Method for injecting fluid into a borehole, control device, system and a mining and / or construction machine

Abstract

The present disclosure relates to a method for assessing injection of a fluid into a borehole (11) defined by a borehole wall (12) extending into a body (10), the method comprising: - initiating (S1) the injection of the fluid into the borehole (11) using a fluid injection arrangement, - detecting (S2) fluid outside the borehole (11) and the fluid injection arrangement (20) using a detection device (30), and - on the basis of at least one of the following: - a detected position of the detected fluid outside the borehole (11) and the fluid injection arrangement (20), - an injection volume of the fluid, and - a time lapse (TL) from the time of initiation of fluid injection into the borehole (11) to the time of fluid detection outside the borehole (11) and the fluid injection arrangement (20), assessing (S3) the injection of fluid.

Description

[0001] METHOD FOR INJECTING FLUID INTO A BOREHOLE, CONTROL DEVICE, SYSTEM AND A MINING AND / OR CONSTRUCTION MACHINE

[0002] TECHNICAL FIELD

[0003] The present disclosure pertains to a method and a control device for injecting fluid into a borehole, a method and a control device for rock bolting, a system and a mining and / or construction machine. By way of example, the present disclosure may be used for rock bolting, a technique commonly employed in the mining, civil engineering, and tunnelling industries to stabilize rock formations.

[0004] BACKGROUND OF THE INVENTION

[0005] Rock bolting is a widely used method for reinforcing rock mass in both mining and civil engineering applications. It involves inserting steel bolts into drilled holes in rock surfaces to provide support and prevent rock fall or collapse. Recent advances have focused on mining and / or construction machines for automated rock bolting, which are capable of autonomously or remotely controlled drilling of a borehole and anchoring a bolt in the borehole. Advanced systems make use of the bolt itself for drilling a hole and for filling the hole, i.e. the bolt has as a drill portion on the outside and a hollow pipe portion on the inside. Conventional rock bolts typically consist of steel rods that are anchored into drilled holes by injection of a binding fluid, such as a resin-based grout or any other binding material. These bolts work by transferring load from the unstable rock mass to the more stable surrounding material, thus preventing movement or collapse of the rock strata.

[0006] Challenges occur due the injection of the binding fluid into the borehole, since the volume of the borehole is unknown, or the borehole walls may be porous. Thus, it is difficult to know how much binding fluid should be injected into the borehole for the borehole to be sufficiently filled. Further problems may arise due to leakages in the injection arrangement which may not be recognized in automated rock bolting.

[0007] Consequently, there is a need for improved methods, devices and mining and / or construction machines for rock bolting. In particular, there is a need for such methods, devices and mining and / or construction machines for assessing the status of injection, e.g. for detecting if the borehole is successfully filled or if any leakages occur. Moreover, there is a need for improved methods for injecting fluid.

[0008] SUMMARY OF THE INVENTION

[0009] A primary object of the present disclosure is to achieve an in at least some aspect improved method for injecting fluid into a borehole and an in at least some aspect improved control device for injecting fluid into a borehole. In particular, it is an object of the present disclosure to achieve an in at least some aspect improved method and control device for at least detecting if the injection of fluid has been performed successfully, i.e. that the borehole has been filled sufficiently, or if a leakage is occurring at the injection arrangement. A secondary object is to achieve a method and a control device that improves the filling of boreholes and detects irregularities in a rock-bolting process.

[0010] According to a first aspect of the disclosure, at least the primary object is achieved by a method for injecting fluid into a borehole defined by a borehole wall extending into a body, the method comprising:

[0011] - initiating the injection of the fluid into the borehole using a fluid injection arrangement,

[0012] - detecting fluid outside the borehole and the fluid injection arrangement using a detection device, and

[0013] on the basis of at least one of the following:

[0014] - a detected position of the detected fluid outside the borehole and the fluid injection arrangement;

[0015] - an injection volume of the fluid, and

[0016] - a time lapse from the time of initiation of fluid injection into the borehole to the time of fluid detection outside the borehole and the fluid injection arrangement, assessing the injection of fluid.

[0017] The first aspect of the disclosure may seek to provide a reliable assessment of the fluid injection status. A technical benefit may include better control of the injection process and detection of irregularities in the injection process, such as leakages. These benefits are particularly important when the exact volume of the borehole is unknown or when the surrounding material is porous. When applied in an automated rock bolting process, the first aspect of the disclosure may provide reliable rock bolting by ensuring a rock bolt or anchor inserted in the borehole is surrounded by a sufficient amount of binding fluid.

[0018] The first aspect of the disclosure does not only detect fluid outside of the borehole and the fluid injection arrangement but also assesses the injection of the fluid. Purely by way of example, information giving hints for assessing the status may be the position of the detected fluid. Further, an injection volume at the time of detection, i.e. how much fluid has been injected, may be useful information. For example, if the injection volume is smaller than a certain threshold volume, it may be concluded that the borehole is not sufficiently filled.

[0019] Another factor useful for the assessment of the injection may be the time lapse from the time of initiation to the time of detection of fluid. This information can be used to distinguish different injection statuses. For example, a detection of fluid shortly after initiation of the injection may indicate a low probability that the borehole is successfully filled.

