AU2010200946A1 - Drilling Apparatus - Google Patents

Abstract

Abstract A drilling apparatus comprising at least one drill rod comprising at least one connection valve for connection of the drill rod to a connection valve of a like drill rod or a connection valve of another drilling apparatus component wherein the at least one drill rod also comprises a barrier adapted to cover an end of the drill rod when the connection valve is disconnected.

Description

James & Wells Intellectual Property Ref: 234270AU2/53 DRILLING APPARATUS STATEMENT OF CORRESPONDING APPLICATIONS This application is based on the complete specification filed in relation to Australian Patent Application No. 2008904823, the entire contents of which are incorporated 5 herein by reference. TECHNICAL FIELD This invention relates to a drilling apparatus. More particularly, this invention relates to a hydraulic "down-the-hole" (DTH) percussion drilling apparatus for drilling holes in a terrain. 10 BACKGROUND ART The service life of hydraulic DTH drilling apparatus' used in situations requiring the addition and removal of rods during drilling is adversely affected by contamination introduced to the oil during rod changes. Controlling and/or removing contamination is a key technical hurdle to be overcome in the pursuit of apparatus 15 reliability and longevity and thus the reduction in overall drilling cost. Controlling contamination requires that the surfaces that are exposed to oil during operation of the apparatus (Le. the drill rod connection valves) are isolated from the surrounding environment. Contamination control and/or removal can be built into a purpose built drilling 20 apparatus design but the applicant is not aware of any system which can be retrofitted to existing DTH drilling apparatus. It is an object of the present invention to address the foregoing problems or at least to provide the public with a useful choice. 1 James & Wells Intellectual Property Ref: 234270AU2/53 Further aspects and advantages of the present invention will become apparent from the ensuing description which is given by way of example only. It is acknowledged that the term 'comprising' may, under varying jurisdictions, be attributed with either an exclusive or an inclusive meaning. For the purpose of this 5 specification, and unless otherwise noted, the term 'comprising' shall have an inclusive meaning - i.e. that it will be taken to mean an inclusion of not only the listed components it directly references, but also other non-specified components or elements. This rationale will also be used when the term 'comprised' or 'comprising' is used in relation to one or more steps in a method or process. 10 DISCLQSJRE OF INVENTION According to a first aspect of the present invention there is provided a drilling apparatus comprising: * at least one drill rod comprising: o at least one connection valve for connection of the drill rod to a 15 connection valve of a like drill rod or a connection valve of another drilling apparatus component; wherein - the at least one drill rod also comprises a barrier adapted to cover an end of the drill rod when the connection valve is disconnected. 20 In this way contamination control is achieved by preventing large debris ingress by the barrier's close fit around the end of the drill rod. Preferably, the barrier is biased to cover the end of the drill rod when the connection valve is disconnected via at least one hydraulic cylinder. 2 James & Wells Intellectual Property Ref: 234270AU2/53 Preferably, the drill rod also comprises a means of supplying pressurised fluid proximal to the connection valve when the connection valve is disconnected. More preferably, the pressurised fluid is pressurised air. In this way fine particle ingress into the drill rod end is also prevented by the 5 pressurised fluid being fed in a controlled manner from the inside of the barrier to the outside environment thus carrying harmful dust particles away from the disconnected drill rod connection valve. Preferably, the barrier is attached to an external sleeve adapted to move the barrier relative to an external surface of the drill rod. 10 More preferably, the external sleeve is adapted to move relative to an external surface of the drill rod via at least one actuator. Still more preferably, the external sleeve also comprises at least one brush adapted to clean the external circumference of the drill rod as drill rod rotates in the barrier and/or the barrier is moved over the drill rod. 15 According to a second aspect of the present invention there is provided a method of using a drilling apparatus, the drilling apparatus comprising the steps: a. disconnecting a drill rod at a connection valve from a like drill rod or a connection valve of a hydraulically powered hammer; b. moving a barrier to a position to cover the end of the drill rod or 20 hydraulically powered hammer; c. activating a flow of pressurised, filtered air proximal to the connection valve to prevent ingress of dust particles into the end of the drill rod. Preferably, the method comprises the pre-step of: 3 James & Wells Intellectual Property Ref: 234270AU2153 moving a drive system comprising the barrier along an external length of the drill rod until the barrier it is proximal to an end of the drill rod. According to a third aspect of the present invention there is provided a device for use with a drill rod, the device comprising: 5 0 an external sleeve adapted to move relative to an external surface of the drill rod; and * a barrier adapted to cover an end of the drill rod when the connection valve is disconnected. Preferably, the external sleeve also comprises at least one brush adapted to clean 10 the external circumference of the drill rod as the drill rod rotates In the sleeve and /or the barrier