WO2011011817A1

WO2011011817A1 - Drill apparatus

Info

Publication number: WO2011011817A1
Application number: PCT/AU2010/000945
Authority: WO
Inventors: Matthew Roesner; Michael Kostarelas
Original assignee: Ausdrill Ltd
Priority date: 2009-07-28
Filing date: 2010-07-27
Publication date: 2011-02-03
Also published as: AU2010278662A1

Abstract

A drill apparatus (10) for drilling an elongate drill hole (12). The drill apparatus (10) includes a body (14) defining an inner passage (16) and an outer passage (18). The inner passage (16) is provided for delivering fluid to the bottom of the drill hole (12) and creating a fluid flowstream that entrains drilled material and directs it to the outside of the body (14) during a normal drilling operation. The outer passage (18) is provided for receiving drilled material entrained in a second fluid flowstream created by fluid delivered through the inner passage (16) during a sampling operation.

Description

DRILL APPARATUS

FIELD OF THE INVENTION

The present invention relates to a drilling apparatus for drilling a drill hole. In one particularly preferred form, the present invention relates to a blast hole drill apparatus for drilling blast holes in an open cut mining operation.

BACKGROUND TO THE INVENTION

In the gold industry there is a need to produce cost-effective grade control systems that are practical and reliable. Currently the accepted practice is to carry out in pit, grade control using large track mounted equipment. This has a high operating cost and large energy inputs.

In some forms of grade control a top hammer drilling process is used. This is particularly the case in blast hole drilling where the drilling operations involve a depth in the order of 4 to 6m. When such depths are involved top hammer drilling processes are convenient and relatively inexpensive.

An example of a top hammer drilling process is illustrated in Figure 1 of the present specification. As shown in Figure 1, a drill bit at the end of a drill stem is used to drill a hole. The drill stem has inner passage extending through it for delivering air to the bottom of the drill hole. The air that is delivered serves to create a fluid flowstream that entrains drilled material and directs the drilled material to the outside of the drill stem during drilling. The drilled material is directed upwardly between the drill stem and the drill hole.

Portion A-A of Figure 2 illustrates a conical formation at the top of the drill hole. Such a conical portion is formed during the drilling process as the drilled material exits the drill hole. The conical formation grows in size as the hole is drilled and typically has a number of layers that are representative of the characteristics of the ground in which the hole is drilled. For this reason, in blast hole drilling, a wedge of the conical formation is often removed for sampling purposes. This is illustrated in portion B-B of Figure 2.

Often with top hammer drilling another process involves placing a dust pot at the top of the drill hole and drawing the cuttings through a hose connected to a vacuum device and a dust collector. In such arrangements, the dust collector is typically connected to a sample pot that is located next to the drill hole. The sample pot provides the entry point for the sample to be drawn to a cyclone or collection box. The cuttings are typically split and bagged ready for analysis after they are collected.

Reverse circulation (RC) drilling processes are commonly used in exploration drilling. RC drilling typically utilises much larger rigs and machinery and depths of up to 500 metres are routinely achieved. The process involves an outer casing and a drill stem having an inner tube. Generally RC is achieved by blowing air down the outer casing with the differential pressure lifting the cuttings up the inner tube. In these systems a sample collection hose is typically located at the top of the drill pipe near a rotary head of the system. From the sample collection hose the cuttings generally travel into a sample collection splitter and cyclone device.

RC drilling processes are distinguished from a top hammer drilling process in that the drilled material travels upwardly, fully contained within the inner tube extending through the drill stem. Australian Patent 638571 to S.D.S. Digger Tools Pty Ltd. provides an example of an RC drilling apparatus. Figure 3 of the present specification illustrates an embodiment of AU638571 in which there is provided an inner tube passage 18 through the drill shaft for the removal of drilled material.

RC systems are relatively expensive to operate and consume large quantities of water. In addition, the hollow nature of the drill shaft, with respect to its width, is considered to mean that the energy required to produce the same power output at the drill bit is greater than with a top hammer system. This is considered to at least be the case for blast hole drilling operations.

It is against this background and the problems and difficulties associated therewith that the present invention has been developed.

SUMMARY OF THE INVENTION

According to a first aspect of preferred embodiments herein described there is provided a drill apparatus for drilling an elongate drill hole, the apparatus including: a body defining an inner passage and an outer passage wherein the inner passage is for delivering fluid to the bottom of the drill hole and creating a first fluid flowstream that entrains drilled material and directs it to the outside of the body during a normal drilling operation; and the outer passage is for receiving drilled material entrained in a second fluid flowstream created by fluid delivered through the inner passage, during a sampling operation.

Preferred forms of the present invention are considered to allow for normal drilling according to a top hammer drilling process. In the process, fluid is delivered to the bottom of a drill hole and a first fluid flowstream is created. The first fluid flowstream entrains drilled material and is directed to the outside of the body of the drill apparatus.

Advantageously the provision of an outer passage for receiving drilled material allows for a sample of material to be taken without exposing the sample to the sides of the drill hole which might otherwise contaminate the sample. Sample techniques using a dust pot with suction through a hose and taking collar samples both have shortfalls on accuracy and contamination due to open hole drilling techniques. These advantages are provided in combination with the advantageous characteristics of a top hammer drill process.

In the context of the invention it is to be appreciated that a top hammer drilling system is more economical to operate in comparison to RC drilling systems and uses much less drill air.

