A method of controlling a drilling equipment

Abstract

A method of controlling a drilling equipment, the drilling equipment comprises a drill head having at least two electrodes, a pulsed power generator for generating high voltage current pulses, and a fluid removal system comprising a first fluid removal device, and the method comprises controlling the drilling equipment in a first operating state during a drill operation, in which first operating state the drill head breaks a mineral substrate and forms a hole in the mineral substrate, and controlling the drilling equipment in a second operating state during a fluid evacuation operation subsequent to the drill operation, in which second operating state the first fluid removal device removes a liquid from the hole formed in the mineral substrate

Description

[0001] A METHOD OF CONTROLLING A DRILLING EQUIPMENT

[0002] TECHNICAL FIELD

[0003] The present disclosure concerns a method for controlling a drilling equipment. The invention also concerns a drilling equipment and a drill rig. The disclosed method and drilling equipment may for example be applied in rock drilling and surface drilling operations.

[0004] BACKGROUND

[0005] During rock drilling it is often necessary to supply a fluid towards the mineral substrate to be drilled; supply of fluid may be necessary to flush a drilled hole. In surface drilling operations, when such a fluid comprises a liquid, the liquid will remain in the drilled hole if no further action is taken. In drilling applications such as blast hole drilling, where a number of drill operations are to be performed, this amount of remaining liquid can be significant and leaving such an amount of liquid down hole can be costly. Remaining liquid can also be problematic in cases where blasting is to be performed subsequent to the drill operation. Blasting comprises the use of explosive agents to fracture the mineral substrate. Explosive agents exist which can be used in wet conditions; however, dry explosive agents are cheaper and so their use is preferable.

[0006] It is possible to use external pumping equipment for fluid evacuation, e.g., from a drilled hole of a mineral substrate. However, installation and operation of the external pumping equipment will take additional time and require additional manual work to be performed. Where an external pumping equipment is to be used, after a drill operation is complete, the drilling equipment must first be removed and then the pumping equipment inserted before fluid evacuation may begin.

[0007] SUMMARY

[0008] A primary objective of the present disclosure is to achieve an in at least some aspect improved method for controlling a drilling equipment. In particular, it is an objective to achieve a method for controlling a drilling equipment which alleviates the drawbacks associated with prior art methods, such as leaving liquid remaining within the hole formed in the mineral substrate after a drill operation, or the necessity to use an external pumping equipment.

[0009] According to a first aspect of the disclosure, at least the primary object is achieved by a method of controlling a drilling equipment according to claim 1. The drilling equipment comprises a drill head having at least two electrodes, a pulsed power generator for generating high voltage current pulses, and a fluid removal system comprising a first fluid removal device, and the method comprises controlling the drilling equipment in a first operating state during a drill operation, in which first operating state the drill head breaks a mineral substrate and forms a hole in the mineral substrate, by passing a high voltage current pulse generated by the pulsed power generator between the at least two electrodes via the mineral substrate, and controlling the drilling equipment in a second operating state during a fluid evacuation operation subsequent to the drill operation, in which second operating state the first fluid removal device removes a liquid from the hole formed in the mineral substrate. The method may be a computer-implemented method performed by an electronic control unit.

[0010] By providing a drilling equipment having a fluid removal system and performing a method in which the drilling equipment is operated in the second operating state after a drill operation, it is possible to remove at least some of the liquid necessary for the drill operation after the completion thereof. By removing the liquid from the hole in the mineral substrate, it may be possible to reuse the liquid, for example for a subsequent drill operation. Additionally, by removing the liquid from the hole it may then be possible to use dry explosives, or to perform other operations which are not possible in a liquid rich environment. The liquid may typically be a liquid used as a flushing fluid during the drill operation. Alternatively, the liquid may be used for electrically insulating or cooling.

[0011] Optionally, in the second operating state the drill head does not break the mineral substrate. Hence, in the second operating state, the drilling equipment may be controlled not to pass any high voltage current pulses between the at least two electrodes.

[0012] Optionally, the drilling equipment further comprises a fluid supply system, wherein, in the first operating state, the fluid supply system supplies the liquid to the hole formed in the mineral substrate. By supplying a liquid to the hole formed in the mineral substrate during the drill operation, it is possible to replace a liquid that has been removed from the mineral substrate, either intentionally, by way of a fluid removal device whereby a flushing function may be achieved, or unintentionally, in the case of seepage or the like.

[0013] Optionally, the fluid removal system comprises a second fluid removal device, wherein the second fluid removal device removes the liquid from the hole formed in the mineral substrate in the first operating state and does not remove the liquid from the hole formed in the mineral substrate in the second operating state. By providing a second fluid removal device that removes liquid from the hole formed in the mineral substrate during the drill operation it is possible to size and adapt the first and second fluid removal devices for each of the operations. For example, during the drill operation the liquid will contain rock particles due to the breaking of the mineral substrate, which may be removed by the second fluid removal device, whilst during the fluid evacuation operation, since the drill operation has stopped, and the second fluid removal device has already removed at least some of the rock particles, the liquid will contain less rock particles. Thus, the first fluid removal device may be more suited for the removal of liquid, whilst the second fluid removal device may be more suited for the removal of both liquid and rock fragments. The second removal device may transfer the liquid out of the hole formed in the mineral substrate via a line or conduit at least partially separate from that of the first fluid removal device. By using the first fluid removal device and second removal device to transfer the liquid via separate lines, it may be possible to transfer fluid containing more rock particles to a first location during a drill operation, and to transfer fluid containing less rock particles to a second location during a fluid evacuation operation.

