EP3854985A1

EP3854985A1 - Lengthwise section, flexible drill rod and method

Info

Publication number: EP3854985A1
Application number: EP20153219.9A
Authority: EP
Inventors: Samuli Verho; Annukka KOKKONEN; Laurent Demia; Guillaume NADDAF; Calixte BLANC-BERNARD
Original assignee: Sandvik Mining and Construction Oy; Sandvik Mining and Construction Lyon SAS
Current assignee: Sandvik Mining and Construction Oy; Sandvik Mining and Construction Lyon SAS
Priority date: 2020-01-22
Filing date: 2020-01-22
Publication date: 2021-07-28
Anticipated expiration: 2040-01-22
Also published as: PL3854985T3; EP3854985B1; FI3854985T3; MX2021000870A

Abstract

A lengthwise section (1) of a flexible drill rod (100), a flexible drill rod and a method. The lengthwise section comprises an outer tube (2), wherein at least part of the outer tube (2) is flexible in a transverse direction of the section (1). The section (1) further comprises an internal pipe (4) inside the outer tube (2) for managing flushing medium flow through the section (1). Connectors (5, 6) are arranged at the ends (7, 8) of the outer tube (2) and the internal pipe (4). The connectors (5, 6) are adapted to be connectable to each other so that a first connector (5) is attachable to a second connector (6) of another lengthwise section (1) of the flexible drill rod.

Description

BACKGROUND

The invention relates to a lengthwise section of a flexible drill rod.
The invention further relates to a flexible drill rod.
The invention still further relates to a method for managing a drilling or a maintenance of a flexible drill rod.
The need for continuous drilling arises especially in the low profile (LP) and extra low profile (XLP) mines where rock support is a critical part of the process. The height of the mine gallery may be as low as 1.2 meters. Due to the rock conditions it is necessary to install up to 2-6 meter long rock reinforcement bolts to the roof of the mine.
Since the drilled length required is much longer than the height of the mine, currently extension drilling by adding rods is used. Adding rods takes time, lowers the efficiency of the process and risks persons when adding rods are often done by hand. Due to the space restriction a mechanic rod handler has not been seen feasible or as effective as manual handling.
A document EP2896780 discloses a flexible drill rod for continuous drilling, in which adding of rods may be avoided. A problem with the flexible drill rod is that it is a quite expensive part, and thus its replacement causes high costs.

BRIEF DESCRIPTION

Viewed from a first aspect, there can be provided a lengthwise section of a flexible drill rod, the section comprising

an outer tube, wherein
at least part of the outer tube is flexible in a transverse direction of the section and
the section is rigid to enable transmitting torque and thrust needed for drilling, the section further comprising
an internal pipe inside the outer tube for managing flushing medium flow through the section,
the section comprising
a first connector arranged at a first end of the outer tube and the internal pipe, the first connector comprising at least one first connector element and at least one first pipe connector element,
a second connector arranged at a second end, opposite to said first end, of the outer tube and the internal pipe, the second connector comprising at least one second connector element and at least one second pipe connector element,
the first connector and the second connector being adapted to be connectable to each other so that the first connector is attachable to the second connector of another lengthwise section of the flexible drill rod, and
the connector elements establishing
a tube connection for transmitting torque for rotation of said sections, and
the pipe connector elements establishing
a pipe connection with an internal channel for allowing flushing medium flow in the internal pipe through said sections.

When a hole is drilled with a flexible drill rod, the front sections or those parts close to a drill bit of the flexible drilling rod are worn much quicker than back sections far from the drill bit. Now the lengthwise section makes it possible to change only those sections of the flexible drill rod that are worn or break, without need for replacing the whole length of the flexible drill rod. Thereby great savings in using flexible drilling rods may be achieved. Additionally, the length of the drilling rod may be tuned according to the wanted drilled hole length by adjusting the number of sections, i.e. by adding or removing the sections, in the drilling rod.
Viewed from a further aspect, there can be provided a flexible drill rod, comprising at least two lengthwise sections as claimed in any of the preceding claims, wherein the first connector of a first of said at least two lengthwise sections is attached to the second connector of a second of said at least two lengthwise sections.
Thereby a drill rod having exceptionally low expenses in its life cycle may be achieved.
Viewed from a still further aspect, there can be provided a method for managing a drilling or a maintenance of a flexible drill rod, the drill rod comprising plurality of the lengthwise sections of a flexible drill rod disclosed above, the method comprising

decoupling a worn-out or damaged lengthwise section from the drill rod by opening connection(s) of said lengthwise section, and
adding a substitutive lengthwise section in the drill rod by connecting connector(s) of said substitutive lengthwise section to connector(s) of at least one lengthwise section in the drill rod.

