Method and apparatus for drilling and positioning a borehole support casing into a blasthole

Abstract

The present invention provides an apparatus and method for preventing surrounding loose rock debris from falling or collapsing into a borehole during drilling and immediately following removal of a drill string from the borehole. The apparatus includes a borehole casing for a borehole drilling tool, the casing comprising a tubular member adapted to be coupled to a mast of a movable borehole drilling tool and positioned in the borehole region, the tubular member including a longitudinal interior passage for receiving the drill string therethrough and an exterior surface for facing outwardly against the wall of the borehole.

Description

Technical Field

[0001] The present invention relates to the field of borehole drilling, particularly but not exclusively to blasting operations for mining and quarrying. Background Art

[0002] Above ground, open-pit mining methods can involve explosive blasting to dislodge large quantities of ore for excavation and recovery. Step blasting is a process that involves drilling holes into rock to depths of 50 meters or more and filling the holes with explosive material to form cylindrical charges that fracture the rock in a controlled manner. Blastholes can be as large as 270 to 311 or even up to 350 millimeters in diameter.

[0003] Blast holes are typically drilled using percussion drilling techniques. Percussive energy is generated by a reciprocating piston, with each piston strike causing carbide buttons in the drill bit to penetrate the rock. The drill string rotates after each strike, moving the drill bit to a new position so that the buttons strike a new rock surface. Top hammer drilling involves applying percussive energy to the upper end of the drill string via a piston. Down-the-hole (DTH) drilling involves applying percussive energy to the lower portion of the drill string, just above the drill bit, via a piston. Top hammer drilling is typically used for drilling relatively small diameter holes, while DTH drilling is typically used for drilling larger diameter holes.

[0004] Rotary drilling is another technique used to drill blastholes. It doesn't use impact. Instead, it uses a feed force and rotational torque. The torque rotates the drill bit, while the feed force holds the drill bit firmly against the rock surface. The combination of rotational torque and feed force enables the drill bit to penetrate the rock by cutting into the rock surface.

[0005] After blasting, the fractured rock is mostly removed by the excavator for further processing. However, a large amount of loose rock fragments, or "pre-processed" material, from the sub-drilled area after reaching the lowering level (RL) may remain on the bench where the blastholes are drilled for subsequent blasting operations. Pre-processing layers up to 4 meters or more in depth can improve the efficiency of the comminution process by maximizing the amount of fine crushing produced by subsequent blasting operations.

[0006] Loose rock fragments from the pre-treated layer around the blasthole, commonly referred to as the "collar" area of the blasthole, can collapse into the blasthole after drilling. The applicant's patent application WO2019014716 discloses a collar support device for preventing loose rock fragments from falling or collapsing into the blasthole. The device includes a generally planar flexible sheet that is formed into a curved form to define a longitudinal channel and is then inserted into the open end of the blasthole. The curved sheet closely faces the inner surface of the blasthole and forms a barrier that prevents surrounding loose rock fragments from falling or collapsing into the open end of the blasthole.

[0007] However, even during or after drilling, and before the borehole support equipment is positioned in place, surrounding loose rock fragments may collapse into the borehole. Therefore, a drilling system is needed to minimize any possibility of loose rock fragments from the pre-treated layer collapsing into the borehole.

[0008] Furthermore, the process of manually manipulating the preformed aperture support device and inserting the aperture support device into the borehole can be time-consuming and labor-intensive. Therefore, a drilling system is needed whereby the aperture support device can be positioned in the borehole with minimal time and effort.

[0009] Any discussion of the background art throughout the specification should in no way be considered as an admission that any document or material referred to is published, known or forms part of the common general knowledge. Summary of the Invention

[0010] Thus, in one aspect, the present invention provides a drilling casing apparatus for a drilling rig, the casing apparatus comprising a tubular member adapted to be coupled to a mast of a movable drilling rig and positioned within an aperture region of a borehole, the tubular member comprising a longitudinal interior passage for receiving a drill string therethrough, and an exterior surface for facing outwardly against a wall of the borehole.

[0011] Preferably, the tubular member and the mast comprise a coupling for securing the tubular member to the mast.

[0012] Preferably, the coupling is adapted for releasably securing the tubular member to the mast.

[0013] Preferably, the coupling is adapted to allow movement of the tubular member relative to the mast between a position in which the tubular member is aligned with the axis of the drill string and another position in which the tubular member is offset from the axis of the drill string while the tubular member and mast remain coupled together.

[0014] Preferably, the coupling comprises a slot mount coupling.

[0015] Preferably, the coupling comprises an adapter secured to the mast, the adapter including a slot for receiving a flange at the end of the tubular member.

[0016] Preferably, the slot is defined between a pair of opposing plates which, in use, are oriented substantially parallel to the step surface.

[0017] Preferably, the flange is adapted to enter and exit the slot with horizontal movement of the adapter relative to the tubular member.

[0018] Preferably, the flange is adapted to move in the slot between a position in which the tubular member is aligned with the axis of the drill string and another position in which the tubular member is offset from the axis of the drill string.

[0019] Preferably, the flange is a substantially planar member fixed to one end of the tubular member. Preferably, the flange has a polygonal shape. Preferably, the flange has opposing tapered edges providing a narrower width at one end of the flange for guiding the flange into the slot.

[0020] Preferably, each of the pair of plates includes an opening, preferably centrally located, for receiving a drill string therethrough and for alignment with the longitudinal internal passage of the tubular member.

[0021] Preferably, the opening through the lower one of the plates is open to one side of the plate for receiving the tubular member therein.

[0022] Preferably, one or more protrusions extend from the flange for engaging the step surface and maintaining a gap between the flange and the step surface. Preferably, the protrusions extending from the flange are adapted to engage the step surface and support the mast thereon. Preferably, the protrusions are adapted to maintain the flange above the step surface to allow one of the plates of the adapter to be placed between the flange and the step surface.

[0023] Preferably, the tubular member is adapted to be self-supporting in the bore aperture so as to receive the aperture support apparatus within the longitudinal internal passage.

[0024] Preferably, the tubular member comprises a rigid, cylindrical body portion having openings at opposite ends and a longitudinal internal passage extending therebetween.

[0025] In a preferred embodiment, the tube member is self-supporting and one end of the longitudinal inner passage is located at the level of the step surface.

[0026] In another aspect, the present invention provides a drilling device comprising:

[0027] Movable platform,

[0028] The mast, placed on the platform, includes a support portion for the drill string;

[0029] A drill string rotation drive mechanism, used to drive the drill string to drill holes in the rock;

[0030] A borehole casing apparatus includes a tubular member coupled to a mast for positioning in a borehole region, the tubular member including a longitudinal interior passage for receiving a drill string therethrough and an exterior surface for facing outwardly against a wall of the borehole.

[0031] In embodiments, the tubular member is movable between a position in which the tubular member is aligned with the axis of the drill string and another position in which the tubular member is offset from the axis of the drill string while remaining coupled to the mast. These embodiments are particularly, but not exclusively, suitable for use with smaller surface drilling platforms, commonly referred to as "crawler drills," which are typically used to drill boreholes having diameters between about 89 and 165 mm.

[0032] In some embodiments, the tubular member is axially movable while remaining coupled to the mast to lower the tubular member into the borehole and raise the tubular member out of the borehole. Preferably, the drilling casing apparatus includes a hydraulic actuator to axially translate, e.g., raise or lower, the tubular member relative to the borehole. These embodiments are particularly, but not exclusively, suitable for use with larger surface drilling platforms, commonly referred to as "platform drills," which are typically used to drill boreholes having diameters between approximately 165 and 351 mm.

