- positioning hydraulic cylinder comprising a cylinder housing and a piston mounted to the first and second forked roller frames. The first and second forked roller frames may each be pivotally connected to the frame of the slips frame assembly. The first and second rollers may be moved to the lowered position when the piston retracts within the housing, and the first and second rollers may be moved to the raised position when the piston extends from the housing.

The slips frame assembly may comprise a guide roller mounted to each end of the frame of the slips frame assembly that engages and rolls along a side wall of the channel.

Preferably, the frame of the slips frame assembly can support conventional slips intermediate the roller assemblies. The slips may be removable from the frame. The slips frame assembly may further serve as a BOP handling system, whereby the slips frame assembly may support a hydraulic BOP lifting cylinder and the cylinder may hold, raise and lower a BOP relative to the work floor. That is, a piston of the hydraulic BOP lifting cylinder may engage a shaft of the BOP stack, it may retract relative to a cylinder housing to lift the BOP, or extend relative to the housing to lower the BOP.

The drilling rig may further comprise one or more platforms, saftey rails and sets of stairs so as to provide an operator access to the slips and rough neck. The platforms, safety rails and stairs may be of any suitable construction. Preferably, they are detachably connected to the derrick mounting frame. Preferably, a platform is extendable over the derrick base-support members, either side of the slips and alongside the lower corner posts of the derrick. Such a platform may be removed when moving the slips frame assembly between working and nonworking positions.

According to a second aspect of the present invention, there is provided a slips frame assembly mountable to a substructure of a drilling rig. The slips frame assembly may be as described above.

According to a third aspect of the present invention, there is provided a pipe positioner mountable to a substructure of a drilling rig. The pipe positioner may be as described above.

Preferred embodiments of the invention will now be described by way of example with reference to the accompanying figures.

Brief Description of the Figures Figure l is a front side perspective view of part of a portable drilling rig mounted onto a vehicle trailer with a derrick of the rig in a collapsed transport position, according to an embodiment of the present invention;

Figure 2 is a rear side perspective view of the drilling rig and vehicle trailer shown in Figure 1; Figure 3 is a top plan view of the drilling rig and vehicle trailer shown in Figure 1 ;

Figure 4 is a side elevation view of the drilling rig and vehicle trailer shown in Figure 1;

Figure 5 is a rear end view of the drilling rig and vehicle trailer shown in Figure 1;

Figure 6 is another rear side perspective view of the drilling rig and vehicle trailer, but showing additional parts of the rig that were omitted from Figure 2;

Figure 7 is the same as Figure 6, but shows the position of the drilling rig and vehicle trailer relative to a rectangular work floor; Figure 8 is an enlarged view of part of the drilling rig and vehicle trailer shown in Figure 7;

Figure 9 is a rear side perspective view of the drilling rig and vehicle trailer shown in Figure 6 as well as a blow-off preventer (BOP) stack, but with the derrick of the rig in a working position;

Figure 10 is a rear side perspective view of the drilling rig shown in Figure 9 with the derrick of the rig in a working position, but additionally shows a pipe positioner of the drilling rig and a drawworks in operation;

Figure 11 is another rear side perspective view of the drilling rig and vehicle trailer, but showing additional parts of the rig that were omitted from Figure 1 ;

Figure 12 is a partial exploded rear side perspective view of the substructure and vehicle trailer shown in Figure 11, and part of the substructure is shown in detail;

Figure 13 is an isometric view of part of the substructure shown in Figure 12;

Figure 14 is an enlarged isometric view of part of the substructure shown in Figure 13;

Figure 15 is an enlarged reverse isometric view of the substructure part shown in Figure 14;

Figure 16 is an isometric view of part of a derrick-mounting frame of the substructure shown in Figure 12; Figure 17 is an isometric view of another part of the derrick-mounting frame of the substructure shown in Figure 12;

Figure 18 is an isometric exploded view of part of the derrick-mounting frame shown in Figure 17;

Figure 19 is a side elevation view of the part shown in Figure 16; Figure 20 is a bottom plan view of the part shown in Figure 19;