[0014] Optionally, the method further comprises automatically activating the second operating state when the first operating state ends. By automatically activating the second operating state after the first operating state ends no additional manual work is necessary.

[0015] Optionally, the drilling equipment further comprises a fluid supply system and the method comprises controlling the drilling equipment in a third operating state during a cleaning operation, in which third operating state the fluid supply system supplies the liquid to the hole formed in the mineral substrate, and the second fluid removal device removes the liquid from the hole. The method may further comprise, when the first operating state ends, automatically activating the third operating state. By providing a third operating state whereby the liquid is cleaned it is possible to further remove at least some rock particles using the second fluid removal device after a drill operation. By providing a cleaning operation before the fluid evacuation operation it is therefore possible to minimize the number of rock particles to be removed by the first fluid transfer device. By automatically activating the third operating state after an end of the first operating state, no additional manual work is necessary.

[0016] Optionally, the method further comprises automatically activating the second operating state after the third operating state has been active for a fixed period of time, such as a predetermined fixed period of time. The fixed period of time may be a period of time sufficient to remove all of the rock particles from the liquid to be removed in the second operating state. Alternatively, the fixed period of time may be sufficient to remove at least some of the rock particles from the liquid. By controlling the drilling equipment in the third operating state for a fixed period of time it can thus be ensured that the first fluid removal device does not need to remove all of the rock particles which are remaining in the liquid after the drill operation. By automatically activating the second operating state after the third operating state ends, no additional manual work is necessary.

[0017] Optionally, the method further comprises, in the third operating state, determining a concentration of rock fragments in the removed liquid, and the method further comprises automatically activating the second operating state when the concentration of rock fragments in the removed liquid is below a threshold level. The threshold level may indicate that there are no rock fragments remaining in the liquid. Alternatively, the threshold level may indicate that at least some of the rock fragments have been removed from the liquid. By controlling the drilling equipment in the third operating state until a concentration of rock fragments in the removed liquid is below a threshold level it can be more accurately ensured that the first fluid removal device does not need to remove all of the rock particles which are remaining in the liquid after the drill operation. The concentration of rock fragments may relate to all of the rock fragments which are present in the liquid, or alternatively the concentration of rock fragments may relate to a single material, or only some of the materials that may be present in the liquid, said materials having a density, or a specific chemical composition or crystal structure, or any other attribute which may present a benefit for removal in the cleaning operation as opposed to the drying operation. By automatically activating the second operating state when the concentration of rock fragments in the removed liquid is below a threshold level no additional manual work is necessary. Optionally, the method further comprises automatically deactivating the second operating state after a fixed period of time, such as a predetermined fixed period of time. The fixed period of time may be a period of time sufficient to remove the liquid from the hole formed in the mineral substrate. Alternatively, the fixed period of time may be sufficient to remove at least some of the liquid from the hole. By automatically deactivating the second operating state after a fixed period of time no additional manual work is necessary.

[0018] Optionally, the method further comprises determining a liquid level within the hole formed in the mineral substrate in the second operating state, and when the liquid level falls below a threshold liquid level, deactivating the second operating state. The threshold liquid level may be a liquid level indicating there is no liquid within the hole. Alternatively, the liquid level may indicate that the amount of liquid within the hole is negligible for future operations to be applied to the mineral substrate, or it may be a level which is indicative of an acceptable amount of liquid loss. By operating the drilling equipment in the second operating state until the liquid level falls below a threshold liquid level it can be more accurately ensured that the liquid has been sufficiently removed from the mineral substrate. By automatically deactivating the second operating state when the liquid level falls below a threshold liquid level no additional manual work is necessary.

[0019] According to a second aspect of the disclosure, at least the primary object is achieved by a drilling equipment according to claim 11. The drilling equipment comprises a pulsed power generator configured to generate high voltage current pulses, a drill head having at least two electrodes, configured to break a mineral substrate and form a hole in the mineral substrate in a first operating state of the drilling equipment, by passing a high voltage current pulse generated by the pulsed power generator between the at least two electrodes via the mineral substrate. It further comprises a fluid removal system, comprising a first fluid removal device configured to remove a liquid from the hole formed in the mineral substrate in a second operating state of the drilling equipment, and an electronic control unit configured to control the drilling equipment to the first operating state during a drill operation, and to the second operating state during a fluid evacuation operation subsequent to the drill operation.

[0020] By providing a drilling equipment having a fluid removal system and electronic control unit configured to operate the drilling equipment in a second operating state, to be performed after a drill operation, in which a fluid removal device of the fluid removal system removes a liquid from the hole formed in the mineral substrate, it is possible to remove at least some of the liquid present after the drill operation after the completion thereof. By removing the liquid from the hole, it is possible to reuse the liquid, for example for a subsequent drill operation. Additionally, by removing the liquid from the hole it is then possible to use dry explosives, or to perform other operations which are not possible in a liquid rich environment.

[0021] Optionally, the drilling equipment is configured such that it does not break the mineral substrate in the second operating state.

[0022] Optionally, the drilling equipment comprises a fluid supply system configured to supply a liquid towards the hole formed in the mineral substrate in the first operating state. The liquid may be a flushing fluid.

