WO2019157572A1

WO2019157572A1 - Drill rod handling apparatus

Info

Publication number: WO2019157572A1
Application number: PCT/AU2019/050135
Authority: WO
Inventors: Jeff William BRANSON; Warren Barry FAIR; Steven John Payne; James Daniel CHOMLEY; John Edward Kennedy; David Bruce CARNEGIE - SMITH
Original assignee: Intelligent Drilling Applications & Technology Pty Ltd
Priority date: 2018-02-19
Filing date: 2019-02-19
Publication date: 2019-08-22
Also published as: AU2019221089A1

Abstract

In accordance with the present invention there is provided a drill rod handling apparatus, the apparatus comprising: a rod drawer adapted to receive one or more drill rods; a rod lifter adapted to move a drill rod between a first position and an elevated orientation; and a rod transfer apparatus adapted to transfer the drill rod from the rod drawer to the rod lifter.

Description

Drill Rod Handling Apparatus

TECHNICAL FIELD

[0001 ] The present invention relates to a drill rod handling apparatus. More specifically, the apparatus of the present invention allows for drill rods to be stored on the deck of a drilling unit for presentation to a drill mast.

BACKGROUND ART

[0002] The following discussion of the background art is intended to facilitate an understanding of the present invention only. The discussion is not an acknowledgement or admission that any of the material referred to is or was part of the common general knowledge as at the priority date of the application.

[0003] Mobile drilling units are typically employed to drill holes for blasting in mining operations. Such units commonly comprise a pivoting mast mounted on a drill platform. A drill string is mounted within or onto the mast to drill into the earth. To prevent the drilling depth from being limited by the length of the mast, a plurality of drill rods are used to extend the depth to which drilling can proceed. As the drilling operation continues, drill rods are sequentially loaded to the drill string to extend the drilling depth. In order to load the drill rod to onto the drill string, a drill rod handling mechanism will move each drill rod from a storage position to a positon adjacent to the drill string. The most basic of systems to position the drill rod is a hoist that drags one end of the drill rod to the top of the mast to allow the other end to swing into position. Not only is this technique slow, but it also presents significant safety risks.

[0004] To facilitate the quicker and safer positioning of the drill rods, the drill rods are often stored within the mast. Alternatively, the drill rods are stored in a carousel, which is mounted to the mast. In each of these techniques, the weight of all the available drill rods is carried by the mast. This puts strain on the mast lifting mechanisms and raises the center of gravity of the drilling unit when the mast is in an elevated, or working, position.

[0005] The above limitations place a restriction on size and number of the drill rods that can be used with such mechanisms. This in turn restricts the depth that can be drilled by such drilling units. As would be appreciated by those skilled in the art, the typical drill depth limit of such drill units for drilling of blastholes is around 80 m. As such, if the mine face or desired drill hole depth design required is greater than 80 m, then multiple blast hole passes need to be drilled and multiple blasts need to occur in order to achieve the required excavation depths.

[0006] Throughout this specification, unless the context requires otherwise, the word "comprise" or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.

SUMMARY OF INVENTION

[0007] In accordance with the present invention there is provided a drill rod handling apparatus, the apparatus comprising: a rod drawer adapted to receive one or more drill rods; a rod lifter adapted to move a drill rod between a first position and an elevated orientation; and a rod transfer apparatus adapted to transfer the drill rod from the rod drawer to the rod lifter.

[0008] In one form of the present invention, the drill rod handling apparatus is mounted to a drill platform of a mobile drill unit.

