GB2584670A

GB2584670A - Drilling rig

Info

Publication number: GB2584670A
Application number: GB1908247.8A
Authority: GB
Inventors: Larkin Brendan
Original assignee: Oiltech Solo Ltd
Current assignee: Oiltech Solo Ltd
Priority date: 2019-06-10
Filing date: 2019-06-10
Publication date: 2020-12-16
Anticipated expiration: 2039-06-10
Also published as: GB201908247D0; GB2584670B

Abstract

A portable drilling rig 100 comprises a plurality of components mounted on a platform CWP wherein some of the components are moveable between first and second positions depending on the mode of operation of the rig. Also disclosed is a drilling rig having a platform mounted on a plurality of legs, wherein in an operational configuration the platform is spaced from the base at a first distance and in a second transportable configuration the platform is closer to the base. Also disclosed is a tube handling apparatus having a first jaw member, a second jaw member and a torque member arranged to supply different values of torque depending on the type of tubes being connected. Also disclosed is a racking system comprising a plurality of non-vertical racking bins and a tube retrieval device arranged to place tubes in the bins and retrieve them therefrom.

Description

Drilling Rig The present invention relates to drilling rigs, such as are used in drilling for oil and gas, and is concerned particularly, although not exclusively, with portable, land-10 based drilling rigs.

Background

Drilling rigs used in the discovery and extraction of hydrocarbons typically comprise at least: a derrick, having a mast for supporting a lifting apparatus for lifting drill tubes, a platform on which are mounted a rotary drive for turning the drill tubes in the well, draw works for hoisting the lifting apparatus, a "roughneck" device for coupling and uncoupling drill tubes, a casing tong for connecting and disconnecting casing tubes, a power unit, a blow-out preventer and a rack for the drill tubes. Portable drilling rigs are known in which much of the essential apparatus may be stowed in a compact configuration for transportation, for example on the back of one or more lorries.

The process of drilling an oil well is complex. Each time a well is drilled there is a requirement to move hundreds tonnes of equipment and the power to drive it. It has been common for the setting up of an oil rig to take between a few days to two weeks or so. Often this is downtime (a time where the contractor receives no funds or limited funds). It is therefore important that this process, known as 'rig up' is minimised. 3 5

The choice of site is an ongoing process and is made by geologists with knowledge of the rocks that lie below, which may be 10,000 ft (3000m), or more. A classic choice would be over a dome-shaped fold (revealed by seismic survey). This is often a gamble and would rely on oil and gas having migrated to the top of the dome and accumulated there, millions of years ago, and been restrained by a layer of impermeable rocks above. Once there, the layers will have separated, with gas on top of the oil and ground water below, all at very high pressures.

The procedure commences by drilling a hole using a relatively large drill to penetrate the soft surface layer down to 1000 ft (300m), or so. The hole is built carefully. A drill bit, on the end of a drill string (of tubes) is rotated from the surface ("drill floor") by a top drive unit, via a quill, within a mast on the rig.

Down below, the drilling bits break the hole into fragments and in order not to choke the hole a special fluid ("mud") is pumped down the inside of the drill string causing the bit to cool and carrying the cuttings back to the surface. The returning mud is collected in a "mud bucket" and is then pumped through fine mesh screens known as "shakers", where the coarse cuttings are removed. Then the mud is pumped through separators and settling bits to get rid of the finer materials. The mud can then be recycled down the hole.

As long as the drill bit is turning the mud must be kept circulating through the top drive, the quill, the drill pipe, 35 the drill bit and up the outside of the hole. However, at intervals of depth (typically every 30' for some drill tubes or e.g. every 45' for others) the drill string will need an additional pipe. The drilling stops to do this and the supply of mud is shut off by an isolating valve in the top drive. At this point a part of the pipe remains protruding upwards from the drill floor (this part being called the "stick-up") and the pipe below is supported by slips (wedge grips) which take the mass of the pipe below.