Figure 21 is a cross-sectional view, taken through plane B-B of Figure 20; Figure 22 is a partially exploded perspective view of a slips frame assembly of the drilling rig shown in Figure 1, according to an embodiment of the present invention;

Figure 23 is an enlarged view of part of that shown in Figure 22;

Figure 24 is a top plan view of the slips frame assembly shown in Figure 22; Figure 25 is a partial perspective view of the slips frame assembly shown in

Figure 24;

Figure 26 is a rear side perspective view of part of the substructure shown in Figure 11 and a BOP stack in a non-working position;

Figure 27 is the same as Figure 26 but with the BOP stack in a working position; Figure 28 is a perspective view of part of the substructure shown in Figure 11 and a BOP stack in a working position on a well head;

Figure 29 is the same as Figure 28 but with the BOP stack in a nonworking position; and

Figure 30 is a perspective view chielfy of the pipe positioner shown in Figure 10.

Description of the Preferred Embodiments

In the figures like reference numerals refer to like features.

Figures 1 -7 show a collapsible drilling rig 1 configured for transport on a vehicle trailer 2. The drilling rig 1 comprises a ground-bearing substructure 3 and a derrick 4 pivotally mounted to the substructure 3 and pivotable relative to the substructure 3 between a working erect position and a nonworking collapsed position for transport.

As seen in Figures 9 and 10, the derrick 4 has a vertical attitude when in the working position and, as seen Figures 1-7, a generally horizontal attitude when in the nonworking position.

Referring now chiefly to Figures 9 and 10, the derrick 4 comprises a complex framework comprising an inner mast 5 and an outer mast 6, and the inner mast 5 is extendable and retractable relative to the outer mast 6. A pair of multi-stage hydraulic mast-extending cylinders 300 are used to extend and retract the inner mast 5 relative to the outer mast 6. A housing 301 of each cylinder is mounted to the inner mast 5 and a piston 302 of each cylinder is mounted to the outer mast 6. In the working position, the inner mast 5 is extended relative to the outer mast 6 and locked in that position by way of locking pins 7 (see Figure 9).

The derrick 4 has an upper end and a lower end. The lower end of the outer mast 6 is rectangular and comprises four corner posts comprising two upper corner posts 10 and two lower corner posts 12. Each corner post 10, 12 has a yoke 305 having openings for receiving a locking pin or pivot pin. A crosspiece 310 extends between the lower corner posts 12 and a further crosspiece 311 (see Figures 6 and 8) extends between each lower corner post 12 and respective upper corner post 10. A derrick positioning pin 315 is supported by each crosspiece 311 intermediate the upper 10 and lower posts 12.

A crown 320 is mounted to the inner mast 5 at the upper end of the derrick 4. The crown 320 supports blocks 321, a top drive 322 as well as other conventional components of drilling rigs. A pair of top drive guide rails 330 extends longitudinally along opposing inner faces of the inner mast 5 and guides movement of the top drive 322 therealong. A step ladder 335 extends along an outer face of the inner mast 5, and an opposing outer face of the inner mast 5 has a pipe rack for storing drill strings. A rough neck 337 pipe handler is mounted within the outer mast 6 at the lower end of the derrick 4.

The substructure 3 comprises a vehicle trailer subframe 15 that is mountable to a wheeled chassis of the trailer 2 and a derrick-mounting frame 17 to which is pivotally mounted the derrick 4. The subframe 15 has a front end and a rear end. The derrick- mounting frame 17 extends from the rear end.

As seen in Figure 13, the subframe 15 comprises an outer frame 340 comprising beams, and inner frame members 341 (only some of which have been labelled) comprising beam crosspieces and gussets extending within the outer frame 340. The inner frame members 341 provide a deck to which is mounted service winches (not shown), drawworks 370, one or more hydraulic power units (not shown) and other standard components of drilling rigs. As seen in Figure 11, the substructure 3 has a rack 20 located at the front end of the subframe 15 for supporting the upper end of the derrick 4 when in the nonworking position (not shown in Figures 1-6) and a box frame 380 for a hydraulic power unit (not shown). The subframe 15 has locating lugs (not shown) that engage and positively lock with the chassis of the trailer 2. The derrick-mounting frame 17 may be configured for both a working position and a collapsed transport position. In the working position, the derrick 4 extends from a top of the derrick-mounting frame 17 (as seen in Figure 9) and in the collapsed transport position the derrick 4 extends laterally of the derrick-mounting frame 17 (as seen in Figure 6).