[0020] Hence, taking into account this additional information upon detection of fluid, a status of fluid injection may be determined reliably.

[0021] In embodiments, the method may further comprise: in response to determining that the detected position of the detected fluid is at a portion of the fluid injection arrangement, determining that the injection of fluid is unsuccessful, preferably determining that a leakage occurs in the fluid injection arrangement.

[0022] Thereby, the position of the detected fluid may be used to determine if the injection is successful or not. In particular the position of the detected fluid may indicate that there is a leakage from the injection arrangement opposed to an expected position of the detected fluid at the collar of the borehole. A leakage may herein indicate that the injection of fluid is not successful.

[0023] In embodiments, the method may further comprise: in response to determining that the detected position of the detected fluid is within a predetermined distance from an intersection between the borehole wall and a surrounding body wall of the body, determining that the injection of fluid is successful. Thereby, it may be determined that the detected fluid originates form the borehole which is expected when the borehole is sufficiently filled.

[0024] In embodiments, the method may further comprise: in response to determining that the detected position of the detected fluid is outside the predetermined distance from an intersection between the borehole wall and a surrounding body wall of the body, determining that the injection of fluid is unsuccessful.

[0025] Thereby, it may be determined that the detected fluid does originate from the borehole which is expected when the borehole is sufficiently filled. Instead, the detected position of the detected fluid may occur at a portion of the fluid injection arrangement being located outside the predetermined distance from the intersection between the borehole wall and the surrounding body wall of the body.

[0026] In embodiments, the method may further comprise:

[0027] - using a time threshold for the injection of fluid into the borehole; and

[0028] - assessing the status of the injection of fluid using the time threshold and the time lapse.

[0029] Thereby, the method may distinguish an expected detection of fluid when the borehole is sufficiently filled, from a leakage occurring at the injection arrangement. Here, the method takes advantage from the fact that an expected detection of fluid when the borehole is sufficiently filled, i.e. indicating a successful injection, usually occurs after a certain time period from the start of the injection, whereas a leakage may occur immediately or shortly after the initiation of injection. Hence, a reliable determination of the injection status may be achieved.

[0030] In embodiments, the method may further comprise:

[0031] in response to determining that the time lapse is equal to or less than the time threshold, determining that the injection of fluid is unsuccessful, preferably determining that a leakage occurs in the fluid injection arrangement.

[0032] Thereby, a reliable detection of a leakage from the injection arrangement may be achieved. In embodiments, the method may further comprise:

[0033] in response to determining that the time lapse is greater than the time threshold, determining that the injection of fluid is successful.

[0034] Thereby, a reliable determination of a successful injection may be achieved. This may be due to the fact that a successful injection indicating that the borehole is sufficiently filled may occur after a certain time threshold after the initiation of the injection.

[0035] In embodiments, the method may comprise determining the time threshold on the basis of information relating to the injection of fluid into the borehole.

[0036] The time threshold may be determined based on the properties of the borehole, such as porosity of the surrounding material, its volume, depth and / or diameter. Further, the time threshold may depend on a rate of injection of the fluid into the borehole.

[0037] Thereby, a reliable and accurate assessment of the injection status may be obtained.

[0038] In embodiments, the method may further comprise: in response to detecting fluid outside the borehole and the fluid injection arrangement, terminating the fluid injection into the borehole.

[0039] As explained before, a detection of fluid outside the borehole and the fluid injection arrangement, may indicate a status of the injection in dependence of the position of the detected fluid, the time of detection of the fluid and / or the volume of injected fluid at the time of the detection. The status may indicate a successful injection or an unsuccessful injection. In both cases, the injection of fluid may be terminated. Hence, an improved injection of fluid into the borehole and / or an improved management of leakage conditions may be achieved.

[0040] In embodiments, the method may comprise, in response to determining that the injection of fluid is unsuccessful, issuing error information.

[0041] When it is determined that the injection is unsuccessful error information may be issued to an operator, a supervisor or an automated system. The error information may trigger an alarm and / or a stop of operation. The error information may be displayed to an operator via a screen or a user device, such as a mobile phone or a tablet.

[0042] In embodiments, the fluid injection arrangement may comprise at least one, preferably each one, of: a pump, at least one hose and a fluid injector.

[0043] Thereby, the injection of fluid into the borehole may be facilitated. In embodiments, the method may further comprise: in response to determining that the detected position of the detected fluid is at the pump, or at the at least one hose or at the fluid injector, determining that the injection of fluid is unsuccessful, preferably determining that a leakage occurs in the fluid injection arrangement.

[0044] Thereby, an improved detection of a leakage may be obtained. In particular, an improved distinguishment of an expected detection of fluid from the collar of the borehole, i.e. at the intersection of the borehole wall and the surrounding body wall of the body, may be achieved.

[0045] In embodiments, the method may further comprise

[0046] - using, preferably determining, a first reference time interval,

[0047] - assessing a status of fluid injection using the time lapse and the first reference time interval.

[0048] This embodiment makes use of the fact that a switch between different injection statuses are mainly expected at different time intervals. Hence, an improved distinguishment of different injection statuses is achieved.