The next drill pipe is brought in from the ramp and is collected by the quill drive, elevated and restrained back to well centre. The new pipe is then gently sat on the stick up and the quill lowers to come clear of the tool joint (the end part of the pipe that contains the thread for connection to another pipe -about 6" or 150mm). At this point a handling tong moves in, grips the stick up, then grips the tool joint on the new pipe and connects the two pipes. This process is called "make-up". The two pipes are threadedly connected together at a pre-set torque to maintain the integrity of the string. The upper end of the new pipe is connected to the quill drive and the top drive valve is opened. The drilling recommences and the mud pumping continues. The procedure is repeated.

In the case of a typical well this operation takes place two 30 hundred times or more before intended bottom of the hole is reached.

Typically, when the hole reaches 1000 ft (with upwards of twenty lengths of drill pipe) a well casing, comprising a 35 series of connected metal tubes, is run into the hole. This process is essential to stabilise the well, i.e. to prevent the softer formation caving in.

At this point the drill string is removed from the hole. The process is known as "tripping out" and there is no rotation 10 of the drill string or pumping of mud. Elevators, including manually or hydraulically operated gripping jaws, lift out the disconnected drill pipes (one, two or three at a time) while the mass of the remaining drill string is supported by mechanically operated wedges called "power slips" at the well centre. Then, the drill pipes are pushed out to for delivery to the storage rack. This process is called "breaking out". (NB: whenever drill pipes are to be reintroduced into the drilled hole, the opposite process -known as "tripping in" is performed).

The casing tubes are then loaded individually onto loader arms and positioned onto the drill floor. Each casing tube is lifted off by the travelling assembly. A so-called "stab arm" collects the pipe and gently eases the casing to the well centre. The casing tube is then lowered through the rotary drive, with centralisers fitted at regular intervals, and held by slips. The elevator then collects the next casing tube and the two tubes are threadedly connected. This procedure is repeated until e.g. 25 casing tubes have been inserted into the well (25 casings of 40' equals 1000 ft (300m)) leaving the casing just clear of the bottom of the drilled hole.

The next task is to cement the casing in place. To do this, 35 cement is pumped down the hole through the casing under pressure. When it reaches the bottom of the hole, it forces the mud and cement back up the outside of the casing (hence the reason for the bottom clearance) and back to the surface. At that point the pumps are stopped and the cement is allowed to set.

The top of the casing is now capped at the top (ground level) by a BOP (Blow Out Preventer) which comprises a group of safety valves to protect the rig against high pressure. In the event of extreme pressure, the BOP seals off the well, closing the gap between the drill string and the casing. As the drilling goes deeper, thereby incurring the possibility of even higher pressures, a series of rams are included within the BOP.

Once the BOP is fitted drilling can recommence. This next phase of the drilling will use a smaller diameter drill bit. The drill bit is connected (and torqued) to the first drill pipe, and the drill pipes are tripped in, for e.g. 25 lengths of 45' pipe (i.e. 1000'), until the drill bit reaches the bottom of the pre-drilled hole. The quill is then reconnected and drilling, and the pumping of mud, is resumed.

The precise formation of the casing string is planned by the geologists and geo-physicists and may involve ever decreasing sizes of casing tube (for example 13%8", 10W', 9", 8", 7"). These will dictate different drill bits and the number of cementing operations required.

Drill bit wear must also be taken into account. As the drill bits drill through a harder formation (e.g. hard rock, granite, etc.) they may wear out more frequently. Drill bits may last as little as a few hours. This becomes noticeable by a loss of cutting power which occurs when the drill bit becomes dull (and the well makes a distinctive noise). The only solution is to pull the whole string (tripping out), change the drill bit and put the new string back in the hole (tripping in).

The next stage involves drilling into the gas and oil and care must be taken to get the correct consistency and chemical composition of the mud to cope with the pressure. Often, prior to going into the formation, an instrument probe is added to the string (meaning full string trip-out, fit probe, trip in). The probe will contain measuring devices which measure certain electrical, acoustical, and radio-active characteristics of the different layers which are sent back to the surface and recorded. At this point an estimation may be made as to how much oil and gas the dome may contain. This information is then analysed to ascertain the full potential of the well. Often additional wells are drilled nearby, allowing a three-dimensional analysis of the dome.