The derrick-mounting frame 17 comprises a pair of upright assemblies 21 spaced from one another. Each upright assembly 21 comprises a vertically extending tubular beam 23 and a main pivot pin 24 mounted to the beam 23 and extending upwardly of the beam 23. Each tubular beam 23 has a yoke 25. A wear plate 390 is connected to a top of each beam 23, as shown in Figure 13.

The derrick-mounting frame 17 comprises a tubular crosspiece 27 extending between the tubular beams 23 as well as brace members 28, 29, 30, 31 extending between and from the beams 23 to the subframe 15. A further articulated crosspiece 391 extends between and beyond the tubular beams 23 below the tubular crosspiece 27. The lower corner posts 12 of the derrick 4 are pivotally mounted to the tubular beams 23 of the upright assemblies 21 in that the respective yokes 25 intermesh and are connected together by way of pivot pins (not shown).

The drilling rig 1 comprises a pair of multi-stage hydraulic derrick lifting cylinders 30 for pivoting the derrick 4 from the nonworking position towards the working position until the derrick 4 is just overcentre. A housing 396 of each cylinder 30 is pivotally mounted to the subframe 15 and a piston 397 of each cylinder 30 is pivotally connected to each lower corner post 12, as seen in Figure 10.

Each upright assembly 21 is of adjustable length. Each upright assembly 21 comprises a hydraulic jack cylinder 35 extending from a bottom of the tubular beam 23, and the jack c)4inder 35 is extendable and retractable relative to the beam 23. This is best seen in Figures 11 and 12.

The derrick-mounting frame 17 comprises a pair of derrick base-support members 40, each pivotally connected to a said upright assembly 21, and pivotable between a nonworking transport position whereby they extend alongside the derrick 4 (as seen in Figure 2) and a working position (as seen in Figures 9-11).

Each derrick base- support member 40 comprises a main beam 50 and a sleeve 53 connected to an end of the main beam 50. The main beam 50 has a longitudinal channel 51 and a derrick upper post connector 52 extending from a top of the main beam 50. Each sleeve 53 extends over a respective main pivot pin 24 of the upright assembly 21 so as to allow pivoting between the working and nonworking positions. A lower surface of the main beam 50 contacts and slide along the wear plate 390 when moving between the working and nonworking positions.

The derrick-mounting frame 17 comprises a hydraulic base-support member positioning cylinder 60 and a linkage assembly 61 extending between the crosspiece 27 and each main beam 50. A housing of the base-support member positioning cylinder 60 is pivo tally mounted to the crosspiece 27. The linkage assembly 61 comprises a swing male link 62 pinned to the crosspiece 27, a swing link female 63 pinned to a bracket 64 of the main beam 50 and to the swing link male 62, and a piston of the cylinder 60 is pinned to the swing link male 62. The linkage assembly 60 enables the derrick base-support member 40 to pivot through an angle of about 180°, such that the derrick base-support member 40 extends about 90° relative to the crosspiece 27 when in the working position. When intermeshed, the yokes 305 of the two upper corner posts 10 of the derrick

4 are lockable to the upper post connectors 52 of the main beams 50 by way of locking pins. Hydraulic locking cylinders 400, that are mounted to the crosspieces 311 that extend from the two upper corner posts 10, have pistons and the ends of the pistons are connected to the locking pins. This is best seen in Figure 8. The derrick-mounting frame 17 comprises a ground-support leg assembly 70 comprising a leg having an upper leg portion 71 extending from the beam 50 and a lower leg portion 72 hinged to the upper leg portion 71, and the lower leg portion 72 is pivotable between an extended ground-engaging working position and a retracted transport position whereby the lower leg portion 72 is raised relative to the ground. Each upper leg portion 71 comprises a tubular beam 74 having a first sleeve 75 supported by a pair of brackets 76 that extends from the beam 74 and a second sleeve 77 supported by a gusset 78 that extends between the beam 74 of the upper leg portion 71 and the beam 50 of the derrick base-support member 40.

