ADAPTIVE COLLARING USING ROCK FRACTURE INDICATION

Description

RELATED APPLICATION DATA

This application claims priority of U.S. Provisional Application No. 63/701,099 filed Sep. 30, 2024, which the entirety thereof is incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to a hole fracture indicator system and method for adapting collaring based on rock conditions of blastholes for drilling machines.

BACKGROUND

Blasthole drilling processes commonly use blasthole drilling rigs to excavate rock. The processes use a rig to drill a plurality of holes and then fill the holes with explosives. The blastholes typically drilled using rotary or percussive drilling equipment vary in diameter, for example 6 to 22 inches, and depth, for example, up to 150 feet or more.

As is known, there are a number of factors that may adversely affect the quality of a borehole. For example, loose material can accumulate on the surface adjacent the borehole, which can result in back-filling of the borehole after completion. The borehole may also be plugged if this material falls into the borehole causing the drill bit to clog and/or jam. Moreover, the ground surfaces that the holes are drilled into are often fractured such that initial drilling of the hole is difficult.

The number of fractures impact the quality, i.e., the drilling and blastability, of a bore hole. Measurement-while-drilling (MWD) data can be related to the physical properties of the rock being drilled. For example, MWD systems on blasthole drills can be used to accurately detect fracture zones within a blasthole. MWD, using signals from sensors installed on the drill, which upon conversion, can be used to guide the drilling operation through either manual or automated (controlled) means. Various drilling parameters, which when plotted against depth are capable of highlighting the location of fractures.

Part of the drilling process includes a collaring operation. Collaring operations are known and are performed manually or automatically. The collaring operation can be used to set a base for the hole. However, the productivity of the drill rig can also be adversely affected if the collar is not properly prepared. As described above, back-filling or plugging of the borehole can occur forcing the drill rig to clear the borehole of obstructions, often more than once.

Current auto-collaring operations automatically creates a stable collar (anthill on top of the hole) for the hole using water and constant back and forth drilling, as well as, managing fracture zones in the blasthole. The idea of collaring is to bind fine dust from the drilling process to the wet sides of the hole using water similar to creating concrete walls. Good collars are needed in soft rock conditions, fracture zones within the hole and/or when holes are blasted with too much explosive material, which can cause the hole to collapse after the drill string is pulled out of the hole.

However, proper collaring takes a lot of time and is typically not done by operators if not mandatory. Moreover, current auto-collaring has a fixed depth set by the operator or predetermined, where the drill automatically keeps creating the collar. This depth may not correspond to the actual required collar depth, i.e., it might be too short (causing collapse and/or requiring a re-drill) or too long (wasting time) or not occur at a fracture zone located via MWD data.

Current auto-collaring also has a fixed water amount that is used to create the solid hole walls. As such, the known systems use high amounts of water throughout the collaring process to water the walls. This means that the dust gets bonded to the walls throughout the collaring depth. This also means that even in fully autonomous drills the operator needs to interact with the rig to activate the auto-collaring or use the extra time to stabilize all the holes.

Thus, there is a need for an adaptive auto-collaring process that can determine positions in the hole depth in addition to the top of the hole that need collaring and also control the water amount applied at the collaring locations throughout the hole depth depending on rock conditions.

SUMMARY

According to an embodiment, the present the hole fracture indicator system can mark the depths which need collar/wall creation using additional measurement/calculation. If the hole is extremely fractured (loose gravel, etc.) the system marks the depth as the start of an area to be fortified. If the fractures stop, the system can end the area where the additional wall creation is needed. In other words, the system can measure where the walls need additional support.

When the hole fracture indicator system knows the amount of fractures and their locations in the hole, the system can define how much “concrete” needs to be created and where. This means that the water amount can automatically be controlled (even along the length of the hole) to help fortify the hole wall. If there are a lot of fractures, extra water can be added to the location and drilling forward can continue.

Also, to further improve the process from drilling to a certain depth and pulling back to the top of the hole, the present hole fracture indicator system will enable the drill to drill until it sees fractures and then start watering that area. After drilling a certain depth past, the system returns to water the area again with excessive water and finally drill down to create the fine dust for the “concrete” to form. If the area has more fractures, the system can repeat the process to bind even more dust to the walls in that area.