Drilling rigs usually require a team of skilled workers to operate them, but in recent times there has been a move towards mechanising, semi-automating and even fully automating many of the functions that were previously carried out manually by operatives. The drive for automation has, in some cases, led to the design of rigs in which a single operative is able to control and oversee all, or almost all, of the key functions using monitors and electronic controls, usually from within the safety and relative comfort of a control room located on the rig. However, fully automated rigs can be prohibitively expensive for many operating companies and are therefore not widely used, particularly in smaller drilling operations.

The move towards mechanisation and semi-automation in smaller rigs has greatly increased their cost. In addition, because of the potentially costly, not to say dangerous, consequences of a failure of the automated equipment, there is a requirement that automated or semi-automated rigs retain the capability of being safely operated in a manual mode.

Embodiments of the present invention aim to provide a drilling rig, and a method of operating a drilling rig, in 20 which at least some of the foregoing problems are addressed.

The present invention is defined in the attached independent claims, to which reference should now be made. Further, preferred features may be found in the sub-claims appended 25 thereto.

According to one aspect of the present invention, there is provided a drilling rig comprising a plurality of drilling components mounted on a well platform, wherein at least some of the components are moveable between a first position in which the rig is configured for a first mode of operation and a second position in which the rig is configured for a second mode of operation.

The first mode of operation may comprise an automated/semiautomated mode. The second mode of operation may comprise a manual/mechanised mode.

Preferably, in the first position, the plurality of components is located at a first minimum radial distance from a centre-well position, and in the second position the plurality of components is located at a second minimum radial distance from a centre-well position, the first minimum radial distance being less than the second minimum radial distance.

The movement of the components between the first and second positions may be controlled manually and/or may be mechanised. Alternatively, or additionally, movement of the components between the first and second positions may be controlled automatically/semi-automatically in response to one or more predetermined conditions.

In a preferred arrangement, one or more of the components is 25 moveable to a third position, in which the one or more components are in a stowed configuration for transportation of the rig.

The moveable components of the drilling rig may include one 30 or more of, but not limited to, draw works, pipe handling apparatus, tailing arm, a mud management apparatus and a power unit.

According to another aspect of the present invention, there 35 is provided a drilling rig comprising a plurality of drilling components mounted on a well platform, the well platform being itself supportable on a plurality of legs and a base, wherein the drilling rig is moveable between a first, operational configuration in which the platform is spaced from the base by the legs at an operational separation distance and a second, transportable configuration in which the platform is substantially closer to the base.

The platform is preferably mounted pivotably on at least one of the legs. Preferably at least one of the legs is mounted pivotably on the base. The movement between the first and second configurations may comprise a folding movement. In a preferred arrangement the movement is under hydraulic control.

The platform may comprise a plurality of drilling components, including one or more of, but not limited to: draw works, pipe handling apparatus, tailing arm, a mud management apparatus and a power unit.

The platform preferably comprises a central drill floor portion. The central drill floor portion is preferably arranged to support several drilling components, including one or more of, but not limited to: draw works, pipe handling apparatus, tailing arm, mud management apparatus and power unit.

The platform preferably supports a control cab for housing a control operative. The control cab is preferably located on the platform so that an operative within the cab is able 35 to observe directly one or more of the drilling components.

The platform preferably supports a mast, which preferably has lifting equipment for lifting well tubes, such as a crown block and a travelling block.

The drilling rig preferably includes a drill pipe storage unit which may comprise pipe racking. The racking is preferably arranged to store a plurality of drill pipes in a non-vertical configuration. The drill pipe storage unit is preferably arranged in use to be positioned substantially adjacent the platform. A ramp may be provided between the racking and the platform for supporting drill tubes as they are moved between the racking and the platform.