Each lower leg portion 72 comprises a tubular beam 80 to which is connected a first yoke 81 and a second yoke 82. A pivot pin 83 locks the second sleeve 77 and second yoke 82 together and enables pivoting of the lower leg portion 72. A locking pin 84 locks the first sleeve 75 and the first yoke 81 together and prevents the lower leg portion 72 from pivoting from the extended ground-engaging working position.

Each ground support leg assembly 70 comprises a hydraulic leg-extending cylinder 85 extending between each lower leg portion 72 and each main beam 50 of each derrick base-support member 40. A housing of the cylinder 85 is pivotally mounted to the main beam 50 of the derrick base-support member 40 and a piston of the cylinder 85 is pivotally mounted to the tubular beam 80 of the lower leg portion 72. When the piston retracts within the housing, the lower leg portion 72 moves to the retracted transport position, as seen in Figure 8.

Each ground-support leg assembly 70 is of adjustable length. Each ground- support leg assembly 70 comprises a hydraulic jack cylinder 90 mounted to the tubular beam 80 of the lower leg portion 72 and is extendable and retractable relative to the tubular beam 80. This is best seen in Figures 16-18. A cross-sectional view of the hydraulic jack cylinder 90 is shown in Figure 21. A piston of the cylinder 90 is numbered 410 and a housing of the cylinder is numbered 411.

The drilling rig 1 comprises a hydraulic derrick-positioning cylinder assembly 100 mounted to each derrick base-support member 40. The assembly 100 comprises a cylinder 101 having a housing 102 pivotally mounted to the main beam 50 by way a cylinder bracket 103, beam yoke 104, pin 105 and torsion spring 106. The cylinder 101 also has a piston having a forked 107 end (catch) for catching the derick positioning pin 315. A top wall of the main beam 50 has a recess 110 within which the forked end 107 of the piston locates and can move. The torsion spring 106 returns the forked end 107 to a resting position at one end of the recess 110. The piston can extend and retract relative to the housing 102 to raise and lower the derrick positioning pin 315. In use, when the derrick 4 is being moved to the working position by the derrick lifting cylinders 30, once the derrick 4 has been moved over centre, the forked ends 107 engage the derricking lifting pins 315 and lower the derrick 4 until fully in the working position. In doing so, the cylinders 101 pivot under weight away from the resting position at the one end of each recess 110. When the derrick 4 is being moved to the nonworking position by the derrick lifting cylinders 101, the pistons extend and once the derrick 4 has been moved over centre, the forked ends 107 disengage the derricking lifting pins 315 and the derrick lifting cylinders 30 lower the derrick 4 until folly in the nonworking position. Once the pins 315 disengaged the forked ends 107, the forked ends 107 return to the resting position under the action of the torsion springs 106. Travel stops 115 prevents the forked ends 107 from pivoting too far from the resting position. The substructure 3 comprises an outrigger assembly 120 extending from the articulated crosspiece 391 each longitudinal side of the subframe 15. Each outrigger assembly 120 is pivotable between working and transport positions relative to the subframe 15, whereby in the working position the outrigger assembly 120 extends perpendicularly from the longitudinal side of the subframe 15 and in the transport position the outrigger assembly 120 extends substantially parallel with the rear end of the subframe 15, as shown in Figure 11.

Each outrigger assembly 120 comprises a jack cylinder 121, a framework 122 comprising a first end pivotally mounted to the articulated crosspiece 391 at the rear end of the subframe 15 and a second end to which is mounted the jack cylinder 121, crosspiece mounting pins 124 and locking pins (not shown) for locking the framework 122 in the working and transport positions. The outrigger assembly 120 is best seen in Figure 12.

The drilling rig 1 comprises a travelling slips frame assembly 140 that is adjustably mounted between the main beams 50 of the derrick base-support members 14, and the slips frame assembly 140 is movable between pipe-engaging and resting positions. The slips frame assembly 140 can also serve as a BOP stack 500 handling system.