For at least these reasons preferred embodiments of present invention are considered to be advantageous. This is at least the case in a blast hole drilling apparatus for open cut mines.

Preferably the outer passage and the inner passage are defined by a drill pipe with the outer passage being concentrically arranged about the inner passage. In addition, preferred embodiments of the drill apparatus preferably include a control system for delivering pressurized fluid to the inner passage and for creating a negative pressure differential between the inner passage and the outer passage during the sampling operation. In these embodiments the outer passage is considered to advantageously receive the drilled material is the second fluid flowstream created by fluid delivered through the inner passage.

Preferably the control system is adapted to deliver pressurized fluid to both the inner passage and the outer passage during a normal drilling operation. With the control system, both the inner passage and the outer passage are preferably arranged for delivering fluid to the bottom of the drill hole to create the first fluid flowstream that entrains drilled material and which is directed to the outside of the body during the normal drilling operation.

In embodiments the control system is adapted to purge the outer passage and to assist with the normal drilling operation where the first fluid flowstream entrains the drilled material. Purging the outer passage advantageously assists with limiting the risk of contamination of the sample from previous drilling operations or installation, when the sample is taken and passes through the outer passage via the delivery system.

Preferably the control system includes a pressurization system for pressurizing fluid and delivering the pressurized fluid to both the inner passage and the outer passage.

Preferably the control system includes a vacuum system for applying a vacuum to the outer passage to assist with drawing the material entrained in the second fluid flowstream upwardly. As such, with the vacuum system, pressurized fluid containing entrained drilled material is advantageously received through the outer passage. The pressurization system may comprise an air pressurization system. In other embodiments a liquid pressurization system may be used. It will be appreciated that the amount of entrained drilled material, in the second fluid flowstream, received in the outer passage during a sampling operation can be increased through the use of the vacuum, however, the drill apparatus can be operated to receive sample via the outer passage without the vacuum applied.

Preferably the drill apparatus includes a collar element for sample collection where the collar element is adapted to assist with improving the flow of the flowstream, during the sampling operation, into the outer passage such that the outer passage advantageously receives entrained drilled material. The collar element preferably includes a frusto- conical portion. The collar element is preferably located adjacent the drill bit and may be provided integrally with the drill stem or provided as an attachment thereto.

Preferably the outer passage is disposed around an outer wall of an element providing the inner passage with the inner passage and outer passage being coaxially aligned.

Preferably, the relative positions of the outer and inner passages are fixed. In this regard, the drill apparatus may further comprise a plurality of support members that fix the relative positions of the inner and outer passages. Preferably, the support members are located in the outer passage. Even more preferably the support members are shaped so as not to have an undue impact on the flow of drilled material in the inner or outer passages. In one particular form of the invention, the lug members are generally tear-drop shaped. Preferably the drill apparatus comprises a sampling member for receiving drilled material that has passed through the outer passage. Preferably a drive element extends through the sampling member for driving a drill bit. Preferably the inner passage extends through the drill bit. Preferably the sampling member has a moveable exit. The moveable exit may be moveable over at least 20-40 degrees, preferably, 30 degrees, in any direction radially from a central location.

According to a second aspect of preferred embodiments herein described there is provided a method of drilling an elongate drill hole comprising: creating a fluid flowstream, during a normal drilling operation, by delivering fluid to the bottom of the drill hole through an inner passage of a drilling apparatus; the fluid flowstream entraining drilled material, and flowing around the outside of the body of the drill apparatus; creating a second fluid flowstream, during a sampling drilling operation, by delivering fluid to the bottom of the drill hole through the inner passage of the drilling apparatus; entraining drilled material in the second fluid flowstream; and receiving a sample of the drilled material with the sample being received through an outer passage of the drill apparatus.

Preferably the method includes delivering pressurized fluid to the inner passage and creating a negative pressure differential between the inner passage and the outer passage during the sampling operation. In one particular form of the invention the negative pressure is provided by a vacuum or suction.

Preferably the method includes delivering fluid to the bottom of the drill hole through the inner passage and applying negative pressure or suction to the outer passage during the normal drilling operation.

Preferably the method includes purging the outer passage during the normal drilling operation to assist with limiting the risk of contamination of the sample. According to a third aspect of preferred embodiments herein described there is provided a drill apparatus for drilling an elongate drill hole, the apparatus including: a body defining a first passage and a second passage wherein the first passage is for delivering fluid to the bottom of the drill hole to remove drilled material by urging the drilled material upwardly around both the first passage and the second passage during a normal drilling operation; and the second passage is for receiving a sample of drilled material urged upwardly by the flow of fluid from the first passage during a sampling operation.

According to a fourth aspect of preferred embodiments herein described there is provided a drill apparatus comprising: a first rod element disposed within a second rod element, there being provided a first passage, through the first rod element, and a second passage between the first rod element and the second rod element; the first and second rod elements being configured such that, in a normal drilling operation, fluid is able to pass through the first passage and then around both the first passage and the second passage to remove drilled material and, in a sampling operation, fluid is able to pass through the first passage and then upwardly into the second passage causing drilled material to travel through the second passage so as to provide a sample.