[0009] In one form of the present invention, the first position is less than 30° to the horizontal plane. In one form of the present invention, the first position is less than 25° to the horizontal plane. In one form of the present invention, the first position is less than 20° to the horizontal plane. In one form of the present invention, the first position is less than 15° to the horizontal plane. In one form of the present invention, the first position is less than 10° to the horizontal plane. In one form of the present invention, the first position is less than 5° to the horizontal plane. Preferably, the first position is substantially in the horizontal plane. Where the drill rod handling apparatus is mounted to a drill platform of a mobile drill unit, the first position is substantially parallel to the drill platform. [0010] As discussed above, the rod lifter is adapted to move a drill rod between a first position and an elevated orientation. Throughout this specification, unless the context requires otherwise, the term "elevated orientation", will be understood to refer to any orientation where the angle between the longitudinal axis of the drill rod and the first position is greater than 0°. Where the drill rod handling apparatus is mounted to a drill platform of a mobile drill unit, the elevated orientation will be understood to refer to any orientation where the angle between the longitudinal axis of the drill rod and the drill platform is greater than 0°. In one embodiment, the elevated orientation is an orientation where the angle between the longitudinal axis of the drill rod and horizontal plane is greater than 30°. In one embodiment, the elevated orientation is an orientation where the angle between the longitudinal axis of the drill rod and horizontal plane is greater than 35°. In one embodiment, the elevated orientation is an orientation where the angle between the longitudinal axis of the drill rod and horizontal plane is greater than 40°. In one embodiment, the elevated orientation is an orientation where the angle between the longitudinal axis of the drill rod and horizontal plane is greater than 45°. In one embodiment, the elevated orientation is an orientation where the angle between the longitudinal axis of the drill rod and horizontal plane is greater than 50°. In one embodiment, the elevated orientation is an orientation where the angle between the longitudinal axis of the drill rod and horizontal plane is greater than 55°. In one embodiment, the elevated orientation is an orientation where the angle between the longitudinal axis of the drill rod and horizontal plane is greater than 60°. In one embodiment, the elevated orientation is an orientation where the angle between the longitudinal axis of the drill rod and horizontal plane is greater than 65°. In one embodiment, the elevated orientation is an orientation where the angle between the longitudinal axis of the drill rod and horizontal plane is greater than 70°. In one embodiment, the elevated orientation is an orientation where the angle between the longitudinal axis of the drill rod and horizontal plane is greater than 75°. In one embodiment, the elevated orientation is an orientation where the angle between the longitudinal axis of the drill rod and horizontal plane is greater than 80°.

[0011 ] Preferably, the elevated orientation is substantially parallel to the drill mast. As would be appreciated by a person skilled in the art, drill rigs typically operate in a wide range of drill angles, the drill rod handling apparatus of the present invention is adapted to lift a drill rod to a position substantially parallel to the drill mast to facilitate the addition of the drill rod to the drill string. Furthermore, the rod lifter may be moved into a position substantially parallel to the drill mast to facilitate the removal of a drill rod from a drill string.

[0012] In one form of the present invention, the rod drawer is adapted to receive the one or more drill rods in an orientation that is less than 30° to the horizontal plane. In one form of the present invention, the rod drawer is adapted to receive the one or more drill rods in an orientation that is less than 25° to the horizontal plane. In one form of the present invention, the rod drawer is adapted to receive the one or more drill rods in an orientation that is less than 20° to the horizontal plane. In one form of the present invention, the rod drawer is adapted to receive the one or more drill rods in an orientation that is less than 15° to the horizontal plane. In one form of the present invention, the rod drawer is adapted to receive the one or more drill rods in an orientation that is less than 10° to the horizontal plane. In one form of the present invention, the rod drawer is adapted to receive the one or more drill rods in an orientation that is less than 5° to the horizontal plane. Preferably, the rod drawer is adapted to receive the one or more drill rods in a substantially horizontal orientation. Throughout this specification, unless the context requires otherwise, the term "horizontal orientation", will be understood to refer to an orientation where the longitudinal axis of the drill rod is substantially parallel to the horizontal plane. Where the drill rod handling apparatus is mounted to a drill platform of a mobile drill unit, the rod draw is adapted to receive drill rods such that the longitudinal axis of the received drill rod is substantially parallel to the drill platform. Preferably, the one or more drill rods are received substantially horizontally in the rod drawer. More preferably, the one or more drill rods are stored substantially horizontally in the rod drawer. Still preferably, the one or more drill rods are releasably retained within the rod drawer.

[0013] In one form of the present invention, the rod drawer is provided with one of more drill rod compartments. Preferably, where there are two or more drill rod compartments, the drill rod compartments are provided in a parallel array.

[0014] In one form of the present invention, each drill rod compartment is adapted to receive one or more drill rods therein. Preferably, when two or more drill rods are provided in a single drill rod compartment, the drill rods are positioned above one another. [0015] Preferably, the rod lifter comprises a rod retaining portion adapted to receive a drill rod. More preferably, the rod retaining portion releasably retains a drill rod. Still preferably, the rod retaining portion is provided with a clamping means, for example clamps that engage to retain the drill rod in the rod retaining portion.