[0033] In an embodiment, the drilling apparatus further comprises a sheet deployment apparatus for arranging the flexible sheet in the open end of the tubular member located in the borehole.

[0034] In an embodiment, the sheet deployment apparatus comprises a sheet forming apparatus adapted to form a planar flexible sheet into a curved form and to feed the curved sheet to the open end of the tubular member located in the borehole.

[0035] Preferably, the forming apparatus comprises a wide inlet gradually narrowing to a narrower circular outlet to define a path for the flexible sheet, and a feeding mechanism for feeding the flexible sheet into the tube member through the inlet and the circular outlet.

[0036] Preferably, the drilling apparatus includes a storage portion for a plurality of flexible sheets and a picker adapted to pick up one sheet at a time. The flexible sheets may be planar and arranged in a stack, or the flexible sheets may be pre-rolled sheets and include a tie to hold each pre-rolled sheet in a rolled form. In an embodiment, the deployment apparatus is adapted to pick up one of the pre-rolled sheets and feed the pre-rolled sheet through the tubular member into the borehole.

[0037] Preferably, the drilling apparatus further comprises a shroud adapted to securely seal to the longitudinal inner passage of the tubular member for guiding cuttings and / or bailings emerging from the borehole during drilling.

[0038] Preferably, the shroud includes an axial passage for receiving the drill string therethrough and a discharge port located transverse to the axial passage.

[0039] Preferably, the exhaust port is adapted as a flexible conduit coupled to a vacuum device.

[0040] Preferably, the shroud is mounted to the mast and the drive is adapted to translate the shroud upwardly and downwardly through a range of linear motion.

[0041] Preferably, the drilling apparatus further comprises an outlet located adjacent to or beneath the movable platform for directing cuttings and / or bailed sand emerging from the borehole during drilling to a pile adjacent to or beneath the movable platform.

[0042] Examples of drilling equipment include various types of mobile drilling equipment, including a movable crawler platform including a drill mast that supports a drill string and an attached percussive rotary air blasting drilling device. In some embodiments, such mobile drilling equipment includes smaller surface drilling platforms, typically used for drilling holes with diameters between about 89 and 165 mm, commonly referred to as "crawler drills," and produced by manufacturers such as Sandvik, Epiroc, Komatsu, and Caterpillar. In other embodiments, such mobile drilling equipment includes larger surface drilling platforms, typically used for drilling holes with diameters between about 165 and 351 mm, commonly referred to as "deck drills," and produced by manufacturers such as Sandvik, Epiroc, Komatsu, and Caterpillar.

[0043] When implemented in larger, mobile drilling platforms, such as those typically used for drilling larger boreholes of 165 to 351 mm diameter, embodiments of the drilling equipment that include a shield for directing cuttings and / or bailing sand that emerge from the borehole during drilling are advantageous. Existing drilling platforms of this type may include a cuttings and / or bailing sand management system that simply surrounds the borehole with a flexible curtain attached to and suspended from below the platform. Embodiments of the present invention may replace or supplement such existing systems.

[0044] In an embodiment, the drilling apparatus comprises a system for injecting a composition between an outer surface of the tubular member and a surrounding wall of a borehole.

[0045] Preferably, the system for injecting the composition comprises a reservoir of the composition coupled to a network of conduits and openings formed in the tubular member so that when the tubular member is placed in the borehole, the composition escapes from the openings and enters the space between the tubular member and the borehole or penetrates surrounding loose rock debris, or both.

[0046] In another aspect, the present invention provides a drilling method comprising:

[0047] coupling a tubular member to a mast of a mobile drilling rig, the tubular member including a longitudinal interior passage for receiving a drill string therethrough;

[0048] A hole is drilled in the stepped surface and a tubular member is lowered into the orifice region of the drilled hole, the tubular member including an outer surface facing outwardly against the wall of the drilled hole.

[0049] In another aspect, the present invention provides a method of placing a borehole support device into a borehole, the method comprising:

[0050] coupling a tubular member to a mast of a mobile drilling rig, the tubular member including a longitudinal interior passage for receiving a drill string therethrough;

[0051] drilling a hole in the stepped surface and lowering a tubular member into an orifice region of the drilled hole, the tubular member including an outer surface facing outwardly against a wall of the drilled hole;

[0052] Providing support in a borehole for stabilizing the borehole mouth area; and

[0053] The tubular member is removed from the drilled hole.

[0054] Preferably, providing support within the borehole comprises inserting an aperture support device comprising a sheet of flexible material into the longitudinal interior passage of the tubular member, and wherein removing the tubular member from the borehole leaves the aperture support device within the borehole.

[0055] Preferably, moving the mast relative to the tubular member comprises moving the mast between a position in which the tubular member is aligned with the axis of the drill string and another position in which the tubular member is offset from the axis of the drill string while the tubular member and the mast remain coupled together.

[0056] Preferably, removing the tubular member from the borehole comprises operating a mast to raise the tubular member out of the borehole.

[0057] Preferably, coupling the tubular member to the mast comprises horizontally translating the mast relative to the tubular member. In an embodiment, decoupling the tubular member and the mast also comprises horizontally translating the mast relative to the tubular member.

[0058] Preferably, the adapter secured to the mast includes a slot and one end of the tubular member includes a flange, whereby horizontal movement of the mast relative to the tubular member causes the flange to move into or out of the slot.

[0059] In an embodiment, providing support in the borehole for stabilizing the borehole head region includes injecting a composition between an outer surface of the tubular member and a surrounding wall of the borehole.

[0060] In embodiments, the injected composition cures or otherwise hardens or solidifies to become self-supporting or to bind loose rock fragments to form a composite orifice support.

[0061] In yet another aspect, the present invention provides a sheet forming apparatus adapted to form a flat flexible sheet into a curved form and to feed the curved sheet to a tubular member within the orifice region of a drilled hole, the apparatus comprising:

[0062] forming equipment adapted to form a flat flexible sheet into a curved form; and

[0063] A feeding mechanism is used to feed the bent sheet material to the tubular member within the orifice region of the drilled hole.

[0064] Preferably, the forming apparatus comprises a wide inlet and gradually narrows to a narrower circular outlet to define a path for the flexible sheet, wherein the feeding mechanism feeds the flexible sheet through the inlet and outlet of the forming apparatus to the tube member.

[0065] Preferably, the plurality of flexible sleeves are arranged in a stack, and the feed mechanism is configured to pick up one sheet at a time from the stack.

[0066] Preferably, the sheet forming apparatus is configured to be attached to a mast of a bore drilling apparatus. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] The present invention will now be described in more detail with reference to preferred embodiments shown in the accompanying drawings, in which:

[0068] Figure 1 Shown is a perspective view of a pipe component of a drilling casing device according to an embodiment of the present invention;

[0069] Figure 2 Shown Figure 1 a side view of a longitudinal section of a pipe member;

[0070] Figure 3 Shown is a perspective view of an adapter of an embodiment of a drilling casing apparatus;

[0071] Figure 4 Shown Figure 3 a top view of a cross section of the adapter;

[0072] Figure 5 Shown is an oblique perspective view of a drilling apparatus comprising a mobile drilling rig having a hydraulic arm and a drilling mast attached thereto, and Figure 3 and 4 The adapter to the mast, and Figure 1 and 2 a pipe member coupled to the adapter;

[0073] Figure 6 Shown Figure 5 A front perspective view of the drilling equipment;

[0074] Figure 7 to 1 4 for the above Figures 1 to 6A set of elevation views of a portion of a drilling mast and a borehole casing apparatus according to an embodiment of the present invention, illustrating a series of steps in a method of drilling a borehole according to an embodiment of the present invention and in a method of providing an orifice support apparatus in a borehole according to an embodiment of the present invention.