According to a fifth aspect of preferred embodiments herein described there is provided a method of drilling comprising: drilling a drill hole in the ground using a drill rod element; delivering pressurized fluid to the bottom of the drill hole to remove drilled material by urging the drilled material upwardly out of the drill hole, the pressurized fluid being delivered through at least one of a first passage and a second passage with the drilled material travelling upwardly around both the first passage and the second passage, the method further including sampling drilled material by delivering fluid through the first passage into the second passage and collecting a sample received by the second passage. According to a sixth aspect of preferred embodiments herein described there is provided a sampling member for a drilling apparatus, the sampling member having a drive opening for receiving a drive element and a drill rod opening for receiving a drill rod, wherein when received in the sampling member the drive element is able to drive the drill rod, the sampling member further including a sample opening for delivery of a sample transported along an outer passage of the drill rod and then though the drill rod opening. Preferred drill apparatus are considered to be ideally suited to in pit grade control to define ore blocks for processing. In comparison to RC systems there is a reduced cost per metre, the penetration rate per energy input is considerably less, and it is safer due to the lower air pressures used. Furthermore, the vacuum function and collar element arrangement reduce the possibility of contamination. The system can be fitted to conventional top hammer drills without major modifications, and the holes can still be used for blasting if drilling benches are required to determine ore blocks.

Drilling methods according to preferred embodiments advantageously provide high quality samples that are considered to be largely equivalent to samples obtained using RC methods. The sample is taken from where the bit impacts ground and is drawn out between the rod and the outer tube, allowing for more convenient sampling and improved sample quality.

Preferred embodiments of the present invention are considered to provide a number of advantageous arrangements including:

(i) Systems and methods that are advantageously adapted to provide a sample when desired without the sample having to be taken from a conical formation of drill material formed at the top of a drill hole during a top hammer drilling process.

(ii) Systems and methods that during a normal drilling operation provide a top hammer drilling process where the fluid flowstream that entrains drilled material is directed it to the outside of the body and which advantageously allow for relatively uncontaminated samples be readily taken when desired.

(iii) Systems and methods that are suited to shallow drilling operations requiring sampling.

(iv) Systems and methods that allow pit grade control without necessarily using large track mounted equipment having relatively high operating costs and large energy inputs.

(v) Systems and methods that allow for convenient drilling of blast holes in an open cut mine. (vi) Systems and methods that can be fitted to conventional top hammer drill rigs without major modifications.

(vii) Systems and methods that reduce the effects of shortages of reverse cycle drill rigs to carry out grade control and which will free up reverse cycle drill rigs to concentrate on exploration activities

The preferred drill apparatus will also have benefits where pit grade control is required to minimise ore treated through the mills and to prove up ore boundaries and grade. This is especially the case because the current practice of using RC drill rigs for pit grade control is costly due to high energy inputs and the inefficient use of energy. By using existing drilling consumables that are industry accepted the preferred systems and methods should be readily put into application.

It is to be recognised that other aspects, preferred forms and advantages of the present invention will be apparent from the specification including the detailed description, drawings and claims provided below. BRIEF DESCRIPTION OF DRAWINGS

In order to facilitate a better understanding of the present invention, several preferred embodiments will now be described with reference to the accompanying drawings, in which:

Figure 1 is an illustrative cross-sectional view of a prior art top hammer drilling system;

Figure 2 provides two illustrative views showing a conical formation of drilled material formed at the top of the drill hole shown in Figure 1 ;

Figure 3 is an illustrative cross-sectional view of a prior art RC drilling system according to Australian Patent 638571;

Figure 4 provides an illustrative side view of a drill apparatus according to a first preferred embodiment of the present invention;

Figure 5 provides a partial cross-sectional view of the drill apparatus shown in Figure 4;

Figure 6 provides an exploded view and an enlarged partial view of the drill apparatus shown in Figure 4; Figure 7 is a schematic view showing the drilling apparatus of Figure 4 being used in a normal drilling operation;

Figure 8 provides several illustrative views of a sampling member of the drilling apparatus shown in Figure 4;

Figure 9 is a cross-sectional illustrative view of the sampling means shown in

Figure 8;

Figure 10 provides several enlarged partial views of Figure 8;

Figure 11 is a schematic view showing the drilling apparatus of Figure 4 being used in a sample drilling operation;

Figure 12 illustrates a method according to a further preferred embodiment of the present invention;

Figure 13 is a table comparing a reverse circulation system described in the table with the drilling apparatus of Figure 4 according to a top hammer sampling system described in the table;

Figure 14 provides two perspective views illustrating a drill apparatus according to another preferred embodiment of the present invention;

Figure 15 provides an exploded perspective view of an upper portion of the drill apparatus shown in Figure 14;

Figure 16 provides a perspective view of a component of the upper portion shown in Figure 15;

Figure 17 provides a partially cut away perspective view and a cross-sectional view of the upper portion of the drill apparatus shown in Figure 15;

Figure 18 provides several views further illustrating the component shown in Figure 16

Figure 19 provides several views of a sealing assembly forming part of the drill apparatus shown in Figure 14;

Figure 20 provides several views of a lower portion of the drill apparatus shown in Figure 14;

Figure 21 provides several views of an upper portion of a drill rod forming part of the drill apparatus shown in Figure 14; and

Figure 22 provides two cross-sectional views illustrating a possible variation. DETAILED DESCRIPTION OF THE DRAWINGS

Referring to Figure 4 there is shown a drill apparatus 10 according to a first preferred embodiment of the present invention. The drill apparatus 10 is provided for drilling an elongate drill hole 12 according to a top hammer drilling process where the drilled material travels upwardly between the walls of the drill hole 12 and the body 14 of the drill apparatus 10.