[0049] In embodiments, the method may further comprise:

[0050] in response to determining that the time lapse is within the first time reference time interval, determining that the injection of fluid is unsuccessful, preferably determining that a leakage occurs in the fluid injection arrangement.

[0051] As mentioned before, the information about the time of detection of fluid can be used to distinguish between different injection statuses. When the fluid is detected within the first reference time interval, it may be determined that the injection is unsuccessful and / or that a leakage occurs. The first time reference interval may be between a first time point from initiation of the injection and a second time point from the initiation of injection. The first time point may refer to a time needed for priming the injection arrangement, i.e. a time that is needed for filling the injection arrangement. The second time point may refer to a time associated with an expected filling time of the borehole. The second time point may be, but does not have to be, the time threshold mentioned above.

[0052] Hence, an improved determination of an unsuccessful injection, such as due to a leakage, may be obtained. In embodiments, the method may further comprise:

[0053] determining the first reference time interval on the basis of information relating to the injection of fluid into the borehole.

[0054] As the time threshold, also the first reference time interval may be determined based on the properties of the borehole, such as porosity of the surrounding material, its volume, depth and / or diameter. Further, the first reference time interval may depend on a rate of injection of the fluid into the borehole.

[0055] Thereby, a reliable assessment of the injection status may be obtained.

[0056] In embodiments, the method may further comprise:

[0057] - using, preferably determining, a second reference time interval,

[0058] - assessing a status of fluid injection using the time lapse and the second reference time interval.

[0059] Analogously to the first reference time interval, the second reference time interval may be used to assess the injection status. Hence, an improved distinguishment of different injection statuses is achieved.

[0060] In embodiments, the method may further comprise:

[0061] in response to determining that the time lapse is within the second time reference time interval, determining that the injection of fluid is successful.

[0062] The second reference time interval may be from a first time point to a second time point form the initiation of the injection. The first time point may be associated with an expected time for obtaining a successfully filled borehole. The second time point may be an upper limit upon which a successful filling of the borehole is no longer expected.

[0063] Hence, a reliable and accurate determination of a successful injection may be obtained.

[0064] In embodiments, the method may further comprise determining the second reference time interval on the basis of information relating to the injection of fluid into the borehole. Thereby, a reliable and accurate assessment of the injection status may be obtained.

[0065] In embodiments, the information relating to the injection of fluid into the borehole comprises one or more of the following: a volume of the borehole, a length and / or diameter of a drill tool used for drilling the borehole, a length and / or diameter of a bolt used for rock reinforcement, and a fluid injection rate. Hence, a reliable and accurate assessment of the injection status may be obtained. In particular, a reliable distinguishing of the different injection statuses may be obtained.

[0066] In embodiments, the information relating to the injection of fluid into the borehole comprises Measuring-While-Driling-data (MWD-data), which has been obtained during drilling of the borehole.

[0067] Here, the method makes use of information obtained during drilling the borehole, i.e. the borehole in this case is a borehole that has been drilled, e.g. by a mining and / or construction machine. The used mining and / or construction machine may also comprise the injection arrangement. In other embodiments, the drilling was performed by a drilling arrangement separate from the fluid injection arrangement.

[0068] Hence, the time threshold, the first time reference interval and / or the second time reference interval may be determined reliably leading to a reliable and accurate assessment of the injection status.

[0069] In embodiments, the MWD-data is indicative of voids around the borehole.

[0070] The MWD-data may comprise measured data during drilling, such as percussion pressure, rpm, drilling duration and the like. The MWD-data may be used to indicate voids and thereby estimate the volume of the borehole reliably, which in turn can be employed to determine the time threshold, the first time reference interval and / or the second time reference interval reliably.

[0071] In embodiments, the method may further comprise:

[0072] - adjusting an orientation and / or a position of the detection device before and / or during the fluid injection.

[0073] Thereby, an improved detection of the fluid outside the borehole and the injection arrangement may be obtained. Further, an improved detection of the position of the detected fluid may be obtained. For example, the detection device may be adjusted to provide a beneficial angle and / or distance between the detection device and the borehole depending on the borehole position and the position of the injection arrangement.

[0074] In embodiments, the detection device comprises a camera, a thermal camera and / or a gas detecting sensor.

[0075] Hence, a reliable detection of the fluid is obtained. In embodiment, the fluid comprises a coloring agent and / or a luminescent agent and / or a reflective agent.

[0076] Hence, an even more reliable detection of the fluid is obtained. Purely by way of example, any one of the agents presented above may imply an appropriate detectability by the detection device.

[0077] In embodiments, the fluid comprises at least two components mixed prior to injection and hardening through an exothermal reaction.

[0078] Hence, a fluid is used that can be employed for various assignments, such as anchoring of a rock bolt inside the borehole.

[0079] In embodiments, the body is a portion of a rock.

[0080] Hence, the method may be used for a borehole in a rock. Purely by way of example, the method may form part of a rock bolting procedure, thereby improving the stability of the rock.

[0081] In embodiments, the fluid is a liquid.

[0082] In embodiments, the fluid is a binding liquid, i.e. a liquid having an adhesive holding capability after hardening.

[0083] In embodiments, the fluid is a resin-based grout material.