Accordingly, the present disclosure is not limited on a fixed depth of the collar, but rather on the competency of the structure of the blasthole as will be described further herein.

In an example embodiment, a hole fracture indicator system for a drilling machine forming boreholes in a rock formation including at least one processing core, at least one memory including computer program code, the at least one memory and the computer program code being configured to, with the at least one processing core, cause the system at least to initiate rotation of a drill bit of the drilling machine; receive, in real time, measurement-while-drilling (MWD) data from one or more sensors of the drilling machine during drilling of the borehole; drill until a fracture start depth in the borehole is determined; mark the fracture start depth; when an amount of fracture and location of the fracture in the borehole is determined, determine how much water is needed to fortify a wall of the borehole at the fracture; and initiate collaring of the borehole at the fracture start depth by initiating watering of the rock formation upon determination of the start of fractured area.

In an example embodiment, a hole fracture indicator system for a drilling machine forming boreholes in a rock formation comprising a control system associated with the drilling machine and arranged to implement collaring of a borehole, the control system being arranged to monitor one or more drilling parameters of the drilling machine, the control system including at least one processor, and at least one memory including computer program code; one or more sensors associated with the drill string of the drilling machine, the one or more sensors being arranged to generate measurement-while-drilling (MWD) data that relates to physical properties of the rock formation; and a water injection system operatively connected to the drill string, the water injection system being operated by the control system to provide water to a drill bit of the drilling machine to collar an opening and wall of the borehole.

In an example embodiment, a method for auto-collaring boreholes for a drilling machine in a rock formation, the method comprising the steps of initiating rotation of a drill bit of the drilling machine; receiving, in real time, measurement-while-drilling (MWD) data from one or more sensors of the drilling machine during drilling of the borehole; drilling until a fracture start in the borehole is determined; marking the fracture start; when an amount of fracture and location of the fracture in the borehole is determined, determining how much water is needed to fortify a wall of the borehole at the fracture; and initiating collaring of the borehole at the fracture start by initiating watering of the rock formation upon determination of the start of the fracture.

The foregoing summary, as well as the following detailed description of the embodiments, will be better understood when read in conjunction with the appended drawings. It should be understood that the embodiments depicted are not limited to the precise arrangements and instrumentalities shown.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic side view of a mining vehicle according to the present disclosure.

FIG. 2 is a schematic illustration of the control system of the mining vehicle of FIG. 1.

FIG. 3 is a cross-section of a blasthole.

FIG. 4 is a flow chart illustrating the hole fracture indicator system of the present disclosure.

FIG. 5A is a graph of MWD data illustrating a fracture indicator along the borehole depth. FIG. 5B visualizes the fracture indicator and depth of the graph of FIG. 5A.

FIG. 6 is a view of the drill.

FIGS. 7A and 7B are cross-sections of the blasthole during the process of FIG. 4.

FIG. 8 is a flow chart of the water control of the present disclosure.

FIG. 9 is a graph of required passes per fracture amount.

DETAILED DESCRIPTION

As shown in FIG. 1, a mining vehicle 10, such as a rotary blasthole drill rig, includes a mobile deck or carriage 12 and a mast 14 mounted on the carriage. Mining vehicle 10 can be a down-the-hole percussive (DTH) drill rig, a boom drill or a rotary blasthole drill rig. It should be appreciated that other types of vehicles are contemplated and the present disclosure is not limited to mining vehicles or a particular type of mining vehicle.

Mast 14 is movable between a horizontal, stored position and a vertical position as shown. The mast carries a rotary head 16, which is capable of rotating a drill string 18 to which a drill bit 20 is mounted. The rotary head 16 can be raised and lowered to enable pipes to be removed or added to the drill string.

The vehicle is powered by a drive assembly, which includes known components. Vehicle 10 also includes other conventional components, which will not be discussed further herein. A cab 22 could also be provided on carriage 12.

Vehicle 10 is arranged for forming or drilling a borehole 8, which can be used to form blastholes of the type commonly used in mining operations. After the vehicle 10 has been used to drill a plurality of blastholes in a desired pattern, the various blastholes are then filled with an explosive material (not shown). The subsequent detonation of the explosive material ruptures or fragments the ground or structure, which may then be collected and processed.