Advantageously the drill apparatus 10 is able to be used to take a sample of drilled material without the sample having to travel up the sides of the drill hole 12. This means that the sample cannot dislodge any fragments from the sides of the wall of the drill hole 12 and consequently become contaminated. The purity of the sample is considered to be advantageously improved in comparison to conventional top hammer drill systems.

As shown in Figure 5, the body 14 of the drill apparatus 10 has an inner passage 16 and an outer passage 18. The inner passage 16 is provided for delivering fluid to the bottom 20 of the drill hole 12 to create a first fluid flowstream 21 during a normal drilling process. As shown in Figure 4 the flowstream 21 entrains drilled material and is directed in an upward direction 24 as per conventional top hammer drilling systems (See Figure 1).

The outer passage 18 is provided for receiving drilled material as a sample entrained in a second fluid flowstream provided during a sampling operation. As indicated the sample does not travel between the body 14 of the drill apparatus 10 and the walls of the drill hole 12 but rather travels upwards in the outer passage 18. Consequently, whilst drilled material may collect in a conical formation 25 during normal drilling, samples do not have to be taken therefrom. Rather samples of improved quality travel up the outer passage 18. This improvement in sample quality is provided along with a top hammer drilling process, during normal drilling.

As shown in Figure 5, the drill apparatus 10 includes a drill bit 26 that is located at a bottom end 28 of the drill apparatus 10. In the embodiment, the drill bit 26 is sized to drill a hole of a diameter of about 120 mm. This is generally adequate for blast hole drilling in the mining industry and most shallow drilling operations to a depth of about 12m. Depending on the rock type or machine capability, preferred systems could of course be capable of drilling to depths more than 12 m. Other arrangements may drill holes say in the order of 50 to 150mm diameters. Clearly preferred embodiments can be applied to a range of drills of differing sizes with different applications such as drills for grade control or even specialist drilling like soil anchor holes.

In this embodiment, the body 14 of the drill apparatus 10 includes a drill stem 30 shown extending into the drill hole 12 in Figure 4. In the drill stem 30 the inner passage 16 and the outer passage 18 are coaxially aligned.

As shown in Figure 5, an inner rod element 32 and an outer rod element 34 define the inner passage 16 and the outer passage 18, respectively. As would be apparent, the inner walls of the inner rod element 32 define the inner passage 16. The outer passage 18 is defined by the inner walls of the outer rod element 34 together with the outer walls of the inner rod element 32.

Figure 6 provides an exploded view of the drill apparatus 10. As illustrated, the inner rod element 32 is adapted to engage the drill bit 26. Referring to Figures 5 and 6, the inner rod element 32 is shown to be permanently fixed to the outer rod element 34 by a number of connector elements 36. The connector elements 36 are welded in position. The connector elements 36 are spaced along the body 14 of the drill apparatus as shown in Figure 4. This provides the stem 30 with advantageous rigidity in comparison to the overall weight.

The outer rod element 34 has a head in the form of a collar element 38 welded to its lower end 39. A threaded or another form of engagement is of course possible. The collar element 38 comprises a frusto conical portion 40 and a collar portion 42 as shown in the enlarged portion A-A of Figure 6. The connector elements 36 and guides are sized, shaped and positioned so as to not unnecessarily inhibit the flow of fluid through either the inner passage 16 or the outer passage 18. The connector elements 36 are advantageously streamlined. In arrangements the connector elements 36 are shaped like a tear drop or an aerofoil for this reason.

During a normal drilling operation, pressurised air is delivered through both the inner passage 16 and the outer passage 18. This serves to ensure that the pressurized air is delivered to the drill hole 12 and that the fluid flowstream 21 is created. As discussed the flowstream 21 serves to entrain drilled material during normal drilling. The entrained drilled material is directed towards to the outside of the body 14.

During a sampling operation the outer passage 18 is relatively depressurized in comparison to the inner passage 16. In the embodiment this is achieved by applying a vacuum to the outer passage 18. This causes air to be delivered through the inner passage 14 to the bottom of the drill hole, to entrain drilled material, and then for at least a portion of the flow to be received by the outer passage 18 as a sample. The entrained material can then be removed and analysed.

It is to be recognised that in the embodiment the sampling operation occurs at a different time to normal drilling. In other embodiments it may be the case that the sampling occurs at the same time as normal drilling.

Nonetheless, the present embodiment allows for both normal drilling according to a top hammer drilling process and for a sampling operation where a sample can be recovered, without the sample having to travel in the region between the walls of the drill hole 12 and the body 14 of the drill apparatus 10. As discussed the samples are considered to be advantageously representative of the actual drilled material and can be taken when desired.

As shown in Figure 7, the drill apparatus 10 includes a control system 44 that is adapted to deliver pressurized air to both the inner passage 16 and the outer passage 18 during a normal drilling operation. The pressurized air that is delivered to the inner passage 16 is provided along a path 46 while the pressurized air that is delivered to the outer passage 18 is provided along a path 48. The path 46 is a conventional path that extends through a drive mechanism 54 that in use is coupled to the inner rod element 32. The path 46 employs both a sample hose (not shown) and a sample facility 50 illustrated in Figures 4 and 5. The sample facility 50 is provided in the form of a side swivel 52 that is located between the drive mechanism 54 and the drill stem 30.