[0075] Figure 15 Shown Figure 7 to 1 4 is a front view of the orifice support device in a planar configuration;

[0076] Figure 16 Shown Figure 7 to 1 4 is a front view of the orifice support device in a bent configuration;

[0077] Figure 17 Shown is an oblique perspective view of a drilling rig comprising a drilling rig similar to Figure 5 Embodiments of a mobile drilling rig having a hydraulic arm and a drilling mast attached thereto, further comprising a sheet forming apparatus adapted to form a planar flexible sheet into a curved form and feed the curved sheet to an open end of a tubular member located in a borehole;

[0078] Figure 18 and 19 for Figure 17 a set of elevational views of a portion of a drilling apparatus comprising a portion of a drilling mast, a sheet forming apparatus and an aperture support apparatus comprising a curved flexible sheet, and illustrating a series of steps of forming a flat flexible sheet into a curved form and feeding the curved sheet into an open end of a drilling casing apparatus positioned in a borehole, and withdrawing the casing apparatus from the borehole to leave the aperture support apparatus behind;

[0079] Figure 20 Shown Figure 5 An embodiment of the drilling apparatus further comprising a shroud adapted to securely seal against the longitudinal interior passage of the tubular member for guiding cuttings and / or bailing sand emerging from the borehole during drilling;

[0080] Figure 21 Shown Figure 5 An embodiment of a drilling apparatus of the type described herein and further comprising a shroud adapted to securely seal against the longitudinal interior passage of the tubular member, wherein the shroud is coupled to a flexible conduit of a vacuum apparatus for directing cuttings and / or bailing sand emerging from the borehole during drilling;

[0081] Figures 22 to 25One embodiment of a drilling method is shown with reference to another embodiment of the drilling apparatus of the present invention, comprising a surface drilling platform of the type typically used for drilling larger diameter boreholes having a diameter between about 165 and 351 millimeters, wherein the casing apparatus includes a hydraulic actuator to axially raise and lower a tubular member relative to the borehole, and wherein the hydraulic actuator is adapted to raise and lower a shroud relative to the tubular member to direct cuttings and / or bailing sand emerging from the borehole during drilling;

[0082] Figure 26 Another embodiment of a drilling method and apparatus is shown adapted to pick up pre-rolled and tied flexible sheets one at a time and place the pre-rolled sheets in a tubular member within a borehole;

[0083] Figure 27 Shown Figures 22 to 26 a bottom view of an embodiment of a surface drilling platform illustrating the arrangement of a curtain attached to and suspended from below the platform to contain cuttings and / or bailing directed by a shroud below the platform; and

[0084] 28-29 illustrate another embodiment of a method of stabilizing the borehole mouth, including injecting a stabilizer into the wall of the borehole or into loose rock fragments surrounding the borehole in the region of the borehole mouth.

[0085] The present invention will now be described in more detail with reference to embodiments shown in the accompanying drawings. DETAILED DESCRIPTION

[0086] Blasthole drilling is a technique used to extract minerals and rock products from open-pit mines and quarries. A drill rig creates a borehole of a predetermined shape and depth. Explosives are then loaded into the hole, breaking up and fragmenting the minerals and rock for removal by an excavator for further processing. Large quantities of loose rock fragments, or "pre-processed" material, from the ultra-deep drilling zone after reaching the lowering level (RL) may remain on the bench. Pre-processing layers of four meters or more in depth improve the efficiency of the comminution process by maximizing the volume of finely crushed rock produced by subsequent blasting operations.

[0087] refer to Figure 5 and 6 , the present invention relates to a casing apparatus 100 adapted for use with a drilling rig 10 for drilling a borehole. Figures 1 to 6 9 to 13, the casing apparatus 100 includes a tubular member 110 adapted to be placed within a borehole in use, as will be described in greater detail below. The tubular member 110 includes a longitudinal interior passage 120 for receiving a drill string of a drilling rig therethrough. The tubular member 110 also includes an exterior surface 125 for facing outwardly against a borehole wall.

[0088] The casing apparatus 100, and in particular the tubular member 110, is adapted to support the aperture of the borehole 2 during drilling and immediately after drilling and before the aperture support device can be placed in position within the aperture of the borehole 2. In some embodiments, the casing apparatus 100, and in particular the tubular member 110, is adapted to receive the aperture support device therein. The tubular member 110 can thus facilitate the steps of forming the generally planar aperture support device into a curved form and inserting the aperture support device into the borehole.

[0089] drilling rig

[0090] Figure 5 and 6 Shown is an exemplary mobile drilling rig 10 for drilling a borehole 2. The illustrated drill rig 10 is a percussive top hammer type drill rig. However, it should be understood that the present invention is more broadly applicable to other types of drill rigs, such as down-the-hole (DTH) drills and rotary drills. The embodiment of the mobile drilling rig 10 shown in the figures is a surface drilling platform of a type typically used for drilling boreholes between about 89 and 165 mm in diameter, commonly referred to as "crawler drills." However, it should be understood that embodiments of various aspects of the present invention are also applicable to larger surface drilling platforms of a type typically used for drilling boreholes between about 165 and 351 mm in diameter, commonly referred to as "platform drills." Smaller and larger types of platforms are well known from many manufacturers, such as Sandvik, Epiroc, Komatsu and Caterpillar, to name a few.

[0091] The drilling rig 10 comprises a self-propelled vehicle 12 having a hydraulic arm 14 supporting a mast 20. The mast 20 is itself adapted to support a drill string 30 comprising a plurality of drill rods 35 and a drill bit 37 at the end of the drill string 30. The drill rods 35 are coupled together by threaded connections therebetween.

[0092] In one aspect, the present invention relates to a borehole casing apparatus 100 adapted to be coupled to a mast 20 in a manner described in greater detail below. In another aspect, the present invention relates to a combination of a mobile drilling rig 10 and a borehole casing apparatus 100.

[0093] The mast 20 carries a drilling head 25 that includes a reciprocating piston or hammer assembly and a rotary assembly that are adapted together to apply percussive force and rotational torque to a drill string 30. The drilling head 25 can be raised and lowered by a hydraulically driven up and down feed system 29 to enable pipe or rod to be removed from or added to the drill string.

[0094] The mast 20 includes a storage section 27 for a plurality of drill rods 35. During drilling operations, when the top of the uppermost drill rod 35 reaches the bottom of the mast 20, the subsequent drill rod 35 is swung into position by the drill rod feed system and axially aligned with the uppermost mast drill rod 35 of the drill string 30. The drilling head 25 then engages and rotates the subsequent drill rod 35 to threadably couple with the top of the lower drill rod 35. The drilling head 25 then continues drilling by applying impact force and rotational torque to the drill string 30.

[0095] Drilling casing equipment

[0096] like Figure 9 to 1 3, casing apparatus 100 includes a tubular member 110 adapted, during use, to be placed within a borehole 2 that has been drilled or is in the process of being drilled by a drilling rig 10. Preferably, tubular member 110 is formed from a rigid and durable material, such as metal (e.g., mild steel). Tubular member 110 is configured to be releasably coupled to the bottom of a mast 20. When coupled to the mast 20, a longitudinal interior passage 120 of tubular member 110 is adapted to align with the axis of a drill string 30 to receive the drill string 30 therethrough.