Thereby a method creating great saving in using flexible drill rods may be achieved.
The arrangement and the method are characterised by what is stated in the independent claims. Some other embodiments are characterised by what is stated in the other claims. Inventive embodiments are also disclosed in the specification and drawings of this patent application. The inventive content of the patent application may also be defined in other ways than defined in the following claims. The inventive content may also be formed of several separate inventions, especially if the invention is examined in the light of expressed or implicit sub-tasks or in view of obtained benefits or benefit groups. Some of the definitions contained in the following claims may then be unnecessary in view of the separate inventive ideas. Features of the different embodiments of the invention may, within the scope of the basic inventive idea, be applied to other embodiments.
In one embodiment, the outer tube comprises at least one corrugated cut extending through a wall of the outer tube in a transverse direction, wherein said at least one corrugated cut has a substantially spiral baseline extending in a circulating manner around the outer tube in the lengthwise direction of the section. An advantage is that a high flexibility of the drill rod may be achieved.
In one embodiment, the at least one first connector element is detachable connectable to said at least one second connector element of said another section. An advantage is that the sections can be decoupled without damaging thereof, and thus the decoupled section may be easily added to the same or another drill rod.
In one embodiment, the connectors comprise at least one locking system for preventing unintentional decoupling of the connectors. An advantage is that the reliability of the arrangement may be improved.
In one embodiment, the locking system is incorporated in at least one of the connectors. An advantage is that number of components relating to the drilling rod may be limited.
In one embodiment, the locking system comprises at least one standalone locking component. An advantage is that the state of the locking may be easily checked.
In one embodiment, the at least one first connector element and said at least one second connector element establishing the tube connection are identical. An advantage is that the manufacturing means of the connectors may be simplified.
In one embodiment, the connector elements comprise lengthwise directed extensions and gaps therebetween arranged around the connector, the gap dimensioned for receiving the extension. An advantage is that a simple way to transfer torque through some teeth between the lengthwise sections may be achieved.
In one embodiment, the pipe connector elements comprise a sealing arrangement adapted to seal the internal pipe connection. An advantage is that risk of bleeding or leaking of the inner pipe may be minimized.
In one embodiment, the flexible drill rod comprises a drill bit, the drill bit having a drill bit connector adapted to be detachable attachable to one of the connectors of the lengthwise section for transmitting torque for rotation from the lengthwise section to the drill bit, and for allowing flushing medium flow in the internal pipe from the lengthwise section to the drill bit. An advantage is that the lengthwise section is also possible to be attached to the drill bit.
In one embodiment, the flexible drill rod comprises a drill bit, the drill bit having a drill bit connector, and an adapter element comprising a third connector adapted to be detachable attachable to the drill bit, and a fourth connector adapted to be detachable attachable to one of the connectors of the lengthwise section, the adapter element being adapted for transmitting torque for rotation from the lengthwise section to the drill bit, and for allowing flushing medium flow in the internal pipe from the lengthwise section to the drill bit. An advantage is that the adapter may allow a drill bit without first or second connector to be attached to the lengthwise section.
In one embodiment, the method comprises decoupling the first lengthwise section behind a drill bit and adding the substitutive lengthwise section to the opposite end of the drill rod. An advantage is that a uniform wear of the drill rod may be achieved after several drilling operations.
In one embodiment, the method comprises adding the decoupled first lengthwise section as the substitutive lengthwise section to the opposite end of the drill rod. An advantage is that the lengthwise section can still be utilized in the drill rod but in section less susceptible to wear.

