Shearing head apparatus

Abstract

The shear head apparatus includes a monitoring head (303) having sensors and emitters within a cylindrical body. A shear head (205) is coupled to the monitoring head from below. The shear head (205) has a tubular structure with a plurality of holes (203) formed around an outer surface of the tubular structure. A plurality of rollers (603) are coupled with a modified cutter head and disposed within the plurality of holes (203). A plate (601) supports the plurality of rollers (603) within the shear head (205). The plate (601) is selectively movable between a first radial position and a second radial position to apply a radial force by the modified cutter head to the rock (605) by adjusting an internal pressure of the shear head (205). The emitters send recorded acoustic emissions to a computing system for determining properties of the rock (605) as the apparatus tests the rock in a borehole.

Description

Background Technology

[0001] In oil fields, drilling operations involve a complex series of procedures necessary to construct wellbores for extracting natural resources. The drilling efficiency typically depends on the rate of return (ROP), which is the speed at which the drill bit breaks up rock to deepen the borehole. As the drill bit breaks up rock in the borehole, drill cuttings are generated, and these cuttings need to be removed from the drill bit so that it can continue breaking up new rock. For drilling operations to be efficient, ROP must be balanced with other aspects of the drilling operation. Therefore, when addressing issues such as reservoir compaction, hydraulic fracturing, borehole stability, and sand production, the properties of the subsurface formation and the rock within the borehole are often required. Summary of the Invention

[0002] In a first generalized example, an apparatus tests rock in a borehole. The apparatus includes a monitoring head with sensors and transmitters within a cylindrical body, and a shear head coupled to the monitoring head from below. The shear head has a tubular structure with a plurality of holes formed around the outer surface of the tubular structure. A plurality of rollers are coupled to a modified cutter head and disposed within the plurality of holes. A plate supports the rollers within the shear head. The plate is selectively movable between a first radial position and a second radial position to apply a radial force to the rock by adjusting the internal pressure of the shear head. When the plate is in the first radial position, the modified cutter head is within the outer surface. When the plate is in a third radial position between the first and second radial positions, the modified cutter head contacts the rock. When the plate is in the second radial position, the modified cutter head is at its maximum penetration distance in the rock. The sensors record acoustic emissions generated between the modified cutter head and the rock, and the transmitter sends the recorded acoustic emissions to a computing system for determining the properties of the rock when the apparatus tests rock in a borehole.

[0003] The monitoring head may include an upper end coupled to the lower end of a tubing string for rotating the device at a predetermined rate and for applying shear force to the rock using the modified cutter head. The plurality of toothed cones may be hardened steel, while the modified cutter head is a polycrystalline diamond composite drill bit with a wear-resistant body. The modified cutter head may include multiple different cutter heads for generating acoustic emissions within a range of amplitudes and frequencies used to accurately determine the properties of the rock. The multiple different cutter heads may include one or a combination of conical cutting teeth, axe-shaped cutting teeth, ball-shaped cutter heads, polygonal cutter heads, etc. The properties of the rock may include its hardness, cohesiveness, angle of friction, tensile strength, brittleness, and resistance to destructive forces.

[0004] In a second generalized example, a system includes a tubular column coupled to an external drive and computing system. A test apparatus is coupled to the lower end of the tubular column and positioned in a borehole to test rock within the borehole. The test apparatus includes a monitoring head with sensors and transmitters within a cylindrical body. A shear head is coupled to the monitoring head from below. The shear head has a tubular structure with a plurality of holes formed around the outer surface of the tubular structure. A plurality of rollers are coupled to a modified cutter head and disposed within the plurality of holes. A plate supports the plurality of rollers within the shear head. The plate is selectively movable between a first radial position and a second radial position to apply a radial force to the rock by adjusting the internal pressure of the shear head. When the plate is in the first radial position, the modified cutter head is within the outer surface; when the plate is in a third radial position between the first and second radial positions, the modified cutter head contacts the rock. When the plate is in the second radial position, the modified cutter head is at its maximum penetration distance in the rock. Sensors record acoustic emissions generated between the modified cutter head and the rock. The transmitter sends the recorded acoustic emissions to a computing system to determine the properties of the rock when the equipment tests the rock in the borehole.