[0097] The outer surface 125 of the tubular member 110 is adapted to face outwardly against the wall of the borehole 2. The diameter of the outer surface 125 of the tubular member 110 is desirably slightly larger than, slightly smaller than, or approximately equal to the diameter of the drill bit 37. The diameter of the outer surface 125 of the tubular member 110 is desirably slightly larger than, slightly smaller than, or approximately equal to the diameter of the borehole 2 to be formed thereby. Accordingly, tubular members 110 of different diameters can be provided for use with drill bits 37 of different diameters and / or boreholes 2 of different diameters.

[0098] In some borehole drilling operations, a pre-treatment layer may be used at depths of 4 meters or more. The portion of the borehole 2 within the pre-treatment layer is sometimes referred to as the "orifice." The pre-treatment layer comprises crushed rock composed of a wide range of particle sizes, including fine, medium, and coarse, ranging from 1 mm to 100 mm or more. The borehole casing apparatus 100 is adapted to provide temporary support to the walls of the borehole 2 in the orifice region both during the drilling operation and after the borehole has been drilled to the desired depth.

[0099] Connectors

[0100] On the other hand, the present invention relates to a coupling between the mast 20 and the tubular member 110 of the drilling rig 10 for securing the tubular member 110 to the mast 20. As apparent from the above description, in the embodiments disclosed herein, the coupling is adapted to allow the tubular member 110 to move relative to the mast 20 between a position in which the tubular member 110 is aligned with the axis of the drill string 30 and another position in which the tubular member 110 is offset from the axis of the drill string 30 while the tubular member 110 and the mast 20 remain coupled together.

[0101] refer to Figure 1 and 2 Tubular member 110 has openings 112 and 114 at opposite ends 111 and 113 thereof. A longitudinal internal passage 120 extends between openings 112 and 114. At one of the ends, 111, tubular member 110 includes a flange 115 extending radially outward from a rim surrounding opening 112. Flange 115 comprises a plate that can be welded or otherwise secured or integrally formed with end 111 of tubular member 110. Flange 115, as shown in the figures, is a generally planar member secured to end 111 of tubular member 110, for example, by welding. Flange 115 has a polygonal shape with opposing side edges 117 and 118. The opposing side edges include parallel side segments 117a and 118a and tapered side segments 117b and 118b. The tapered side segments 117b and 118b provide a narrower width dimension at one end 119 of flange 115. In other embodiments, the flange 115 may be circular, partially circular, or oval. A raised portion 116 extends from the lower surface of the flange 115 and is adapted to engage the surface of the step during use. The raised portion 116 functions to keep the flange 115 spaced above the surface of the step, or to protrude from the surface.

[0102] refer to Figure 3 and 4 , an adapter 150 is provided, such as Figure 5 、 6 8 to 14, is configured to be secured to the mast 20. The adapter 150 includes a foot pad 155 that, in some cases, is adapted to engage the stepped surface to at least partially support and maintain stability of the mast 20 during drilling operations. A riser 157 extends upwardly from the foot pad 155 and is adapted to be coupled to an end of the mast 20. The riser 157 can be configured to replace and match the position of a riser of a proprietary foot pad assembly for the mast 20 of the drilling rig 10, for example Figure 7 In other words, the adapter 150, including the foot pad 155 and the riser 157, is configured to be compatible with, for example, Figure 7 The proprietary foot pad assembly 9 shown is directly interchangeable. In other embodiments, the adapter 150 is constructed without the foot pad 155 or without the foot pad 155 and the riser 157, but is coupled to the riser and foot pad of the proprietary foot pad assembly 9.

[0103] Adapter 150 also includes a horizontal slot 160 defined between horizontal upper and lower plates 164, 174. Slot 160 is closed at laterally opposing sides 161, 163 and is open at one end 162. In an embodiment not shown, lower plate 174 is turned outward, however, both upper and lower plates 164, 174 may be turned outward at open end 162 of slot 160, or neither. Upper and lower plates 164, 174 are positioned horizontally adjacent to foot pad 155.

[0104] The riser 157 is formed with a vertical upright section 156 and a pair of opposing gusset sections 158, 159 extending between the upright section and the upper and lower plates 164, 174. The gusset sections 158, 159 provide structural support and rigidity to the connection between the vertical upright section 156 and the upper and lower plates 164, 174.

[0105] The upper plate 164 and the lower plate 174 each include a central opening 165, 175 that are axially aligned with the drill string 30 when coupled to the mast 20. The gusset sections 158, 159 are disposed opposite one another and are spaced apart by a distance that is at least equal to or greater than the diameter of the central opening 165 in the upper plate 164. The central opening 175 in the lower plate 174 is open to the side so that the flange 115 can be received in the slot 160 through the opening on the side and positioned between the upper and lower plates 164, 174, and the tubular member 110 extends downwardly through the central opening 175 in the lower plate 174, as shown. Figure 4 and 5 The horizontal slot 160 and flange 115 together provide a slot-mount coupling between the tubular member 110 and the adapter 150. As will be appreciated, in some cases, the tubular member 110 and the adapter 150, and thus the mast 20, may be releasably coupled by horizontally translating the adapter 150 relative to the tubular member 110.

[0106] As adapter 150 moves horizontally relative to pipe member 110, lower plate 174 of adapter 150 is received in the space between flange 115 and the surface of the step held by bosses 116. Thus, bosses 116 raise flange 115 above the surface of the step to allow flange 115 to lie beneath and engage the bottom surface of flange 115.

[0107] Tubular member 110 and adapter 150 are configured such that tubular member 110 is movable between a position in which tubular member 110 is aligned with the axis of drill string 30 and another position in which tubular member 110 is offset from the axis of drill string 30. This can be achieved in various ways. However, in the embodiment shown in the figures, this is achieved by relative movement of flange 115 relative to horizontal slot 160. During movement of tubular member 110 and adapter, flange 115 is positioned within slot 160 between upper plate 164 and lower plate 174 of adapter 150.

[0108] The height of the raised portion 116 extending from the flange 115 of the tubular member 110 is greater than the combined height of the lower plate 174, the foot pad 155, and any raised portions associated with the foot pad. Raised portion 116 elevates the flange 115 above the surface of the step by a sufficient height to allow the lower plate 174 and any raised portions associated with the foot pad 155 (if any) to be positioned below the flange 115 and still clear the surface of the step. Accordingly, raised portion 116 of the tubular member 110 is of sufficient height to allow the adapter 150 to clear the surface of the step while resting on it, and to allow for horizontal movement relative to the tubular member 110 while the flange 115 is positioned within the slot 160.

[0109] In use, the drill string 130 passes through the central openings 165, 167 of the upper and lower plates 164, 174, and then through the longitudinal internal passage 120 in the tubular member 110. Figures 8 to 10 shown.

[0110] In another embodiment, the adapter 150 can be configured to match a proprietary foot pad assembly. In such an embodiment, the adapter 150 can include no foot pad 155 or riser 157 , but can primarily include only the horizontal upper plate 164 and lower plate 174 .

[0111] Drilling method

[0112] exist Figure 9 to 1 4, a cross-section of the top, open end of a single borehole 2 is shown in elevation. However, it should be understood that multiple such boreholes 2 may be drilled on a bench for a single blasting operation. The borehole 2 can be drilled to a diameter of 270 to 311 mm, or 350 mm or greater, and to a depth of 50 meters or greater. After drilling, the borehole 2 is filled with an explosive material appropriate to the ground conditions, such as a mixture of ammonium nitrate and fuel oil (ANFO) or an emulsion, or a mixture thereof, and prepared for detonation.

