DEVICE FOR NON-ENTRY MINING

Abstract

A bore hole tool 10 for removing minerals from the earth. The tool has a case 11 having a nose 12. The case contains a drilling sub-system A, a mining sub-system B, and a pumping sub-system C. The drilling sub-system ablates material in front of the nose providing a space into which the tool can be advanced. The mining sub-system breaks down mineral resources and creates a slurry around the tool. The pumping sub-system pumps the slurry created by the mining sub-system away from the case. A method of removing minerals involves providing a bore hole tool 10, ablating material in front of the nose 12 of the case to provide a space into which the tool can be advanced, breaking down mineral resources and creating a slurry around the tool, and pumping the slurry created by the mining sub-system away from the case.

Description

FIELD OF THE INVENTION

The invention relates to mining equipment and more particularly to a multi-purpose bore hole tool that is capable of drilling, mining and pumping.

BACKGROUND OF THE INVENTION

Non-entry mining is a method of removing minerals from the earth using a device that is remotely operated from the surface. Non-entry mining is particularly useful in the recovering of mineral resources that cannot be mined using conventional methods, for example, a coal seam that is too deep for open cut mining and too thin for underground mining.

OBJECTS AND SUMMARY OF THE INVENTION

It is an object of the invention to provide a bore hole tool having a drilling sub-system, a mining sub-system and a pumping sub-system.

In accordance with a first aspect of the invention, there is provided a bore hole tool for removing minerals from the earth, the tool comprising:

a case having a nose, the case containing:

• a drilling sub-system for ablating material in front of the nose of the case providing a space into which the tool can be advanced;
• a mining sub-system for breaking down mineral resources and creating a slurry around the tool; and
• a pumping sub-system for pumping the slurry created by the mining sub-system away from the case.

In an embodiment, the drilling sub-system is adapted to ablate material around the nose of the casing.

In an embodiment, the nose is substantially conical.

In an embodiment, the case comprises a substantially longitudinal component in which the drilling sub-system is located near the nose of the case, and the pumping sub-system and the mining sub-system are located behind the drilling sub-system towards a tail of the case.

In an embodiment, the case is connectable to a drill string. The case and drill string are preferably flexible so as to bend through an approximately 50 m radius.

In an embodiment, the tool further comprises a flexible joint interposed between the case and the drill string.

In an embodiment, the drilling sub-system comprises one or more drilling jet nozzles. In an embodiment, the one or more drilling jet nozzles comprises a centrally located and forward facing drilling jet nozzle. The one or more drilling jet nozzles may further comprise an array of drilling jet nozzles located behind the centrally located and forward facing drilling jet nozzle. The array of drilling jet nozzles are preferably positioned in a circular array. The nozzles in the circular array are preferably subdivided into sub-arrays.

In an embodiment, the one or more drilling jet nozzles each comprises a central opening for water surrounded by an annular air sub-nozzle.

In an embodiment, the nose comprises a plurality of openings adapted to cooperate with the high pressure nozzles associated with the drilling sub-system.

In an embodiment, the mining sub-system comprises a plurality of radially directed jet nozzles.

In an embodiment, each jet nozzle comprises a central opening for water surrounded by an annular air sub-nozzle.

In an embodiment, the case comprises an array of radial openings adapted to cooperate with the radially directed jet nozzles.

In an embodiment, the pumping sub-system comprises a laterally directed throat for receiving the slurry. The throat is preferably adapted to cooperate with an adjacent slurry inlet formed in the case. The throat is preferably adapted to supply a venturi, the venturi comprising a low pressure zone and a slurry pumping jet with a nozzle located within the throat and directed toward the low pressure zone. In an embodiment, the pumping system comprises a pair of laterally directed throats, each throat having an associated venturi. In an embodiment, the tool further comprises one or more guide jets for propelling and/or manoeuvring the tool.

In an embodiment, the case comprises one or more guide jet openings adapted to cooperate with the one or more guide jets.