According to another aspect of the present invention, there is provided a tube handling apparatus for connecting and disconnecting threadedly engaging tubes used in a drill rig, the apparatus comprising a first jaw member for gripping a first tube in use, a second jaw member for gripping a second tube in use and a torque member for applying a turning force to cause relative rotation between the first and second tubes in use thereby to connect or to disconnect the tubes, depending on the direction of the turning force, wherein the torque member is arranged to supply different values of torque according to the type of tubes being connected or disconnected.

In a preferred arrangement, the torque member is arranged to apply a turning force to one tube while the other tube remains stationary.

The torque member may comprise one or more drive motors. Alternatively, or in addition, the torque member may comprise at least one motor with plural power settings.

The tube handling apparatus may comprise a positioning apparatus arranged to move the tube handling apparatus in one dimension, preferably at least two dimensions and more preferably in three dimensions to engage optimally with the or each tube.

At least one of the jaw members may comprise a locking gate arranged to ensure the releasable retention of a tube within the jaw member.

At least one of the jaw members may be arranged to grip the 20 tube automatically in response to a control signal. Preferably the torque member is arranged in use to apply torque automatically in response to a control signal.

The invention also includes a racking system for tubes used in a drilling rig, the racking system including a plurality of non-vertical racking bins for accommodating one or more tubes in a non-vertical configuration, and a tube retrieval device arranged to place tubes in the bins and retrieve tubes therefrom.

The tube retrieval device is preferably automated or semi-automated. Preferably the system is arranged to store the tubes in a substantially horizontal configuration.

The invention also includes a method of operating a drilling rig comprising a plurality of drilling components mounted on a well platform, wherein the method comprises moving at least some of the components between a first position in which the rig is configured for a first mode of operation and a second position in which the rig is configured for a second mode of operation.

The first mode of operation may comprise an automated/semiautomated mode. The second mode of operation may comprise a 15 manual/mechanised mode.

Preferably, the method comprises moving at least some of the components between a first position, in which the plurality of components is located at a first minimum radial distance from a centre-well position, and a second position, in which the plurality of components is located at a second minimum radial distance from a centre-well position, the first minimum radial distance being less than the second minimum radial distance.

In a preferred arrangement, the method comprises moving one or more of the components to a third position, in which the one or more components are in a stowed configuration for transportation of the rig.

The invention may include any combination of the features or limitations referred to herein, except such a combination of 10 features as are mutually exclusive, or mutually inconsistent.

A preferred embodiment of the present invention will now be described, by way of example only, with reference to the 15 accompanying diagrammatic drawings, in which: Figure 1 shows, in perspective view, a drilling rig according to an embodiment of the present invention; Figure 2 is a more detailed view-of part of the rig of Figure 1, including a mast; Figure 3 is a more detailed view of part of the rig of Figure 1, including a pipe storage apparatus; Figure 4 is a more detailed view of a part of the rig of Figure 1, including well-centre apparatus; Figure 5 is a simple schematic side view of the rig of Figure 30 1; Figure 6 is a simple schematic plan view of the rig of Figure 1; Figure 7 shows in schematic plan view a platform part of the rig in an automated, or semi-automated operational configuration; Figure 8 shows in schematic plan view a platform part of the 10 rig in a manual operational configuration; Figure 9 shows in schematic plan view a platform part of the rig in a transit configuration; Figure 10 is a perspective view of the platform part of the 15 rig in a transit configuration; Figure 11 is a more detailed perspective view of an embodiment of tube-handling apparatus of the rig in accordance with the present invention; Figure 12 is a schematic perspective view showing a mast and a centre-well platform loaded onto a truck for transportation; and Figure 13 is a schematic perspective view showing a pipe storage unit loaded onto a truck for transportation.

Turning to Figure 1, this shows generally at 100, a portable drilling rig, according to an embodiment of the present invention. The rig 100 comprises the following key components: a mast 110, a crown block 120, a travelling block 130, a top drive 140, a top drive guide dolly 150, draw works 160 and a combined tube handler 170. A tailing arm 180 is used to support drill tubes DT at a lower end, while the tube is lifted by the travelling block 130. A hydraulic power unit 190 supplies hydraulic power to the rig.