[0016] In one form of the present invention, the rod lifter comprises a lifting arm coupled to the rod retaining portion. Preferably, the lifting arm is adapted to move the rod retaining portion between a horizontal position and a vertical position.

[0017] In one form of the present invention, the rod lifter has a lower end and an upper end. In one embodiment, the lower end is mounted to the drill platform. Preferably, the lower end is in hingedly engaged with the drill platform. The hinged engagement permits the movement of the rod lifter between a horizontal position and a vertical position.

[0018] In one form of the present invention, the rod lifter further comprises a rod locating arrangement. Preferably, the rod locating arrangement is adapted to engage with the drill rod to assist in the retention of the drill rod in the rod lifter. In a preferred form of the present invention, the rod locating arrangement comprises a rod locating pin. Preferably, the rod locating pin is adapted to be received by a drill rod. More preferably, the rod locating pin is positioned at the lower end of the rod lifter. Still preferably, the rod locating pin is in communication with the rod retaining portion.

[0019] In one form of the present invention, the rod drawer is open at one end. Preferably, the open end allows for the length of the drill rods to exceed the length of the rod drawer. Furthermore, the open end may allow for the length of the drill rods to exceed the length of the drilling platform.

[0020] In one form of the present invention, the drill rod handling apparatus is adapted to receive multiportion drill rods. Preferably, the multiportion drill rod comprises two or more drill rod portions coupled at a tooling joint. More preferably, the tooling joint is a screw type joint. Still preferably, the multiportion drill rod has an increased diameter at the tooling joint. In one form of the present invention, the multiportion drill rod comprises two drill rod portions at least 4.5 m in length.

[0021 ] In one form of the present invention, the drill rod handling apparatus further comprises one or more rod rotators. Preferably, the one or more rod rotators facilitate the coupling and uncoupling of two or more drill rod portions. More preferably, the one or more rod rotators are adapted to rotate one portion of a multiportion drill rod relative to another to permit the coupling and uncoupling of the drill rod portions. Still preferably, each rod rotator comprises one or two rotating drums which engage with one portion of the multiportion drill rod to rotate the portion relative to another portion of the multiportion drill rod.

[0022] In one form of the present invention, the one or more rod rotators are coupled with the rod lifter. It is envisaged that the individual portions of a multiportion drill rod may be positioned in the rod lifter for coupling by the one or more rod rotators. Preferably, the multiportion drill rod may then be transferred to the rod drawer for storage. It is envisaged that by incorporating the rod rotator into the rod lifter, the overall footprint of the rod handling apparatus is reduced.

[0023] In one form of the present invention, the rod transfer apparatus is adapted to releasably engage with a drill rod. Preferably, the rod transfer apparatus is adapted to vertically lift a drill rod out of the rod drawer. More preferably, the rod transfer apparatus engages and lifts a drill rod in a substantially horizontal orientation.

[0024] In one form of the present invention, the rod transfer apparatus is provided with one or more engagement means adapted to engage with the drill rod. In a preferred form of the present invention, the rod transfer apparatus is provided with two or more engagement means adapted to engage with the drill rod. Preferably, where the rod transfer apparatus comprises two or more engagement means, the engagement means are distributed along the length of the drill rod. More preferably, the engagement means comprises two rod lifting arms. It is envisaged that by providing two engagements points will assist in maintaining the drill rod in a substantially horizontal orientation during the transfer between the rod drawer and the rod lifter.

[0025] Preferably, the rod transfer apparatus further comprises a track positioned between the rod drawer and the rod lifter. More preferably, the one or more engagement means are adapted to engage with the track. Still preferably, the engagement of two or more engagement means with the track allows for the two or more engagement means to be positioned along the track. [0026] Preferably, the rod lifter will lift the distal end of the drill rod towards the drill mast of the drilling unit. Preferably, the rod lifter will substantially align the drill rod with the drill mast. It is envisaged that the alignment of the drill rod with the drill mast will facilitate the coupling of the drill rod to a drill rotation source.

[0027] Preferably, the one or more drill rods are retained in the rod drawer by a retention means. In one form of the present invention, the retention means comprise clamps. In an alternative form of the present invention, the retention means comprise forks. Preferably, the forks are sized to prevent the lateral movement of the drill rods in the rod draw. In embodiment where multiportion drill rods with a tooling joint that has an increased diameter relative to the drill rod, it is envisaged that the fork may be sized to prevent the tooling joint from passing in either direction through the fork width. In an alternative form of the present invention, one or more grooves may be provided along the drill rod. Preferably, the grooves are adapted to engage with the forks. As the grooves have a reduced diameter relative to the remainder of the drill rod, the fork will prevent the lateral movement of the drill rod beyond the width of the groove.