In accordance with a second aspect of the invention, there is provided a bore hole tool for removing minerals from the earth, the tool comprising:

• a case having a nose, the case containing:
• a drilling sub-system for ablating material in front of and around the nose of the case providing a space into which the tool can be advanced, the drilling sub-system comprising a centrally located and forward facing drilling jet nozzle and an array of drilling jet nozzles located behind the centrally located and forward facing drilling jet nozzle;
• a mining sub-system for breaking down mineral resources and creating a slurry around the tool, the mining sub-system comprising a plurality of radially directed jet nozzles; and
• a pumping sub-system for pumping the slurry created by the mining sub-system towards the earth's surface.

In accordance with a third aspect of the invention, there is provided a method of removing minerals from the earth, the method comprising:

• (a) providing a bore hole tool as described in relation to the first aspect;
• (b) ablating material in front of the nose of the case to provide a space into which the tool can be advanced;
• (c) breaking down mineral resources and creating a slurry around the tool; and
• (d) pumping the slurry created by the mining sub-system away from the case.

In an embodiment, step (b) further comprises ablating material around the nose of the case.

In an embodiment, the method further comprises providing a drill string and step (d) comprises pumping the slurry created by the mining sub-system towards the earth's surface using the drill string.

In an embodiment, the bore hole tool comprises one or more drilling jet nozzles and step (b) comprises using the one or more drilling jet nozzles to ablate material in front of and around the nose of the case. The one or more drilling jet nozzles may comprise a central nozzle, and the method comprises activating the central nozzle continuously during step (b). The drilling sub-system may further comprise an array of drilling jet nozzles located behind the central nozzle, the array of drilling jet nozzles being subdivided into sub-arrays, and the method comprises activating the sub-arrays in sequence, one sub-array at a time to produce a circular jetting action during step (b).

In an embodiment, the the tool comprises a plurality of radially directed jet nozzles, the nozzles directing water outwardly from the tool to carry out step (c).

In an embodiment, the pumping sub-system comprises a laterally directed throat and a venturi, the venturi having a low pressure zone and a slurry pumping jet with a nozzle located within the throat and directed toward the low pressure zone, and step (d) comprises directing fluid towards the low pressure zone with the nozzle, thereby drawing slurry through the throat.

In an embodiment, step (d) comprises pumping the slurry created by the mining sub-system towards the earth's surface.

In an embodiment, the tool comprises one or more guides jets and the method further comprises activating the one or more guide jets for changing the direction of the tool.

In an embodiment, the method further comprises using the one or more guide jets to guide slurry into the slurry inlets.

In an embodiment, the method further comprises inserting the tool into the earth through a pre-drilled bore.

In an embodiment, the method further comprises the step of deactivating the drilling sub-system.

In an embodiment, the method further comprises the step of retracting the tool towards the surface of the earth.

In an embodiment, the method further comprises repeating steps (b) to (d).

The invention consists in the foregoing and also envisages constructions of which the following gives examples only.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

In order that the invention be better understood, the present invention will now be described by way of example only and reference is now made to the following drawing figures in which:

FIG. 1 is a perspective view of a device for non-entry mining.

FIG. 2 is a side elevation of the device depicted in FIG. 1.

FIG. 3 is a side elevation of the components within the tool depicted in FIG. 1.

FIG. 4 is a perspective view of the components depicted in FIG. 3.

FIG. 5 is a side elevation of a drilling jet array.

FIG. 6 is a front elevation of the array depicted in FIG. 5.

FIG. 7 is a side elevation of a mining array.

FIG. 8 is a perspective view of the array depicted in FIG. 7.

FIG. 9 is top plan view of the slurry pump within the tool depicted in FIG. 1.

FIG. 10 is a side elevation, partially cross-sectioned of the apparatus depicted in FIG. 9.

FIG. 11 is a top plan view of the operation of the tool depicted in FIG. 1, with the case removed for clarity.

FIG. 12 is an end view of the operation of the tool depicted in FIG. 1.

FIG. 13 is a schematic showing two sections of a drill string attached to the tool depicted in FIG. 1.

FIG. 14 is a schematic showing the device from the earth's surface to a coal seam.