[0084] Hence, a reliable rock-bolting process is obtained.

[0085] According to a second aspect of the disclosure, at least the primary object is achieved by a control device for assessing injection of fluid into a borehole of a body, the control device being configured to control a fluid injection arrangement and a detection device, wherein the control device is configured to control the fluid injection arrangement and the detection device to perform the method according to the first aspect.

[0086] Advantages and advantageous embodiments of the second aspect largely correspond to those of the first aspect.

[0087] In embodiments, the detection device comprises a camera, a thermal camera or a gas detecting sensor. In embodiments, the fluid injection arrangement comprises a pump, at least one hose and a fluid injector.

[0088] According to a third aspect of the disclosure, at least the secondary object is achieved by a method for rock bolting of a set of boreholes in a body using a mining and / or construction machine comprising a drilling arrangement, a fluid injection arrangement and a detection device, the method comprising

[0089] - controlling the drilling arrangement to drill a borehole of the set of boreholes; - performing the method according to the first aspect;

[0090] - if the feature of assessing the injection of fluid indicates that the fluid injection is successful, proceeding to a next borehole in the set of boreholes or ending the rock bolting process if the last borehole in the set of boreholes has been reached; - if the feature of assessing the injection of fluid indicates that the the injection of fluid is unsuccessful, preferably if a leakage occurs in the fluid injection arrangement, aborting the rock bolting process and issue error information.

[0091] Hence, a rock-bolting process is obtained, which may achieve a reliable determination of the injection status. In particular, the method may achieve a rock bolting process which ensures that the boreholes are sufficiently filled and which provides for an improved detection of irregularities during the injection, such as leakages from the injection arrangement. By way of example only, the method for rock bolting according to the third aspect of the disclosure may be automated.

[0092] According to a fourth aspect of the disclosure, at least the secondary object is achieved by a control device for rock bolting of a set of boreholes in a body, the control device being configured to control a drilling arrangement, a fluid injection arrangement and a detection device, wherein the control device is configured to control the drilling arrangement, the fluid injection arrangement and the detection device to perform the method according to the third aspect.

[0093] Advantages and advantageous embodiments of the fourth aspect largely correspond to those of the third aspect.

[0094] According to a fifth aspect of the disclosure, at least the primary and / or the secondary object is achieved by a system comprising a fluid injection arrangement, a detection device and the control device according to the second aspect and / or the control device according the fourth aspect.

[0095] Advantages and advantageous embodiments of the fifth aspect largely correspond to those of the first and third aspect.

[0096] According to a sixth aspect of the disclosure, at least the primary and / or the secondary object is achieved by a mining and / or construction machine comprising the system according to the fifth aspect.

[0097] Advantages and advantageous embodiments of the sixth aspect largely correspond to those of the first and third aspect.

[0098] According to a seventh aspect of the disclosure, at least the primary and / or the secondary object is achieved by a computer program product comprising program code for performing the method according to the first aspect or the method according to the third aspect.

[0099] Advantages and advantageous embodiments of the seventh aspect largely correspond to those of the first and third aspect.

[0100] According to an eighth aspect of the disclosure, at least the primary and / or the secondary object is achieved by a non-transistory computer-readable storage medium comprising executable program instructions to perform the method according to the first aspect or the method according to the third aspect.

[0101] Advantages and advantageous embodiments of the eighth aspect largely correspond to those of the first and third aspect.

[0102] BRIEF DESCRIPTION OF THE DRAWINGS

[0103] In the following, the technology disclosed will be described in detail, with reference to exemplifying embodiments and to the enclosed drawings. In the drawings:

[0104] Fig. 1 schematically illustrates a mining and / or construction machine for rock bolting according to an embodiment of the disclosure, Fig. 2 schematically illustrates an injector according to embodiments of the disclosure,

[0105] Fig. 3a-3c schematically illustrate an automated rock bolting process according to embodiments of the disclosure,

[0106] Fig. 4 is a flow-chart illustrating steps of a method according to embodiments of the disclosure,

[0107] Fig. 5 is a flow-chart illustrating steps of a method according to embodiments of the disclosure,

[0108] Fig. 6 is a flow-chart illustrating steps of a method according to embodiments of the disclosure,

[0109] Fig. 7 is a flow-chart illustrating steps of a method according to embodiments of the disclosure,

[0110] Fig. 8 is a flow-chart illustrating steps of a method according to embodiments of the disclosure.

[0111] 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.

[0112] DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0113] The following detailed description illustrates embodiments of the present disclosure and ways in which they can be implemented. Although some modes of carrying out the present disclosure have been disclosed, those skilled in the art would recognize that other embodiments for carrying out or practicing the present disclosure are also possible.