As will be described further herein, vehicle 10 includes a control system 30 that monitors one or more drill parameters while the boreholes are being formed or drilled. The monitored drill parameter is compared with a predetermined specification for the parameter. If the monitored drill parameter is outside the specification, the control system ensures that the borehole is drilled to the desired specification.

Referring to FIG. 2, control system 30 can include a control unit 32 having control console and a display with a graphic user interface (GUI) for control by an operator. Control unit can be located within cab 22 or a remote location for autonomous operation. As will be described further herein, control unit 32 includes controls for operating the drill rig, such as programmable logic controllers, and controller area network based devices for processing and displaying data obtained from, for example, sensors 24 (FIG. 1) located on the rotary head 16. FIG. 2 schematically shows the control system 30. It should be appreciated that FIG. 2 is not limiting, and the control system 30 may include other and further components relevant to its function.

Measurement-while-drilling (MWD) data can also be determined during drilling. The MWD data can then be related to the physical properties of the rock being drilled. The at least one sensor 24 can generate the MWD data indicative of the properties of the rock being drilled. It should also be appreciated that other sensors can be provided to generate information corresponding to positions corresponding to the rock hardness data.

Such MWD data can include, inclination of the bit, direction of the bit, downhole weight on bit, downhole torque and the like, but is not limited thereto. As will be described further herein the MWD data can be used to determine a fracture indicator of the rock formation.

In addition to control unit 32, control system 30 includes a computer or microprocessor 50 and/or a signal processor possibly having memory capacity external thereto in order to execute necessary calculation and comparison procedures by the software contained therein.

Computer/processor 50 may be a programmable digital computer having a read-only memory, a non-transitory computer readable storage medium for storing instructions executable by a processor (such as a random-access memory), at least one central processing unit or processor, and a hard drive or flash memory or the like for further storage of programs and data, as well as input and output ports.

There is provided a computer program, a computer program product or non-transitory computer-readable medium including computer program code for, when executed in a data processor, causes the system to perform the method or an embodiment thereof. In other words, the computer program may include computer readable code means, which when run by the system causes the device/system to perform the method steps described in any of the described embodiments.

The computer program may be carried by a computer program product connectable to the processing circuitry. The computer program product may be the memory. The memory may be realized as for example a RAM (Random-access memory), ROM (Read-Only Memory) or an EEPROM (Electrical Erasable Programmable ROM). Further, the computer program may be carried by a separate computer-readable medium, such as a CD, DVD or flash memory, from which the program could be downloaded into the memory. Alternatively, the computer program may be stored on a server or any other entity connected to the system. The computer program may then be downloaded from the server into the memory. The method(s) may thus be computer-implemented based algorithm(s) executable by the generic processing functions, an example of which is the at least one processor.

Control unit 32 and computer 50 are operatively associated with the vehicle, as well as various systems thereof, e.g., drill feed system 42, motor system 44, air injection system 46, and water injection system 48, etc. Control system 30 monitors various drill parameters generated or produced by the various drill systems and controls them as necessary to form the blasthole 8. In doing so, control system 30 may also implement various hole routines.

Referring again to FIG. 2, drill feed system 42, which is connected to the drill string 20, may be operated by control system 30 to raise and lower drill bit 20. Drill feed system 42 can include sensors and transducers to monitor and sense the position of the drill bit, as well as, for example, the hoisting force and weight on bit.

Drill motor system 44, which is also connected to the drill string 18, may be operated by control system 30 to provide a rotational force or torque to rotate the drill bit 20. The drill motor system 44 may also be provided with various sensors and transducers to allow the control system 30 to monitor or sense the torque applied to the drill bit, as well as the rotational speed and direction of rotation of drill bit 20.

It should be appreciated that the present disclosure should not be limited to control system 30 including any particular device or system. Accordingly, control system 30 may have a variety of systems and devices suitable for performing particular functions.

As set forth above, control system 30 may include a general purpose programmable computer, such as a personal computer, that is programmed to implement the various processes and steps described herein and that can interface with the particular systems provided on vehicle 10 as described herein.

Referring again to FIG. 2, control system 30 includes air injection system 46, connected to the drill string 18, which is arranged to provide high-pressure air thereto. High-pressure air from air injection system 46 is directed through a suitable conduit (not shown) provided in the drill string 18, and which exits through one or more openings provided in drill bit 20. As described above, the control system 30 is operatively connected to the air injection system 46 to control the operation thereof. In addition, control system 30 also monitors the air pressure provided to the drill string 18.

