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EP-4735726-A1 - A DRILLING APPARATUS AND A METHOD FOR CONTROLLING A DRILLING APPARATUS

EP4735726A1EP 4735726 A1EP4735726 A1EP 4735726A1EP-4735726-A1

Abstract

A drilling apparatus comprising a drill string, a drill head, and a sealing arrangement formed around the drill string. The sealing arrangement and the drill string are movable relative to one another. The sealing arrangement comprises: a radial sealing element, configured to seal between the sealing arrangement and the drill string, a covering body, formed around the drill string and defining a cavity therethrough, with an opening at an end portion. The covering body comprising: an axial sealing element configured to seal the cavity such that it forms a first volume delimited by the covering body and the mineral substrate. The drilling apparatus comprises a fluid transfer arrangement comprising a first fluid channel in fluid communication with a volume containing the drill head when the sealing arrangement forms the first volume, and a second fluid channel in fluid communication with the first volume.

Inventors

  • JAKOBSSON, Erik
  • Merkel, Harald Franz Arno
  • SKYTTEDAL, André

Assignees

  • Epiroc Rock Drills Aktiebolag

Dates

Publication Date
20260506
Application Date
20230629

Claims (14)

  1. 1. A drilling apparatus (4), said drilling apparatus (4) comprising: - a drill string (6), extending along a central axis (X), - a drill head (8), located at an end of said drill string (6) and configured to break a mineral substrate (10), - a sealing arrangement (12) formed around the central axis (X) of said drill string (6), wherein said sealing arrangement (12) and said drill string (6) are movable relative to one another, said movement being directed along the central axis (X) of said drill string (6), said sealing arrangement (12) comprising: - a radial sealing element (14), configured to seal between said sealing arrangement (12) and said drill string (6), - a first covering body (16), formed around the central axis (X) of said drill string (6), and defining a first cavity (18) therethrough, with a first opening (20) at an end portion of said first covering body (16) for said drill head (8), said first covering body (16) comprising: - a first axial sealing element (22) associated with said first opening (20) and configured to seal said first cavity (18) towards said mineral substrate (10) when said sealing arrangement (12) is positioned such that it forms a first volume (24) located at least partly inside said first cavity (18) and delimited by at least said first covering body (16) and said mineral substrate (10), wherein said drilling apparatus (4) comprises a fluid transfer arrangement (26), said fluid transfer arrangement (26) comprising a first fluid channel (28) in fluid communication with a volume containing said drill head (8) when said sealing arrangement (12) forms said first volume (24), and a second fluid channel (30) in fluid communication with said first volume (24).
  2. 2. The drilling apparatus (4) according to claim 1, wherein said fluid comprises a flushing fluid, wherein said flushing fluid comprises a liquid.
  3. 3. The drilling apparatus (4) according to any one of the preceding claims, wherein said fluid transfer arrangement (26) comprises a first pump (32) configured to pump said fluid through said first fluid channel (28).
  4. 4. The drilling apparatus (4) according to any one of the preceding claims, wherein said fluid transfer arrangement (26) comprises a second pump (34) configured to pump said fluid through said second fluid channel (30).
  5. 5. The drilling apparatus (4) according to any one of the preceding claims, wherein said fluid transfer arrangement (26) is configured to generate a pressure in said first volume (24) higher than an atmospheric pressure.
  6. 6. The drilling apparatus (4) according to any one of claims 1-4, wherein said fluid transfer arrangement (26) is configured to generate a pressure in said first volume (24) lower than an atmospheric pressure.
  7. 7. The drilling apparatus (4) according to any one of the preceding claims, wherein said sealing arrangement (12) comprises a second covering body (36) formed around the central axis (X) of said drill string (6), and defining a second cavity (38) therethrough, with a second opening (40) at an end portion of said second covering body (36) for said drill head (8), said second covering body (36) comprising: - a second axial sealing element (42), associated with said second opening (40) and configured to seal said second cavity (38) towards said mineral substrate (10) when said sealing arrangement (12) is positioned such that it forms a second volume (44) surrounded by said first volume (24) and delimited by said second covering body (36) and said mineral substrate (10).
  8. 8. The drilling apparatus (4) according to claim 7, wherein said fluid transfer arrangement (26) is configured to generate a pressure in said second volume (44) greater than a pressure in said first volume (24).
  9. 9. The drilling apparatus (4) according to any one of claims 7-8, wherein said sealing arrangement (26) comprises at least one spring element (45) extending between the first covering body (16) and said second covering body (36) and configured to bias said second covering body (36) towards said mineral substrate (10).
  10. 10. The drilling apparatus (4) according to any one of the preceding claims, wherein said drilling apparatus (4) comprises an actuation arrangement (46) configured to move said sealing arrangement (12) along the central axis (X) of said drill string (6) towards said mineral substrate (10).
  11. 11. The drilling apparatus (4) according to any one of the preceding claims, wherein said second fluid channel (30) is in fluid communication with said first volume (24) via a hole (48) formed in said first covering body (16).
  12. 12. The drilling apparatus (4) according to any one of the preceding claims, wherein said first fluid channel (28) and said second fluid channel (30) are in fluid communication with a reservoir (50) and said fluid transfer arrangement (26) is configured to circulate fluid between a volume enclosed by said first volume (24) and said reservoir (50).
  13. 13. A drill rig (2) comprising the drilling apparatus (4) according to any one of the preceding claims.
  14. 14. A method of controlling the drilling apparatus (4) according to any one of claims 1- 12, said method comprising: - adjoining said sealing arrangement (12) with said mineral substrate (10) by moving said sealing arrangement (12) along the central axis (X) of said drill string (6) towards said mineral substrate (10), - supplying a fluid to a volume containing said drill head (8) via said fluid transfer arrangement (26) - controlling a pressure in a volume enclosed by said sealing arrangement (12) by controlling a fluid flow through said fluid transfer arrangement (26).