[0023] Optionally, the drilling equipment comprises a sensor configured to provide the electronic control unit with a measurement indicative of a concentration of rock fragments in the removed liquid. The measurement may comprise a liquid concentration. Alternatively, the measurement may comprise a concentration of a substance suspended in the liquid.

[0024] Optionally, the drilling equipment comprises a liquid level sensor configured to provide the control unit with a measurement indicative of a liquid level within the hole formed in the mineral substrate.

[0025] Optionally, the liquid level sensor comprises a pressure transducer.

[0026] Optionally, the liquid comprises water. The water may contain impurities, for example the water may comprise saline water.

[0027] Optionally, the liquid comprises an oil. The oil may be a biopolymer oil, an oil-water emulsion, or any oil suitable for the drill operation.

[0028] The electronic control unit of the drilling equipment according to the second aspect may be configured to perform the method according to any one of the embodiments of the first aspect. According to a third aspect of the disclosure at least the primary object is achieved by a drill rig comprising the drilling equipment according to the second aspect.

[0029] BRIEF DESCRIPTION OF THE DRAWINGS

[0030] With reference to the appended drawings, below follows a more detailed description of embodiments of the disclosure cited as examples.

[0031] Fig. 1 is a schematic diagram of a drill rig according to an embodiment of the disclosure,

[0032] Fig. 2 is a schematic diagram of a drilling equipment according to a first embodiment of the disclosure,

[0033] Fig. 3 is a schematic diagram of a drilling equipment according to a second embodiment of the disclosure,

[0034] Fig. 4 is a schematic diagram of a drilling equipment according to a third embodiment of the disclosure,

[0035] Fig. 5 is a perspective view of a drill head according to a fourth embodiment of the disclosure,

[0036] Fig. 6 is a flow chart illustrating a method according to embodiments of the disclosure.

[0037] The drawings show diagrammatic, exemplifying embodiments of the present disclosure and are thus not necessarily drawn to scale. It shall be understood that the embodiments shown and described are exemplifying and that the disclosure is not limited to these embodiments. It shall also be noted that some details in the drawings may be exaggerated in order to better describe and illustrate the disclosure. Like reference characters refer to like elements throughout the description, unless expressed otherwise.

[0038] DETAILED DESCRIPTION

[0039] Fig. 1 illustrates schematically a drill rig 2 comprising a drilling equipment 4. The drilling equipment 4 comprises a drill head 8 configured to break a mineral substrate 6 in the form of a rock. The mineral substrate 6 comprises a ground surface extending substantially in a horizontal plane below the drill rig 2. In alternative embodiments the mineral substrate 6 comprises a surface extending at an angle with respect to a horizontal plane. Alternatively, the mineral substrate 6 may comprise a wall surface, or a roof surface such that the drilling equipment is operating in a substantially horizontal, or inverted configuration. As the mineral substrate 6 is drilled, a hole 32 is formed in the mineral substrate 6. The hole 32 extends into the mineral substrate 6, the bottom of the hole 32 being defined by a drilled surface 15, whereby the depth of the hole 32 increases as the mineral substrate 6 is broken by the drill head 8 at the drilled surface 15. The hole 32 may have a circular cross-section or a square cross-section, or any cross-sectional shape, dependent on how the drill head 8 is configured.

[0040] The drilling equipment 4 extends along a central axis X, the central axis X of the drilling equipment 4 extending substantially perpendicular to the mineral substrate 6. In alternative embodiments, the central axis X of the drilling equipment 4 may extend at any inclination to the mineral substrate less than 90°.

[0041] The drill head 8 is configured to break a mineral substrate 6 in a first operating state of the drilling equipment 4. The drill head 8 comprises two electrodes 30 configured to break the mineral substrate 6 by passing of electric pulses between the two electrodes 30 via the mineral substrate 6, i.e. , by pulsed plasma drilling. The drill head may have more than two electrodes, for example three, four, or five electrodes. In some embodiments the drill head 8 may further comprise, rotary, top-hammer, or down-the-hole drilling means, or any known drilling means, which may be electrically, hydraulically, or pneumatically powered.

[0042] The drill rig 2 comprises an electrical power supply 34 which will be discussed in detail with Fig. 2. The drill rig 2 further comprises an actuated arm 36. The arm 36 may be actuated by hydraulic, pneumatic, or electrical means, for at least vertical positioning of the drilling equipment 4, such as in response to signals from one or more position sensors (not shown), or similar, sensing the distance between the drill head 8 and the mineral substrate 6 surface. The drill rig 2 further comprises ground engaging members 38 for moving the drill rig 2 in a direction parallel with the mineral substrate 6.

[0043] Fig. 2 illustrates schematically a drilling equipment 4 according to an embodiment of the disclosure. The drilling equipment 4 comprises a fluid removal system 11, comprising a first fluid removal device 20, located on a first fluid removal line 21, and a second fluid removal device 14, located on a second fluid removal line 17, configured to remove a liquid from the hole 32 formed in the mineral substrate 6. It is possible that the fluid removal system 11 comprises only one fluid removal device, and / or one fluid removal line. Additionally, it is possible that the fluid removal system comprises more than two fluid removal devices, and / or more than two fluid removal lines. The liquid may comprise water, or oil, or any liquid used to facilitate the drill operation. For example, the liquid may be any known liquid which may be used as a flushing fluid / and or an insulator for a drill operation.