As seen in figures 22-25, the slips frame assembly 140 comprises a frame 141 for holding the slips and roller assemblies 142 comprising rollers 149, 150 mounted to opposing ends of the frame 141 that locate within the longitudinal channels 51 of the main beams 50. The frame 141 comprises a pair of end walls 145, a pair of longitudinal walls 146 extending between the end walls 145, and a pair of crosspieces 147, 148 extending between the longitudinal walls 146 and parallel with the end walls 145. Conventional slips 505 (shown in Figure 9) readily locate within a space 506 between the crosspieces 147, 148.

The rollers 149, 150 are movable between raised and lowered positions relative to the frame 141, wherein in the raised position the frame 141 rests on a base of the channel 51 and in the lowered position the frame 141 does not rest on the base and the rollers 149, 150 enable the frame 141 to be moved along the channel 51 between the pipe engaging and resting positions. The pipe engaging position is shown in Figures 9-11.

A roller assembly 142 is located at each end of the frame 141 and comprises a first roller 149, a second roller 150, a first forked roller frame 151 connected to the first roller 149, a second fork roller frame 152 connected to the second roller 150, and a hydraulic roller-positioning cylinder 155 comprising a cylinder housing 156 and a piston 157 mounted to the first and second forked roller frames 151, 152. The first and second forked roller frames 151, 152 are pivotally connected to the frame 141 by way of a pivot pin that extends through the forked roller frame 151, 152 and a bracket 158 of the longitudinal wall 146. The first and second rollers 149, 150 may be moved to the lowered position when the piston 157 retracts within the housing 156, and the first and second rollers 149, 150 may be moved to the raised position when the piston 157 extends from the housing 156. The slips frame assembly 140 comprises a pair of travel stops 143 connected to each end wall 145 of the frame 141 that limit the travel of the forked roller frames 151, 152 between the raised and lowered positions.

The slips frame assembly 140 comprises a guide roller 170 mounted to each comer of the frame 141. Each guide roller 170 engages and rolls along a side wall of the channel 51. This is best seen in Figures 22 and 25.

The slips frame assembly 140 can also serve as a BOP stack 500 handling system - in which the slips 505 is replaced with a carrier frame 510 to which is mounted a hydraulic BOP lifting cylinder 511. This is shown in Figures 28 and 29.

The carrier frame 510 comprises four side walls and two opposing side walls 515 are interconnected by a crosspiece 516. The BOP lifting cylinder 511 has a housing 518 mounted to the crosspiece and a forked end 519 of the piston of the cylinder 511 can be pinned to a mounting shaft 520 of the BOP stack 500. Retracting the piston can raise the BOP stack 500 relative to a well head and allow it to be rolled away from the well head, as shown in Figure 29. Figures 26 and 27 show the slips frame assembly 140 without the carrier frame 510. Figures 26 and 28 show the BOP stack 500 in the well head location.

Figures 10 and 30 show a pipe positioner 600 of the drilling rig 1, to help manoeuvre pipes between the derrick 4 and an elevated trough assembly of a tubular load handler that is located on the opposite side of the work floor 575. The tubular load handler can be as described in the specification of Australian Patent Application No.

2008202799.

The pipe positioner 600 comprises a mounting bracket assembly 601, a base 602, a boom 603, an arm assembly 604, a guide roller 605, a hydraulic base cylinder 606, a hydraulic boom cylinder 607, a hydraulic arm cylinder 608 and a hydraulic arm elevating cylinder 609.

The mounting bracket assembly 601 includes a bracket 610 connected to an end of the main beam 50 and a sleeve 611 connected to the bracket 610 and extending upwardly from the main beam 50. The base 602 comprises a tube 620 having a first end pivo tally connected to the sleeve 611 by way of a pivot pin 621. The hydraulic base cylinder 606 has a first end pivo tally mounted with a pin 617 to lateral extensions 616 of the bracket

610 and sleeve 611. The hydraulic base cylinder 606 has a second end pivotally mounted with a pin (not shown) to an underside of the tube 620 at a second end of the tube 620. The base 602 has a sleeve 623 extending upwardly from the second end of the tube 620.