[0005] The external drive can be configured to rotate the drill string, causing the testing equipment to rotate at a predetermined rate, thereby applying shear force to the rock through the modified cutter head. The external drive can also be configured to move the testing equipment along the borehole to different locations to test different types of rock.

[0006] The modified cutting head may include multiple different cutting heads for generating acoustic emissions within a range of amplitudes and frequencies used to accurately determine the properties of the rock. The multiple different cutting heads may include one or a combination of conical cutting teeth, axe-shaped cutting teeth, spherical cutting heads, polygonal cutting heads, etc. The properties of the rock may include its hardness, cohesiveness, angle of friction, tensile strength, brittleness, and resistance to destructive forces.

[0007] In a third generalized example, a method includes lowering a shearing head device coupled to the lower end of a tubing string to test rock in a borehole. The method also includes supplying pressurized fluid to the shearing head device through a conduit in the tubing string. The pressurized fluid pushes outward a plate supporting a plurality of roller cones, and modified cutter heads coupled to the roller cones contact the rock. The method further includes receiving acoustic data from the shearing head device of acoustic emissions generated between the modified cutter heads and the rock. The method also includes using the acoustic data to determine the properties of the rock while the shearing head device is testing the rock in the borehole.

[0008] The method may also include rotating the tubing string to rotate the shear head device, thereby causing the modified cutter head to apply shearing force to the rock. The method may also include rotating the tubing string to rotate the shear head device, thereby causing the modified cutter head to move laterally within the rock with a maximum penetration distance. The method may also include moving the shear head device along the borehole to test second rock at different locations.

[0009] Pressurized fluid can push the plate to a second radial position that defines the maximum penetration distance of the modified cutter head in the rock, thereby causing rock fracturing. Acoustic data can be data on the amplitude and frequency range of acoustic emissions generated between the rock and the modified cutter head with multiple different cutter heads. The multiple different cutter heads may include one or a combination of conical cutting teeth, axe-shaped cutting teeth, ball-shaped cutter heads, polygonal cutter heads, etc. Rock properties may include rock hardness, cohesion, angle of friction, tensile strength, brittleness, and resistance to fracturing.

[0010] The foregoing general description and the following detailed description are examples of the invention and are intended to provide an overview or framework for understanding the nature of the claimed invention. The accompanying drawings are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification. The drawings illustrate various embodiments of the invention and, together with the description, serve to explain the principles and operation of the invention. Attached Figure Description

[0011] The following is a description of the figures in the accompanying drawings. In the drawings, the same reference numerals denote similar elements or actions. The dimensions and relative positions of the elements in the drawings are not necessarily drawn to scale. For example, the shapes and angles of various elements are not necessarily drawn to scale, and some of these elements may be arbitrarily enlarged and positioned to improve the readability of the drawings. Furthermore, the specific shapes of the elements drawn are not necessarily intended to convey any information about the actual shape of the particular element, and are chosen solely for ease of identification in the drawings.

[0012] Figure 1 This is a schematic diagram of a system used to test rocks in a borehole.

[0013] Figure 2 A shear head device according to one or more embodiments is shown.

[0014] Figure 3 yes Figure 1 The system block diagram.

[0015] Figure 4A , Figure 4B , Figure 4C and Figure 4D A modified cutter head according to one or more embodiments is shown.

[0016] Figure 5An exploded view of a modified cutter head according to one or more embodiments is shown.

[0017] Figure 6 A shear head for a test rock is shown according to one or more embodiments.

[0018] Figure 7 A shear head for a test rock is shown according to one or more embodiments.

[0019] Figure 8 A shear head for a test rock is shown according to one or more embodiments.

[0020] Figure 9A A computing system according to one or more embodiments is shown.