BRIEF DESCRIPTION OF FIGURES

Some embodiments illustrating the present disclosure are described in more detail in the attached drawings, in which

Figure 1a is a schematic view of two lengthwise sections of a flexible drill rod,
Figure 1b is a schematic side view of the lengthwise sections shown in Figure 1a in partial cross-section,
Figure 2a is a schematic view of a part of another flexible drill rod,
Figure 2b is a schematic view of the assembled flexible drill rod shown in Figure 2a,
Figure 2c is a schematic side view of the flexible drill rod shown in Figure 2a in partial cross-section,
Figure 2d is a schematic side view of a detail of the flexible drill rod shown in Figure 2a in partial cross-section,
Figure 3 is a schematic side view of a drilling machine, and
Figure 4 illustrates a method for managing a drilling or a maintenance of a flexible drill rod.

In the figures, some embodiments are shown simplified for the sake of clarity. Similar parts are marked with the same reference numbers in the figures.

DETAILED DESCRIPTION

Figure 1a is a schematic view of two lengthwise sections of a flexible drill rod, and Figure 1b is a schematic side view of the lengthwise sections shown in Figure 1a in partial cross-section.
The lengthwise section 1 comprises an outer tube 2 and an internal pipe 4 inside the outer tube 2. At least part of the outer tube 2 is flexible to enable bending in a transverse direction of the section 1. The section 1 is sensibly rigid in rotation to enable transmitting torque and thrust needed for drilling, or pulling force for removing the drilling rod, the torque and thrust at least mainly transmitted by the outer tube 2.
The internal pipe 4 is adapted for managing flushing medium flow through the section 1 pumped from the machine to a drill bit. In an embodiment, the flushing medium is liquid, such as water. In another embodiment, the flushing medium is gas or gas mixture, such as air. In still another embodiment, the flushing medium is a mixture of liquid and gas, such as water and air. In still another embodiment, the flushing medium is a mixture of air and cuttings acting by air sucked from the drill bit to the machine for removing the cuttings from the drill bit. The internal pipe 4 has an ability to bend with the outer pipe 2.
The length of the section 1 may be selected e.g. in range of 0,5 meter to 1,5 meters, or even more.
The section 1 comprises a first connector 5 arranged at a first end 7 of the outer tube 2 and the internal pipe 4. The first connector comprises at least one first connector element 9 and at least one first pipe connector element 17.
Additionally, the section 1 comprises a second connector 6 arranged at a second end 8 that is opposite to the first end of the outer tube 2 and the internal pipe 4. The second connector 6 comprises at least one second connector element 10 and at least one second pipe connector element 18.
In an embodiment, the first and second connectors 5, 6 are manufactured separately and welded to the section. In another embodiment, the connectors may be attached to the section by fixing means, such as screws.
In an embodiment, the outer diameter of the outer tube 2 and the connectors 5, 6 is preferably below 30mm.
In an embodiment, the first connector 5 is arranged to establish a male connector and the second connector 6 is arranged to establish a female connector. The first connector 5 and the second connector 6 are designed so that a first connector 5 of a first lengthwise section 1 can be attached to a second connector 6 of a second lengthwise section 1. Thus, it is possible to build flexible drill rods 100 which are essentially longer than a single lengthwise section 1.
The connector elements 5, 6 establishes a tube connection 11 for transmitting torque and rotational movement over the connection from one lengthwise section to another one. The connector elements also transmit longitudinal movements. In some embodiments, such as one shown in Figures 1a - 1b, the connector elements 9, 10 comprise lengthwise directed extensions 14 and gaps or bays 15 therebetween arranged around the connector 5, 6. The extensions 14 and gaps 15 arranged in the first connector 5 are dimensioned so that they may receive gaps and extensions of the second connector, respectively. According to an idea, the connection looks like a flute assembly.
The pipe connector elements 17, 18 comprises internal channels that establish a pipe connection 12 allowing flushing medium flow in the internal pipe 4 from one lengthwise section to another one.