Description

A DRILLING APPARATUS AND A METHOD FOR CONTROLLING A DRILLING APPARATUS TECHNICAL FIELD The present disclosure concerns a drilling apparatus. The invention also concerns a method for controlling said drilling apparatus. The disclosed drilling apparatus and method may for example be applied in rock drilling, surface drilling, and blast hole drilling operations. BACKGROUND During rock drilling it is often necessary to supply a fluid towards the mineral substrate. Supply of fluid may be necessary to flush a drilled hole, to provide cooling, or may be necessary for the drill type. For example, plasma drilling electrodes must be submerged in a liquid. When a fluid is to be supplied for a drilling operation it is advantageous to contain the fluid such that fluid loss is mitigated. It is known to prepare the drill site to prevent such fluid loss, by lining the hole for example. However, for example, for operations where the drill site is temporary, such as in blast hole drilling, or when there is insufficient time for preparations, this may not be possible. It is therefore a need to develop improved technology relating to rock drilling. SUMMARY A primary objective of the present disclosure is to achieve an in at least some aspect improved drilling apparatus, drill rig and/or method. For example, it is an objective to achieve a drilling apparatus whereby a fluid can be sealed at the drill site which at least partially alleviates the drawbacks associated with prior art methods, such as long preparation and installation times. According to a first aspect of the disclosure, at least the primary object is achieved by an apparatus according to claim 1. Hence, there is provided a drilling apparatus comprising a drill string, extending along a central axis, a drill head, located at an end of the drill string and configured to break a mineral substrate, a sealing arrangement, formed around the central axis of the drill string, wherein the sealing arrangement and the drill string are movable relative to one another, the movement being directed along the central axis of the drill string, the sealing arrangement comprising a radial sealing element, configured to seal between the sealing arrangement and the drill string, a first covering body, formed around the central axis of the drill string, and defining a first cavity therethrough, with a first opening at an end portion of the first covering body for the drill head, the first covering body comprising a first axial sealing element associated with the first opening and configured to seal the first cavity towards the mineral substrate when the sealing arrangement is positioned such that it forms a first volume located at least partly inside the first cavity and delimited by at least the first covering body and the mineral substrate, wherein the drilling apparatus comprises a fluid transfer arrangement, the fluid transfer arrangement comprising a first fluid channel in fluid communication with a volume containing the drill head when the sealing arrangement forms the first volume, and a second fluid channel in fluid communication with the first volume. By providing a drilling apparatus having a sealing arrangement whereby the sealing arrangement and drill string are movable relative to one another it is possible to move the sealing arrangement relative to the drill string such that sealing may be ensured, and/or to move the drill string relative to the sealing arrangement such that a distance between the drill head and the mineral substrate may be adjusted whilst maintaining the sealing arrangement in sealing engagement with the mineral substrate. Furthermore, by having a first fluid channel in communication with a volume containing the drill head, and a second fluid channel in communication with a first volume formed by the first covering body and the mineral substrate it is possible to remove and supply fluid whilst maintaining the sealing arrangement in sealing engagement with the mineral substrate. Optionally, the fluid comprises a flushing fluid, wherein the flushing fluid comprises a liquid. The liquid may comprise water, an oil, or mixture of liquids, such as an oil-water emulsion. It could be advantageous to use a biopolymer oil, or any biodegradable oil. The liquid may contain impurities, for example the liquid may comprise saline water. By providing a flushing fluid comprising a liquid to the volume containing the drill head, as opposed to a gas, the removal of cuttings may be improved due to a higher viscosity, improved cooling may also be achieved, and it may be possible to use specific drilling means, such as plasma drilling whereby electrodes must be submerged in a liquid. Optionally, the drilling equipment comprises a drill head having at least two electrodes, a pulsed power generator for generating high voltage current pulses, whereby the drill head breaks the mineral substrate and forms a hole in the mineral substrate, by passing a high voltage current pulse