[0028] In one form of the present invention, where two or more drill rod compartments are provided in the rod drawer, the rod transfer apparatus may engage with drill rods in any compartment.

[0029] Preferably the drill rotation source is mounted on the exterior of the drill mast. More preferably, the drill mast is solid. Where the drill rotation source is mounted on the exterior of the drill mast, the rod lifter is preferably adapted to position the drill rod beneath the drill rotation source to facilitate attachment.

[0030] In accordance with a further aspect of the present invention, there is provided a method of drilling, the method comprises operation of a drilling unit having a drill rod handling apparatus as described above mounted thereon for the addition and/or removal of drill rods.

BRIEF DESCRIPTION OF THE DRAWINGS

[0031 ] Further features of the present invention are more fully described in the following description of several non-limiting embodiments thereof. This description is included solely for the purposes of exemplifying the present invention. It should not be understood as a restriction on the broad summary, disclosure or description of the invention as set out above. The description will be made with reference to the accompanying drawings in which:

Figure 1 is a side elevation of the drill rod handling apparatus of the present invention;

Figure 2 is a side elevation of the drill rod handling apparatus of the present invention showing the rod lifter;

Figure 3 is a plan view of the drill rod handling apparatus of the present invention;

Figures 4a-b are front elevations of the rod drawer at two locations along its length;

Figure 5 is a side elevation of the rod lifter of the present invention during elevation;

Figure 6 is a side elevation of the a drill rod retained in the rod lifter of Figure 5 during elevation;

Figure 7 is a side elevation of the rod transfer apparatus of the present invention;

Figure 8 is a front elevation of the rod transfer apparatus of the present invention; and

Figure 9 is plan view of a multiportion drill rod in accordance with the present invention.

DESCRIPTION OF EMBODIMENTS

[0032] In Figures 1 - 9, there is shown a drill rod handling apparatus 10 in accordance with the present invention. The drill rod handling apparatus 10 is primarily adapted for use on a drilling unit 12.

[0033] In Figures 1 - 3 there is shown the drill rod handling apparatus 10 as mounted on a drilling unit 12. In the embodiment shown in Figures 1 - 3 the drill rod handling apparatus 10 is mounted on a drill platform 14. The drill platform 14 is supported on a crawler undercarriage 16 that allows the drill platform 14 to be positioned relative to the area to be drilled. The drill platform 14 further comprises levelling jacks 18 that may be positioned to provide stability when drilling.

[0034] The mobile drilling unit 12 includes drill mast 20 which is hinged to the drill platform 14, such that the drill mast 20 is able to tilt relative to the drill platform 14. The drill mast 20 is able to move between a first position to an elevated positon for drilling at varying angles. The horizontal positon allows for the transport of the drill platform 14. Hydraulic cylinders 15 control the movement of the drill mast 20.

[0035] The drilling unit 12 further comprises an operator cab 22 which houses the operating controls for the drilling operation, together with monitoring instruments. Whilst the embodiment shown in Figures 1 - 3 comprises an operator cab, it is envisaged that operation of the drilling unit 12 may be controlled autonomously. Where drilling is completed by autonomous drilling methods, it is envisaged that the operator cab 22 may be used as a control room for remote signalled drilling operations, along with monitoring instruments.

[0036] The drilling unit 12 comprises a drill rotation source 24 supported on the drill mast 20. The drill rotation source 24 is guided for longitudinal movement along the drill mast 20. Movement of the drill rotation source 24 is controlled by a hoist (not shown). Hydraulic head actuators (not shown) control the movement of the drill rotation source 24 and the hoist. Whilst the drill rotation source 24 shown in the Figures is adapted move along the drill mast 20, it is envisaged that other rotation drive mechanisms may be employed, such as for example a Table Drive. As would be understood by a person skilled in the art, where a Table Drive is utilised, it does not move along the drill mast 20.

[0037] The drilling unit 12 further comprises a hydraulic pump mechanism (not shown) adapted to supply hydraulic fluid for hydraulic operations. The hydraulic pump mechanism is operated by a diesel engine (not shown) mounted on the drill platform 14.