The tube connection 11 and the pipe connection 12 can be opened and the lengthwise sections 1 separated from each other. In an embodiment, the connectors 5, 6 comprise at least one locking system 13 for preventing unintentional decoupling of the connectors 5, 6. The locking system 13 comprises in the second connector element 10 a knob 21 that is arranged at an end of a flexible arm 22. In the first connector element 9 there is a pit or groove 23. The locking system 13 locks the connector elements 9, 10 together by forcing the knob 21 in the pit 23. It is to be noted that the design and number of the locking systems 13 may vary. For instance, two locking systems 13 can be arranged on opposite sides of the circumference of the connectors.
The first connector element 9 may be detached from the second connector element 10 without breaking the lengthwise sections 1 or the connector elements. For instance, in the embodiment shown in Figures 1a - 1b, the knob 21 may be removed from the corresponding pit 23 by bending the flexible arm 22 outwards. In an embodiment, the locking system can be un-lock with a screw driver or a specific tool. In another embodiment, the locking system can be un-lock manually.
In an embodiment, the pipe connector elements 17, 18 comprises a sealing arrangement 19 that is adapted to seal the pipe connection 12 in order to prevent flushing medium to leak out from the internal pipe 4. The sealing arrangement may comprise e.g. at least one O-ring (as shown in figure 1b) or some another sealing element. In an embodiment, the sealing arrangement automatically seal the pipe connection 12 as the connectors 5, 6 are attached to each other.
In an embodiment, the flexibility of the outer tube 2 is created by at least one cut 3, such as a corrugated cut, that extends through a wall of the outer tube 2 in a transverse direction thereof. The corrugated cut 3 may have a substantially spiral baseline extending in a circulating manner around the outer tube 2 in the lengthwise direction of the section 1. In an embodiment, the corrugated cut 3 is arranged to deviate from its baseline on both sides of the baseline forming a cut of a substantially corrugated shape spiraling along the outer tube 2.
In an embodiment, the pipe connector elements 17, 18 are fixed to and rotated with the first and second connector elements 9, 10 and the outer pipe 2. Also the internal pipe 4 is rotating with the connector elements 9, 10 and the outer pipe 2. In another embodiment, the pipe connector elements 17, 18 are not fixed to the second connector elements 9, 10 and the outer pipe 2. Then, at least in principle, the pipe connector elements 17, 18 and the internal pipe 4 is able to rotate in relation to the outer tube 2. However, there are no apparatus forcing the internal pipe to rotate.
A flexible drill rod 100 may be construed by connecting required number (at least two) of lengthwise sections 1 in succession and arranging a drill bit therein. Thus, the length of the drill rod 100 may be adjusted by selecting the number of the lengthwise sections 1 arranged in the drill rod 100.
Figure 2a is a schematic view of a section of another flexible drill rod, Figure 2b is a schematic view of the flexible drill rod shown in Figure 2a, Figure 2c is a schematic side view of the flexible drill rod shown in Figure 2a in partial cross-section, and Figure 2d is a schematic side view of a detail of the flexible drill rod shown in Figure 2a in partial cross-section.
In an embodiment, such as shown in Figures 2a - 2c, the connector elements 9, 10 that transfers the torque, i.e. establishes the tube connection 11, are at least largely identical.
In one embodiment, the locking system 13 comprises at least one standalone locking component 20. In the embodiment shown in Figures 2a - 2d, the standalone locking component 20 has a C-shape of section of a circle. The locking component 20 is flexible so that it can be expanded and arranged around the first and the second connector 5, 6. Said first and second connectors 5, 6 have sections of grooves 24 on their outer perimeter. The sections of grooves 24 create a circumferential groove around the tube connection when the connectors 5, 6 are connected to each other. As the locking component 20 is aligned in the groove, it prevents separation of the lengthwise sections 1. The lengthwise sections 1 can be detached after the locking component 20 is removed from the groove, e.g. manually or with a tool.