As will be described below, the drill tubes DT1 are guided along a ramp R as they are taken from a tube scorage rack 200, where they are stowed, substantially horizontally. The rack 200 is situated to the side of the rig 100. The rack 200 comprises an automated gantry crane 210 for picking the tubes.

An operator's control cab CC is mounted on the platform CWP close to a centre well position. The operator (not shown) is able to observe the key components of the rig from this position, from windows in the cab.

The platform CWP, together with the components situated thereon, is supported on pivotable legs 300 that are themselves erected by hydraulic rams 310 from a base 320 and locked into place. The mast 110 itself is pivotally mounted on the platform and is erected to the position shown by hydraulic rams 105 and locked into place.

Figure 2 shows the platform CWP and mast 110 in more detail and Figure 3 shows the storage rack 200 in more detail, including horizontally arranged casing tubes CT alongside 30 the drilling tubes DT.

Figure 4 shows the centre well platform CWP in more detail, including the combined tube handler 170 in the process of joining two drill tubes DT (described in more detail below).

Figures 5 and 6 are simplified schematics, respectively in side view and plan view, showing the rig of Figures 1-4 in the process of connecting drill tubes DT. The drill tubes are shown connected together in broken lines.

Figures 7 is a simple schematic view of part of the drilling rig 100 in plan. The mast 110 and the tube rack 200 have been omitted for reasons of clarity. In this configuration the rig is set for automatic, or semi-automatic operation, with the various drill floor apparatus being located close by the control cab so that a controller can observe closely the operations he controls.

The well centre is shown at OW. The combined tube handler 170, for connecting and disconnecting drill tubes and casing tubes, is shown at the OW position, whilst other components, such as a doper/cleaner 340 and a mud bucket 350, for collecting drilling fluid and other material that is flushed from the well during drilling, are positioned close by the well centre. During semi-automated drilling the controller operates the components of the rig in turn using controls in the cab CC whilst observing the operations on one or more monitors. The operational tasks that can be managed automatically or semi-automatically there include, among others: the connection and disconnection of the drill tubes and connection and disconnection of the casings using the combined tube handler.

Figure 6 is a corresponding view to Figure 7 but with the rig set for manual operations. The rig may readily convert 35 to manual operations, for example if a fault develops in any of the automated control systems. In this configuration, all of the key components are moved out to a greater radial distance from the well centre that is sufficient to allow operatives to step in and perform the operational tasks, e.g. connecting and disconnecting drill tubes or casing tubes, manually.

The minimum operational distance of the components from the well centre for automated/semi-automated operation is shown by radius Rl. The distance for manual operation is shown by radius R2. Some or all of the components can be moved between the radius R1 and R2 manually, or else by a powered actuator (not shown), which may activate automatically in the event of a trigger condition, such as a fault in a computer operating system. In the closer configuration (Radius R1)the operator in the cab is able to observe all of the components. In the extended configuration (Radius R2) there is provided greater space for manual operatives to perform the tasks otherwise undertaken by the controller in his cab.

During drilling, the various processes for which the controller/operator has responsibility can be divided into three categories: namely those that require full attention, those that require checks and those that take place automatically.

Those that require full attention include: monitoring of well pressure and of the rotational speed of the drilling, the rate of mud pumping, the torque applied to the drill pipes by the top drive unit, the condition of the drill bit and the isolation of the mud supply which connecting drill pipes. The processes that require checks include the alignment of joints of the tubes, using the tube handler, the setting of the slips, the setting of the torque of the tube handler, the position of the travelling assembly and a visual check of the mud bucket. The responsibilities that are largely automated include the collection of the pipes from the rack and delivery to the ramp, ensuring that there is no clash at the well centre -i.e. that equipment cannot be taken to the well centre when the traveling assembly is lowered and the operation of the mud bucket and of the doper/cleaner.

During tripping the controller focusses less on the "full attention" matters above and concentrates more on the checks and automatic functions.