BEST MODE AND OTHER EMBODIMENTS

As shown in FIG. 1, a bore hole tool for non-entry mining 10 comprises a case 11 that contains a drilling sub-system, a mining sub-system and a pumping sub-system (see FIGS. 3 and 4). The case 11 further comprises a nose cone 12 in which is formed a circular array of openings 13 and a central opening 13′ that cooperates with the high pressure nozzles associated with the drilling sub-system. The case comprises a substantially longitudinal component in which the drilling sub-system is located near the nose of the case, and the pumping sub-system and the mining sub-system are located behind the drilling sub-system towards a tail of the case. The case 11 is connected to a cylindrical drill string 21 having approximately the same diameter as the case. Together, the case 11 and string 21 need to be flexible so as to bend through an approximately 50 m radius. In a preferred embodiment the case 11 or the case and string 11, 21 are covered with three layers, being polyethylene over an epoxy primary layer and polyethylene adhesive. The nose cone 12 is preferable formed from a high nickel, high chromium stainless steel. In the alternative, the nose cone 12 may be formed from an anti-galling stainless steel alloy such as Armco Nitronic 32 or 60. In some embodiments, a flexible joint 22 is interposed between the case 11 and the drill string 21. The flexible joint 22 may also be used between adjacent sections of the string 21. With reference to FIG. 13, the drill string may comprise sections of pipe 21b attachable to the tool 10. The sections of pipe may be threaded or clipped together. The drill string delivers the slurry away from the case, towards the earth's surface 100, as shown in FIG. 14. In particular, the slurry is delivered to a delivery device 21a.

The case has a pair of lateral openings 14 that serve as slurry inlets. The case also has a circumferential array of radial openings 15 that cooperate with the mining sub-system. In preferred embodiments, the slurry inlets 14 are spaced less than 180 degrees apart and are located between the drilling array 13 and the mining array 15. With respect to the orientation depicted in FIG. 2, the slurry inlets 14 are both located below the medial centre line 16 of the case 11. The case also has a pair of guide jet openings 17 located below the mid-line 16. The guide jet openings are located between the slurry inlets 14 and the nose cone 13.

FIGS. 3 and 4 illustrate an embodiment of the components located within the case 11. The drilling sub-system is shown in detail A of FIG. 3. The drilling sub-system includes one centrally located and forward facing drilling jet nozzle 31, behind which is located an array of nine other high pressure drilling jet nozzles 32. Each jet nozzle 31, 32 (as well as all of the other jet nozzles herein disclosed) comprises a central opening for water surrounded by an annular air sub-nozzle (see FIGS. 6-8). In preferred embodiments, the jets are fabricated from a hardwearing material such as Tungsten Carbide. High pressure water is supplied to each nozzle 31, 32 by an inlet hose 33. Compressed air is supplied to each sub-nozzle by an air hose 34. In one preferred embodiment, the central nozzle 31 is always and continuously activated during drilling operations. The nine nozzles 32 in the circular array are subdivided into three sub-arrays. Each sub-array comprises three generally equally spaced nozzles. The sub-arrays are activated in sequence, one sub-array at a time to produce a circular jetting action. The nozzles in the drilling sub-system are each actuated using an electronically actuated valve 35. The valves are connected to a main electricity supply by wires 36.

Utilisation of the drilling sub-system (A) results in an excavation of material in front of and around the nose cone. This excavation caused by the nozzles 31, 32 provide a space into which the tool 10 can be advanced. The drilling sub-system A also includes a pair of guide jets 37. The guide jets are selectively and individually activated for the purpose of changing the direction of the tool. The case 11 contains a pair of openings 17 that allow the guide jets 37 to discharge through the case 11. The guide jets are selectively activated, one at a time or in unison with a pair of electronic valves 38 that operate similarly to but are controlled separately from the mining jets 31, 32.