[0044] The first fluid removal device 20 is configured to remove a liquid from the hole 32 formed in the mineral substrate 6. The fluid is removed following drilling in order to obtain a sufficiently dry environment within the hole 32. It is also possible to use the first fluid removal device 20 during drilling for the removal of liquid, either on its own, or in combination with an additional fluid removal device, such as the second fluid removal device 14. Further details of the method of controlling the first fluid removal device 20 will be described in detail with reference to Fig. 6.

[0045] The second fluid removal device 14 is configured to remove a liquid from the hole 32 formed in the mineral substrate 6 during drilling. The second fluid removal device 14 may be used for the removal of liquid during drilling, either on its own, or in combination with an additional fluid removal device, such as the first fluid removal device 20. It is also possible to use the second fluid removal device 14 after drilling during a cleaning operation. The second fluid removal device 14 comprises a pump. Alternatively, the second fluid removal device may comprise any known fluid transfer device. Further details of the method of controlling the second fluid removal device 14 will be described in detail with reference to Fig. 6.

[0046] The drilling equipment 4 further comprises a fluid supply system 10, located on a fluid supply line 12, and configured to supply a liquid towards the hole 32 formed in the mineral substrate 6. The fluid supply system 10 is configured to supply a liquid towards the hole 32 during a drill operation. It is also possible to use the fluid supply system 10 to supply a liquid towards a surface of the mineral substrate 6 before a drill operation in order to prepare the mineral substrate 6 for drilling, or after a drill operation in order to replace a liquid containing rock particles in a cleaning operation, described in detail with reference to Fig. 6. The fluid supply system 10 is configured to supply the hole 32 with a liquid from a reservoir 40. The reservoir 40 may be located at the drill rig 2 or may be an external source. In the case of an external source the fluid reservoir 40 may be used to supply multiple drill rigs 2. The reservoir may comprise a tank, or alternatively any natural or man-made body for containment of liquid. The reservoir 40 may be further connected to the fluid removal system 11 such that liquid may be circulated between the reservoir 40 and the mineral substrate 6. Alternatively, the fluid removal system 11 may be connected to a different reservoir or may simply release the liquid to be drained at a location distanced from the hole 32 formed in the mineral substrate 6. The reservoir 40 may comprise separation means, such as filters, shale shakers, centrifuges, or cyclone separators, or the like, or combinations thereof, for removing rock fragments from the liquid. The reservoir 40 may contain a plurality of separation stages, such that rock fragments comprising different materials, grain sizes, or the like may be removed, for example having a coarse grain separation stage followed by a fine grain separation stage.

[0047] The fluid removal system 11 may be only partially connected to the reservoir 40, for example the second fluid removal device 14 may be connected to the reservoir 40, whilst the first fluid removal device 20 may be connected to a different reservoir or may be configured to simply release the liquid to be drained at a location distanced from the hole 32. Alternatively, the first fluid removal device 20 may be connected such that it supplies a liquid after a separation means at the reservoir 40, or at a later stage, for example the second fluid removal device 14 is connected such that is supplies liquid at a coarse grain separation stage, and the first fluid removal device 20 is connected such that it supplies liquid at a fine grain removal stage.

[0048] The first fluid removal device 20 is in the form of a submergible pump 20. The submergible pump 20 may be located inside the drilling equipment 4 or may be attached thereunder. The submergible pump 20 may be configured to receive a liquid through a hose, or the like, extending outwards from the drill head 8. The hose may be flexible or rigid. It is also possible that the submergible pump 20 may be configured to receive a liquid through multiple hoses, or the like. The hose may be actuatable, such that it can be extended, or repositioned, relative to the drill head 8, such that it can effectively remove the liquid from the hole 32 formed in the mineral substrate 6. Alternatively, the submergible pump 20 may be actuatable, such that it can be extended, or repositioned, relative to the drill head 8, such that it can effectively remove the liquid from the hole 32. In the illustrated embodiment the submergible pump 20 is located on and may transfer the liquid away from the hole 32 formed in the mineral substrate 6 via a first fluid removal line 21, separate from the second fluid removal line 17 of the second fluid removal device 14. Alternatively, the submergible pump 20 and the second fluid removal device 14 may be located on only partially separated lines, for example the submergible pump 20 and the second fluid removal device 14 may transfer the liquid through a shared inlet and / or outlet.

[0049] Fig. 3 illustrates shows an alternative drilling equipment 4 in which the first fluid removal device is in the form of a pump 22. The pump 22 is located on a jet ejector line 23 and is configured to work in a jet ejector arrangement. The jet ejector arrangement comprises a first fluid removal line 21 configured to transfer fluid away from the hole 32 formed in the mineral substrate 6. The first fluid removal line 21 is in fluid communication with the hole 32 via a non-return valve 25. In the illustrated embodiment the first fluid removal line 21 is configured to transfer fluid to the reservoir 40. Additionally, the jet ejector line 23 is configured to be supplied from the reservoir 40. In alternative embodiments the first fluid removal line 21 may be configured to transfer fluid to a different location, and / or the jet ejector line 23 may be supplied from a different source. The pump 22 is configured to pump the fluid through the jet ejector line 23 which communicates with the first fluid removal line 21 via a jet forming nozzle 27, to form a jet of liquid in the first fluid removal line 21 in a direction away from the hole 32 such that a suction of the liquid at the drilled surface 15 can be achieved. The pump 22 may be located at a distance from the drilled surface 15, for example the pump 22 when operated in the jet ejector arrangement can achieve evacuation of liquid from holes deeper than 10m while still having the pump 22 located above the hole 32. The advantage of the having a pump 22 in a jet ejector arrangement is that complexity can be reduced towards the drill head 8 as the jet ejector 27 has no moving parts, and additionally, the wear on the pump may be reduced as the driven flow can be free from rock particles.