In an embodiment, the flexible drill rod 100 comprises a drill bit 16. In an embodiment, such as shown in Figures 2a - 2d, the drill bit 16 has a drill bit connector 25 adapted to be detachable attachable directly to a lengthwise section 1. The drill bit connector 25 transmits torque from the lengthwise section 1 to the drill bit 16. The drill bit connector 25 further comprises a pipe connection that allows flushing medium flow in the internal pipe 4 from the lengthwise section to the drill bit 16.
In another embodiment, there is an adapter element 30 that is arrangeable between a lengthwise section 1 and the drill bit 16. The adapter element comprises a third connector 31 for detachable attachment to the drill bit 16, and a fourth connector 32 adapted to be detachable attachable to one of the connectors 5, 6 of the lengthwise section 1. The adapter element transmits torque from the lengthwise section to the drill bit and leads flushing medium flow from the internal pipe 4 to the drill bit 16 or vice versa.
Figure 2d is showing the connection between two lengthwise sections in a more detailed way. An arrow is showing flow of flushing medium through the lengthwise sections 1 and the pipe connection 12. The pipe connection is sealed with a seal 29 that is an O-ring. It is to be noted that the sealing arrangement 19 may be realized many alternative ways.
In the end opposite to the drill bit end, there is a connector (not shown) that connects the internal pipe 4 to a supply hose (not shown) for supplying flushing medium fluid in the internal pipe 4. In an embodiment, the connector comprises a turning joint that allows the supply hose being unrotating while the internal pipe 4 is rotating.
Figure 3 is a schematic side view of a mine drilling machine.
The mine drilling machine 26 has at least one drilling arrangement 28 that comprises a flexible drill rod 100 discussed in this description.
The mine drilling machine 26 may comprise a boom 27 that is provided with the drilling arrangement 28. This particular type of a mine drilling machine 26 is especially suitable for tunnels and other drilling spaces of limited height, such as low profile mines.
The mine drilling machine 26 may comprise not only drilling arrangement(s) 28 with the flexible drill rod 100, but also other type of mining equipment.
Figure 4 illustrates a method for managing a drilling or a maintenance of a flexible drill rod.
In the method, it is decoupled a worn-out or damaged lengthwise section 1 from the drill rod 100 by opening 401 connection (s) 11, 12 of the lengthwise section to be decoupled. Then, one or more substitutive lengthwise section(s) is/are added 402 in the drill rod 100. The connector (s) 5, 6 of the substitutive lengthwise section(s) are connected 403 to connector (s) 5, 6 of the lengthwise section(s) in the drill rod (100).
In an embodiment of the method, it is changed the first lengthwise section 1 behind a drill bit 16 and added the substitutive lengthwise section 1 to the opposite end of the drill rod 100, i.e. the last lengthwise section 1 counted from the drill bit 16. In an embodiment, the decoupled first lengthwise section 1 is used as the substitutive lengthwise section 1 that is added to the opposite end of the drill rod 100. However, in another embodiment, the decoupled first lengthwise section 1 is not attached back to the drill rod 100, but the sent e.g. to be repaired.
In an embodiment, the length of the drill rod 100 is adjusted by adding or removing lengthwise sections 1 in the drill rod 100.
It is to be noted that it is possible to attach or detach not only one but two or even more lengthwise sections 1 at the same time.
The invention is not limited solely to the embodiments described above, but instead many variations are possible within the scope of the inventive concept defined by the claims below. The variation may deal with the connector shape, the locking system or also the internal pipe connection, for instance. Within the scope of the inventive concept the attributes of different embodiments and applications can be used in conjunction with or replace the attributes of another embodiment or application.
The drawings and the related description are only intended to illustrate the idea of the invention. The invention may vary in detail within the scope of the inventive idea defined in the following claims.