Figures 9 and 10 show the rig in a transit configuration, ready for transportation to a site. The transportation of the rig will be discussed below with reference to Figures 11 and 12.

Figure 11 is a detailed view of the combined tube handler 170. The tube handler 170, performs the functions of both the roughneck, used for connecting and disconnecting drill tubes at high torque, and the casing tong, used for connecting casings, in previously considered drilling rigs.

Historically, these two functions have been performed by separate apparatus because of the very different operational requirements. In particular, drill tube collars require a 35 high torque (ca 120,000 ft-lbs) with a taper thread, whereas casings require a lower torque (ca 20,000 ft-lbs to 60,000 lbs), have a parallel thread and a gentler (continuous) threaded engagement. Also, drill tubes and their collars are up to 9.5" diameter and smaller, whereas casings are typically 7" upwards to 30".

The tube handler 170 is mounted within the mast on a base plate BP that is bolted down to drill floor (not shown).

The tube handler 170 has a lower jaw 1710 and an upper jaw 1720. In use, the lower jaw 1710 grips a portion of tubular pipe CT1 (shown in broken lines) protruding from the drill floor and known as the "stick-up". This stick up is locked to the drill floor by power slips. The power slips can function automatically and consist of a series of wedges within a bowl. Once the wedges are powered up they are cleared of the pipe and once they are powered down they grip the pipe, taking its mass. When the load is transferred to the slips the wedges ensure that the pipe cannot slip. If the operator wishes to retain direct control of the slips he can directly control the powering up and down. A powered up state cannot be entered without the travelling assembly confirming to the operator that it is carrying the load.

By gripping the stick-up the whole assembly is locked to the drill floor, which is essential to take the reaction from the torqueing. The upper jaw 1720 has a plurality of gripping portions 1730 on a circular frame with a slew gear on the outer perimeter. It is a rack and pinion drive. In use, the grips 1730 grip an upper portion of a pipe CT2, in this example a casing tube, and rotate it, engaging The threads of the two tubes to the required torque. For casings alone one motor M could supply the required torque but for drill collars three motors are preferred.

Movement in the direction of arrow A brings the apparatus 10 forward relative to the base plate BP.

Movement in the direction of arrow B is necessary to move the whole assembly up and down, because stick up heights vary.

Movement in the direction of arrow C is the locking of a gate G to ensure the integrity of the upper jaw 1720 before gripping and rotation.

Movement in the direction of arrow D is the vertical float as threads engage.

Rigs according to the present invention allow a single operative, the "driller" to control all of the processes described above. The driller may stand or sit in the control cab CC, or "drill house" which is a safe, clean, relatively quiet environment that may be temperature-controlled, and from where he can see all of the essential equipment for which he is responsible. These conditions are conducive to allow the operative to focus on a plurality of tasks. The driller is presented with all of the information inside the drill house that is necessary for drill a well effectively and efficiently, including tripping drill pipes in and out and installing the casing.

A key advantage of rigs according to the presenc invention is that the driller has full knowledge of all of the functions of the rig, whether they be down the hole, on the drill floor or in the pipe storage rack. The full knowledge can be obtained by direct observation and does not rely on CCTV cameras, for example.

The simplicity of the racking process and the preciseness of the racking locations allows the driller to be confident that racking can operate automatically i.e. without intervention by the driller. Even then, the driller can directly observe the racking if he wishes, and intervention is possible (hence the system becomes semi-automatic).

When the driller wishes to connect or disconnect pipes he needs to know accurately the height at which the pipe is protruding from the centre well platform (the "stick up"). This is because during the application of torque to the two tubes each must be gripped independently. To assist the driller a camera or other sensor is provided on the cab which is able to travel vertically with the tube and which sends data to the cab regarding the height of the stick up. In particular, the position of the tool joint -the portion of the tube that forms a connection to other tubes -must be known accurately. This informs the pipe handler where to grip the tube.