[0050] Fig. 4 illustrates shows an alternative drilling equipment 4 comprising a sealing arrangement 42, as described later with reference to Fig. 2, in which the first fluid removal device is in the form of a compressed air source 24. The compressed air source is configured to pressurize the fluid supply line 12 with air, such that the area enclosed by the sealing arrangement 42 becomes pressurized, and the liquid is forced, via the annular space formed between the wall of the hole 32 and the drilling equipment 4, through the hole 44 formed in the sealing arrangement 42, and removed from the hole 32 formed in the mineral substrate 6 via the second fluid removal line 17. Alternatively, the compressed air source may be configured to pressurize the second fluid removal line 17 with air, such that liquid may be removed from the hole 32 formed in the mineral substrate 6 via the fluid supply line 12. In alternative embodiments, for example in absence of a fluid supply system 10, the compressed air source 24 may be located on a separate line, which is in fluid communication with the hole 32 formed in the mineral substrate 6, and the fluid is pushed out of the second fluid removal line 17. It is also possible to have both a fluid supply system 10 and the compressed air source 24 on separate lines, and in absence of a dedicated fluid removal line, whereby the fluid may be pushed out through the fluid supply line 12. Furthermore, it is possible to have the compressed air source 24 on a separate line in a system having multiple fluid supply and or removal lines whereby control of the fluid supply / removal line by which the liquid is pushed out may be controlled by way of valves on at least one of the fluid supply / removal lines.

[0051] Turning back to Fig. 2, a sealing arrangement 42 is formed around the central axis X of the drilling equipment 4 and seals a volume to be drilled by the drill head 8. The sealing arrangement 42 comprises a cup-shaped body which seals axially towards the mineral substrate 6, and radially towards the drilling equipment 4. In alternative embodiments the sealing arrangement 42 may comprise any suitable shape for sealing the volume to be drilled, for example the sealing arrangement 42 may comprise a disc shaped body which seals radially towards the wall of the hole 32 formed in the mineral substrate 6, and radially towards the drilling equipment 4. The sealing arrangement 42 is configured to prevent excessive loss of liquid. Pressurization of the liquid may be advantageous for the process of breaking the mineral substrate 6, such as in the case of pulsed plasma drilling, as shown in the illustrated embodiment. In the shown embodiment the fluid supply system 10 and the first fluid removal device 20 may communicate with the drilled surface 15 of the mineral substrate 6 via channels extending through the drilling equipment, and the second fluid removal device 14 through a channel which communicates via a hole 44 formed in the sealing arrangement 42. In alternative embodiments any one of the fluid channels may be formed through the drilling equipment 4, or through any number of holes formed in the sealing arrangement 42.

[0052] The drilling equipment 4, according to the embodiments illustrated in Figs. 2-4, further comprises a pulsed power generator 46 for generating high voltage current pulses for supplying the two electrodes 30 at the drill head 8. The drill rig 2 further comprises an electrical power supply 34 for powering the pulsed power generator 46. In alternative embodiments the drill head 8 may comprise rotary, top-hammer, or down-the-hole drilling means, or any known drilling means, which may be electrically, hydraulically or pneumatically powered, in which case the supply may comprise an electric, hydraulic or pneumatic source, such that the drill head 8 can be appropriately supplied such that it can break the mineral substrate 6.

[0053] The pulsed power generator 46 comprises a pulse transformer 48 in the form of a bank of capacitors, connected to a power supply 34 via a charger 50. The electrodes 30 are selected and connected using switches (not shown). Using the switches, a short high voltage pulse is generated. The pulse is transferred to the electrodes 30. The pulsed power generator 46 is configured for generating pulses used for breaking the mineral substrate 6, such as nanosecond (ns) pulses that are passed to the electrodes 30.

[0054] The drilling equipment 4 further comprises an electronic control unit 16. The electronic control unit 16 is configured to control said drilling equipment 4 to a first operating state during a drill operation, and a second operating state during a fluid evacuation operation subsequent to the drill operation. According to an embodiment, the electronic control unit 16 is further configured to control said drilling equipment 4 to a cleaning operation subsequent to a drill operation and before the fluid evacuation operation.

[0055] The electronic control unit 16 may be configured to control operation of the drilling equipment 4 in response to signals received from an external control unit, such as a control unit of a machine in which the drilling equipment is provided. The electronic control unit may include a microprocessor, a microcontroller, a programmable digital signal processor or another programmable device. Thus, the control unit comprises electronic circuits and connections (not shown) as well as processing circuitry (not shown) for communicating with different parts of the drilling equipment as well as with the external control unit. For example, the control unit may be configured for communicating with various sensors, devices, systems, and control units of the drilling equipment. In the shown embodiment, the control unit 16 controls the fluid supply system 10 and the fluid removal system 11. The control unit 16 may also control the charger 50 as well as the switches (not shown). Alternatively, several separate control units may be provided. The electronic control unit 16 may comprise modules in either hardware or software, or partially in hardware or software, and communicate using known transmission buses such a CAN-bus and / or wireless communication capabilities. The processing circuitry may be a general-purpose processor or a specific processor. The control unit may comprise a non- transitory memory for storing computer program code and data. Thus, the skilled person realizes that the electronic control unit 16 may be embodied by many different constructions.