The side swivel 52 is further illustrated in Figures 8, 9 and 10. Figure 8 provides a perspective exploded view, a top view, a rear view and a partially cut away side view. Figure 9 provides an illustrative cross sectional view. Figure 10 provides several enlarged views of the portions marked A-A, B-B, C-C and D-D in Figure 9. As shown in Figures 8, 9 and 10, the side swivel 52 includes a drive opening 58 for receiving a drive element 60. The drive element 60 is shown in a perspective view in Figure 6.

The drive opening 58 includes two seals 62. The seals ensure that pressurized air does not escape when delivered through a passage in the drive element 60. Accordingly the drive element 60 allows for the delivery of pressurized air into the internal passage 16 of the drill stem 30. This is clearly illustrated in Figure 5.

In the side swivel 52, there is further provided a drill rod opening 64 for receiving a top portion 66 of the drill stem 30. The drill rod opening 64 is aligned with the drive opening 58. In the embodiment, the drill rod opening 64 is provided by a cylindrical portion 68 having seals 70 at the lower end thereof. This is highlighted in portion C-C of Figure 10.

When the drive element 60 and the top portion 66 of the drill stem 30 are received in the side swivel 52, the drive element 60 mates with a female portion 61 of the inner rod element 32. In this manner the drive element 60 is able to drive the inner rod element 32 and the drill stem 30 as a whole.

The side swivel 52 includes an anti-vibration arrangement 72 comprising two helical springs 74 and two location rods 75 either side of the drive opening 58. In the anti- vibration arrangement 72, the springs 74 and the location rods 76 (extending therethrough) allow for a degree of movement of the body 76 of the sample swivel 52 relative to the drive element 60.

The side swivel 52 further includes a sample opening 78 if the form of a moveable conduit 80. The moveable conduit 80 allows for the delivery of a sample of drilled material therethrough. The moveable conduit 80 is able to move by about 15 degrees in any direction radially from a central location as illustrated.

In the side swivel 52, once the sample has been urged up the outer passage 18 of the drill stem, though the drill rod opening 64, the sample is received by and then passes through the moveable conduit 80. As shown in Figure 7, the drive element 60 extends through the moveable conduit 80 which seals against the drive element 60. In the drill apparatus 10, the control system 44 includes a flexible hose (not shown) that extends from the moveable conduit 80. The control system 44 is adapted to purge the outer passage 18 and to assist with the normal drilling operation.

As shown in Figure 6, the control system 44 includes a pressurization system 84 for pressurizing air and delivering the pressurized air to the inner passage 16 and the outer passage 18.

It is to be appreciated that delivering the pressurized air through the outer passage 18 advantageously assists with purging the outer passage 18 so as to limit the risk of contamination of any samples.

The control system 44 further includes a vacuum system 86 for applying a vacuum to the outer passage 18 during the sampling operation. When the vacuum system 86 is operated pressurized a containing entrained drilled material is received through the outer passage 18.

Figure 11 illustrates the sampling operation in comparison to the normal drilling operation. While similar to the normal drilling operation shown in Figure 7 the flowstream provided is significantly different. In the sampling operation, air from the inner passage 16 is drawn into the outer passage 18 along with entrained drilled material using the vacuum system 86 and pressurization system 84. The drill apparatus 10 includes the collar element 38 to assist with the passage of entrained material into the outer passage 18. In this particular embodiment, the vacuum includes a bagging system

90 for collecting the samples for analysis.

A method 100 of drilling an elongate drill hole 102, according to a further preferred embodiment of the present invention shown in Figure 12. In the method 100, at block 104 a fluid flowstream 106 is created during a normal drilling operation. This is achieved by delivering fluid 107 to the bottom of the drill hole 102 through an inner passage 108 of a drilling apparatus 110.

At block 112 the fluid flowstream 106 entrains drilled material, and flows around the outside of the body of the drill apparatus 110. Following the normal drilling operation a second fluid flowstream 114 is created, at block 113, during a sampling drilling operation. This is achieved by delivering fluid 115 to the bottom of the drill hole 102 through the inner passage 108 of the drilling apparatus 110. Drilled material is entrained in the second fluid flowstream 114. At block 118 a sample of the drilled material is received through the outer passage 120 of the drill apparatus 110.

In the method 100 the collaring of the hole is carried out by conventionally drilling an open hole. During the sampling, at blocks 113 and block 118, the outer passage 120 is depressurised with a vacuum system. At block 112, fluid 107 is also delivered through the outer passage 120 in addition to the passage 108 to assist with normal drilling and clean the outer passage. As such the depressurisation is reversed to blow mode while collaring during the normal drilling operation.

In the normal drilling operation cuttings are propelled with the drill rig air and are deposited at ground level around the top of the hole as with a conventional top hammer drilling system. The vacuum system is activated to receive material through the outer passage of the drill apparatus.

In the method 100 it is considered advantageous to use both pressure from the drilling air and suction created from the vacuum system through to the sample collection point. In the method 100 a conventional cyclone system is used.

In blast hole drilling operations there is a particular need to carry out pit grade control using large track mounted equipment which has high operating costs and large energy inputs. The drill apparatus 10 and the method 100 are considered to advantageously provide high quality ore samples equivalent to current technology using reverse circulation but without the accompanying disadvantages of reverse circulation systems.