[0114] Fig. 1 illustrates a mining and / or construction machine 1 for rock-bolting. The mining and / or construction machine 1 may comprise an injection arrangement 20 adapted inject a fluid into the borehole 11 of the body 10. For this purpose, the injection arrangement may comprise an injector 21, a pump 22, and at least one hose 23. In rock stabilizing applications, the body 10 may be a rock and the borehole 11 may be a drilled hole. The borehole 11 comprises a borehole wall 12 and the body comprises a surrounding body wall 13. The mining and / or construction machine 1 may be adapted to perform a rock bolting process, i.e. it may be adapted to for instance autonomously drill a borehole 11, place a rock bolt 14 into the borehole (or use the drill tool as rock bolt 14), and inject a fluid into the borehole 11. The fluid may be a binding liquid, such as a resin-based grout material. The fluid may comprise at least two components mixed prior to injection and hardening through a chemical reaction, such as an exothermal chemical reaction.

[0115] The drilling operation may be performed using a drill tool. The drill tool may be a reusable drill tool such as a drill rod, a drill pipe, a drill bit, or a drill string. Alternatively, the drill tool may be single-use such as a hollow core bolt 14 or a self-drilling anchor bolt 14 or a drill string. The bolt 14 may be hollow for allowing injection of the fluid through the bolt 14. Alternatively, the rig 1 is adapted to place a bolt 14 in an already existing borehole 11 and to inject the fluid into the borehole. In other examples, no bolt 14 may be used and the rig I may be adapted to inject the fluid directly in the borehole 11, for instance via the above-mentioned injector 21. The mining and / or construction machine 1 may by way of example only be adapted to operate autonomously or remotely controlled.

[0116] In some examples, the mining and / or construction machine may be configured to perform a rock bolting process involving a set of boreholes comprising a plurality of predetermined boreholes or borehole positions. The mining and / or construction machine 1 may be configured to autonomously drill boreholes 11, place a bolt 14 (or use the drill tool as bolt 14) and inject the fluid at a plurality of predetermined borehole positions. The mining and / or construction machine 1 may further comprise a system 200 comprising the injection arrangement 20, a control device 100 and at least one detection device 30. The detection device may be an image capturing device, such as a camera, a thermal camera, an infrared camera, a gas sensor or any other device suitable for detection of the fluid. The detection device 30 may be arranged on the mining and / or construction machine 1 or at portions of the injection arrangement 20.

[0117] The detection device 30 may be arranged movably to provide a good view of the borehole I I and the injection arrangement 20 in different positions. The detection device 30 may take advantage of the fact that the fluid may develop heat and / or gas emissions due to chemical hardening reactions. Hence, the detection device 30 may comprise a heat detector, such as an infrared sensor, or a gas sensor. In case of the detection device 30 being an image capturing device, the control device 100 may be configured to receive image data and process the image data in order to determine a position of the detected fluid. Further, good detection performance may be achieved by using a coloring agent, a luminescent agent and / or a reflective agent in the fluid.

[0118] Fig. 2 shows an enlarged view of a borehole 11 with a bolt 14. The at least one detection device 30 (see Fig. 1) may be adapted to detect a fluid outside of the borehole 12 and the injection arrangement 20. For example, fluid may be detected at a borehole collar, i.e. an intersection 15 between the borehole wall 12 and the surrounding body wall 13, or at portions of the injection arrangement 20. A detection of leakage at the borehole collar may indicate that the borehole is successfully filled with fluid. A detection of fluid at portions of the injection arrangement, e.g. at a connection point 16 between the injector 21 to the bolt 14, may indicate that the borehole is not filled successfully, e.g. due to a leakage occurring at the injection arrangement 20.

[0119] Figs. 3a-c schematically illustrate a rock bolting process. In the shown example, the mining and / or construction machine 1 is configured to perform a whole rock bolting cycle, including drilling of a borehole 11 and injecting a fluid in the borehole 11. In Fig. 3a, a drilling arrangement 25 is connected to a drill tool such as a bolt 14. The bolt 14 is here a drilling bolt 14 with cutting edges. The drilling arrangement 25 drives the bolt 14 into the rock 10 thereby forming a borehole 11. When the drilling of the borehole 11 is finished, the drilling arrangement 25 is detached from the bolt 14 and the injection arrangement 21 is connected to the bolt 14, see Figs. 3b-c. Next, the fluid is injected through the bolt 14. As mentioned before, the bolt 14 may be hollow, thereby forming a channel for the flow of fluid into the borehole.

[0120] Turning to Fig. 4, a method for assessing an injection of fluid into borehole 11 of body 10 is explained. When injecting a fluid into a borehole 11 , as for example during a rock stabilizing process as explained above, it is difficult to assess whether the borehole is sufficiently filled. It is therefore beneficial to use a detection device 30 in order to detect fluid outside of the borehole and the injection arrangement. However, an additional problem is that it is hard to distinguish between an expected detection of fluid, when the borehole 11 is sufficiently filled, from an unexpected detection of fluid, e.g. due to leakage from the injection arrangement 20.

[0121] To address this problem a method illustrated in Fig. 4 is proposed. The method comprises the following actions: S1 : initiating injection of the fluid into the borehole 11 using a fluid injection arrangement,

[0122] S2: detecting fluid outside the borehole 11 and the fluid injection arrangement 20 using a detection device 30, and

[0123] S3: on the basis of at least one of the following:

[0124] a detected position of the detected fluid outside the borehole 11 and the fluid injection arrangement 20;

[0125] an injection volume of the fluid, and

[0126] a time lapse TL from the time of initiation of fluid injection into the borehole 11 to the time of fluid detection outside the borehole 11 and the fluid injection arrangement 20,

[0127] assessing (S3) the injection of fluid.