[0021] Figure 9B A network system according to one or more embodiments is shown. Detailed Implementation

[0022] In the following detailed description, certain specific details are set forth to provide a thorough understanding of the various implementations and embodiments disclosed. However, those skilled in the art will recognize that implementations and embodiments can be practiced without one or more of these specific details or using other methods, components, materials, etc. In other instances, related well-known features or processes have not been shown or described in detail to avoid unnecessarily obscuring the implementations and embodiments. For the sake of continuity and brevity, the same or similar reference numerals may be used for the same or similar objects in the various figures.

[0023] Figure 1 A system 111 for testing rock in borehole 101 according to one or more embodiments is shown. A shear head device 103 coupled to the lower end of a work string 109 can descend along borehole 101 to a desired location to test rock A around the desired location. At the desired location, the shear head device 103 can interact with rock A, and rock A can be tested by analyzing the acoustic signals generated by the interaction between rock A and the shear head device 103. An external drive 107 can be used to control the shear head device 103 to interact and can record the generated acoustic signals and send them to a computing system 105 to determine the properties of rock A while the shear head device 103 is testing rock A in borehole 101. Methods of using the shear head device 103 may include moving the shear head device 103 along borehole 101 to test rocks B, C at different locations.

[0024] Figure 2A shearing head device 103 according to one or more embodiments is shown. The shearing head device 103 may include a monitoring head 201, a shearing head 205, and a base 207 connected together to form a cylinder. The base 207 is disposed at the bottom of the shearing head device 103 to protect the shearing head device 103 from damage that may occur during descent operations of the shearing head device 103 through a bore. The monitoring head 201 may have an upper end for connection to a working string 109 and a lower end for connection to the shearing head 205 (e.g., threaded connection). The shearing head 205, connected from below to the monitoring head 201, has a tubular structure with a plurality of holes 203 formed around the outer surface of the tubular structure. A plurality of toothed cones equipped with modified cutter heads (not shown) may be disposed inside the shearing head, and each hole 203 around the outer surface of the shearing head 205 provides a channel for the corresponding toothed cone to move along the hole 203. Here, the term "toothed cone" does not limit or define the physical shape of the toothed cone. Without departing from the scope of the invention, the shape of the shearing head can be a cone-like shape, or any other shape known in the art, such as a cylinder-like shape. When the shearing head device 103 interacts with the rock, the modified cutter head can selectively move outward to interact with the rock, thereby generating an acoustic signal. The monitoring head 201 may include a sensor for detecting the acoustic signal generated from the rock, a recorder for recording the detected acoustic signal, and a transmitter for transmitting the recorded acoustic signal to the computing system 105 to determine the properties of the rock as the shearing head device 103 interacts with the rock in the borehole.

[0025] Figure 3 A block diagram of system 111 according to one or more embodiments is shown. For the interaction between the shear head device 103 and the rock, an external drive 107 can be used to control the shear head 205, which can cause multiple toothed cones inside the shear head 205 to protrude outwards and penetrate into the rock. The external drive 107 can also be used to rotate the shear head device to scrape the rock. This interaction can generate an acoustic signal, which can be detected by a sensor 303. The sensor 303 can be one or more sensors to record acoustic signals with different amplitudes and frequencies. According to one or more embodiments, the sensor 303 may include one or more seismic detectors. The acoustic signal can vary depending on the rock formation type, the shape of the modified cutter head, and the penetration distance of the modified cutter head into the rock, which will be explained in more detail below. A recorder 305 can record the detected acoustic signal from the sensor 303, and a transmitter 301 can transmit the acoustic signal to a computing system 105 for determining the properties of the rock.

[0026] Extensive field and laboratory tests have shown that the frequency and amplitude of the acoustic signal generated by the interaction between the shear head device 103 and the rock can vary depending on the rock's stratigraphic type. For example, ochre (a type of natural clay) exhibits a relatively lower sound pressure level compared to coal when interacting with the shear head device 103. The dominant frequencies of the acoustic signals from ochre and coal also differ, providing information for identifying rock types when analyzing the acoustic signals.