Water injection system 48 is also operatively connected to the drill string 18. Control system 30 may operate the water injection system 48 to provide a drilling fluid, such as water, to the drill bit 20. Pressurized water from the water injection system 48 can be supplied via a conduit or passageway (not shown) provided in drill string 18 so as to exit drill bit 20. Control system 30 is arranged to monitor or sense various drill parameters relating to the function and operation of the water injection system 48 so that the water from water injection system 48 can be used to collar the opening and wall of the blasthole. The water control process is further described herein in relation to the water control flow chart in FIG. 8.

Air-injection system 46 and water-injection system 48 are also operatively connected to the computer 50. Both systems may also include various sensors and transducers to allow the control system 30 to monitor or sense the amounts or flows of injected fluids.

Computer/processor 50 of control system 30 is operatively connected to a database 40 of predetermined drilling parameters. As is known, database 40 can be provided with predetermined settings and parameters for performance of the drilling process.

As previously mentioned, the control system 30 is operatively connected to the various systems and devices of vehicle 10 and receives information (i.e., the MWD data and parameters above) from the various systems and devices. In addition, control system 30, described above, also implements a collaring routine, which will be described further herein.

Referring to FIG. 3, the control system 30 may be programmed to implement a method of collaring. Fractured areas 60 often occur within the blasthole 8. As shown, fractured areas can be subsurface and can be located in numerous areas along the depth of the blasthole. As drill bit 20 is advanced or driven into the ground to form blasthole 8 or during retraction when the drill bit 16 is being withdrawn from the borehole, the water injection system can be activated.

Control system 30 is arranged to monitor or sense various drill parameters/signals/data from MWD and in conjunction with the water injection system 48 to operate a hole fracture indicator routine, shown in a flowchart 70 in FIG. 4, and water control flow chart of FIG. 8 so that the quality of the hole structure is monitored during the drilling operation and water from water injection system 48 can be selectively used to collar the opening and determined wall parts of the blasthole.

Adaptive, automatic collaring with fracture information is described in FIGS. 4-9. In the flowchart 70 of FIG. 4, in a first step 72, drilling begins at upper collar 56 with the predefined information of the borehole 8, as shown in FIG. 3, i.e., initiating rotation of the drill bit based on predefined collar settings of the borehole. During drilling control system 30 receives, in real time, measurement-while-drilling (MWD) signals from the one or more sensors of the drilling machine during drilling of the borehole. Water will initially follow the chosen drill recipe, in which it can be set to any value between 0-100%. Usually, water is used throughout the hole, but less than during collaring.

Drilling continues to step 74. In step 74, the fracture indicator of the rock formation is determined, i.e., fracture mapping begins. Referring to FIG. 5A data coming from the MWD is used to determine a fracture indicator of the rock formation along the depth of the borehole. The fracture indicator is a number from 0 to 1, with zero (0) meaning that the rock formation is solid and without any fracture, and one (1) meaning that there is no solid rock, i.e., basically sand. During drilling the fracture indicator number can be calculated in real time. For example, a sample can be generated every 20 ms or if during drilling about 2 m/min, which would generate a sample for every 0.033 mm. If should be appreciated that the fracture amount changes rapidly so the system uses a median to sample for the system. As shown in FIG. 5B, data visualized on the GUI of the system can be used to determine the fracture indicator at particular depths, Accordingly, from the graph of FIG. 5A one can see a sample from FIG. 5B. Thus, the collaring process is adaptive based on the above.

Referring again to FIG. 4, if in step 74 if the determined fracture indicator is not greater than a predetermined limit, drilling will continue in step 76. If the fracture indicator number is greater than the predetermined limit, the system will measure and store a fracture start depth F_s in step 78.

In step 80 the fracture indicator number from step 78 is determined to be greater than the limit. If the fracture indicator is greater than the limit, in step 82, it is determined if drilling past a wide section of the tooling has occurred.