[0128] Hence, the method does not only detect fluid outside the borehole 11 and the fluid injection arrangement 20, but uses further information, such as the position of the detected fluid, an injection volume of the fluid, and / or a time lapse from the time of initiation to the time of detection, to assess the injection of fluid.

[0129] Optionally, the method may comprise the following optional actions shown with dashed lines in Fig. 4:

[0130] S4a: in response to determining that the detected position of the detected fluid is at a portion of the fluid injection arrangement 20, determining that the injection of fluid is unsuccessful, preferably determining that a leakage occurs in said fluid injection arrangement 20.

[0131] S4b: in response to determining that the detected position of the detected fluid is within a predetermined distance from an intersection 14 between the borehole wall 12 and a surrounding body wall 13 of said body 10, determining that the injection of fluid is successful.

[0132] Hence, a detection of fluid at the collar of the borehole 11, i.e. at the intersection 15 between the borehole wall 12 and the surrounding body wall 13, indicates a successful injection of fluid into the borehole 11. In other words, when fluid comes out of the borehole at the collar of the borehole it may be concluded that the borehole is sufficiently filled. If, on the other hand, the position of the detected fluid is not at the borehole collar, but at a portion of the fluid injection arrangement 20, it may be concluded that the injection was not successful and / or that a leakage from the injection arrangement 20 has occurred. Although Fig. 4 exemplifies that a method may comprise each one of the optional actions S4a and S4b as presented above, it is also envisaged that other alternatives of the method may comprise only one of the optional actions S4a and S4b, such as only the second optional action S4b.

[0133] Fig. 5 shows a flow-chart of a method according to another example. The method illustrated in Fig. 5 compares the time lapse TL to a time threshold TT and comprises the following actions in addition to the already mentioned actions S1 and S2:

[0134] S2-2: using a time threshold TT for the injection of fluid into the borehole 11. S3’: assessing said status of said injection of fluid using said time threshold TT and said time lapse TL.

[0135] S4a’: in response to determining that said time lapse TL is equal to or less than the time threshold TT, determining that the injection of fluid is unsuccessful, preferably determining that a leakage occurs in said fluid injection arrangement 20.

[0136] S4b’: in response to determining that said time lapse TL is greater than the time threshold TT, determining that the injection of fluid is successful.

[0137] Hence, the time lapse TL is compared with the time threshold TT. The time threshold may be determined on the basis of information relating to the injection of fluid into the borehole 11 , such as the volume of the borehole 11 , the rate of fluid injection into the borehole 11 , porosity of the borehole 11, information about voids in the borehole, etc. The time threshold may be associated with an expected time needed for filling the borehole 11, such that a time lapse TL shorter than the time threshold TT may indicate an unsuccessful injection, since it may be deemed unlikely that the borehole 11 has been filled in this relatively short time lapse TL.

[0138] Fig. 6 shows a flow chart of another method according to an example. The method shown in Fig. 6 comprises the following actions in addition to the actions S1 and S2:

[0139] S2-3: Using, preferably Determining, a first reference time interval RTI-1. S3”: Assessing a status of fluid injection using said time lapse TL and the first reference time interval RTI-1.

[0140] S4a”: in response to determining that said time lapse TL is within the first time reference time interval RTI-1, determining that the injection of fluid is unsuccessful, preferably determining that a leakage occurs in said fluid injection arrangement 20.

[0141] The first time reference interval RTI-1 is indicative of an unsuccessful injection of fluid. The first time reference interval RTI-1 may be between a first time point from initiation of the injection and a second time point from the initiation of injection. The first time point may refer to a time needed for priming the injection arrangement, i.e. a time that is needed for filling the injection arrangement. The second time point may refer to a time associated with an expected filling time of the borehole 11. The second time point may be, but does not have to be, the time threshold mentioned above.

[0142] Moreover, Fig. 6 illustrates an alternative addition to the method comprising:

[0143] S2-3: Using, preferably Determining, a second reference time interval RTI-2. S3’”: Assessing a status of fluid injection using said time lapse TL and the second reference time interval RTI-2.

[0144] S4b”: In response to determining that said time lapse TL is within the second time reference time interval, determining that the injection of fluid is successful.

[0145] The second reference time interval RTI-2 may be indicative of a successful injection. The second reference time interval RTI-2 may generally be later than the first reference time interval RTI-1 , but may be overlapping with the first reference time interval RTI-1.

[0146] As for the time threshold TT, also the first reference time interval RTI-1 and / or the second reference time interval RTI-2 may be determined on the basis of information relating to the injection of fluid into the borehole 11. The information relating to the injection of fluid into the borehole 11 may comprises a volume of the borehole 11, a length and / or diameter of a drill tool used for drilling the borehole 11, a length and / or diameter of a bolt used for rock reinforcement, and / or a fluid injection rate. The fluid injection rate may be an instantaneous rate of fluid exiting from the injector 20. Still further, the information relating to the injection of fluid into the borehole 11 may comprise Measuring-While-Drilling, MWD-data, which has been obtained during drilling of the borehole 11. MWD-data may comprise percussion pressure, water pressure, feed pressure, and / or drill length over time during drilling. The MWD-data may give hints about voids in the body 1 or about the porosity of the body 1. Fig. 7 shows another example of a method according to the present disclosure.