The base 602 has a tab 624 extending from the first end of the tube 620.

The boom 603 comprises a tube 630 having a first end pivotally connected to the sleeve 623 of the base 602 by way of a pivot pin 632. A tab 635 extends from the first end of the tube 630 of the boom 603. The hydraulic boom cylinder 607 has a first end pivotally mounted with a pin 642 to the tab 624 of the base 602. The hydraulic boom cylinder 607 has a second end pivotally mounted with a pin 644 to an underside of the tube 620 of the boom 603.

The arm assembly 604 comprises a swivel base assembly 660 having a base plate

661 that is pivotally mounted to tube 630 of the boom 603 by way of a pivot pin 663. A yoke 665 extends laterally of the base plate 661. An L-shaped tubular arm 666 extends upwardly from the base plate 661. The L-shaped tubular arm 666 comprises a lower tube

667 and an upper tube 668. The guide roller 605 is connected to an end of the upper tube

668 by way of roller supporting member 670. The guide roller 605 is pinned to an end of the roller supporting member 670 with a pin 672. The hydraulic arm cylinder 608 has a first end pivotally mounted with a pin 676 to the tab 635 of the boom 603. The hydraulic arm cylinder 608 has a second end pivotally mounted with a pin 680 to the yoke 665 of the swivel base assembly 660. A pair of brackets 682 extends from the base plate 661 and the lower tube 667 of the L-shaped tubular arm 666 is mounted with a pivot pin 685 between those brackets 682 and pivotable between raised and lowered positions relative to the base plate 661. A bracket 688 also extends laterally of the lower tube 667 intermediate the ends of the tube 667.

The hydraulic arm elevating cylinder 609 has a housing 690 pinned to bracket 682 and a piston 691 pinned to bracket 688.

When the hydraulic base cylinder 606 extends and retracts, the base 602 pivots relative to main beam 50. When the hydraulic boom cylinder 607 extends and retracts, the boom 603 pivots relative to the base 602. When the hydraulic arm cylinder 608 extends and retracts, the swivel base assembly 660 rotates relative to the boom 603. When the hydraulic arm elevating cylinder 609 extends and retracts, the guide roller 672 moved through an arc and is raised and lowered relative to the main beam 50. Such freedom of movement enables the guide roller 605 to be positioned as required to manoeuvre pipes between the tubular load handler and the derrick 4.

In order to transport the drilling rig 1 by vehicle trailer 2 to a location of interest, first the subframe 15 is mounted to the wheeled chassis of the trailer 2 with the derrick 4 in the lowered nonworking position. The derrick-mounting frame 17 is also collapsed for transport and the outrigger assemblies 120 are pivoted to the transport position, as shown in Figure 1. The slips frame assembly 140 is connected to a top of the crosspiece 27 of the derrick-mounting frame 17, as shown in Figure 6. The rig-laden vehicle is not grossly oversized in that it has overall dimensions of 25 m length (inclusive of the prime mover and helper dolly), 3.5 m width and 4.6 m height.

In order to erect the drilling rig 1, the main beams 50 of the base-support members 40 are pivoted to the working position, the leg assemblies 70 are extended to the ground- engaging working position, the derrick 4 is pivoted and locked in position to the derrick- mounting frame 17, the outrigger assemblies 120 are extended relative to the subframe 15, and the jacking cylinders 35, 90, 121 are extended or retracted as required to provide the drilling rig 1 with stability. In this way, a drilling rig may be transported by vehicle without being grossly oversized, and the drilling rig may be assembled and rendered operational in a short period of time in a safe manner. Whilst the above has been given by way of illustrative example of the invention, many modifications and variations may be made thereto by persons skilled in the art without departing from the broad scope and ambit of the invention as herein set forth.

The term "comprise" and variants of the term such as "comprises" or "comprising" are used herein to denote the inclusion of a stated integer or stated integers but not to exclude any other integer or any other integers, unless in the context or usage an exclusive interpretation of the term is required.

Claims

1. A collapsible drilling rig comprising: a ground-bearing substructure; and a derrick pivotally mounted to the substructure and pivotable relative to the substructure between an erect working position and a nonworking collapsed position, wherein in the working position the derrick has a vertical attitude and in the nonworking position the derrick has a generally horizontal attitude.