[0113] The operator of the drilling rig 10 causes the hydraulic arm 14 to manipulate the mast 20, to which the adapter 150 is attached. The tubular member 110 is preferably supported upright, such as on a vehicle or some other support structure, with the flange 115 at the top. The mast 20 is manipulated so that the slot 160 is oriented to align with the flange 115. The mast 20 is then manipulated relative to the tubular member 110 so that the flange 115 is received in the slot 160, thereby coupling the tubular member 110 and the adapter 150, and the mast 20 connected thereto, together.

[0114] The width dimension of the slot 160 between the closed laterally opposed sides 161, 163 is greater than the width dimension between the parallel side segments 117a, 118a of the flange 115. The tapered side segments 117b, 118b provide a narrower width dimension at one end 119 of the flange 115 to help guide the flange 115 into the slot 160.

[0115] The drilling machine 10 is moved to a position adjacent to the location where the borehole 2 is to be drilled. Figure 8 As shown, the drill string 30 is then lowered through the tubular member 110 and engages the surface of the step. The drilling head 25 is activated, and because the top material is pre-processed, the drill bit 37 penetrates relatively easily. The operator causes the hydraulic arm 14 to lower the mast 20, which in turn lowers the tubular member 110 until the boss 116 extending from the lower surface of the flange 115 engages the surface of the step, as shown. Figure 9 At this point, the tubular member 110 is almost completely below the surface of the step with the outer surface 125 of the tubular member 110 facing outwardly against the wall of the borehole 2 and the flange 115 is spaced above or protruding from the surface of the step.

[0116] Drilling continues until the desired hole depth is reached. The drill string 30 is then withdrawn from the borehole 2. Figure 10 As shown in FIG. 11 , the mast 20 is manipulated horizontally so that the flange 115 moves relative to the slot 160 .

[0117] In an embodiment not shown in the figures, the mast 20 is manipulated horizontally so that the flange 115 moves out of the slot 160, thereby separating the tubular member 110, the adapter 150, and the mast 20 connected thereto. In the embodiment shown in the figures, the mast 20 is manipulated horizontally so that the flange 115 moves relative to the slot 160 but remains within the slot 160 between the upper plate 164 and the lower plate 174 of the adapter 150. Embodiments in which the flange 115 remains within the slot 160 are advantageous because they do not require the operator to reposition the lower plate 174 of the adapter 150 in the relatively small space between the flange 115 and the surface of the step.

[0118] Orifice support equipment

[0119] The borehole casing apparatus 100 is adapted for use with a borehole support apparatus 200 for preventing loose rock fragments in the pre-treated layer from falling or collapsing into the borehole, for example Figure 15 and 16 Device 200 is shown.

[0120] The orifice support device 200 includes a flexible sheet 210 including a pair of opposed surfaces 211, 212, a pair of spaced-apart longitudinally extending side edges 214, 216, and a pair of spaced-apart transversely extending end edges 215, 217. The generally planar sheet 210 is adapted to be formed into a curved, substantially cylindrical shape in use to define a longitudinal channel 218 extending between openings at the longitudinally opposed ends 211, 219.

[0121] The flexible sheet 210 preferably comprises an elastic material, such as a resilient, flexible polymeric material reinforced with nylon or some other flexibility enhancing agent. The sheet 210 is preferably rectangular in shape, with the side edges 214, 216 being parallel and the end edges 215, 217 also being parallel. The side edges 214, 216 taper at one end. The sheet 210 includes a series of apertures 213 that are laterally spaced and arranged in pairs aligned longitudinally for handholding and for hanging the orifice support device 200 when not in use.

[0122] As shown in FIG12 , the orifice support device 200 can be inserted into the longitudinal interior passage 120 within the tubular member 110 while the tubular member 110 is positioned within the borehole 2. As shown in FIG12 to FIG14 , the tubular member 110 can then be removed from the borehole 2 by performing the reverse of the above process. That is, the flange 115 is moved within the slot 160 by horizontally manipulating the mast 20 until the flange 115 is substantially completely within the slot 160. The mast 20 is then raised to carry the tubular member 110 upward and out of the borehole 2, leaving the orifice support device 200 within the orifice region of the borehole 2. The elastic properties of the material forming the sheet 210 allow the sheet 210 to expand and assume a substantially cylindrical form within the borehole 2, as shown in FIG14 .

[0123] One of the surfaces 211, 212 of the sheet 210 faces outwardly against the inwardly facing surface of the borehole 2 and forms a barrier that prevents surrounding loose rock debris from falling or collapsing into the borehole 2. Because the material forming the sheet 210 is resilient, the sheet 210 tends to assume its planar form, and this property causes the outwardly facing surfaces 211, 212 of the sheet 210 to exert pressure against the inwardly facing surface of the borehole 2. At least a portion of the aperture support device 200 can also be raised above the step surface to provide additional protection against surrounding loose rock debris on the step surface from falling or collapsing into the borehole 2.

[0124] The longitudinal dimension of the sheet 210 between longitudinally opposed end edges 215, 217 can be 1 meter, 1.5 meters, 2 meters, 2.5 meters, 3 meters, 3.5 meters, 4 meters, or more in length, or any length therebetween. When positioned within the blasthole 2, the sheet 210 provides support to the interior surface of the borehole 2 through most of the wall of the borehole 2 in the region of the hole mouth.

[0125] The width of the sheet 210 between the pair of parallel side edges 214, 216 is preferably, but not necessarily, slightly greater than the perimeter of the borehole 2. When the sheet 210 assumes a substantially cylindrical form within the borehole 2, the side edges 214, 216 of the sheet 210 slightly overlap. However, in another embodiment, the side edges 214, 216 of the sheet do not overlap but are slightly spaced apart.

[0126] The drill rig 10 is moved to a location adjacent to the location where the next borehole 2 is to be drilled, and the above process is repeated. During the subsequent steps of placing explosives and other consumables into the borehole 2, the borehole support device 200 remains in place within the blasthole. After the borehole is filled and prepared, the borehole support device 200 can be removed from the borehole 2 or partially withdrawn and funneled before placing the packing material into the borehole 2.

[0127] Figures 17 to 19 Another embodiment of a mobile drilling rig 310 for drilling a borehole 2 is shown. The drilling rig 310 shown is Figure 5 and 6 The drilling rig 310 is similar to the drilling rig 10 of FIG. 1 , and like reference numerals are used to identify like features. The primary difference is that the drilling rig 310 further includes a deployment device 350 mounted on the mast 20 for forming the flat flexible sheet 210 into a curved form and inserting the curved sheet 210 into the borehole casing apparatus 100 located in the orifice region of the borehole 2, thereby forming the orifice support apparatus 200.

[0128] The deployment apparatus 350 includes a plurality of sheets 210 arranged in a stack 315. The stack 315 of sheets 210 is supported on a frame 209. The apparatus 350 includes a sheet pick feeder 355 operable to pick a single sheet 210 from the stack 315 and feed the sheet 210 into the vertical forming apparatus 330. Figure 9 In the illustrated embodiment, the pick feeder 355 includes a driven roller arrangement and a belt arrangement operable to pick up the sheets 210 one at a time from the stack 315. However, any mechanical arrangement adapted to pick up one sheet 210 from the stack 315 and feed the sheet 210 to the vertical forming apparatus 330 may constitute another embodiment of the present invention.