In step 82, referring to FIG. 6, if drilling past the widest section of the tooling is determined. This is relevant as rocks and dirt can fall above bit sub 28 and drilling past such cannot happen without fortifying the walls or the drill will get stuck. As shown in FIG. 6, the wide section of the tooling W is the sum of the length of bit 20 and bit sub 28. In some cases, bit sub 28 is as wide as the pipe 18 and in these cases only the length of bit 20 is used. If drilling past the wide section is not necessary drilling continues in step 84.

Referring again to FIG. 5A, hole depth can be determined by using an absolute encoder that can be used to determine the location of the head and utilize predefined tooling lengths and added pipe count to define the location of the bit. This value is referenced to a detected or predefined ground level to define the hole depth.

The fractures are mapped, see FIGS. 5a and 5B, and based on the map the system knows the location of the fractures throughout the hole. As previously described, the fracture map comes by using the depth and the fracture indicator.

If the fracture indicator determined in step 80 is not greater than the limit or if it is necessary to drill past the side section of the tooling, then collaring can begin in step 86.

Referring to FIGS. 7A and 7B, if the hole is extremely fractured (loose gravel, etc.) the system marks the depth as a start 64 or Fs of fracture area 62 to be fortified in steps 86-94, shown in FIG. 4 and described further herein. If the fractures stop, the system can end the area where the additional wall creation is needed. To clarify, system 70 can measure where the walls need additional support.

When the system knows the amount of fractures and their locations in borehole 8, the system can define how much “concrete” needs to be created and where. This means that when water injection 68 starts at step 86, the water amount can automatically be controlled (even through the length of the hole) to help fortify the hole walls. If there is not a lot of fractures, extra water can be provided to the location and drilling forward continued.

Referring again to FIG. 4, in step 86 the drill is pulled above the fracture start depth F_s or 64, this is recorded as a pass count +1. Step 74 resets the pass count to zero. Step 86 coordinates with step 100 of the water control flow chart of FIG. 8. In step 88, and referring again to FIGS. 7A and 7B, bit 20 is slowly past the fracture areas 60, 62 and water injection 68 waters the wall. In step 90, drilling to ground creates dust for the concrete to form. Step 90 coordinates with step 104 of the water control flow chart of FIG. 8, which will be described further herein.

In step 92, it is determined if the required passes have been completed, i.e., if the pass count is greater than the required number. Referring to FIG. 9, the graph illustrates the number of passes (pass count) that are required to fortify the rock such that the fracture amount drops at a point at which the rock cannot be further fortified as there are no walls to tie the dust with water.

If the required passes are completed then normal drilling continues in step 94. If not, steps 86-92 are repeated. If the operator has high volume water injection active, the system limits the water amount so that dust can be formed.

As shown in FIG. 8, the water control starts at step 72 when drilling begins. The water level is determined from pre-set drilling recipes based on the drilling state of the particular rock formation. A recipe can be a set of drilling values for a drilling domain. Thus, drilling domain is the rock hardness (or recipe), which defines a set points for all the drilling settings, in this case for example, a setting for water amount in drilling states find rock (above ground), collaring and full power (past collaring depth).

In step 98, if the drill bit is pulled back for fractures detected the water level will increase to the wall watering level at step 100. As set forth previously, step 100 coordinates with step 86 of the flow chart of FIG. 4. Pull back for fractures can happen at any stage of the drilling sequence.

Drilling new ground is determined at step 102 and water injection continues where in step 104 the water level is reduced to the dust level until it is determined in step 106 that the fractures have ended, such as point 66 in FIG. 7A, i.e., that the fracture mapping/fracture indicator is less than the limit. If yes, step 96 through 106 is repeated. Step 104 coordinates with step 90 of FIG. 4.

Thus, to further improve the process from drilling to a certain depth and pulling back to top of the hole, the system can drill and pull back to just above the fracture and increase the watering of that area and finally drill down to create the fine dust for the “concrete” to form.

Water injection is reduced to minimum when creating dust and increased to high value when watering the walls. Drilling occurs as long as possible (defined by the wide portions of the tooling that support the walls) and pull up when it is necessary to add water to the hole walls. Watering occurs when pulling up and when going back. Drilling 1 with minimal water amount creates dust that binds to the hole walls with the water.

Although the present embodiment(s) has been described in relation to particular aspects thereof, many other variations and modifications and other uses will become apparent to those skilled in the art. It is preferred therefore that the present embodiment(s) be limited not by the specific disclosure herein, but only by the appended claims.