[0056] The drilling equipment 4 may comprise a sensor 26 configured to provide the electronic control unit 16 with a measurement indicative of a concentration of rock fragments in the removed liquid. The measurement may comprise a liquid concentration. Alternatively, the measurement may comprise a concentration of a rock fragments suspended in the liquid. The concentration of rock fragments may relate to all the rock fragments present in the liquid, alternatively the concentration of rock fragments may relate to a single material, or only some of the materials that may be present in the liquid, said materials having a density, or a specific chemical composition or crystal structure, or any other attribute which may present a benefit to the operation of the drilling equipment 4. The sensor 26 may be located at the drill head 8. In the shown embodiments, the sensor 26 is located after the second fluid removal device 14 on the second fluid removal line 17. Alternatively, the sensor 26 may be located on any line which is used for fluid removal. Alternatively, the sensor 26 may be located at the reservoir 40, or on a surface of the drill head 8, alternatively the fluid concentration sensor 26 may be attached such that it extends from a surface of the drill head 8.

[0057] The drilling equipment 4 in the illustrated embodiments further comprises a liquid level sensor 28 configured to provide the control unit 16 with a measurement indicative of a liquid level within the hole 32 formed in the mineral substrate 6. The liquid level sensor 28 may comprise a pressure transducer 29. Alternatively, the liquid level sensor 28 may comprise an ultrasonic, optical, capacitance, or radar-based sensor, a float switch, or any known sensor for determining a liquid level. In the shown embodiments the liquid level sensor 28 is located at a surface of the drill head 8. The liquid level sensor 28 may be attached on the drill head 8, or alternatively it may extend from the surface of the drill head 8. Alternatively, the liquid level sensor 28 may be located elsewhere on the drilling equipment 4, the drill rig 2, or a sensor which is not part of the drilling equipment may be provided. A method for controlling a drilling equipment 4 as described above is illustrated in Fig. 6.

[0058] The method comprises the following actions:

[0059] S1: controlling the drilling equipment 4 in a first operating state during a drill operation, in which first operating state the drill head 8 breaks a mineral substrate 6 and forms a hole 32 in the mineral substrate 6 by passing a high voltage current pulse generated by the pulsed power generator 46 between the at least two electrodes 30 via the mineral substrate 6.

[0060] S2: controlling the drilling equipment 4 in a second operating state during a fluid evacuation operation subsequent to the drill operation, in which second operating state the first fluid removal device 20, 22, 24 removes a liquid from the hole 32 formed in the mineral substrate 6.

[0061] The method may also comprise an optional step S3 of controlling the drilling equipment 4 in a third operating state during a cleaning operation, in which third operating state the fluid supply system 10 supplies the liquid to the hole 32 formed in the mineral substrate 6, and a second fluid removal device 14 removes the liquid from the hole 32 formed in the mineral substrate 6.

[0062] The method may further comprise, in the second operating the drill head 8 does not break the mineral substrate 6. It may be possible in the second operating state to not break the mineral substrate 6, but to break particles suspended in the liquid to be removed such that they be removed more easily, either using the drill head, or additional means. Additionally, the method may comprise, in the third operating state the drill head 8 does not break the mineral substrate 6.

[0063] The drill operation may be manually controlled by an operator via an external control unit (as described with reference to Fig. 2). Alternatively, the drill operation may be fully automated when the drill rig 2 is placed in position. Alternatively, the drill operation may be at least partially automated. For example, the operator may control the start of the drill operation via the external control unit and the electronic control unit 16 may subsequently control the drill operation. The operator may define parameters, such as a maximum drill time, drill depth, etc, which the electronic control unit 16 can use to control the drill operation. Alternatively, the electronic control unit 16 can be pre-programmed with operating parameters. The drill equipment 4 may comprise external sensors which supply data to the electronic control unit 16 which can be used for control of the drill operation based on the defined parameters.

[0064] When the drilling equipment 4 comprises a fluid supply system 10, in the first operating state, the fluid supply system 10 may supply the liquid to the hole 32 formed in the mineral substrate 6. The supplying of liquid during the drill operation may be controlled such that it replaces a liquid that has been removed from the hole 32 formed in the mineral substrate 6, either intentionally, by way of the fluid removal system 11, or unintentionally, in the case of seepage or the like.

[0065] When the fluid removal system 11 comprises a second fluid removal device 14, the second fluid removal device 14 may be controlled to remove the liquid from the hole 32 formed in the mineral substrate 6 in the first operating state and to not remove the liquid from the hole 32 formed in the mineral substrate 6 in the second operating state. The removal of liquid can then be performed by the second fluid removal device 14 during drilling and by the first fluid removal device 20, 22, 24 during drying. The second fluid removal device 14 can therefore be controlled to remove the liquid and the rock fragments, resulting from the breaking of the mineral substrate 6, and the first fluid removal device 20, 22, 24 can be controlled to remove the liquid remaining within the hole 32 formed in the mineral substrate 6 after the drill operation.