The drill apparatus 10 and method 100 advantageously use existing top hammer drilling consumables that are readily available and proven. In fact the outer rod element 34 in the drill apparatus 10 is fitted to a conventional T51 inner rod element 32.

Figure 13 provides a tabular comparison between reverse circulation drills in general and a top hammer sampling systems in the form of the drill apparatus 10. As detailed in the Figure 13 the top hammer system is generally much more efficient.

A further benefit of the drill apparatus 10 is that it is particularly suited to difficult drilling, such as drilling through cavities, broken, wet or porous ground where conventional open hole drilling has its limitations. The applicant has performed a number of comparisons of conventional drill systems. One such system is known as the RC Hammer and another is known as the DTH Hammer. There is a considerable price differential in the consumables alone. A comparison of the RC Hammer and the drill apparatus 10 has highlighted the savings in the consumables are even more pronounced. This is considered to be particularly advantageous.

The fuel consumption in the RC Hammer will also be much higher due to the fact that the equipment for reverse circulation has relatively large compressed air consumption and horse power requirements. The top hammer sampling system of the form of the drill apparatus 10 is considered to be particularly productive in holes less than say 12m.

It is envisaged that in holes between 12 and 30 metres the top hammer sampling system will be suitable for use in dry holes. In wet holes the capacity of the system to be operated in a fashion that prevents material entering the outer passage 120 will also be advantageous.

The applicant has tested a number of purpose built RC drills on a project with a hole size of 133 mm and achieved penetration rates, on average, of 20m/hr. The holes were 15- 30m deep, the rod length was 7.6 m and the angle of the holes was at 70 degrees.

Figure 14 illustrates a drill apparatus 200 according to a further preferred embodiment of the present invention. The drill apparatus 200 includes a drill rod base 202 and a diverter assembly 204. As shown in Figure 1 the diverter assembly 204 is mounted to the drill rod base 202 and has a drill pipe 206 extending therefrom.

As shown in Figure 15, the drill rod base 202 includes two arms 208 with mounting holes 210. The mounting holes 210 allow the diverter assembly 204 to be mounted to the drill rod base 202 using a number of anti-vibration mounts 212 mounted on opposite sides of the arms 208 as illustrated.

The drill apparatus 200 includes a shank assembly 214 that is adapted to be received by an upper housing 216 provided by the body of the diverter assembly 204. A sling ring 218 is adapted to fit over a drive shaft 220 of a drive mechanism (shown in phantom) and engage the lower end of the shank assembly 214.

The body of the diverter assembly 204 includes a mount arrangement 222 in the form of two members 224 spaced either side of the upper housing 216. The diverter assembly 204 further includes a lifting hole 226 to allow for the diverter assembly 204 and the drill pipe 206 to be lifted when separated from the drill rod base 202.

As shown in Figure 16, the diverter assembly 204 provides a first opening 228, a second opening 230, and a third opening 232. The first opening 228 comprises a drill material inlet 234 and drill air outlet 235 and is adapted to receive the drill pipe 206. The second opening 230 comprises a drill air inlet 236 and drive shaft inlet 237 and is disposed above and within the horizontal extent of the first opening 228. The third opening 232 comprises a sample material outlet 238 and drill air inlet 229. As shown, the body of the diverter assembly 204 provides an elbow arrangement 240.

In the present embodiment, the first opening 228 is provided by a labyrinth seal 242 having a seal air fitting 244. Advantageously the seal air fitting 244 delivers seal air taken from drill air system during drilling operation. The advantage of the seal air fitting 244 is that sealing air passes into a sealing gallery 246 as shown in Figure 17. This assists with pressurizing the labyrinth seal preventing leakage of drill cuttings.

As would be apparent, the second opening 230 is provided by the upper housing 216 and is adapted to receive the shank assembly 214. The third opening 232 is provided by a reducer fitting 248 which is fixed in position by being welded to the remainder of the diverter assembly 204.

Referring to Figure 18, the diverter assembly 204 includes a guide bush 250 in the upper housing 216 to seal around the shank assembly 214. An air inlet 252 in the form of a nipple 254 is arranged to be in communication with the guide bush 250. This advantageously serves to act as a guide for the shank and provide lubrication. A lower lip seal 256 is provided to prevent release of air and sample cuttings from the diverter 204.

The diverter assembly 204 includes two o-rings 255 that fit over a labyrinth seal sleeve 257 that is adapted to fit into the body of the diverter assembly to provide the sealing gallery 246.

The provision of the shank assembly cap 214 that is adapted to fit within the upper housing 216 is considered to be advantageous because it allows for removal of shank for maintenance and inspection purposes. The provision of the sealing gallery 246 is considered to be advantageous because it allows for prevents the loss of vacuum pressure and as such drill cuttings.

The form of the shank assembly 214 is shown in Figure 19. The shank assembly 214 includes a locking ring 258, a sleeve tube 260 and a sleeve end ring 262. An o-ring seal 264 and taper locking element 266 are provided to engage a split clamp collar 268 adjacent the sleeve end ring 262. Adjacent the locking ring 258 there is provided a further taper locking element 270, an o-ring seal 272 and a spacer ring 274. With this arrangement the split clamp collar 268 is advantageously designed to allow for the step down nature of the shank and collection box geometry. This advantageously allows for easy change out of shank / striking bar as required.