[0027] When testing rock within a borehole using a shear head device, computational and network systems can be used to determine rock properties, including hardness, cohesion, friction angle, tensile strength, brittleness, and resistance to destructive forces. Specifically, any combination of mobile devices, desktops, servers, routers, switches, embedded devices, or other types of hardware can be used to control the shear head device 103 within the borehole while simultaneously determining the properties of the rock being tested. For example, as... Figure 9A As shown, the computing system 105 may include one or more computer processors 902, non-persistent memory 904 (e.g., volatile memory, such as random access memory (RAM), cache memory), persistent memory 906 (e.g., hard disk, optical drive such as optical disc (CD) drive or digital versatile disc (DVD) drive, flash memory, etc.), communication interface 912 (e.g., Bluetooth interface, infrared interface, network interface, fiber optic interface, etc.), output device 908, and numerous other components and functions.

[0028] The computer processor 902 may be an integrated circuit for processing instructions. For example, the computer processor may be one or more cores or microcores of a processor. The computing system 105 may also include one or more input devices 910, such as a touch screen, keyboard, mouse, microphone, touchpad, electronic pen, or any other type of input device.

[0029] The communication interface 912 may include an integrated circuit for connecting the computing system 105 to a network (not shown) (e.g., a local area network (LAN), a wide area network (WAN) such as the Internet, a mobile network, or any other type of network) and / or to another device such as another computing device.

[0030] In addition, the computing system 105 may include one or more output devices, such as a screen (e.g., a liquid crystal display (LCD), plasma display, touch screen, cathode ray tube (CRT) monitor, projector, or other display device), printer, external storage, or any other output device. One or more output devices may be the same as or different from the input devices. Input and output devices may be connected locally or remotely to the computer processor 902, non-persistent storage 904, and persistent storage 906. Many different types of computing systems exist, and the aforementioned input and output devices may take other forms.

[0031] Software instructions in the form of computer-readable program code for performing embodiments of the present disclosure may be stored, wholly or partially, temporarily or permanently, on a non-transitory computer-readable medium such as a CD, DVD, storage device, disk, magnetic tape, flash memory, physical memory, or any other computer-readable storage medium. Specifically, the software instructions may correspond to computer-readable program code that, when executed by a processor, is configured to perform one or more embodiments of the present disclosure.

[0032] Figure 9A The computing system 105 in the system can be connected to a network or act as part of a network. For example, such as Figure 9B As shown, network 920 may include multiple nodes (e.g., node X 922, node Y 924). Each node may correspond to, for example... Figure 9A The computing system shown, or a combination of nodes, can correspond to a computing system like the one described. Figure 9A The computing system shown is illustrated. As an example, embodiments of this disclosure can be implemented on nodes of a distributed system connected to other nodes. As another example, embodiments of this disclosure can be implemented on a distributed computing system with multiple nodes, wherein each part of this disclosure can reside on a different node within the distributed computing system. Furthermore, one or more elements of the computing system 105 described above can be located in remote locations and connected to other elements via a network.

[0033] Despite Figure 9B Not shown, but a node can correspond to a blade in a server chassis connected to other nodes via a backplane. As another example, a node can correspond to a server in a data center. As yet another example, a node can correspond to a computer processor or a microcore of a computer processor with shared memory and / or resources.

[0034] Nodes in network 920 (e.g., node X 922, node Y 924) can be configured to provide services to client device 926. For example, a node may be part of a cloud computing system. A node may include the ability to receive requests from client device 926 and send responses to client device 926. Client device 926 may be a computing system, such as... Figure 9A The computing system 105 shown is used in this network connection. This network connection allows operators to determine the properties of rocks located in different boreholes while using the same computing system 105.