As shown in FIGS. 5 and 6, high pressure water is supplied to the drilling jets 31, 32 from a central water supply pipe 51 that extends along the length of, and within, the case 11. Each input hose 33 is associated with an independently controllable electronic valve 35. The supply pipe 51 feeds a manifold 52 that distributes the high pressure water to the input hoses 33. As shown in the embodiment of FIG. 6, the circular array of nozzles 32 behind the central nozzle 31 is subdivided into, in this example, three sub-arrays. The nozzles labelled Ai, Bi and Ci form a sub-array of generally equally spaced nozzles formed around the central nozzle 31. Nozzles labelled Aii, Bii and Cii form a second sub-array. Nozzles labelled Aiii, Biii and Ciii form a third sub-array. As previously mentioned, each sub-array is activated in sequence and repetitively to provide an optimised cutting action. In preferred methods, the jet nozzles in the mining array are 17 in number but only opposing pairs are activated at any given time. Water exiting the mining jets breaks down mineral resources and creates a slurry around the tool 10. The mining sub-system (B) in FIG. 3 is shown in more detail in FIGS. 7 and 8. The mining jet nozzle array in this embodiment includes a plurality of radially directed jet nozzles 71. Each nozzle 71 is associated with an electrically controlled valve 72. Each nozzle 71 is supplied with high pressure water from an individual supply hose 73. The electrical wiring required to operate each of the valves 72 is contained in a protective harness 74 carried (with reference to the direction of forward travel) ahead of the circular array of nozzles 71 and within the case. In preferred embodiments, the harness 74 is insulated and waterproofed even though this internal space within the case 11 is dry.

The slurry pumping sub-system (C) in FIG. 3 is shown in FIGS. 9 and 10. In preferred embodiments, the pumping sub-system comprises a pair of laterally directed throats or inlets 91. Each throat 91 cooperates with an adjacent slurry inlet 14 formed in the case 11. The throats 91 each supply an individual venturi 92. The venturi 92 comprises an intermediate necked portion 93 that is adjacent to the inner wall of the case. Slurry material in the area of the slurry inlets 14 are drawn into the venturi 92 by the effect of a motive fluid or water jet 94. Each slurry pumping jet 94 includes a tip or nozzle 95 located within the inlet 91 and directed toward the mouth or low pressure zone of the venturi 92. Each pumping jet 94 is controlled by an individual electronically controlled valve 96. The jets 94 are supplied with high pressure water from the main high pressure water supply pipe 51 that extends longitudinally within the casing. The slurry pumping jets are supplied with high pressure water from the main water supply pipe 51.

The operation of the tool 10 is suggested by the schematic illustration of FIGS. 11 and 12. As shown in FIG. 11, the tool 10 has been inserted into a coal seam 200 through a pre-drilled bore, for example, a 600 mm bore 110. Material can be ablated in front of the nose cone 12 by the array of drilling jets 31, 32 located in the nose cone 12. As shown in FIG. 12, the tool 10 can be selectively propelled, manoeuvred and steered by the lateral guide jets 113. As follows the lateral guide jets 113 may also be used to guide slurry into the inlets 14, thus working in cooperation with the slurry pumping jets 94. Thereafter, the drilling sub-system is deactivated. The mineral slurry is created by the mining jet array and then drawn into the slurry inlets 14 by the action of the slurry pumping jets 94. The guide jets 113 may also help guide the slurry into the area of the inlets 14. In preferred methodologies, after a quantity of slurry has been extracted, the entire tool is retracted and the mining and pumping operations are repeated.

Although the invention has been described with reference to specific examples, it will be appreciated by those skilled in the art that the invention may be embodied in many other forms.

Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment, but many. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner, as would be apparent to one of ordinary skill in the art from this disclosure, in one or more embodiments.

Similarly it should be appreciated that in the above description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited.

Thus, while there has been described what are believed to be the preferred embodiments of the invention, those skilled in the art will recognize that other and further modifications may be made thereto without departing from the spirit of the invention, and it is intended to claim all such changes and modifications as fall within the scope of the invention.

While the present invention has been disclosed with reference to particular details of construction, these should be understood as having been provided by way of example and not as limitations to the scope or spirit of the invention.

The term ‘comprising’ as used in this specification and claims means ‘consisting at least in part of”. When interpreting statements in this specification and claims which include the term ‘comprising’, other features besides the features prefaced by this term in each statement can also be present. Related terms such as ‘comprise’ and ‘comprised’ are to be interpreted in a similar manner.

As used herein the term “(s)” following a noun means the plural and/or singular form of that noun.

As used herein the term “and/or” means “and” or “or”, or where the context allows both.