2. The collapsible drilling rig of claim 1, wherein the derrick comprises a framework comprising an inner mast and an outer mast, the inner mast is extendable and retractable relative to the outer mast, and in the working position the inner mast is extended relative to the outer mast and lockable in that position.

3. The collapsible drilling rig of claim 2, wherein the derrick comprises at least one mast extending hydraulic cylinder extending between the inner and outer masts, for extending and retracting the inner mast relative to the outer mast.

4. The collapsible drilling rig of claim 2, wherein a lower end of the outer mast is generally rectangular and comprises two upper corner posts and two lower corner posts, and the two upper corner posts have apertures for receiving locking pins when in the erect working position.

5. The collapsible drilling rig of claim 4, wherein the substructure comprises a derrick-mounting frame to which is pivotally mounted the derrick.

6. The collapsible drilling rig of claim 5, wherein the derrick-mounting frame comprises a pair of upright assemblies spaced from one another and a crosspiece extending between the upright assemblies, wherein each upright assembly comprises a vertically extending tubular beam and a pivot pin mounted to the tubular beam and extending upwardly of the tubular beam.

7. The collapsible drilling rig of claim 6, wherein the lower corner posts of the derrick are pivotally mounted to the tubular beams of the upright assemblies by way of pivot pins that extend through coinciding apertures of the lower corner posts and the tubular beams.

8. The collapsible drilling rig of claim 7 further comprising at least one derrick lifting hydraulic cylinder extending between the substructure and the derrick.

9. The collapsible drilling rig of claim 5 further comprising at least one derrick positioning hydraulic cylinder extending between the derrick-mounting frame and the derrick, wherein each said derrick positioning hydraulic cylinder extends from the derrick-mounting frame and each has a catch that engages an extension of the derrick intermediate the upper and lower corner posts, when raising or lowering the derrick above to the derrick-mounting frame.

10. The collapsible drilling rig of claim 6, wherein the derrick-mounting frame is configurable for both a working position and a collapsed transport position, wherein in the working position the derrick extends from a top of the derrick-mounting frame and in the collapsed transport position the derrick extends laterally of the derrick-mounting frame.

1 1. The collapsible drilling rig of claim 10, wherein the derrick-mounting frame comprises a pair of derrick base-support members, each pivotally connected to a said upright assembly, and pivotable between a nonworking transport position whereby they extend alongside the derrick (when in the nonworking position) and a working position whereby the derrick base-support members extend directly beneath the two upper corner posts of the derrick and are lockable thereto.

12. The collapsible drilling rig of claim 11, wherein each said derrick base-support member comprises a beam and a sleeve connected to an end of the beam, and each sleeve extends over a respective pivot pin of the upright assembly so as to allow pivoting between the working and nonworking positions.

13. The collapsible drilling rig of claim 12, wherein the derrick-mounting frame comprises a base-support member positioning hydraulic cylinder and a linkage assembly extending between the crosspiece and each beam of the derrick base-support member, the linkage assembly is connected to a piston of the base-support member positioning cylinder and enables the beam to pivot through an angle of about 180°, such that the beam extends about 90° relative to the crosspiece when in the working position.

14. The collapsible drilling rig of claim 12, wherein the two upper corner posts of the derrick are lockable to the derrick base-support members, whereby a locking pin is extendable through coinciding apertures in the upper corner posts and the beams of the derrick base-support members.

15. The collapsible drilling rig of claim 12, wherein the derrick-mounting frame comprises a ground-support leg assembly comprising a leg having an upper leg portion extending from the beam of the derrick base-support member and a lower leg portion hinged to the upper leg portion, and the lower leg portion is pivotable between an extended ground-engaging working position and a retracted transport position whereby the lower leg portion is raised relative to the ground.

16. The collapsible drilling rig of claim 15, wherein each said ground support leg assembly comprises a leg-extending hydraulic cylinder extending between each lower leg portion and each beam of each derrick base-support member.