[0147] Additionally, to the already described actions, the method according to this example comprises the following actions:

[0148] S5: in response to detecting fluid outside the borehole 11 and the fluid injection arrangement 20, terminating the fluid injection into the borehole 11.

[0149] When fluid is detected outside of the borehole 11 and the fluid injection arrangement 20, the injection of fluid may be terminated regardless of the assessed status of injection either because the borehole 11 is deemed to be sufficiently filled or a leakage is occurring.

[0150] S6: in response to determining that the injection of fluid is unsuccessful, issuing error information.

[0151] In case the injection status is unsuccessful, error information may be issued, e.g. to an operator, a control system, or the like. The error information may be issued to a user device of an operator and shown on a display.

[0152] Fig. 8 shows a flow-chart of a method for performing a rock bolting process at a set of boreholes. The method may be performed by a control device 100 of an autonomous mining and / or construction machine 1. The mining and / or construction machine 1 may comprise a drilling arrangement 25, a fluid injection arrangement 20 and a detection device 30. The method comprises the following actions:

[0153] SO: Controlling the drilling arrangement 25 to drill a borehole 11 of the set of boreholes.

[0154] The set of boreholes may comprise at least one desired borehole position for each borehole 11. The set of boreholes may be pre-programmed by an operator, e.g. at a remote location, whereupon the set of boreholes is received at the control device 100 of the mining and / or construction machine 1. Alternatively, the control device 100 of the mining and / or construction machine 1 may comprise an input arrangement for inputting the set of boreholes 11. The drilling may be performed as explained above using a rock bolt 14 adapted for drilling. Next, the actions pertaining to the injection S1 of the fluid, detection S2 of fluid and assessment S3 of the injection status are performed. Optionally, any of the optional actions described above may be performed.

[0155] Further the method comprises the following actions:

[0156] S7: if fluid injection is successful, proceeding to a next borehole 11 in the set of boreholes or ending the rock bolting process if the last borehole 11 in the set of boreholes has been reached.

[0157] Hence, unless an unsuccessful injection is identified, the mining and / or construction machine 1 proceeds from one borehole to the next until all boreholes have been drilled and rock bolted.

[0158] S8: if the injection of fluid is unsuccessful, preferably if a leakage occurs in said fluid injection arrangement 20, aborting the rock bolting process and issue error information.

[0159] If an unsuccessful injection is identified the rock bolting process is aborted, such that an operator can investigate the error and take counter-measures.

[0160] It is to be understood that the present disclosure is not limited to the examples 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 present disclosure and appended claims.

Claims

CLAIMS1. A method performed by a mining and / or construction machine for injecting a fluid into a borehole (11) defined by a borehole wall (12) extending into a body (10), the method comprising:- initiating (S1) the injection of the fluid into the borehole (11) using a fluid injection arrangement (20),- detecting (S2) fluid outside the borehole (11) and the fluid injection arrangement (20) using a detection device (30), and- on the basis of at least one of the following:- a detected position of the detected fluid outside the borehole (11) and the fluid injection arrangement (20);- an injection volume of the fluid, and- a time lapse (TL) from the time of initiation of fluid injection into the borehole (11) to the time of fluid detection outside the borehole (11) and the fluid injection arrangement (20),assessing (S3) the injection of fluid.

2. The method according to claim 1 , wherein the method comprises, in response to determining that the detected position of the detected fluid is at a portion of the fluid injection arrangement (20), determining (S4a) that the injection of fluid is unsuccessful, preferably determining that a leakage occurs in said fluid injection arrangement (20).

3. The method according to claim 1 or claim 2, wherein the method comprises, in response to determining that the detected position of the detected fluid is within a predetermined distance from an intersection (14) between the borehole wall (12) and a surrounding body wall (13) of said body (10), determining (S4b) that the injection of fluid is successful.

4. The method according to any one of the preceding claims, wherein the method comprises,- using (S2-2) a time threshold (TT) for the injection of fluid into the borehole (11);and- assessing (S3’) said status of said injection of fluid using said time threshold (TT) and said time lapse (TL).

5. The method according to claim 4, wherein said method comprises:in response to determining that said time lapse (TL) is equal to or less than the time threshold (TT), determining (S4a’) that the injection of fluid is unsuccessful, preferably determining that a leakage occurs in said fluid injection arrangement (20).

6. The method according to claim 4 or claim 5, wherein said method comprises:in response to determining that said time lapse (TL) is greater than the time threshold (TT), determining (S4b’) that the injection of fluid is successful.

7. The method of any one of claims 4 - 6, wherein the method comprises determining the time threshold (TT) on the basis of information relating to the injection of fluid into the borehole (11).

8. The method of any one of the preceding claims, wherein the method comprises: in response to detecting fluid outside the borehole (11) and the fluid injection arrangement (20), terminating (S5) the fluid injection into the borehole (11).