Claims

1. A bore hole tool for removing minerals from the earth, the tool comprising: a case having a nose, the case containing:a drilling sub-system for ablating material in front of the nose of the case providing a space into which the tool can be advanced;a mining sub-system for breaking down mineral resources and creating a slurry around the tool; anda pumping sub-system for pumping the slurry created by the mining sub-system away from the case.

2. A bore hole tool as claimed in claim 1, wherein the case comprises a substantially longitudinal component in which the drilling sub-system is located near the nose of the case, and the pumping sub-system and the mining sub-system are located behind the drilling sub-system towards a tail of the case.

3. A bore hole tool as claimed in claim 1, wherein the case is connectable to a drill string.

4. A bore hole tool as claimed in claim 3, wherein the case and drill string are flexible so as to bend through an approximately 50 m radius.

5. A bore hole tool as claimed in claim 3, further comprising a flexible joint interposed between the case and the drill string.

6. A bore hole tool as claimed in claim 1, wherein the drilling sub-system comprises one or more drilling jet nozzles.

7. A bore hole tool as claimed in claim 6, wherein the one or more drilling jet nozzles comprises a centrally located and forward facing drilling jet nozzle.

8. A bore hole tool as claimed in claim 7, wherein the one or more drilling jet nozzles further comprises an array of drilling jet nozzles located behind the centrally located and forward facing drilling jet nozzle.

9. A bore hole tool as claimed in claim 1, wherein the mining sub-system comprises a plurality of radially directed jet nozzles.

10. A bore hole tool as claimed in claim 1, wherein the pumping sub-system comprises a laterally directed throat for receiving the slurry, the throat being adapted to cooperate with an adjacent slurry inlet formed in the case, the throat being further adapted to supply a venturi, the venturi comprising a low pressure zone and a slurry pumping jet with a nozzle located within the throat and directed toward the low pressure zone.

11. A bore hole tool as claimed in claim 1, further comprising one or more guide jets for propelling and/or manoeuvring the tool.

12. A bore hole tool for removing minerals from the earth, the tool comprising: a case having a nose, the case containing:a drilling sub-system for ablating material in front of and around the nose of the case providing a space into which the tool can be advanced, the drilling sub-system comprising a centrally located and forward facing drilling jet nozzle and an array of drilling jet nozzles located behind the centrally located and forward facing drilling jet nozzle;a mining sub-system for breaking down mineral resources and creating a slurry around the tool, the mining sub-system comprising a plurality of radially directed jet nozzles; anda pumping sub-system for pumping the slurry created by the mining sub-system towards the earth's surface.

13. A method of removing minerals from the earth, the method comprising: (a) providing a bore hole tool as claimed in claim 1;(b) ablating material in front of the nose of the case to provide a space into which the tool can be advanced;(c) breaking down mineral resources and creating a slurry around the tool; and(d) pumping the slurry created by the mining sub-system away from the case.

14. A method as claimed in claim 13, wherein the bore hole tool comprises one or more drilling jet nozzles and step (b) comprises using the one or more drilling jet nozzles to ablate material in front of and around the nose of the case.

15. A method as claimed in claim 14, wherein the one or more drilling jet nozzles comprise a central nozzle, and the method comprises activating the central nozzle continuously during step (b).

16. A method as claimed in claim 15, wherein the drilling sub-system further comprises an array of drilling jet nozzles located behind the central nozzle, the array of drilling jet nozzles being subdivided into sub-arrays, and wherein the method comprises activating the sub-arrays in sequence, one sub-array at a time to produce a circular jetting action during step (b).

17. A method as claimed in claim 16, wherein the tool comprises a plurality of radially directed jet nozzles, the nozzles directing water outwardly from the tool to carry out step (c).

18. A method as claimed in claim 13, wherein the pumping sub-system comprises a laterally directed throat and a venturi, the venturi having a low pressure zone and a slurry pumping jet with a nozzle located within the throat and directed toward the low pressure zone, and wherein step (d) comprises directing fluid towards the low pressure zone with the nozzle, thereby drawing slurry through the throat.

19. A method as claimed in claim 13, wherein the tool comprises one or more guides jets and the method further comprises activating the one or more guide jets for changing the direction of the tool.

20. A method as claimed in claim 19, wherein the method further comprises using the one or more guide jets to guide slurry into the slurry inlets.