The driller must focus on the essential activities at the well centre on the platform. In order to allow this, the sending of tubes to, or fetching of tubes from, the storage 35 racking is largely automated. The tubes are racked sequentially in special storage positions in the rack, known as bins. To do this each tube is placed in a horizontal configuration and at a known datum position. The tubes are send to, or collected from, their positions automatically by the gantry crane 210.

Racking of the pipes on the ground is unusual, if not entirely unknown in the prior art. In most rigs the pipes are racked vertically within or beside the mast. However, this requires a heavier, bulkier mast which requires a greater transportation provision and is difficult to modularise.

Embodiments of the present invention utilise a ground racking system. Where this has been attempted previously, the pipes have been stored randomly in a horizontal rack. In contrast, according to embodiments of the present invention, the system utilises smart bins to accommodate pipes accurately in precisely known positions. This allows for the racking process to be automated or semi-automated and this, in turn, ensures that the racking process does not become the bottleneck in the tripping in/out procedure.

The control cab CC is mounted on the centre well platform within the drill floor during transportation, as can be seen in Figure 9. To put the cab in operational configuration it is slid or swung into place. When in operational configuration the cab allows the driller excellent visibility of the drill operations while keeping the drill floor clear in case the need arises for the rig to be operated manually.

For the management of mud, optionally, the mud bucket 350 may be replaced by a mud sluice device (not shown). The mud sluice has gates that sit within the drill floor at the outside of a drain grating. During tripping out functions, the individual pipes have a head of mud within them which, when the pipe is disconnected, will drop from the pipe. The mud that falls out of the pipe at this stage is directed through the tube handler and is contained within the sluice gates and directed to drains. Although this approach may be less efficient at collecting mud, when the drill floor is unmanned this is not problematic and is more than compensated for by the improvements In efficiency of the tripping operation, as there is no need for a mud bucket to be repeatedly introduced and removed.

Figure 12 shows generally at 800 the mast 110 and centre well platform CWP loaded onto the back of a truck Ti. The mast has been conveniently folded for transportation and the centre well components have been moved to a transit configuration, as described above with reference to Figure 9. In addition, the legs of the platform have been folded within the base 320. Cables C are already in an operational configuration, to save time setting up at the site.

Figure 12 shows generally at 900 the racking assembly 200 folded and mounted on a truck T2, for transportation to a site.

Embodiments of the present invention provide a number of 35 advantages over previously considered drilling rigs. The closeness of the equipment in the automated or semi-automated mode is beneficial mechanically, for example due to the equipment being lighter, quicker and less prone to mechanical failure. It also allows the equipment to be modularised more readily.

The pipe handling equipment and controls can be site-set in workshop conditions and delivered in set mode to the site on a single truck. Once delivered to the location and set on the substructure, the mast is elevated and the rotary equipment is ready to operate.

The racking system is also site-set in advance, with the component parts all arriving on a single truck. The taking down of the rig is also comparably efficient. The result is a drilling operation that requires less down time and is therefore much more cost effective than previously considered rigs.

The vital equipment controlled by the operator, including for the lift (draw works), for the holding and rotating ( top drive), for the connection of pipes (by the pipe handling apparatus), the power source (hydraulic power unit), the tubular restraint (stab arm) and the string support (rotary table and power slips) is within the assembly and can be supplied pre-set at the workshop.

Whilst the above-described embodiments refer to the introduction to, and withdrawal from, the well of single drill pipes, the skilled person will appreciate that the invention is also applicable to the use of so-called "doubles" and "triples", in which plural pipes are left connected together.

Whilst endeavouring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance, it should he understood that the applicant claims protection in respect of any patentable feature or combination of features referred to herein, and/or shown in the drawings, whether or not particular emphasis has been placed thereon.