9. The method of claim 8, when dependent on any one of claims 2 or 5, wherein said method comprises, in response to determining that the injection of fluid is unsuccessful, issuing (S6) error information.

10. The method according to any one of the preceding claims, wherein the fluid injection arrangement (20) comprises at least one, preferably each one, of: a pump (22), at least one hose (23) and a fluid injector (21).

11. The method according claim 10, wherein the method comprises, in response to determining that the detected position of the detected fluid is at the pump, or at said at least one hose or at the fluid injector (21), determining that the injection of fluid is unsuccessful, preferably determining that a leakage occurs in said fluid injection arrangement (20).

12. The method according to any one of the preceding claims, further comprising- using, preferably determining, (S2-3) a first reference time interval (RTI-1), - assessing (S3”) a status of fluid injection using said time lapse (TL) and the first reference time interval (RTI-1).

13. The method according to claim 12, wherein said method comprises:in response to determining that said time lapse (TL) is within the first time reference time interval, determining (S4a”) that the injection of fluid is unsuccessful, preferably determining that a leakage occurs in said fluid injection arrangement (20).

14. The method of any one of claims 12 - 13, wherein the method comprises determining the first reference time interval (RTI-1) on the basis of information relating to the injection of fluid into the borehole (11).

15. The method according to any one of the preceding claims, further comprising- using, preferably determining, (S2-3) a second reference time interval (RTI-2), - assessing (S3’”) a status of fluid injection using said time lapse (TL) and the second reference time interval (RTI-2).

16. The method according to claim 15, wherein said method comprises:in response to determining that said time lapse (TL) is within the second time reference time interval, determining (S4b”) that the injection of fluid is successful.

17. The method of any one of claims 15 - 16, wherein the method comprises determining the second reference time interval (RTI-2) on the basis of information relating to the injection of fluid into the borehole (11).

18. The method of any one of claims 7, 14 or 17, wherein the information relating to the injection of fluid into the borehole (11) comprises one or more of the following: a volume of the borehole (11), a length and / or diameter of a drill tool used for drilling the borehole (11), a length and / or diameter of a bolt (14) used for rock reinforcement, and a fluid injection rate.

19. The method according to claim 18, wherein the information relating to the injection of fluid into the borehole (11) comprises Measuring-While-Drilling (MWD)-data, which has been obtained during drilling of the borehole (11).

20. The method of claim 19, wherein the MWD-data is indicative of voids around the borehole (11).

21. The method according to any one of the preceding claims, further comprising- adjusting an orientation and / or a position of the detection device (30) before and / or during the fluid injection.

22. The method according to any one of the preceding claims, wherein the detection device (30) comprises a camera, a thermal camera and / or a gas detecting sensor.

23. The method according to any one of the preceding claims, wherein the fluid comprises a coloring agent and / or a luminescent agent and / or a reflective agent.

24. The method according to any one of the preceding claims, wherein the fluid comprises at least two components mixed prior to injection and hardening through an exothermal reaction.

25. The method according to any one of the preceding claims, wherein the body (10) is a portion of a rock.

26. The method according to any one of the preceding claims, wherein the fluid is a resinbased grout material.

27. A control device (100) for assessing injection of fluid into a borehole (11) of a body (10), the control device (100) being configured to control a fluid injection arrangement (20) and a detection device (30), wherein the control device (100) is configured to control the fluid injection arrangement (20) and the detection device (30) to perform the method according to any one of the preceding claims.

28. The control device (100) according to claim 27, wherein the detection device (30) comprises a camera, a thermal camera or a gas detecting sensor.

29. The control device (100) according to claims 27-28, wherein the fluid injection arrangement (20) comprises a pump (22), at least one hose (23) and a fluid injector.

30. A method for rock bolting of a set of boreholes in a body (10) using a mining and / or construction machine (1) comprising a drilling arrangement (25), a fluid injection arrangement (20) and a detection device (30), the method comprising- controlling (SO) the drilling arrangement (25) to drill a borehole (11) of the set of boreholes;- performing (S1-S6) the method according to any one of claims 1-26;- if the feature of assessing the injection of fluid indicates that the fluid injection is successful, proceeding (S7) to a next borehole (11) in the set of boreholes or ending the rock bolting process if the last borehole (11) in the set of boreholes has been reached;- if the feature of assessing the injection of fluid indicates that the injection of fluid is unsuccessful, preferably if a leakage occurs in said fluid injection arrangement (20), aborting (S8) the rock bolting process and issuing error information.

31. A control device (100) for rock bolting of a set of boreholes in a body (10), the control device (100) being configured to control a drilling arrangement (25), a fluid injection arrangement (20) and a detection device (30), wherein the control device (100) is configured to control the drilling arrangement (25), the fluid injection arrangement (20) and the detection device (30) to perform the method according to claim 30.

32. A system (200) comprising a fluid injection arrangement (20), a detection device (30) and the control device (100) according to claims 27-29 and / or the control device (100) according to claim 31.

33. A mining and / or construction machine (1) comprising the system (200) according to claim 32.

34. A computer program product comprising program code for performing the method of claims 1-26 or claim 3035. A non-transitory computer-readable storage medium comprising executable program instructions to perform the method of claims 1-26 or claim 30.

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