REFERENCE SYMBOLS

1: lengthwise section
2: outer tube
3: corrugated cut
4: internal pipe
5: first connector
6: second connector
7: first end
8: second end
9: first connector element
10: second connector element
11: tube connection
12: pipe connection
13: locking system
14: extension
15: gap
16: drill bit
17: first pipe connector element
18: second pipe connector element
19: sealing arrangement
20: standalone locking component
21: knob
22: arm
23: pit
24: groove
25: drill bit connector
26: drilling machine
27: boom
28: drilling arrangement
29: seal
30: adapter element
31: third connector
32: fourth connector
100: flexible drill rod
401-403: method steps

Claims

A lengthwise section (1) of a flexible drill rod (100), the section comprising
- an outer tube (2), wherein

- at least part of the outer tube (2) is flexible in a transverse direction of the section (1) and

- the section (1) is rigid to enable transmitting torque and thrust needed for drilling, the section (1) further comprising

- an internal pipe (4) inside the outer tube (2) for managing flushing medium flow through the section (1),
the section (1) comprising

- a first connector (5) arranged at a first end (7) of the outer tube (2) and the internal pipe (4), the first connector comprising at least one first connector element (9) and at least one first pipe connector element (17),

- a second connector (6) arranged at a second end (8), opposite to said first end, of the outer tube (2) and the internal pipe (4), the second connector comprising at least one second connector element (10) and at least one second pipe connector element (18),

- the first connector (5) and the second connector (6) being adapted to be connectable to each other so that the first connector (5) is attachable to the second connector (6) of another lengthwise section (1) of the flexible drill rod, and
the connector elements (9, 10) establishing

- a tube connection (11) for transmitting torque for rotation of said sections, and
the pipe connector elements (17, 18) establishing

- a pipe connection (12) with an internal channel for allowing flushing medium flow in the internal pipe (4) through said sections.
The lengthwise section as claimed in claim 1, wherein the outer tube (2) comprises
- at least one corrugated cut (3) extending through a wall of the outer tube (2) in a transverse direction, wherein

- said at least one corrugated cut (3) has a substantially spiral baseline extending in a circulating manner around the outer tube in the lengthwise direction of the section (1) .
The lengthwise section as claimed in claims 1 or 2, wherein said at least one first connector element (9) is detachable connectable to said at least one second connector element (10) of said another section.
The lengthwise section as claimed in any of the preceding claims, wherein the connectors (5, 6) comprise at least one locking system (13) for preventing unintentional decoupling of the connectors (5, 6).
The lengthwise section as claimed in claim 4, wherein the locking system (13, 20 ,21) is incorporated in at least one of the connectors (5, 6).
The lengthwise section as claimed in claim 4, wherein the locking system (13) comprises at least one standalone locking component (20).
The lengthwise section as claimed in any of the preceding claims, wherein said at least one first connector element (9) and said at least one second connector element (10) establishing the tube connection (11) are identical.
The lengthwise section as claimed in claim 7, wherein the connector elements (9, 10) comprise lengthwise directed extensions (14) and gaps (15) therebetween arranged around the connector (5, 6), the gap (15) dimensioned for receiving the extension (14).
The lengthwise section as claimed in any of the preceding claims, wherein the pipe connector elements (17, 18) comprises a sealing arrangement adapted to seal the pipe connection (12).
A flexible drill rod, comprising at least two lengthwise sections (1) as claimed in any of the preceding claims, wherein the first connector (5) of a first of said at least two lengthwise sections is attached to the second connector (6) of a second of said at least two lengthwise sections.
The flexible drill rod as claimed in claim 10, comprising a drill bit (16), the drill bit (16) having a drill bit connector (25) adapted to be detachable attachable to one of the connectors (5, 6) of the lengthwise section (1) for transmitting torque for rotation from the lengthwise section (1) to the drill bit (16), and for allowing flushing medium flow in the internal pipe (4) from the lengthwise section to the drill bit (16) or vice versa.
The flexible drill rod as claimed in claim 10, comprising
- a drill bit (16), the drill bit (16) having a drill bit connector (25), and

- an adapter element (30) comprising
-- a third connector (31) adapted to be detachable attachable to the drill bit (16), and

-- a fourth connector (32) adapted to be detachable attachable to one of the connectors (5, 6) of the lengthwise section (1),

- the adapter element (30) being adapted for transmitting torque for rotation from the lengthwise section to the drill bit (16), and for allowing flushing medium flow in the internal pipe (4) from the lengthwise section to the drill bit (16) .
A method for managing a drilling or a maintenance of a flexible drill rod (100), the drill rod (100) comprising plurality of the lengthwise sections (1) of a flexible drill rod claimed in any of claims 1 - 9, the method comprising
- decoupling a worn-out or damaged lengthwise section (1) from the drill rod (100) by opening (401) connection(s) (11, 12) of said lengthwise section, and

- adding (402) a substitutive lengthwise section (1) in the drill rod (100) by connecting (403) connector(s) (5, 6) of said substitutive lengthwise section to connector(s) (5, 6) of at least one lengthwise section in the drill rod (100) .
The method as claimed in claim 13, comprising
- decoupling the first lengthwise section (1) behind a drill bit (16), and

- adding the substitutive lengthwise section (1) to the opposite end of the drill rod (100).
The method as claimed in claim 14, comprising
- adding the decoupled first lengthwise section (1) as the substitutive lengthwise section (1) to the opposite end of the drill rod (100).