is moved over the drill rod. BRIEF DESCRIPTION OF DRAWINGS Further aspects of the present invention will become apparent from the following description which is given by way of example only and with reference to the 15 accompanying drawings in which: Figure 1A shows a top view of a preferred embodiment of the drilling apparatus of the present invention in the form of a rod connection; Figure 1B shows a front view of the preferred embodiment of the present invention shown in Figure 1A; 20 Figure 1C shows a side view of the preferred embodiment of the present invention shown in Figure IA: Figure 2 shows a sectional view of the preferred embodiment of the present invention shown in Figure 1A with two adjacent drill rods connected; 4 James & Wells Intellectual Property Ref: 234270AU2/53 Figure 3 shows a sectional view of the preferred embodiment of the present invention shown in Figure 1A with two adjacent drill rods disconnected and with the barrier door closed; and Figure 4 shows a sectional view of a preferred embodiment of drilling 5 apparatus. BEST MODES FOR CARRYING OUT THE INVENTION The invention is now described in relation to one preferred embodiment as shown in Figures 1 to 4. Given the harsh underground environment that DTH drilling apparatus 100 (shown 10 in Figure 4) has to operate in there will always be a certain amount of contamination introduced by the rod handling process. Figures 1A to 3 show a barrier in the form of a sliding door I which is open during drilling, but which is closed when the connection valve 4 of a drill rod 5 (shown in Figures 2 and 3) is separated from an adjacent connection valve 2 of a like drill rod 15 3 or another component of the drilling apparatus 100 such as a hydraulically powered hammer 10 or filer drill rod 12 (as shown in Figure 4). In this way, oil within the drill rod 3 is protected from contamination from large rock debris when the drill rod is disconnected or connected. The sliding door 1 is connected to a pair of actuators in the form of hydraulic (or air) 20 rams 6A, 6B, which are adapted to move the sliding door 1 from an open to a closed position in the direction of arrow A (shown on figure 1A) in a plane perpendicular to the plane of an end of a drill rod 3. The displacement of the sliding door 1 during movement in the direction of arrow A is limited by the barrels (6C, 6D) of the rams 6A, 6B and and stops 7A. 7B which can co-operate with 25 leading edge of sliding door 1 in known fashion. 5 James & Wells Intellectual Property Ref: 234270AU2/53 The sliding door 1 is mounted on a sleeve 8 (best seen in Figure 2) adapted to fit over the external surface of the drill rod 3 and is movable up and down the drill rod 3. The movement of the sleeve 8 over the drill rod 3 may be achieved via an external drive system, such as a hydraulic cylinder (not shown). A short linkage 5 (not shown) back to a drilling rig mast or breakout table prevents the sleeve 8 from turning with the drill rods 3, 5 during drilling. The sleeve 8 and sliding door may be retrofitted to existing drilling apparatus or used as part of a dedicated drilling apparatus 100. Figure 2 shows the sleeve 8 in situ during drilling with the sliding door 1 open, 10 Figure 3 shows the sleeve 8 positioned over an end of the drill rod 3, after disconnection of connection valve 2 of drill rod 3 from connection valve 4 of drill rod 5, with the sliding door 1 closed thereby covering the connection valve 2 of the drill rod 3. In use, when a drill rod 3, 5 is to be added or removed from the drilling apparatus 100 the sleeve 8 is moved into position on the end of the drill rod 3 15 connected to the hammer 10 (not shown) and proximal to the joint between the drill rods 3, 5 and then the drill rods 3. 5 are disconnected. Once the drill rods 3, 5 are separated the sliding door 1 is closed over the end of drill rod 3 and the sleeve 8 is fed pressurised fluid in the form of filtered air, via fitting 9 to supply the pressurised air proximal to the disconnected connection valve 2 until the connection is ready to 20 be re-established. It should be appreciated that there may be different embodiments of a means of supplying pressurised fluid to fitting 9 without departing from the scope of the present invention. Examples include a fan comprising an inlet filter positioned on the sleeve 8 which is activated on disconnection of the drill rods 2, 3 or a separate 25 valve and hose arrangement for supplying the fluid from a separate fluid source. Alternatively, the pressurised fluid may be supplied internally in the drill rod 3. 6 James & Wells Intellectual Property Ref: 234270AU2/53 The sleeve 8 also comprises a replaceable brush section 8A that cleans the drill rods 3, 5 as the rods rotate and/or as the sleeve 8 is moved over up and down the drill rod 3, 5. The flow of pressurised fluid from the inside of the sleeve to the outside 5 environment prevents fine particle ingress into the end of the drill rod 3 by carrying harmful dust particles away from the disconnected connection valve 2. Thus, preferred embodiments of the present invention may have a number of advantages over the prior art which can include: " failsafe contamination protection of oil from drilling debris (cuttings); 10 e failsafe contamination protection of cuttings from oil (important in mineral sampling applications); and * improved reliability through prolonged service life and consequent reduced maintenance costs * Universal application to a wide variety of drilling situations and drilling rig 15 designs " Low construction cost. Aspects of the present invention have been described by way of example only and it should be appreciated that modifications and additions may be made thereto without departing from the scope thereof as defined in the appended claims. 7