[0129] The forming apparatus 330 is operable to form the sheet material 210 into a curved, substantially cylindrical shape, thereby defining a longitudinal channel 218 extending between openings at the longitudinally opposite ends 211, 219. The forming apparatus 330 includes a wide mouth 331 that tapers to a narrower circular outlet 333 to define a path 335 for the flexible sheet material. A feeding mechanism feeds the flexible sheet material 210 through the wide mouth 331 and the circular outlet 333 into the tubular member 110.

[0130] The illustrated embodiment of the forming apparatus 330 includes a funnel-shaped portion 332 defining a wide mouth 331 and transitioning to a cylindrical portion 336 defining a narrower circular outlet 333. The funnel-shaped portion 332 and the cylindrical portion 336 are defined by a sidewall 338, preferably formed from sheet metal or a similar material. Instead of the funnel-shaped portion 332, the forming apparatus includes an elongated, substantially planar opening that resembles the shape of the planar sheet 210 and gradually transitions to the circular shape of the cylindrical portion 336. However, other mechanical arrangements adapted to be mounted to the mast 20 of the drilling rig 10 for picking a single sheet 210 from the stack 315, forming the sheet 210 into a curved form, and inserting the sheet into the tubular member 110 are within the scope of the disclosure herein.

[0131] refer to Figure 18 and 19 After the borehole 2 is drilled to the desired depth, the drill string 30 is withdrawn from the borehole 2, and the mast 20 is manipulated horizontally so that the flange 115 of the tubular member 110 moves relative to the slot 160 and the drill string 30 deviates from the opening of the tubular member 110. The circular outlet 333 is thereby located above and aligned with the open end of the tubular member 110, as shown in FIG. Figure 18 and 19 The deployment device 350 is activated, thereby picking up a single sheet 210 from the stack 315 and forming it into a curved form and inserting it into the tubular member 110 located in the borehole 2, as shown. Figure 19 The deployment apparatus 350 includes another feed mechanism 339 comprising one or more driven rollers or a belt drive located at the outlet 333 for inserting the curved sheet 210 into the tubular member 110 and the open end of the borehole 2 to a desired depth.

[0132] The tubular member 110 can then be withdrawn from the borehole 2 in the same manner as described above with reference to the embodiment shown in Figures 12 to 14. That is, the flange 115 is moved within the slot 160 by horizontally manipulating the mast 20 until the flange 115 is substantially completely within the slot 160. The mast 20 is then lifted to carry the tubular member 110 upwardly out of the borehole 2, leaving the aperture support apparatus 200 including the bent sheet material 210 within the aperture region of the borehole 2.

[0133] The deployment device 350 can be mounted on the mast 20 of the drilling rig 310, or in another embodiment can be mounted on a separate vehicle (not shown) or a trailer (not shown) coupled to the vehicle, or any other movable device suitable for maneuvering around a site. The vehicle or other movable device can be a truck that can be manually operated by a driver or, in one embodiment, can be configured for fully or semi-automatic operation. The vehicle or other movable device can include a control module that includes a GPS positioning device and is adapted to control the vehicle's drive and steering mechanisms. The control module is adapted to receive or be programmed with the location coordinates of one or more of the plurality of blast holes and automatically operate the deployment device 350.

[0134] Figure 20 and 21 The illustrated embodiment includes a removable shroud 400 for directing cuttings and / or bailing sand emerging from the borehole 2 during drilling operations. Shroud 400 includes a main body 410 having a hollow interior with openings at the bottom and top. The top of main body 410 is adapted to be mounted to a removable shroud adapter 420 coupled to the mast 20 of the drilling rig 10. Removable shroud adapter 420 is adapted to translate upward and downward within a linear range of motion of approximately 50 cm. Shroud 400 is made of a durable material, such as an alloy, and has a tapered upper portion 405 and a flexible and durable plastic or rubber lower shroud 407. Lower shroud 407 seals around the opening at the bottom of main body 410. Shroud 400 is positioned to align with the axis of the drill string 30, and the openings at the top and bottom of shroud 400 allow the drill string 30 to pass therethrough.

[0135] In use, the movable shroud adapter 420 is adapted to lower the shroud 400 downwardly toward the adapter 150 so that the lower shroud 407 contacts the upper plate 164. The lower shroud 407 of the adapter thereby seals around the central opening 165 of the upper plate 164 of the adapter 150. The shroud 400 is aligned with the longitudinal interior passage 120 of the tubular member 110 so that the drill string 30 can pass therethrough to allow drilling to commence. The shroud 400, including the lower shroud 407, is sized and configured to be positioned between the gusset sections 158, 159 of the adapter 150.

[0136] During drilling, if Figure 9 and 10 As shown, cuttings and / or bailing emerging from the borehole 2 travel upward through the longitudinal interior passage 120 of the tubular member 110 and emerge from the opening 112. The cuttings and / or bailing escaping from the opening 112 of the tubular member 110 are directed upward into the body 410 of the shroud 400. The shroud 400 includes an exhaust port 415 for the cuttings and / or bailing to exit from the body 410 of the shroud. The exhaust port 415 is oriented transversely to the axis of the drill string 30.

[0137] exist Figure 20 In the illustrated embodiment, the discharge port 415 is uncovered, allowing cuttings and / or bailed sand to freely emerge from the discharge port 415 and be distributed to a bench surface adjacent to the borehole 2 being drilled. This embodiment is suitable for wet drilling operations in which a slurry containing cuttings and / or bailed sand mixed with water emerges from the borehole 2.

[0138] exist Figure 21 In the illustrated embodiment, the discharge port 415 is coupled to a flexible hose 425, which in turn is coupled to a vacuum pump system. Cuttings and / or bailed sand emerging from the discharge port 415 are drawn through the flexible hose 425 and deposited onto the bench surface in a pile at a sufficient distance from the borehole 2 being drilled. This embodiment is suitable for dry drilling operations in which the cuttings and / or bailed sand emerging from the borehole 2 are dry and comprise a significant proportion of dry particles.

[0139] The opening at the top of the main body 410 of the shroud 400 includes a seal between the opening and the drill rod 35 comprising the drill string 30. The seal between the opening at the top of the main body 410 of the shroud 400 and the drill rod 35 prevents cuttings and / or bailed sand that enter the shroud 400 from emerging from the opening at the top of the main body 410 of the shroud 400. The seal may include a ring made of metal or a durable polymer or rubber material. The seal is sized to within a relatively small tolerance around the outer circumference of the drill rod 35.

[0140] Drilling Platform

[0141] Figures 22 to 27 Another embodiment of a mobile platform drill rig 510 for drilling a borehole 2 is shown. The drilling rig shown can be used for rotary drilling or hammer drilling specifically designed for mining, but it should be understood that embodiments of the present invention have broader application. The mobile drill rig 510 shown in the figure is a type of surface drilling rig commonly used for drilling larger diameter boreholes between approximately 165 and 351 mm in diameter, and is commonly referred to as a "platform drill." These larger-class rigs are believed to originate from a number of manufacturers, such as Sandvik, Epiroc, Komatsu, and Caterpillar.

[0142] The drilling rig 510 comprises a self-propelled tracked platform 512 including a hydraulic arm supporting a mast 520. The mast 520 is itself adapted to support a drill string 530 comprising one or more drill rods 535 and a drill bit 537 at the end of the drill string 530. The drill rods 535 are coupled together by threaded connections therebetween.

