Hydraulic torque variable directional drilling tool and method of using the same

Abstract

The present invention belongs to the technical field of oil and gas resource drilling, and discloses a hydraulic torque variable directional drilling tool and a method for using the same. The device includes a tool housing, a central shaft is inserted into the tool housing, and a seal is provided between the tool housing and the central shaft to enclose and form a sealing annulus. The central shaft is configured to rotate relative to the tool housing; and a plurality of stator impellers connected to the tool housing and a plurality of rotor impellers connected to the central shaft are provided in the sealing annulus; the stator impeller and the rotor impeller rotate independently; the sealing annulus can accommodate a viscous fluid, and when the central shaft rotates, the viscous fluid is driven to rotate in the sealing annulus through the rotor impeller, so as to drive the stator impeller and the tool housing to rotate. Thus, the rotation transmission is realized by the interaction between the stator impeller, the rotor impeller and the viscous fluid provided in the sealing annulus, thereby avoiding the use of complex devices such as electrical signal technology, and different forms of rock breaking can be realized when used.

Description

Technical Field

[0001] The invention relates to the technical field of oil and gas resource drilling, and in particular to a hydraulic torque-variable directional drilling tool and a use method thereof. Background Art

[0002] Directional drilling refers to drilling according to the pre-designed well inclination and azimuth to achieve the expected wellbore trajectory. Existing directional drilling technology can be divided into sliding directional drilling technology and rotary directional drilling technology according to the different working modes of the steering tool. Sliding directional drilling technology and rotary directional drilling technology have different adaptability ranges, so it is necessary to choose different drilling methods for different working conditions during the drilling process.

[0003] Application publication number CN108868604B discloses a "mechanical downhole torque separation and transmission tool", which is based on a conventional bent screw lower drilling tool assembly. The tool is installed on the drill string, and the torque separation of the tool is used to achieve rotary directional drilling of the drill string. The tool can replace the rotary directional drilling system to achieve rotary drill string directional drilling, and is used for directional drilling of complex wells such as directional wells, horizontal wells, and extended reach wells. However, it can only achieve rotary drilling.

[0004] Application publication number CN111411904B discloses a "downhole torque clutch-type drilling drag reduction device based on RFID", which transmits ground control signals through radio frequency balls and adopts an integral gear pair structure, allowing the inner gear and the outer gear to achieve engagement and separation through up and down movement, overcoming the defect of the separation tooth clutch that is prone to eccentric wear, and at the same time overcoming the defect of the mechanical clutch structure that random effective engagement cannot be guaranteed, and improving the reliability and stability of the clutch system. However, the use of RFID technology increases the difficulty of operation.

[0005] Application publication number CN105525871B discloses a "Hydraulic Torque Converter", which proposes a hydraulic torque converter with simple structure, reliable performance, high control accuracy and easy operation. When the orientation of the tool face needs to be changed during drilling, the rotation speed of the drill string is increased. Since the drill string is connected to the center shaft, the rotation speed of the center shaft will also increase accordingly. The center shaft is connected to the torque generator. For the torque generator, as the input rotation speed increases, its output clockwise torque will also increase. When the clockwise torque generated is greater than the counterclockwise torque transmitted by the bottom drill assembly, the bottom drill assembly will rotate in a clockwise direction. When the tool face is turned to the designed orientation, reducing the drill string rotation speed will also reduce the output torque of the torque generator. When drilling and breaking rocks, as long as the drill string rotation speed is controlled so that the output torque of the torque generator is equal to the counter-torque of the bottom drill assembly, directional drilling construction can be carried out. However, the need to identify the changes in the tool face angle during drilling brings difficulties to the operation. Summary of the invention

[0006] The object of the present invention is to provide a hydraulic torque-variable directional drilling tool, which is driven to rotate by a stator impeller and a rotor impeller in a sealed annulus, thereby avoiding the use of complex electrical control and being able to change the rotational torque by the rotational speed of the central shaft, thereby facilitating operation.

[0007] To achieve this object, the present invention adopts the following technical solutions:

[0008] Hydraulic torque-converting directional drilling tool, used to connect drilling tools, including:

[0009] A tool housing, one end of which is used to connect the drilling tool, a central shaft is inserted into the tool housing, a sealing member is provided between the tool housing and the central shaft to enclose and form a sealing annulus, and the central shaft is configured to rotate relative to the tool housing;

[0010] The sealing annulus is provided with a plurality of stator impellers connected to the tool housing and a plurality of rotor impellers connected to the central shaft; the stator impellers and the rotor impellers rotate independently of each other; the sealing annulus can accommodate a viscous fluid, and when the central shaft rotates, the viscous fluid is driven to rotate in the sealing annulus through the rotor impeller, thereby driving the stator impeller and the tool housing to rotate.