Referring to Figure 20, the drill pipe 206 comprises an inner rod 276 that can be removably positioned within an outer tube 278. The inner rod 276 is hollow to provide a first passage 280. The outer tube 278 provides a second passage 282 between the outer tube 278 and the inner rod 276. At the lower end 284 of the outer tube 278 (shown in Figure 1) there is provided a collar 286 (shown in Figure 20). The collar 286 expands outwardly and is connected to a first connector element 288. The connector element 288 includes three bridge elements 290 extending from the outer wall 292 of the connector element 288 to a support 294. Two rings 296 in the form of spring lock rings are fixed in position in respective grooves 298 on the outer surface of the inner rod 276 by using an end connector element 300. The end connector element 300 is adapted to be fixed to the connector element 288 by fastening fasteners 302 though holes in bridge elements 304 provided by the end connector element 300. Advantageously, by having a removable end connector element 300, it is possible to fix the rings 296 in the region between the first connector element 288 and the end connector element 300. This is advantageous because the rings 296 allow for the outer pipe to be reused once the inner drill rod is broken or worn out. Moreover the inner rod 276 can be readily removed from the outer tube 278.

As shown in Figure 14 the drill apparatus 200 includes a number of connector elements 306. The upper connector element 307 fits into the labyrinth seal sleeve 257 is shown in Figure 18. As shown in Figure 18, the upper connector element 307 includes a first connector 310 having an extension sleeve 312. The drive shaft 220, shown in Figure 14, is adapted to engage the upper end 314 of the inner rod 276 and to deliver pressurized air therethrough. A sample is able to be recovered through the passage 282 disposed between the inner rod 276 and the outer tube 278. Similarly to the drill apparatus 10 shown in Figure 4, the drill apparatus 100 provides a inner passage 280 and an outer passage 282. The inner passage 280 is provided for delivering fluid to the bottom of the drill hole and creating a fluid flowstream that entrains drilled material and directs it to the outside of the body during a normal drilling operation; and the outer passage 282 is for receiving drilled material entrained in a second fluid flow stream created by fluid delivered through the inner passage 280 during a sampling operation.

Figure 22 illustrates a threaded coupling 316 with no diverging collar. The use of a diverging collar 318 is considered to be advantageous for the reason that it can increase velocity in 114.

A number of advantages of the embodiments described have been described above. In terms of grade control it is considered that:

(1) The use of the drill apparatus described will serve to reduce the effect of shortages of reverse cycle drills to carry out grade control and will free up drills to concentrate on exploration activities.

(2) The drill apparatus will have benefits where pit grade control is required to minimise ore treated through the mills and to prove up ore boundaries and grade.

This is especially the case because the current practice of using reverse cycle drill rigs for in pit grade control is costly due to high energy inputs and inefficient use of energy.

(3) The use of existing drilling consumables that are industry accepted will mean that the systems and methods can be readily put into application.

(4) Conventional top hammer systems such as the Terex™ GD5000 and Atlas Copco™L7 can be readily converted.

Both the drilling apparatus 10 and method 100 are considered to be able to provide high quality ore samples equivalent to current technology using reverse circulation (RC) drilling systems in such environments. A top hammer drilling process is advantageously provided in each case.

As would be apparent, various alterations and equivalent forms may be provided without departing from the spirit and scope of the present invention. This includes modifications within the scope of the appended claims along with all modifications, alternative constructions and equivalents. For example the inner and outer passages may merely comprise first and second passages arranged side by side.

In the present specification, the presence of particular features does not preclude the existence of further features. The words "comprising", "including" and "having" are to be construed in an inclusive rather than an exclusive sense.

Claims

CLAIMS :

1. A drill apparatus for drilling an elongate drill hole, the apparatus including: a body defining an inner passage and an outer passage wherein the inner passage is for delivering fluid to the bottom of the drill hole and creating a fluid flowstream that entrains drilled material and directs it to the outside of the body during a normal drilling operation; and the outer passage is for receiving drilled material entrained in a second fluid flowstream created by fluid delivered through the inner passage during a sampling operation.

2. A drill apparatus for drilling an elongate drill hole as claimed in claim 1 wherein the outer passage and the inner passage are defined by a drill pipe with the outer passage being concentrically arranged about the inner passage.

3. A drill apparatus as claimed in claim 2 including a plurality of support members located in the outer passage so as to extend between the walls of the outer and inner passage to fix the relative positions of the outer and inner passage.

4. A drill apparatus as claimed any one of claims 1 to 3 wherein the drill apparatus includes a control system for delivering pressurized fluid to the inner passage and for creating a negative pressure differential between the inner passage and the outer passage during the sampling operation.

5. A drill apparatus as claimed in claim 4 wherein the control system includes a vacuum system for applying a vacuum to the outer passage to assist with drawing the material entrained in the second fluid flowstream up the outer passage.

6. A drill apparatus as claimed in claim 4 or 5 wherein the control system is adapted to deliver pressurized fluid to both the inner passage and the outer passage during a normal drilling operation.

7. A drill apparatus as claimed in claims 6 wherein the control system is adapted to purge the outer passage to assist with limiting the risk of contamination.

8. A drill apparatus as claimed in any one of claims 1 to 7 including a collar element for sample collection where the collar element is adapted to assist with improving the flow of the flowstream, during the sampling operation, into the outer passage such that the outer passage advantageously receives entrained drilled material.

9. A drill apparatus as claimed in claim 8 wherein the collar element includes a frusto-conical portion and is located adjacent a drill bit of the drill apparatus.