[0035] Figures 4A to 4DA modified cutting head 409 according to one or more embodiments is shown. The modified cutting head 409 may include a diamond abutment 403 attached to a substrate 401 having a cylindrical body with a diameter between 6 mm and 22 mm. The substrate 401 may be a composite material consisting of tungsten carbide particles bonded by a metallic adhesive, which effectively bonds to the diamond abutment 403 while preventing erosion damage to the modified cutting head 409. The interface 501 between the diamond abutment 403 and the substrate 401 may be non-planar, such as... Figure 5 As shown, the non-planar interface 501 ensures an increased contact area between the substrate 401 and the diamond stage 403, thereby improving bonding and reducing the stress level at interface 501. Those skilled in the art will understand how this modified tool head construction improves resistance to chipping, spalling, and diamond stage delamination.

[0036] According to one or more embodiments, the modified cutter head 409 may include cutting surfaces 405 of different shapes and sizes. For example, Figure 4A A flat cutting surface 405 is shown, while other embodiments may include... Figure 4B 407 spherical cutting surface in the middle Figure 4C The tapered cutting surface 408 and Figure 4D The axe-shaped cutting face 411 is present in the drill bit. This modified geometry of the drill bit improves penetration into rock, which may have different strata and properties depending on the location along the borehole. Furthermore, modified drill bits 409 with different cutting faces can produce different acoustic signals when interacting with the rock. For example, a blunt drill bit (e.g., a ball-shaped drill bit) can produce acoustic signals in a relatively low frequency range, while a sharp drill bit (e.g., a triangular drill bit) can produce acoustic signals in a higher frequency range compared to those produced by a blunt drill bit. To produce acoustic signals that vary greatly in frequency and amplitude, multiple drill bits can include modified drill bits 409 with different shaped cutting faces 405. This allows for a relatively large amount of acoustic signal data to be obtained for the same rock being tested. Those skilled in the art will readily understand how multiple drill bits with different cutters can produce acoustic signals over a wide frequency and amplitude range, thereby providing greater accuracy in rock analysis.

[0037] Other embodiments of the modified cutting head 409 may include more than one diamond abutment 403, wherein the primary diamond abutment in contact with the substrate may have an interface to reduce stress. Secondary diamond abutments are located in high-wear areas on the contact side of the modified cutting head. This configuration of the modified cutting head protects the substrate from wear without compromising the substrate's structural ability to support the diamond abutments. The die is made of hardened steel, while the diamond abutments are polycrystalline diamond, and other materials are conceivable depending on the type of rock. The thickness of the diamond abutment 403 may range from 2 mm to 4 mm and may have a slight bevel, which reduces stress on the modified cutting head 409 upon initial contact with the rock.

[0038] Figure 6 A plate 601 supporting a plurality of toothed cones 603 is shown according to one or more embodiments. The plurality of toothed cones 603 within the bore 203 can be selectively moved, for example, by adjusting the internal pressure of the shear head 205. Specifically, the adjustment of the internal pressure can be selectively... Figure 8 The plate 601 moves between radial positions A and C. Radial position A can be defined in the normal state of the shear head 205, in which the modified cutter head 409 is positioned within the outer surface of the shear head 205. When the internal pressure increases, the plate 601 pushes multiple toothed wheels 603 outwards, such as... Figure 7 As shown, when plate 601 is in radial position B, the modified cutter head 409 contacts rock 605. At this time, the adjustment of internal pressure allows the modified cutter head 409 on the plurality of toothed cones 603 to apply a radial force to rock 605. The method of using the shearing head device 103 may include rotating the shearing head device 103 to apply a shearing force, wherein the modified cutter head 409 scrapes the inner surface of the drill hole 101 and generates an acoustic signal.

[0039] Figure 8 A plate 601 supporting multiple rollers 603 at radial position C is shown. When plate 601 is at radial position C, the modified cutter head 409 is at its maximum penetration distance. Laboratory tests also show that the frequency and amplitude of the acoustic signal generated by the interaction between the shear head device 103 and the rock 605 can vary depending on the penetration distance of the modified cutter head 409 into the rock 605. For example, the acoustic signal generated from the interaction at radial position C can be different from the acoustic signal generated at radial position B. Those skilled in the art will readily understand how the acoustic signals obtained at both radial positions B and C improve the accuracy of the analysis of the rock 605 being tested.