[0038] The drill rod handling apparatus 10 of the present invention is adapted to add and remove drill rods 26 from a drill string. As would be appreciated by a person skilled in the art, the drill rotation source 24 engages with the top of a drill string to rotate the bit. The drill rotation source 24 is moved down the drill mast 20 to force the bit into the earth. As drilling progresses, additional drill rods 26 are added to the drill string.

[0039] The drill rod handling apparatus 10 comprises a rod drawer 28 which is adapted to receive one or more drill rods 26. As best seen in Figures 3 and 4, the rod drawer 28 comprises one or more compartments 30. The compartments 30 are arranged in along the drill platform 14 such that the drill rods 26 lay substantially horizontally along the drill platform 14 when stored in the rod drawer 28. When multiple rod compartments 30 are used, these compartments 30 are arranged parallel to one another. Each individual rod compartment 30 may retain more than one drill rod 26. In the embodiment shown in Figure 4, each rod compartment is adapted to retain two drill rods 26 that are stacked vertically on one another.

[0040] As best seen in Figure 3, each drill compartment has a closed end 32 and an open end 34. The open end allows for drill rods 26 to be longer than the length of the rod drawer 28 to be received in the rod drawer 28. The open end also permits the drill rods 26 to overhang the back of the drill platform 14 if necessary.

[0041 ] The drill rod handling apparatus 10 comprises a rod lifter 36. In the embodiment shown in Figures 1 - 4, the rod lifter 36 is mounted to the drill platform 14 adjacent to the rod drawer 28. The rod lifter 36 has a lower end 38 which is position proximate to the drill mast 20 and an upper end 40 at the distal to the lower end 38. As best seen in Figure 3, the rod lifter 36 is arranged parallel to the direction of the drill rods 26 in the rod drawer 28. As best seen in Figure 5 and 6, the rod lifter 36 comprises a rod retaining portion 42 adapted to receive a drill rod 26. In the embodiment shown in the figures, the rod retaining portion 42 is provided in the form of a“U” shaped section that is sized to receive the drill rod. The rod lifter 36 also comprises a lifting arm 44 coupled to rod retaining portion 42. In the embodiment shown in the figures, the lifting arm 44 is a hydraulically actuated cylinder (not visible). The rod lifting arm 44 actuates to adjust the rod retaining portion 42 from a first position that is substantially parallel to the drilling platform towards an elevated orientation that is substantially parallel to the drill mast. The lifting arm 44 functions to properly position the rod retaining portion 42 whether the drill mast 20 is vertical or at an angle from vertical. When a drill rod 26 is retained within the rod retaining portion 42, the rod lifter 36 will adjust the drill rod 26 from a horizontal orientation to an elevated orientation. In order to facilitate this movement, the lower end 38 of the rod retaining portion 42 is hingedly attached to the drill platform 14, allowing the lifting arm 44 to pivot the rod retaining portion 42 about the hinge. Alternative lifting means may be used to position the rod retaining portion. For example, a screw feed type system may be implemented.

[0042] At the lower end of the rod retaining portion 42 there is provided a rod locating arrangement, for example a rod locating pin 46. As best seen in Figure 6, the rod locating pin 46 extends from the lower end 38 towards the upper end 40. The rod locating pin 46 is sized such that the hollow drill rod 26 may slide over the rod locating pin 46. Once the drill rod 26 has engaged with the rod locating pin 46, the rod locating pin 46 acts to prevent lateral movement of the drill rod 26. This is particularly important from a safety perspective as the drill rod 26 is prevented from swinging out of position during loading/unloading. It is envisaged that as the rod lifter 36 moves the rod retaining portion 42 from a horizontal orientation towards an elevated orientation, a linear action will move the drill rod 26 down towards the lower end of the rod lifter 42. By providing the rod locating pin 46 at the lower end of the rod retaining portion 42, the drill rod 26 is intended to slide and be guided onto the rod locating pin 46. In one form or the present invention, a linear actuator is used to move the drill rod 26 towards the lower end of the rod lifter 42. Additionally or alternatively, the rod locating pin 46 may be linearly actuated to move towards the drill rod 26. Alternative drill rod locating arrangements may be implemented. It is envisaged that any retention means that will secure the drill rod 26 within the rod retaining portion 42 may be used, for example clamps.