[0066] The method may comprise automatically activating the second operating state when the first operating state ends. The end of the first operating state can be determined by an action taken by the operator, such as by communicating with the electronic control unit 16 via an external control unit the intention to stop drilling. Alternatively, the drill operator may define parameters for stopping the drill operation, or the parameters may be preprogrammed. Parameters may comprise a maximum drill time, drill depth, etc, which when achieved commence the end of drilling. The end of drilling can be determined by the electronic control unit 16, using data from external sensors, for example to indicate that the defined parameters have been met, or that further drilling will not be cost effective. Alternatively, the drill operation may end due to the physical limitations of drilling equipment 4 for example the drill equipment 4 reaches a maximum possible depth, or when progress of the drill head 8 is prevented, by a blockage, or the like. When the drilling equipment 4 comprises a fluid supply system 10 the method may comprise controlling the drilling equipment 4 in a third operating state. The third operating state comprises a cleaning operation in which the fluid supply system 10 supplies liquid to the hole 32 formed in the mineral substrate 6, and the second fluid removal device 14 removes the liquid from the hole 32 formed in the mineral substrate 6.

[0067] When the first operating state ends, the third operating state may be automatically activated. The end of the first operating state can be determined by an action taken by the operator, such as by communicating with the electronic control unit 16 via an external control unit the intention to stop drilling. Alternatively, the drill operator may define parameters for stopping the drill operation, or the parameters may be pre-programmed. Parameters may comprise a maximum drill time, drill depth, etc, which when achieved commence the end of drilling. The end of drilling can be determined by the electronic control unit 16, using data from external sensors, for example to indicate that the defined parameters have been met, or that further drilling will not be cost effective. Alternatively, the drill operation may end due to the physical limitations of drilling equipment 4, for example when the drill equipment 4 reaches a maximum possible depth, or when progress of the drill head 8 is prevented, by a blockage, or the like.

[0068] The method may comprise automatically activating the second operating state after the third operating state has been active for a fixed period of time. The fixed period of time may be a period of time sufficient to remove all of the rock particles from the liquid to be removed in the second operating state. Alternatively, the fixed period of time may be sufficient to remove at least some of the rock particles from the liquid to be removed in the second operating state. The fixed period of time may be derived from experimental or operational data. Alternatively, the fixed period of time may be calculated in the electronic control unit 16 based on a known parameter, taken from external sensors, or the like, prior to starting the cleaning operation. Alternatively, the fixed period of time may be set by an operator.

[0069] The method may further comprise, in the third operating state, determining a concentration of rock fragments in the removed liquid, wherein the method comprises automatically activating the second operating state when the concentration of rock fragments in the removed liquid is below a threshold level. The determination of the concentration of rock fragments may be performed by a sensor such as the sensor 26 (as described with reference to Fig. 2). The sensor 26 may take measurements continuously, or intermittently at least in the third operating state. The sensor 26 may comprise a fluid concentration sensor configured to measure a concentration of the liquid. Alternatively, the sensor 26 may comprise a sensor configured to measure a concentration of a substance suspended in the liquid. Alternatively, the sensor 26 may comprise an optical sensor. The sensor 26 may be located on the fluid removal system 11. Alternatively, the sensor 26 may be located in the reservoir 40, or on a surface of the drill head 8, alternatively the sensor 26 may be attached such that it extends from a surface of the drill head 8. Alternatively, the determination of the concentration of rock fragments may be determined from the flow in the fluid removal system 11 , such as by determining the work performed by the second fluid removal device 14.

[0070] The method may further comprise automatically deactivating the second operating state after a fixed period of time. The fixed period of time may be a period of time sufficient to remove all the liquid from the hole 32 formed in the mineral substrate. Alternatively, the fixed period of time may be sufficient to remove at least some of the liquid from the hole 32 formed in the mineral substrate. The fixed period of time may be derived from experimental or operational data. Alternatively, the fixed period of time may be calculated in the electronic control unit based on a known parameter, taken from external sensors, or the like, prior to starting the drying operation. Alternatively, the fixed period of time may be set by an operator.

[0071] The method may further comprise determining a liquid level within the hole 32 formed in the mineral substrate 6 in the second operating state, and when the liquid level falls below a threshold liquid level L0, deactivating the second operating state. As illustrated in Fig. 5 the threshold liquid level L0 defines a horizontal plane. Alternatively, the threshold liquid level L0 may define a plane inclined relative to the horizontal plane, for example the plane may be parallel to the drilled surface, or the drill head, which may be inclined relative to the horizontal plane, or any other inclination may be possible. The threshold liquid level L0 may further comprise a plane coincident with the drilled surface 15 of the mineral substrate 6. Alternatively, the threshold liquid level L0 may comprise a plane distanced from the drilled surface 15 of the mineral substrate 6. The threshold liquid level L0 may be defined with reference to at least a point of the drilled surface 15 of the mineral substrate 6. Alternatively, the threshold liquid level L0 may be defined with reference to a point of the drilling equipment 4, for example, the drill head 8, the electrodes 30, or a liquid level sensor 28. The threshold liquid level L0 may be derived from experimental or operational data. Alternatively, the threshold liquid level L0 may be calculated in the electronic control unit 15 based on a known parameter, taken from external sensors, or the like, prior to starting the fluid evacuation operation, for example a different threshold liquid level L0 could be defined based on a local temperature value. Alternatively, the threshold liquid level L0 may be calculated in the electronic control unit 15 based on a future operation to be performed. Alternatively, the threshold liquid level L0 may be set by an operator. It is to be understood that the present disclosure is not limited to the embodiments described above and illustrated in the drawings; rather, the skilled person will recognize that many changes and modifications may be made within the scope of the appended claims.