17. The collapsible drilling rig of claim 16, wherein each said ground-support leg assembly comprises a hydraulic jack cylinder mounted to the lower leg portion and is extendable and retractable relative to the lower leg portion.

18. The collapsible drilling rig of claim 1, wherein, the drilling rig is transportable by way of a vehicle.

19. The collapsible drilling rig of claim 5, wherein the substructure comprises a vehicle trailer subframe extending from the derrick-mounting frame, wherein the subframe is mountable to a wheeled chassis of the trailer.

20. The collapsible drilling rig of claim 1, wherein the substructure comprises a wheeled chassis of a trailer, with or without a trailer subframe.

21. The collapsible drilling rig of claim 1, wherein the substructure is no wider than about 3.5 m and no longer than about 25 m when combined with a length of a prime mover and helper dolly.

22. The collapsible drilling rig of claim 5, wherein the substructure comprises an outrigger assembly extending from each longitudinal side of the derrick-mounting frame and pivotable between working and transport positions relative to the derrick-mounting frame, whereby in the working position the outrigger assembly extends perpendicularly from the longitudinal side of the derrick-mounting frame and in the transport position the outrigger assembly extends substantially parallel with a rear end of the derrick-mounting frame.

23. A slips frame assembly adjustably mountable between channeled beams of a substructure of a drilling rig, and movable between pipe-engaging and resting positions.

24. The slips frame assembly of claim 23 comprising a frame for holding slips and roller assemblies comprising rollers mounted to opposing ends of the frame, wherein the channeled beams receive the rollers such that the frame is movable relative to the beams.

25. The slips frame assembly of claim 24, wherein the rollers are movable between raised and lowered positions relative to the frame, wherein in the raised position the frame rests on a base of the channelled beam and in the lowered position the frame does not rest on the base and the rollers enable the frame to be moved along the channelled beam between the pipe-engaging and resting positions.

26. The slips frame assembly of claim 25, wherein a roller assembly is located at each end of the frame of the slips frame assembly and comprises a first roller, a second roller, a first forked roller frame connected to the first roller, a second fork roller frame connected to the second roller, and a roller-positioning hydraulic cylinder comprising a cylinder housing and a piston mounted to the first and second forked roller frames, wherein the first and second forked roller frames are each pivotally connected to the frame of the slips frame assembly, the first and second rollers are moved to the lowered position when the piston retracts within the housing, and the first and second rollers are moved to the raised position when the piston extends from the housing.

27. The slips frame assembly of claim 23, wherein the slips frame assembly comprises a guide roller mounted to each end of the frame of the slips frame assembly that engages and rolls along a side wall of the channelled beam.

28. The slips frame assembly of claim 23, wherein the slips frame assembly is able to support a hydraulic BOP lifting cylinder and the cylinder can hold, raise and lower a BOP relative to a work floor.

29. A pipe positioner mountable to a substructure of a drilling rig, said positioner comprising a guide roller for receiving a pipe, and the guide roller is movable horizontally as well as vertically relative to the substructure.

30. The pipe positioner of claim 29 further comprising a substructure mounting bracket assembly, a base, a boom, an arm assembly, a hydraulic base cylinder, a hydraulic boom cylinder, a hydraulic arm cylinder and a hydraulic arm elevating cylinder.

31. The pipe positioner of claim 30, wherein the base is pivotally connected to the mounting bracket assembly such that the base is pivotable in a parallel plane to the main beam, the boom is pivotally connected to the base such that the boom is pivtoable in a parallel plane to the base, the arm assembly comprises a swivel base and an L-shaped arm having a lower end pivotally connected to the swivel base and an upper end connected to the guide roller, the swivel base is pivotally connected to the boom such that the swivel base is pivotable in a parallel plane to the boom, and the L-shaped arm is pivotally connected such that the guide roller can be raised and lowered relative to the swivel base.

32. The pipe positioner of claim 31, wherein the hydraulic base cylinder is pinned to both the mounting bracket and the base, the hydraulic boom cylinder is pinned to both the base and the boom, the hydraulic arm cylinder is pinned to both the boom and the swivel base, and the hydraulic arm elevating cylinder is pinned to both the swivel base and the L- shaped arm.