[0043] The drill rod handling apparatus 10 further comprises a rod transfer apparatus 48 adapted to transfer drill rods 26 between the rod drawer 28 and the rod lifter 36. In the embodiment shown in Figure 7, the rod transfer apparatus 48 comprises two opposed rod grip arms 50 that are moveable between a raised position and a lowered position by a hydraulic cylinder. At the lower end of each rod grip arm 50 there are provided rod grip clamps 51 that are adapted to releasably engage and retain a drill rod 26.

[0044] As best seen in Figure 7, each rod grip arm 50 is mounted on a bracket 52. The brackets 52 are each suspended on a track 54 that spans the distance between the rod drawer 28 and the rod lifter 36. In the embodiment shown in Figure 7, two parallel tracks 52 are used to provide localise support for each rod grip arm 50. Additional stability is provided by a link beam 53 that spans the two tracks 52. The engagement of the bracket 52 and the track 54 permits the brackets 52 the slide along the length of the track 54 between the rod drawer 28 and the rod lifter 36. It is envisaged that the movement of the brackets 52 along the track 54 may be actuated by any linear actuator available in the art. In the embodiment shown in the figure 7 a rack 55 and pinion 57 arrangement is used to actuate the movement of the brackets 52 along the track 54.

[0045] In use, the brackets 52 can be moved along the track 54 such that the rod grip arms 50 are positioned above a rod compartment of the rod drawer 28. The rod grip arms 50 extend such that the rod grip clamps 51 can engage with the drill rod 26. Once engaged, the rod grip arms 50 can retract, thereby lifting the drill rod out of the rod drawer 28. As best in seen in Figure 8, the brackets 52 may then slide along the tracks 54 such that the drill rod 26 is carried towards the rod lifter 36. Once positioned above the rod retaining portion 42, the rod grip arms 50 can again extend to position the rod drill 26 in the rod retaining portion 42. The rod grip clamps 51 can then disengage the drill rod 26, retract and be positioned clear of the rod lifter 36 to allow elevation of the rod lifter 36. When the drill rods 26 are being removed from the drill string, the operation is reversed. Whilst the rod transfer apparatus 48 shown in the figures comprises a pair of opposed rod grip arms 50 suspended on tracks 54 it is envisaged that other arrangements are possible. Any apparatus that is adapted to reliably engage and vertical lift the drill rods 26 out of the rod drawer 28 and deposit them in the rod lifter 36 will be suitable for use.

[0046] The rod transfer apparatus 48 shown in the Figures is particularly useful as the rod grip arms 50 may be positioned above any of the rod compartments 30 to retrieve drill rods 26. This allows the drill rod 26 selection to be cycled through, thereby improving overall longevity of the drill rods 26.

[0047] Once a drill rod 26 is loaded into the rod retaining portion 42, the rod lifting arm 44 can be actuated to lift the upper end 40 of the rod retaining portion 42, thereby moving the rod retaining portion 42 and the drill rod towards an elevated orientation. As the rod retaining portion 42 is lifted, linear action will move the drill rod 26 to the lower end 38 of the rod retaining portion 42 and onto the rod locating pin 46. The rod retaining portion 42 is lifted until it is in aligned with the drill mast 20 and in a positon ready to be added to the drill string.

[0048] The inventors have found that it is particularly advantageous to provide the drill rotation source 24 on the outside of the drill mast 20. As best seen in Figure 2, having the drill rotation source 24 on the outside of the drill mast 20 allows the rod retaining portion 42 to positon the drill rod 26 directly under the drill rotation source 24. In the embodiment shown in the figures, the drill mast is solid 20. Unlike conventional lattice masts, the inventors have found that solid mast allows for the overall cross section of the drill mast 20 to be reduced, whilst maintaining structural integrity. This has been found by the inventors to provide additional space on the drilling platform relative to conventional lattice masts. Once in positon, the drill rotation source 24 can be engaged with the drill rod 26. It is envisaged that the drill rotation source 24 may then be lifted upwards to lift the drill rod off the rod locating pin 46. Once lifted clear of the rod locating pin 46, the lower tool joint of the suspended drill rod 26 must be coupled to the clamped tool joint of suspended drill string. To assist in the coupling, the apparatus of the present invention further comprises a tilt adjustable rod support 56 adapted to facilitate the alignment of the lower tool joint to the clamped tool joint. It is envisaged that the tilt adjustable rod support 56 is used to guide the suspended drill rod 26 onto the supported tool joint for coupling and attachment to the drill string. Once the drill rod 26 has been removed, the rod lifter 36 can again be lowered to a positon to receive another drill rod 26.