[0143] The mast 520 carries a drilling head that includes a reciprocating piston or hammer assembly and a rotary assembly adapted to apply percussive force and / or rotational torque to the drill string 530. The drilling head 525 can be raised or lowered by a hydraulically driven up and down feed system to allow pipe or rod to be removed from or added to the drill string.

[0144] The borehole casing apparatus 600 is adapted to be coupled to the mast 520 in a manner described in more detail below. The casing apparatus 600 is similar to the casing apparatus embodiment 100 described above and therefore like reference numerals are used to identify like features.

[0145] like Figures 22 to 26 As shown, the casing device 600 includes a tubular member 110 that is adapted to be placed in a borehole 2 that has been drilled or is in the process of being drilled by a drilling rig 510. Figures 22 to 27 In the embodiment of FIG. 5 , the adapter 550 is fixed to the platform 512 relative to the mast 520. The adapter 550 is similar in construction to the adapter 150 described above, and thus like reference numerals are used to identify like features.

[0146] like Figure 22 As shown, the adapter 550 supports and holds the casing apparatus 600 relative to the platform 512, enabling the drill string 530 to be passed axially therethrough. The drill bit 537 engages the stepped surface to initiate drilling of the borehole 2. The platform 512 includes a linear actuator, such as a hydraulic actuator, to axially translate and thereby raise or lower the adapter 550 and the casing apparatus 600 coupled thereto in the axial direction of the drill string 530 and the borehole 2.

[0147] like Figure 23 As shown, the casing apparatus 600 is lowered into the borehole 2 until the boss 116 extending from the lower surface of the flange 115 engages the surface of the step. At this point, the tubular member 110 is almost completely below the surface of the step and the outer surface 125 of the tubular member 110 faces outwardly against the wall of the borehole 2, with the flange 115 spaced above or protruding from the surface of the step.

[0148] The shroud adapter 420 and the movable shroud 400 are coupled to the platform 512 to enable the shroud to move up and down within a linear range of motion. The shroud adapter 420 includes a linear actuator, such as a hydraulic actuator, coupled to the shroud 400 to translate axially and thereby raise and lower the shroud 400. Figure 23 As shown, the shroud 400 is lowered onto the cannula apparatus 600 and provides a seal around the central opening 165 of the upper plate 164 of the adapter 550 .

[0149] During drilling, if Figure 24 and 27As shown, cuttings and / or bailed sand emerging from the borehole 2 travel upward through the longitudinal interior passage 120 of the tubular member 110 and emerge from the opening 112. The cuttings and / or bailed sand emerging from the opening 112 of the tubular member 110 are directed upward into the body 410 of the shroud 400. The exhaust port 415 of the shroud 400 directs the cuttings toward the bottom of the platform 512. Figures 22 to 27 In the embodiment shown, the discharge outlet 415 is coupled to a flexible hose 425, however, it will be appreciated that there could be no hose and the cuttings and / or bailed sand emerging directly from the discharge outlet.

[0150] like Figure 24 and 27 As shown, a curtain 511 is positioned beneath the platform 512. The curtain 511 extends along the length of the platform 512, adjacent to the rails 502 supporting the platform 512, to block chips and / or bailing from entering the rails 502. A strip of curtain 515 extends laterally across the rear of the platform 512 between the rails 502. Optionally, another curtain 516 is also positioned beneath a portion of the support mast 520 of the platform 512 to contain any chips and / or bailing that escapes the shroud 400 or otherwise moves forward beneath the platform 512.

[0151] When the desired depth of the borehole 2 is reached, the drill string 530 is retracted and the shroud 400 is raised. The deployment device 350 is mounted on the platform 512 and is adapted to pick up the sheet 210 from the stack 315, form the sheet 210 into a roll, and feed it through the tubular member 110 to the borehole 2. The deployment device 350 includes an inclined chute 352 to guide the rolled sheet 210 into the tubular member 110 and out of the raised shroud 400.

[0152] In another embodiment, Figure 26 As shown, a storage portion of pre-rolled sheets 210 is supported on a platform 512. Each pre-rolled sheet 210 includes a tie 21 for holding each pre-rolled sheet 210 in a rolled form. A deployment device 350 is mounted on the platform 512 and is adapted to pick up one of the pre-rolled sheets 210 and feed the pre-rolled sheet 210 into the borehole 2 through the tubular member 110. The tie 21 can be connected to a cable that, when pulled, releases the tie and thereby allows the sheet 210 to unfold and come into face-to-face contact with the wall of the borehole 2.

[0153] The platform 512 can then be moved to the location of the next borehole 2 to be drilled and the above process repeated.

[0154] Composite stable support

[0155] 28 and 29 illustrate another embodiment of a method for stabilizing the orifice of a borehole 2. The tubular member 110 of the borehole casing apparatus 100 provides temporary support to the walls of the borehole 2 in the orifice region and serves as a form, and in some embodiments, is capable of penetrating the surrounding walls of the borehole 2 while the composition is injected. The composition is injected and cures or otherwise hardens or solidifies, becoming self-supporting or binding loose rock fragments to form a composite orifice support 613.

[0156] The composition can be a fluid that is injected into a pipe 610 connected to a network of conduits and openings 612 formed in the tubular member 110. Thus, when the tubular member 110 is placed in the borehole 2, the injected fluid exits the openings 612 and enters the space between the tubular member 110 and the borehole 2, or penetrates the surrounding loose rock fragments, or both. The tubular member 110 remains in the borehole 2 for a period of time sufficient to allow the composition to harden, solidify, and become self-supporting or otherwise combine with the surrounding fine and coarse aggregate to form a composite orifice support 613.

[0157] In the time it takes to complete the drilling operation, the composition will have cured and the borehole casing apparatus 100 can then be withdrawn from the borehole 2. A small rotational motion may be applied to the borehole casing apparatus 100 to break the adhesion to the surrounding composite orifice support 613.

[0158] The composition may be comprised of a material, such as a polymer or resin, that is injected as a liquid and subsequently hardened to form a structural, self-supporting casing between the tubular member 110 and the borehole 2. Alternatively, the composition may be comprised of a material, such as a polymer or resin, that is injected as a liquid and penetrates into the surrounding fine and coarse aggregate (e.g., pretreated material) to form a composite orifice support 613.

[0159] The composition may comprise a polyurethane resin, a cross-linked polymer or resin, an epoxy resin, a polyester or a phenolic resin, or may also comprise a mineral binder such as Portland cement.

[0160] Although the disclosure has been described with reference to specific examples, it will be appreciated by those skilled in the art that the disclosure may be embodied in many other forms without departing from the broad principles and spirit of the disclosure.

Claims

1. A drilling casing device for a drilling tool, the casing device comprising: a tubular member adapted to be coupled to a mast of a movable drilling tool and positioned within an aperture region of a borehole, the tubular member including a longitudinal interior passage for receiving a drill string therethrough and an exterior surface for facing outwardly against a wall of the borehole; a coupling including an adapter configured to be fixed relative to the mast and for engaging an upper end of the tubular member to couple the tubular member relative to the mast when a lower end of the tubular member is located within the aperture region of the borehole; The upper end of the tube member includes a flange extending radially outward from an opening, the flange including a lower surface; The adapter includes a lower plate positioned below the flange for engaging the lower surface of the flange to lift the tubular member upwardly out of the borehole, and A driver is provided for raising and lowering the tubular member relative to the borehole for temporary insertion and support of the orifice region of the borehole.