Claims (14)

1. A drilling apparatus comprising: * at least one drill rod comprising: o at least one connection valve for connection of the drill rod to a connection valve of a like drill rod or a connection valve of another drilling apparatus component: wherein * the at least one drill rod also comprises a barrier adapted to cover an end of the drill rod when the connection valve is disconnected.

2. A drilling apparatus as claimed in claim 1 wherein the barrier is biased to cover the end of the drill rod when the connection valve is disconnected via at least one hydraulic cylinder.

3. A drilling apparatus as claimed in claim 1 or claim 2 wherein the drill rod also comprises a means of supplying pressurised fluid proximal to the connection valve when the connection valve is disconnected.

4. A drilling apparatus as claimed in claim 3 wherein the pressurised fluid is pressurised air.

5. A drilling apparatus as claimed in any one of claims I to 4 wherein the barrier is attached to an external sleeve adapted to move the barrier relative to an external surface of the drill rod.

6. A drilling apparatus as claimed in claim 5 wherein the external sleeve is adapted to move relative to an external surface of the drill rod via at least one actuator. 8 James & Wells Intellectual Property Ref: 234270AU/53

7. A drilling apparatus as claimed in claim 5 or claim 6 wherein the external sleeve also comprises at least one brush adapted to clean the external circumference of the drill rod as drill rod rotates in the barrier and/or the barrier is moved over the drill rod.

8. A method of using a drilling apparatus. the drilling apparatus comprising the steps: d. disconnecting a drill rod at a connection valve from a like drill rod or a connection valve of a hydraulically powered hammer; e. moving a barrier to a position to cover the end of the drill rod or hydraulically powered hammer; f. activating a flow of pressurised, filtered air proximal to the connection valve to prevent ingress of dust particles into the end of the drill rod.

9. A method of using a drilling apparatus as claimed in claim 8 wherein the method comprises the pre-step of: moving a drive system comprising the barrier along an external length of the drill rod until the barrier it is proximal to an end of the drill rod.

10. A device for use with a drill rod, the device comprising: * an external sleeve adapted to move relative to an external surface of the drill rod; and - a barrier adapted to cover an end of the drill rod when the connection valve is disconnected.

11. A device for use with a drill rod as claimed in claim 10 wherein the external sleeve also comprises at least one brush adapted to clean the external circumference 9 James & Wells Intellectual Property Ref: 234270AU/53 of the drill rod as the drill rod rotates in the sleeve and /or the barrier is moved over the drill rod.

12. A drilling apparatus substantially as described herein and with reference to any one of Figures 1 to 4.

13. A method of using a drilling apparatus substantially as described herein and with reference to any one of Figures 1 to 4.

14. A device for use with a drill rod substantially as described herein and with reference to any one of Figures 1 to 4. 10