[0040] A method may include lowering a shearing head device coupled to the lower end of a work string into a position within a borehole to test the rock surrounding the borehole. The method may also include supplying pressurized fluid to the shearing head device. The pressurized fluid pushes a plate supporting multiple roller cones outward, and modified cutter heads coupled to the roller cones contact the rock. The method may further include receiving acoustic data from the shearing head device of acoustic signals generated due to the interaction between the modified cutter heads and the rock. The method may also include using the acoustic data to determine the properties of the rock while the shearing head device is testing the rock in the borehole.

[0041] The method may further include rotating the work string to rotate the shear head device within the borehole, while the modified cutter head contacts the rock, thereby applying a shearing force to the rock. The rotational speed of the shear head device can be adjusted according to the desired shearing force on the rock. The internal pressure of the shear head can also be adjusted for pressurized fluid, thereby pushing the plate to a second radial position that defines the maximum penetration distance of the modified cutter head in the rock. Maximum penetration results in rock fracturing, thereby generating an acoustic signal different from that from scraping. The method may also include rotating the work string to rotate the shear head device, thereby causing the modified cutter head to move laterally in the rock at the maximum penetration distance.

[0042] This detailed description, together with the summary and abstract, is not intended to be exhaustive or to limit the embodiments to the precise forms described. Although specific embodiments, implementations, and examples have been described herein for illustrative purposes, as those skilled in the art will recognize, various equivalent modifications can be made without departing from the spirit and scope of this disclosure.

Claims

1. An apparatus for testing rock in a borehole, the apparatus comprising: The monitoring head (201) has a sensor (303) and a transmitter (301) inside a cylindrical body. A shear head (205) is coupled from below to the monitoring head (201), the shear head having a tubular structure having a plurality of holes (203) formed around the outer surface of the tubular structure. Multiple toothed cones (603), said multiple toothed cones being coupled to a modified cutter head (409) and disposed within said multiple holes (203), and A plate (601) supports the plurality of toothed cones (603) within the shear head (205) and is selectively movable between a first radial position (A) and a second radial position (C) to apply a radial force to the rock (605) by adjusting the internal pressure of the shear head (205) using the modified cutter head (409). Specifically, when the plate (601) is in the first radial position (A), the modified cutter head (409) is within the outer surface; when the plate (601) is in the third radial position (B) between the first radial position (A) and the second radial position (C), the modified cutter head (409) contacts the rock (605); and when the plate (601) is in the second radial position (C), the modified cutter head (409) is at its maximum penetration distance in the rock (605). The sensor (303) records the acoustic emission generated between the modified cutter head (409) and the rock (605), and the transmitter (301) sends the recorded acoustic emission to the computing system (105) for determining the properties of the rock (605) when the device tests the rock (605) in the borehole.

2. The device according to claim 1, wherein, The monitoring head (201) also includes an upper end coupled to the lower end of a tubing (109) for rotating the device at a predetermined rate and for applying shearing force to the rock by the modified cutter head (409).

3. The device according to claim 1, wherein, The plurality of roller cones (603) are hardened steel, while the modified cutting head (409) is a polycrystalline diamond composite drill bit with a wear-resistant body.

4. The device according to claim 1, wherein, The modified cutter head (409) includes multiple different cutter heads for generating acoustic emissions within an amplitude and frequency range used to accurately determine the properties of the rock (605).

5. The device according to claim 4, wherein, The various cutting heads include one or a combination of conical cutting teeth, axe-shaped cutting teeth, spherical cutting heads, and polygonal cutting heads.

6. The device according to any one of claims 1 to 5, wherein, The properties of the rock (605) include its hardness, cohesiveness, angle of friction, tensile strength, brittleness, and resistance to damage.