Claims

CLAIMS1. A method of controlling a drilling equipment (4), said drilling equipment (4) comprising: a drill head (8) having at least two electrodes (30), a pulsed power generator (46) for generating high voltage current pulses, and a fluid removal system (11), comprising a first fluid removal device (20, 22, 24), the method comprising: controlling (S1) said drilling equipment (4) in a first operating state during a drill operation, in which first operating state said drill head (8) breaks a mineral substrate (6) and forms a hole (32) in said mineral substrate (6), by passing a high voltage current pulse generated by the pulsed power generator (46) between the at least two electrodes (30) via the mineral substrate (6), controlling (S2) said drilling equipment (4) in a second operating state during a fluid evacuation operation subsequent to said drill operation, in which second operating state said first fluid removal device (20, 22, 24) removes a liquid from the hole (32) formed in said mineral substrate (6).

2. The method of controlling the drilling equipment (4) according to claim 1 , wherein in the second operating state the drill head (8) does not break said mineral substrate (6).

3. The method of controlling the drilling equipment (4) according to any one of the preceding claims, wherein the drilling equipment (4) further comprises a fluid supply system (10), and wherein, in said first operating state, said fluid supply system (10) supplies said liquid to the hole (32) formed in said mineral substrate (6).

4. The method of controlling the drilling equipment (4) according to any one of the preceding claims, wherein said fluid removal system (11) comprises a second fluid removal device (14), wherein said second fluid removal device (14) removes said liquid from the hole (32) formed in said mineral substrate (6) in said first operating state and does not remove said liquid from the hole (32) formed in said mineral substrate (6) in said second operating state.

5. The method of controlling the drilling equipment (4) according to any one of the preceding claims, wherein the method comprises automatically activating said second operating state when said first operating state ends.

6. The method of controlling the drilling equipment (4) according to claim 4, wherein the drilling equipment (4) further comprises a fluid supply system (10) and the method comprises: controlling (S3) said drilling equipment (4) in a third operating state during a cleaning operation, in which third operating state said fluid supply system (10) supplies said liquid to the hole (32) formed in said mineral substrate (6), and said second fluid removal device (14) removes said liquid from the hole (32) formed in said mineral substrate (6),- when said first operating state ends, automatically activating said third operating state.

7. The method of controlling the drilling equipment (4) according to claim 6, wherein the method comprises automatically activating said second operating state after said third operating state has been active for a fixed period of time.

8. The method of controlling the drilling equipment (4) according to claim 6, wherein the method further comprises, in the third operating state, determining a concentration of rock fragments in the removed liquid, wherein the method comprises automatically activating said second operating state when said concentration of rock fragments in said removed liquid is below a threshold level.

9. The method of controlling the drilling equipment (4) according to any one of the preceding claims, wherein the method comprises automatically deactivating said second operating state after a fixed period of time.

10. The method of controlling the drilling equipment (4) according to any one of claims 1- 8, wherein the method further comprises: determining a liquid level within the hole (32) formed in (6) said mineral substrate (6) in said second operating state,- when said liquid level falls below a threshold liquid level (L0), deactivating said second operating state.

11. A drilling equipment (4) comprising:a pulsed power generator (46) configured to generate high voltage current pulses, a drill head (8) having at least two electrodes (30), configured to break a mineral substrate (6) and form a hole (32) in said mineral substrate (6) in a first operating state of the drilling equipment (4), by passing a high voltage current pulse generated by the pulsed power generator (46) between the at least two electrodes (30) via the mineral substrate (6), a fluid removal system (11), comprising a first fluid removal device (20, 22, 24) configured to remove a liquid from the hole (32) formed in said mineral substrate (6) in a second operating state of the drilling equipment (4), and an electronic control unit (16) configured to control said drilling equipment (4) to said first operating state during a drill operation, and to said second operating state during a fluid evacuation operation subsequent to the drill operation.

12. The drilling equipment (4) according to claim 11 , wherein the drilling equipment (4) is configured such that it does not break said mineral substrate (6) in said second operating state.

13. The drilling equipment according to claim 11 or 12, further comprising a fluid supply system (10) configured to supply a liquid towards the hole (32) formed in said mineral substrate (6) in said first operating state.

14. The drilling equipment (4) according to any one of claims 11-13, wherein said drilling equipment (4) comprises a sensor (26) configured to provide said electronic control unit (16) with a measurement indicative of a concentration of rock fragments in said removed liquid.

15. The drilling equipment (4) according to any one of claims 11-14, wherein said drilling equipment (4) comprises a liquid level sensor (28) configured to provide said control unit (16) with a measurement indicative of a liquid level within the hole (32) formed in said mineral substrate.

16. The drilling equipment (4) according to claim 15, wherein said liquid level sensor (28) comprises a pressure transducer (29).

17. The drilling equipment (4) according to any one of claims 11-16, wherein said liquid comprises water.

18. The drilling equipment (4) according to any one of claims 11-16, wherein said liquid comprises an oil.

19. A drill rig (2) comprising a drilling equipment (4) according to any one of claims 11-18.

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