[0011] Preferably, it further comprises radial bearings, wherein two radial bearings are located at two ends of the sealing annulus, and the central shaft is plugged into the radial bearings to be transferred to the tool housing through the radial bearings.

[0012] Preferably, two of the sealing members are spaced apart between the two radial bearings.

[0013] Preferably, the stator impeller and the rotor impeller both include an inner sleeve, an impeller ring wall is arranged on the outer periphery of the inner sleeve, and a plurality of impellers are arranged between the impeller ring wall and the inner sleeve; the center shaft is inserted into the inner sleeves of the stator impeller and the rotor impeller, the inner sleeve of the stator impeller is fixedly connected to the center shaft, and the impeller ring wall of the rotor impeller is fixedly connected to the tool housing.

[0014] Preferably, the tool housing is provided with an injection hole, the injection hole is connected to the sealing annulus to inject the viscosity fluid into the sealing annulus, and the injection hole is provided with a detachable plugging member.

[0015] Preferably, the central shaft is provided with a downflow channel extending through the central shaft along its axial direction, and a friction block sliding along the tool housing is provided at one end of the central shaft close to the drill tool, and the friction block is provided with a liquid hole along the extension direction of the downflow channel. An elastic part is connected between the friction block and the end of the central shaft, a friction plate layer is provided on the inner periphery of the tool housing, and the friction block is located between the central shaft and the friction plate layer.

[0016] Preferably, the friction block is provided with a spherical groove, the spherical groove faces the central axis, the liquid passage hole is penetrated through the spherical groove, and the diameter of the liquid passage hole is smaller than the diameter of the lower flow channel.

[0017] Preferably, it also includes a drive shaft assembly, which includes a drive shaft, and the drive shaft is provided with an upper flow channel extending axially therethrough, and the drive shaft seal is inserted at one end of the center shaft away from the friction block so that the upper flow channel is connected to the lower flow channel.

[0018] Preferably, a limiting boss is provided on the outer wall of the end of the driving shaft, and a limiting groove which is matched and plugged with the limiting boss is provided on the inner wall of the end of the central shaft away from the drilling tool.

[0019] A method for using a hydraulic torque-variable directional drilling tool is also provided, which is used to achieve different forms of rock breaking by using the hydraulic torque-variable directional drilling tool. The method is as follows:

[0020] Controlling the central shaft to rotate to drive the viscosity fluid;

[0021] When driving the viscosity fluid to obtain a torque F t Greater than the friction resistance F between the drilling tool and the well wall f and the reaction torque F b When the sum of the above values ​​is reached, the drill bit rotates to perform composite drilling and rock breaking;

[0022] When driving the viscosity fluid to obtain a torque F t Greater than the reaction torque F b The friction resistance F between the drilling tool and the well wall f The difference is less than the counter torque F b and the friction resistance F between the drilling tool and the well wall f When the sum of the above values ​​is reached, the drilling tool performs directional drilling to break the rock.

[0023] Beneficial effects of the present invention:

[0024] Thus, the rotation transmission is realized through the interaction between the stator impeller, the rotor impeller and the viscosity fluid arranged in the sealing annulus. After the tool housing is connected to the drill bit, when the center shaft is driven to rotate, the center shaft drives the rotor impeller to rotate, and the rotation of the rotor impeller drives the viscosity fluid to rotate, thereby providing torque through the shear stress of the viscosity fluid to drive the stator impeller to rotate and then drive the tool housing and the drill bit to rotate. Therefore, when the number of stator impellers, the number of rotor impellers, and the viscosity of the fluid remain unchanged, the rotation torque of the drill bit can be determined according to the rotation torque of the center shaft, thereby avoiding the use of complex devices such as electrical signal technology, and through the soft characteristic medium of the viscosity fluid, the peaks and troughs of the torque fluctuation can be eliminated to a certain extent; in addition, the control method can be used to break rocks in different forms. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a cross-sectional view of the hydraulic torque variable directional drilling tool of the present invention;

[0026] Figure 2 It is a schematic diagram of a stator impeller and a rotor impeller in a hydraulic torque-variable directional drilling tool of the present invention;

[0027] Figure 3 It is a schematic diagram of the connection between the friction block and the elastic member in the hydraulic torque-changing directional drilling tool of the present invention;

[0028] Figure 4 It is a schematic diagram of a hydraulic torque-variable directional drilling tool connected to a drive shaft assembly of the present invention;

[0029] Figure 5 Schematic diagram of the drive shaft assembly of the present invention.