7. A system for testing rock in a borehole, the system comprising: A column (109) is connected to an external drive (107) and a computing system (105). A testing device, coupled to the lower end of the tubing string (109) and disposed in the borehole to test the rock (605) in the borehole, the testing device comprising: The monitoring head (201) has a sensor (303) and a transmitter (301) inside a cylindrical body. A shear head (205) coupled from below to the monitoring head has a tubular structure with a plurality of holes (203) formed around the outer surface of the tubular structure. Multiple toothed cones (603), said multiple toothed cones being coupled to a modified cutter head (409) and disposed within said multiple holes (203), and A plate (601) supports the plurality of toothed cones (603) within the shear head (205) and is selectively movable between a first radial position (A) and a second radial position (C) to apply a radial force to the rock by adjusting the internal pressure of the shear head (205) via the modified cutter head (409). Specifically, when the plate (601) is in the first radial position (A), the modified cutter head (409) is within the outer surface; when the plate (601) is in the third radial position (B) between the first radial position (A) and the second radial position (C), the modified cutter head (409) contacts the rock (605); and when the plate (601) is in the second radial position (C), the modified cutter head (409) is at its maximum penetration distance in the rock (605). The sensor (303) records the acoustic emission generated between the modified cutter head (409) and the rock (605), and the transmitter (301) sends the recorded acoustic emission to the computing system (105) for determining the properties of the rock (605) when the test equipment tests the rock (605) in the borehole.

8. The system according to claim 7, wherein, The external drive (107) is configured to rotate the string (109) to rotate the test equipment at a predetermined rate, thereby causing the modified cutter head (409) to apply a shearing force to the rock (605).

9. The system according to claim 7, wherein, The modified cutter head (409) includes multiple different cutter heads for generating acoustic emissions within an amplitude and frequency range used to accurately determine the properties of the rock (605).

10. The system according to claim 9, wherein, The various cutting heads include one or a combination of conical cutting teeth, axe-shaped cutting teeth, spherical cutting heads, and polygonal cutting heads.

11. The system according to claim 7, wherein, The properties of the rock (605) include its hardness, cohesiveness, angle of friction, tensile strength, brittleness, and resistance to damage.

12. The system according to any one of claims 7 to 11, wherein, The external drive (107) is configured to move the test equipment along the borehole to different positions to test different rocks (605).

13. A method for testing rock in a borehole, the method comprising: The shear head device (103) coupled to the lower end of the tubing (109) is lowered to test the rock (605) in the borehole. Pressurized fluid is supplied to the shearing head device (103) through a pipe in the tubing (109), wherein the pressurized fluid pushes outward a plate (601) supporting a plurality of rollers (603), and a modified cutter head (409) coupled to the plurality of rollers contacts the rock (605). Acoustic data of acoustic emissions generated between the modified cutter head (409) and the rock (605) are received from the shearing head device (103), and When the shear head device (103) tests the rock (605) in the borehole, the acoustic data is used to determine the properties of the rock (605).

14. The method according to claim 13, wherein, The method further includes rotating the tubing (109) to rotate the shear head device (103), thereby causing the modified cutter head (409) to apply shearing force to the rock (605).

15. The method according to claim 13, wherein, The pressurized fluid pushes the plate (601) to a second radial position (C) that defines the maximum penetration distance of the modified cutter head (409) in the rock (605), thereby causing the rock to break.

16. The method of claim 15, further comprising rotating the tubing (109) to rotate the shear head device (103), thereby causing the modified cutter head (409) to move laterally in the rock (605) at the maximum penetration distance.

17. The method according to claim 13, wherein, The acoustic data are data on the amplitude and frequency range of acoustic emissions generated between the rock (605) and the modified cutter head (409) having multiple different cutter heads.

18. The method according to claim 17, wherein, The various cutting heads include one or a combination of conical cutting teeth, axe-shaped cutting teeth, spherical cutting heads, and polygonal cutting heads.

19. The method according to claim 13, wherein, The properties of the rock (605) include its hardness, cohesiveness, angle of friction, tensile strength, brittleness, and resistance to damage.

20. The method according to any one of claims 13 to 19, wherein, The method also includes moving the shear head device (103) along the borehole to test a second rock at different locations.

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