10. A drill apparatus as claimed in any one of claims 1 to 9 including a drive element, and a sampling member, the sampling member for receiving drilled material that has passed through the outer passage and the drive element extending through the sampling member for driving a drill bit.

11. A drill apparatus as claimed in claim 10 wherein the sampling member has a moveable exit operatively connected to the outer passage wherein the moveable exit is moveable over at least 30 degrees, in any direction radially from a central location.

12. A drill apparatus as claimed in any one of claims 1 to 11 wherein the drill apparatus is a top hammer blast hole drilling apparatus for open cut mining.

13. A drill apparatus for drilling an elongate drill hole, the apparatus including: a body defining an inner passage and an outer passage wherein the inner passage is for delivering fluid to the bottom of the drill hole and creating a fluid flowstream that entrains drilled material and directs it to the outside of the body during a normal drilling operation; and the outer passage is for receiving drilled material entrained in a second fluid flowstream created by fluid delivered through the inner passage during a sampling operation, the drilling apparatus further comprising a collar element for sample collection where the collar element is adapted to assist with improving the flow of the flowstream, during the sampling operation, into the outer passage.

14. A method of drilling an elongate drill hole comprising: creating a fluid flowstream, during a normal drilling operation, by delivering fluid to the bottom of the drill hole through an inner passage of a drilling apparatus; the fluid flowstream entraining drilled material, and flowing around the outside of the body of the drill apparatus; creating a second fluid flowstream, during a sampling drilling operation, by delivering fluid to the bottom of the drill hole through the inner passage of the drilling apparatus; entraining drilled material in the second fluid flowstream; and receiving a sample the of the drilled material with the sample being received through an outer passage of the drill apparatus.

15. A method as claimed in claim 14 including delivering pressurized fluid to the inner passage and creating a negative pressure differential between the inner passage and the outer passage during the sampling operation

16. A method as claimed in claim 14 or 15 including delivering fluid to the bottom of the drill hole through both the inner passage and the outer passage during the normal drilling operation

17. A method as claimed in claim 16 including purging the outer passage to assist with limiting the risk of contamination.

18. A drill apparatus for drilling an elongate drill hole, the apparatus including: a body defining a first passage and a second passage wherein the first passage is for delivering fluid to the bottom of the drill hole to remove drilled material by urging the drilled material upwardly around both the first passage and the second passage during a normal drilling operation; and the second passage is for receiving a sample of drilled material urged upwardly by the flow of fluid from the first passage during a sampling operation.

19. A drill apparatus as claimed in claim 18 wherein the drill apparatus includes a control system for delivering pressurized fluid to the inner passage and for creating a negative pressure differential between the inner passage and the outer passage during the sampling operation.

20. A drill apparatus as claimed in claim 19 wherein the control system includes a vacuum system for applying a vacuum to the outer passage to assist with drawing the material entrained in the second fluid flowstream up the outer passage.

21. A drill apparatus as claimed in claim 19 or 20 wherein the control system is adapted to deliver pressurized fluid to both the inner passage and the outer passage during a normal drilling operation.

22. A drill apparatus as claimed in any one of claims 18 to 21 including a drive element, and a sampling member, the sampling member for receiving drilled material that has passed through the outer passage and the drive element extending through the sampling member for driving a drill bit.

23. A drill apparatus as claimed in claim 22 wherein the sampling member has a moveable exit operatively connected to the outer passage wherein the moveable exit is moveable over at least 30 degrees, in any direction radially from a central location.

24. A drill apparatus comprising: a first rod element disposed within a second rod element, there being provided a first passage, through the first rod element, and a second passage between the first rod element and the second rod element; the first and second rod elements being configured such that, in a normal drilling operation, fluid is able to pass through the first passage and then around both the first passage and the second passage to remove drilled material and, in a sampling operation, fluid is able to pass through the first passage and then upwardly into the second passage causing drilled material to travel through the second passage so as to provide a sample.

25. A drill apparatus as claimed in claim 24 wherein first rod element is connected to a drive element, and the second rod element is connected to a sampling member, the drive element extending through the sampling member for driving a drill bit and the sampling member for receiving drilled material that has passed through the outer passage.

26. A drill apparatus as claimed in claim 25 wherein the sampling member has a moveable exit operatively connected to the outer passage wherein the moveable exit is moveable over at least 30 degrees, in any direction radially from a central location.

27. A method of drilling comprising: drilling a drill hole in the ground using a drill rod element; delivering pressurized fluid to the bottom of the drill hole to remove drilled material by urging the drilled material upwardly out of the drill hole, the pressurized fluid being delivered through at least one of a first passage and a second passage with the drilled material travelling upwardly around both the first passage and the second passage, the method further including sampling drilled material by delivering fluid through the first passage into the second passage and collecting a sample received by the second passage.

28. A method as claimed in claim 27 including applying a vacuum to the second passage to assist with drawing the material upwardly.

29. A sampling member for a drilling apparatus, the sampling member having a drive opening for receiving a drive element and a drill rod opening for receiving a drill rod, wherein when received in the sampling member the drive element is able to drive the drill rod, the sampling member further including a sample opening for delivery of a sample transported along an outer passage of the drill rod and then though the drill rod opening.

30. An apparatus substantially as herein described with reference to the accompanying drawings.

31. A method substantially as herein described with reference to the accompanying drawings.