[0049] The inventors have found that the arrangement of the present invention allows for a drill rod 26 to be loaded into the rod retaining portion 42 whilst drilling operations are occurring. It is envisaged that this will increase the speed at which overall drilling can proceed.

[0050] The inventors have determined that the apparatus of the present invention allows for the use of multiportion drill rods 26. As would be appreciated by a person skilled in the art, typical drilling operations add a single piece drill rod 26 to a drill string at a time due to the size constraints. As best seen in Figure 9, the apparatus of the present invention allows for at least separate portions 26a; 26b of a drill rod 26 to be loaded on to the apparatus separately. The separate portions 26a; 26b of the drill rod 26 are adapted to screw into one another in the substantially horizontal plane on the rod lifter 36 by way of complementary female and male joints. The apparatus further comprises two rod rotators 58 adapted to couple the separate portions 26a; 26b of drill rods 26. In the embodiment shown in the figures, the rod rotators 58 are mounted on the rod retaining portion 42 of the rod lifter 36. The rod rotators 58 are mounted on the upper end 40 of the rod retaining portion 42 and is adapted to rotate a drill rod portion 26b mounted in it. One portion 26a of the drill rod 26 is loaded into the rod retaining portion 42 and is retained in position. The second portion 26b of the drill rod 26 is mounted into the rod retaining portion 42 and mounted in the rod rotators 58. The actuation of the rod rotators 58 will rotate the second drill rod portion 26b relative to the first 26a, thereby screwing the second portion 26b into the first 26a. In the embodiment shown in the figures, the rod rotator 58 comprises a rotating rubber/nylon drum (not shown) that the drill rod 26 portion rest on. When the drum is rotated, the drill rod 26 portion 26a is also rotated. To prevent the other drill rod 26 portion from moving, it is clamped in position to rod retaining portion 42. Once the portions 26a; 26b of the drill rod 26 are coupled, the rod transfer apparatus 48 can transfer the drill rod 26 from the rod retaining portion 42 to the rod drawer 28 for use. As an alternative to drums, the rod rotator could comprise a clamping arrangement that includes an actuation mechanism to rotate one portion relative to the other.

[0051 ] It is envisaged that the apparatus of the present invention will be suited to handling 4.5 m or greater portions of drill rods 26. Once coupled on the apparatus, the drill rods 26 will be approximately 9 m or greater. As would be appreciated by a person skilled in the art, typical drill rods 26 are in excess of 10 metres in length and can weigh in excess of 1050kg. This makes the loading of such drill rods 26 onto the drill rig for use in drilling operations difficult and potentially unsafe. By utilising two smaller drill rod portions 26a; 26b, the apparatus of the present invention allows for the safer loading of the drill rods 26. Loading of typical 6 m to 7.5 m or greater drill rod 26 onto the drill deck can be completed using any normal approved vehicle, for example a flat bed truck. As would again be appreciated by a person skilled in the art, this is typically difficult and at times not possible with current drill rod lengths of >7.5m. Current practice is normally to use a lifting bail and winch which is mounted onto drill rig mast and then by pulling the drill rod 26 into the vertical position and then manoeuvring it into position for fastening to the drill rotation source 24 or loading into conventional rod carousels or rod storage systems. This activity is potentially hazardous and slow. The inventors envisage that the drill rod handling apparatus 10 of the present invention eliminates this hazardous activity as any approved truck mounted Vehicle Lifting Crane can simply lift the drill rod portions directly from the approved vehicle into the rod lifter 36 on the drill platform 14 for coupling to together into approximate 12 m or greater length coupled rods.

[0052] As discussed above, the rear end of the rod drawer 28 is open, allowing for the use of drill rods 26 that exceed the length of the drill platform 14. As shown in Figure 9, the drill rods 26 are prevented from falling out the back end of the rod drawer 28 with the use of a retention means, for examples forks 60. By providing the tooling joints 62 of the multiportion drill rod 26 with an increased diameter than the remainder of the drill rod 26, the fork 60 can be sized to fit over the drill rod 26, but not allow the increased diameter tooling joint 62 to pass through, thereby preventing the rod 26 passing through the fork 60 width.