Claims

CLAIMS1. A drilling rig comprising a plurality of drilling components mounted on a well platform, wherein at least some of the components are moveable between a first position in which the rig is configured for a first mode of operation and a second position in which the rig is configured for a second mode of operation.
2. A rig according to Claim 1, wherein in the first position, the plurality of components is located at a first minimum radial distance from a centre-well position, and in the second position the plurality of components is located at a second minimum radial distance from a centre-well position, the first minimum radial distance being less than the second minimum radial distance.
3. A rig according to Claim 1 or 2, wherein one or more of the components is moveable to a third position, in which the one or more components are in a stowed configuration for transportation of the rig.
4. A rig according to any of Claims 1-3, wherein the moveable components of the drilling rig may include one or more of, but not limited to, draw works, pipe handling apparatus, tailing arm, a mud management apparatus and a power unit.
5. A drilling rig comprising a plurality of drilling components mounted on a well platform, the well platform being itself supportable on a plurality of legs and a base, wherein the drilling rig is moveable between a first, operational configuration in which the platform is spaced from the base by the legs at an operational separation distance and a second, transportable configuration in which the platform is substantially closer to the base.
6. A rig according to Claim 5, wherein the platform is mounted pivotably on at least one of the legs.
7. A rig according to Claim 5 or 6, wherein ac least one of the legs is mounted pivotably on the base.
8. A rig according to any of Claims 5-7, wherein the platform supports a control cab for housing a control operative.
9. A rig according to Claim 8, wherein the control cab is located on the platform so that an operative within the cab is able to observe directly one or more of the drilling components.
10.A rig according to any of the preceding claims, wherein the rig includes a drill pipe storage unit comprising pipe racking arranged to store a plurality of drill pipes in a non-vertical configuration.
11.A rig according to Claim 10, wherein the drill pipe storage unit is arranged in use to be positioned substantially adjacent the platform.
12 Tube handling apparatus for connecting and disconnecting threadedly engaging tubes used in a drill rig, the apparatus comprising a first jaw member for gripping a first tube in use, a second jaw member for gripping a second tube in use and a torque member for applying a turning force to cause relative rotation between the first and second tubes in use thereby to connect or to disconnect the tubes, depending on the direction of the turning force, wherein the torque member is arranged to supply different values of torque according to the type of tubes being connected or disconnected.
13.Apparatus according to Claim 12, wherein the torque member is arranged to apply a turning force to one tube while the other tube remains stationary.
14.Apparatus according to Claim 12 or 13, wherein the torque member comprises one or more drive motors.
15.Apparatus according to any of Claims 12-14, wherein the torque member comprises at least one motor with plural power settings.
16.Apparatus according to any of Claims 12-15, wherein the tube handling apparatus comprises a positioning apparatus arranged to move the tube handling apparatus in one dimension, preferably at least two dimensions and more preferably in three dimensions to engage optimally with the or each tube. 3 5
17.Apparatus according to any of Claims 12-16, wherein at least one of the jaw members comprises a locking gate arranged to ensure the releasable retention of a tube within the jaw member.
18.Apparatus according to any of Claims 12-17, wherein at least one of the jaw members is arranged to grip the tube automatically in response to a control signal.
19.Apparatus according to any of Claims 12-18, wherein the torque member is arranged in use to apply torque automatically in response to a control signal.
20.A racking system for tubes used in a drilling rig, the racking system including a plurality of non-vertical racking bins for accommodating one or more tubes in a non-vertical configuration, and a tube retrieval device arranged to place tubes in the bins and retrieve tubes therefrom.
21.A system according to Claim 20, wherein the tube retrieval device is preferably automated or semi-automated.
22.A system according to Claim 20 or 21, wherein the system is arranged to store the tubes in a substantially horizontal configuration.
23.A method of operating a drilling rig comprising a plurality of drilling components mounted on a well platform, wherein the method comprises moving at least some of the components between a first position in which the rig is configured for a first mode of operation and a second position in which the rig is configured for a second mode of operation.
24.A method according to Claim 23, wherein the method comprises moving at least some of the components between a first position, in which the plurality of components is located at a first minimum radial distance from a centre-well position, and a second position, in which the plurality of components is located at a second minimum radial distance from a centre-well position, the first minimum radial distance being less than the second minimum radial distance.
25.A method according to Claim 23 or 24, wherein the method comprises moving one or more of the components to a third position, in which the one or more components are in a stowed configuration for transportation of the rig.