2. The casing apparatus of claim 1, wherein the coupling is adapted to releasably secure the tubular member to the mast.

3. The casing apparatus of claim 1 , wherein the coupling is adapted to allow movement of the tubular member relative to the mast between a position in which the tubular member is aligned with the axis of the drill string and another position in which the tubular member is offset from the axis of the drill string while the tubular member and the mast remain coupled together.

4. The cannula apparatus of claim 1, wherein the coupler comprises a slot mount coupler.

5. The cannula apparatus of claim 1, wherein the adapter member includes a slot for receiving the flange at the end of the tubular member.

6. A cannula apparatus according to claim 5, wherein the slot is defined by a pair of opposed plates which, in use, are oriented substantially parallel to the step surface.

7. The casing apparatus of claim 5, wherein the flange is adapted to move within the slot between a position in which the tubular member is aligned with an axis of the drill string and another position in which the tubular member is offset from the axis of the drill string.

8. The casing apparatus of claim 6, wherein each of the pair of plates includes an opening for receiving the drill string therethrough and for aligning with the longitudinal interior passage of the tubular member.

9. The cannula apparatus of claim 8, wherein the opening through the lower one of the plates is open to one side of the plate to receive the tube member.

10. The bushing apparatus of claim 5, wherein one or more protrusions extend from the flange for engaging the step surface and for maintaining a gap between the flange and the step surface.

11. The casing apparatus of claim 1 , wherein the tubular member is self-supporting in the aperture of the borehole and is adapted to receive an aperture support apparatus within the longitudinal interior passage.

12. The cannula apparatus of claim 1, wherein the tubular member comprises a rigid cylindrical body portion having openings at opposite ends of the body portion, and the longitudinal interior passage extends between the openings.

13. The casing apparatus of claim 1, further comprising a shroud adapted to substantially seal the longitudinal interior passage of the tubular member to direct cuttings and / or bailing sand emerging from a borehole during drilling.

14. The casing apparatus of claim 13, wherein the shroud includes an axial passage for receiving the drill string therethrough and a discharge port positioned transverse to the axial passage.

15. A drilling device comprising: movable platform; a mast placed on the platform and including a support portion for a drill string; A drill string rotation drive mechanism, used to drive the drill string to drill a hole in the rock; a borehole casing apparatus comprising a tubular member coupled to the mast for positioning into an aperture region of a borehole, the tubular member including a longitudinal interior passage for receiving the drill string therethrough and an exterior surface for facing outwardly against a wall of the borehole; a coupling including an adapter configured to be fixed relative to the mast and for engaging an upper end of the tubular member to couple the tubular member relative to the mast when a lower end of the tubular member is located within the aperture region of the borehole; The upper end of the tube member includes a flange extending radially outward from an opening, the flange including a lower surface; The adapter includes a lower plate positioned below the flange for engaging the lower surface of the flange to lift the tubular member upwardly out of the borehole, and A driver is provided for raising and lowering the tubular member relative to the borehole for temporary insertion and support of the orifice region of the borehole.

16. The drilling apparatus of claim 15, wherein the tubular member is movable between a position in which the tubular member is aligned with an axis of the drill string and another position in which the tubular member is offset from the axis of the drill string while remaining coupled to the mast.

17. The drilling apparatus of claim 15, wherein the tubular member is axially movable while remaining coupled to the mast to lower the tubular member into the borehole and to lift the tubular member out of the borehole.

18. The drilling apparatus of claim 15, comprising a sheet deployment apparatus for deploying a flexible sheet into the open end of the tubular member within the borehole.

19. The drilling apparatus of claim 18, wherein the sheet deployment apparatus comprises a sheet forming apparatus adapted to form a planar flexible sheet into a curved form and feed the curved sheet to the open end of the tubular member within the borehole.

20. The drilling apparatus of claim 19, wherein the forming apparatus comprises a wide inlet gradually narrowing to a narrower circular outlet to define a path for the flexible sheet, and a feeding mechanism for feeding the flexible sheet into the tubular member through the inlet and the circular outlet.

21. The drilling apparatus of claim 15, comprising a storage portion of a plurality of flexible sheets and a picker adapted to pick up one sheet at a time.

22. The drilling apparatus of claim 15, further comprising a shroud adapted to substantially seal the longitudinal interior passage of the tubular member to direct cuttings and / or bailing sand emerging from a borehole during drilling.

23. The drilling apparatus of claim 22, wherein the shroud includes an axial passage for receiving the drill string therethrough and a discharge port positioned transverse to the axial passage.

24. The drilling apparatus of claim 23, wherein the exhaust port is adapted as a flexible conduit coupled to a vacuum apparatus.

25. The drilling apparatus of claim 22, wherein the shroud is mounted to the mast and the drive is adapted to move the shroud upward and downward through a range of linear motion.

26. The drilling apparatus of claim 22, further comprising an outlet proximate to or beneath the movable platform for directing cuttings and / or bailed sand emerging from the borehole during drilling to a pile adjacent to or beneath the movable platform.

27. The drilling apparatus of claim 15, comprising a system for injecting a composition between the outer surface of the tubular member and the surrounding wall of the borehole.

28. A method for drilling a borehole, comprising: coupling a tubular member to a mast of a mobile drilling rig, the tubular member including a longitudinal interior passage for receiving a drill string therethrough; drilling a hole into the stepped surface and lowering the tubular member into the orifice region of the bore, the tubular member including an outer surface facing outwardly against a wall of the bore and a flange including a lower surface extending radially outwardly from an upper end of the tubular member, positioning a lower plate of the adapter below the flange and engaging the lower surface of the flange, and The lower plate of the adapter is lifted, thereby lifting the tubular member away from the borehole, so that the tubular member provides temporary support to the orifice area of the borehole.

29. A method for positioning an aperture support device in a borehole, the method comprising: coupling a tubular member to a mast of a mobile drilling rig, the tubular member including a longitudinal interior passage for receiving a drill string therethrough; drilling a hole into the stepped surface and lowering the tubular member into the orifice region of the bore, the tubular member including an outer surface facing outwardly against a wall of the bore and a flange including a lower surface extending radially outwardly from an upper end of the tubular member; providing support in a borehole for stabilizing the orifice region of the borehole; as well as Positioning a lower plate of an adapter below the flange and engaging the lower surface of the flange and lifting the lower plate of the adapter to lift and remove the tubular member from the borehole so that the tubular member provides temporary support to the orifice area of the borehole.

30. The method of claim 29, wherein providing support in the borehole comprises inserting an orifice support device comprising a sheet of flexible material into the longitudinal interior passage of the tubular member, and wherein Removing the tubular member from the borehole leaves the aperture support apparatus within the borehole.

31. The method of claim 30, comprising moving the mast relative to the tubular member to access the longitudinal interior passage of the tubular member.

32. The method of claim 31 , wherein moving the mast relative to the tubular member comprises moving the mast between a position in which the tubular member is aligned with an axis of the drill string and another position in which the tubular member is offset from the axis of the drill string while the tubular member and the mast remain coupled together.

33. The method of claim 29, wherein removing the tubular member from the borehole comprises manipulating the mast to raise the tubular member out of the borehole.

34. The method of claim 29, wherein coupling the tubular member to the mast comprises horizontally translating the mast relative to the tubular member.

35. The method of claim 29, wherein: Providing support in a borehole for stabilizing the orifice region of the borehole includes injecting a composition between the outer surface of the tubular member and a surrounding wall of the borehole.

36. The method of claim 35, wherein the injected composition cures or hardens or solidifies to become self-supporting or to bind loose rock fragments to form a composite orifice support.

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