[0053] The inventors have determined that by using a rod transfer apparatus 48 that maintains the drill rod 26 in a horizontal position during transfer between the rod drawer 28 and the rod lifter 36 is particularly useful as the weight of the stored drill rods 26 is spread out across the drill platform 14. Furthermore, when the drill mast is extended, the drill platform maintains a low centre of gravity assisting to prevent the drill platform 14 from tipping over. With a lower centre of gravity, the drill has improved stability during drilling operations. Further, the loads imposed on the drill mast 20 are reduced because the weight of the stored drill rod 26 is carried by the rig platform instead of by the mast structure allowing for reduced cross-section drill mast 20. Productivity may be increased by allowing the drill unit to propel faster between holes due to the lower centre of gravity of the drilling unit 12.

[0054] It is envisaged by the inventors that the apparatus of the present invention allows for greater number of long drill rods 26 to be stored on mobile drilling units 12 to be available for drilling. This means that drilling depth can exceed the current depth limitations of typical mobile drilling units 12. In the embodiment shown in the figures, ten at least 12 metre drill rods 26 are available for drilling. This equates to a drilling depth of ~120 metres or greater. This far exceeds the current limit of around 80 metres.

[0055] Those skilled in the art will appreciate that the invention described herein is susceptible to variations and modifications other than those specifically described. The invention includes all such variation and modifications. The invention also includes all of the steps, features, formulations and compounds referred to or indicated in the specification, individually or collectively and any and all combinations or any two or more of the steps or features.

Claims

1. A drill rod handling apparatus, the apparatus comprising: a rod drawer adapted to receive one or more drill rods; a rod lifter adapted to move a drill rod between a first position and an elevated orientation; and a rod transfer apparatus adapted to transfer the drill rod from the rod drawer to the rod lifter.

2. A drill rod handling apparatus according to claim 1 , wherein the drill rod handling apparatus is mounted to a drill platform of a mobile drill unit.

3. A drill rod handling apparatus according to claim 2, wherein the first position is substantially horizontal to the drill platform.

4. A drill rod handling apparatus according to any one of the preceding claims, wherein the rod drawer is adapted to receive the one or more drill rods in a substantially horizontal orientation.

5. A drill rod handling apparatus according to claim 4, wherein the one or more drill rods are received substantially horizontally in the rod drawer.

6. A drill rod handling apparatus according to any one of the preceding claims, wherein the rod drawer is provided with one of more drill rod compartments.

7. A drill rod handling apparatus according to claim 6, wherein each drill rod

compartment is adapted to receive one or more drill rods therein.

8. A drill rod handling apparatus according to any one of the preceding claims, wherein the rod lifter comprises a rod retaining portion adapted to receive a drill rod.

9. A drill rod handling apparatus according to claim 8, wherein the rod lifter

comprises a lifting arm coupled to the rod retaining portion.

10. A drill rod handling apparatus according to claim 9, wherein the lifting arm is adapted to move the rod retaining portion between a first position and an elevated orientation.

11. A drill rod handling apparatus according to any one of the preceding claims, wherein the rod lifter has a lower end and an upper end.

12. A drill rod handling apparatus according to claim 11 , wherein the lower end is hingedly engaged with the drill platform.

13. A drill rod handling apparatus according to anyone of the preceding claims, wherein the rod lifter further comprises a rod locating pin adapted to be received by a drill rod.

14. A drill rod handling apparatus according to any one of the preceding claims, wherein the rod drawer is open at one end.

15. A drill rod handling apparatus according to any one of the preceding claims, wherein the drill rod handling apparatus is adapted to receive multiportion drill rods.

16. A drill rod handling apparatus according to any one of the preceding claims, wherein the drill rod handling apparatus further comprises one or more rod rotators.

17. A drill rod handling apparatus according to claim 16, wherein the one or more rod rotators facilitate the coupling of two or more drill rod portions.

18. A drill rod handling apparatus according to any one of the preceding claims, wherein the rod transfer apparatus is adapted to releasably engage with a drill rod.

19. A drill rod handling apparatus according to any one of the preceding claims, wherein the rod transfer apparatus is adapted to vertically lift a drill rod out of the rod drawer.

20. A drill rod handling apparatus according to any one of the preceding claims, wherein the rod transfer apparatus is provided with one or more engagement means adapted to engage with the drill rod.

21.A method of drilling, the method comprises operation of a drilling unit having the drill rod handling apparatus of any one of claims 1 to 20 mounted thereon for the addition and/or removal of drill rods.