[0030] In the figure:

[0031] 1. Tool housing; 2. Center shaft; 3. Seal; 4. Sealing annulus; 5. Stator impeller; 6. Rotor impeller; 7. Radial bearing; 8. Inner sleeve; 9. Impeller ring wall; 10. Blade; 11. Blocking piece; 12. Downstream channel; 13. Friction block; 14. Elastic piece; 15. Liquid hole; 16. Friction plate layer; 17. Spherical groove; 18. Drive shaft assembly; 181. Drive shaft; 182. Upstream channel; 183. Drive housing; 184. Drive bearing group; 1841. TC bearing; 1842. Serial bearing. DETAILED DESCRIPTION

[0032] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0033] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0034] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0035] In the description of this embodiment, the terms "upper", "lower", "left", "right" and other directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of description and simplification of operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operate in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0036] In order to solve the problems in the above-mentioned prior art, the present embodiment provides a hydraulic torque variable directional drilling tool, which includes a tool housing 1, a central shaft 2 is inserted into the tool housing 1, and a seal 3 is provided between the tool housing 1 and the central shaft 2 to enclose a sealing annulus 4, and the central shaft 2 is configured to rotate relative to the tool housing 1; and a plurality of stator impellers 5 connected to the tool housing 1 and a plurality of rotor impellers 6 connected to the central shaft 2 are arranged in the sealing annulus 4; the stator impeller 5 and the rotor impeller 6 rotate independently of each other; the sealing annulus 4 can accommodate a viscous fluid, and when the central shaft 2 rotates, the viscous fluid is driven to rotate in the sealing annulus 4 through the rotor impeller 6, so as to drive the stator impeller 5 and the tool housing 1 to rotate.

[0037] Thus, the rotation transmission is realized through the interaction between the stator impeller 5, the rotor impeller 6 and the viscosity fluid arranged in the sealing annulus 4. Specifically, after the tool housing 1 is connected to the drill bit, when the center shaft 2 is driven to rotate, the center shaft 2 drives the rotor impeller 6 to rotate, and the rotation of the rotor impeller 6 drives the viscosity fluid to rotate, thereby providing torque through the shear stress of the viscosity fluid to drive the stator impeller 5 to rotate and then drive the tool housing 1 and the drill bit to rotate. Therefore, when the number of stator impellers, the number of rotor impellers, and the viscosity of the fluid remain unchanged, the rotation torque of the drill bit can be determined according to the rotation torque of the center shaft, thereby avoiding the use of complex devices such as electrical signal technology; in addition, through the soft characteristic medium of the viscosity fluid, the peaks and troughs of the torque fluctuation can also be eliminated to a certain extent.

[0038] The present embodiment is described in detail below. The hydraulic torque conversion directional drilling tool comprises a tool housing 1. One end of the tool housing 1 is connected to the drill tool, and a central shaft 2 is inserted into the tool housing 1. The end of the central shaft 2 away from the tool housing 1 connected to the drill tool is connected to the upper drill string to connect the device in the middle of the drill string system. There is a gap between the central shaft 2 and the tool housing 1, and the central shaft 2 rotates relative to the tool housing 1. In order to ensure the stability of rotation, the hydraulic torque conversion directional drilling tool is provided with a radial bearing 7. The central shaft 2 passes through the radial bearing 7 and rotates relative to the tool housing 1 through the radial bearing 7. There are spaced seals 3 between the tool housing 1 and the central shaft 2 to enclose a sealing annulus 4. Specifically, two seals 3 are spaced between the two radial bearings 7. In this embodiment, the seal 3 is a sealing ring, which is sleeved on the central shaft 2. Since the tool housing 1 is vertically arranged when in use, the radial bearing 7 close to the drill tool has a high risk of leakage, so the thickness of the sealing ring close to the drill tool is greater than the thickness of the sealing ring away from the drill tool. In order to further prevent leakage in the sealing annulus 4, a seal 3 is also arranged close to the radial bearing 7 of the drilling tool, on the side facing the drilling tool.

[0039] The sealing annulus 4 is provided with a plurality of stator impellers 5 connected to the tool housing 1 and a plurality of rotor impellers 6 connected to the central shaft 2; wherein the stator impeller 5 and the rotor impeller 6 rotate independently of each other. Specifically, the stator impeller 5 and the rotor impeller 6 each include an inner sleeve 8, an impeller ring wall 9 is provided on the outer periphery of the inner sleeve 8, and a plurality of blades 10 are provided between the impeller ring wall 9 and the inner sleeve 8; the central shaft 2 is inserted into the inner sleeve 8 of the stator impeller 5 and the rotor impeller 6, the inner sleeve 8 of the rotor impeller 6 is fixedly connected to the central shaft 2, and the impeller ring wall 9 of the stator impeller 5 is fixedly connected to the tool housing 1. For example, welding or screwing can be selected. When the viscosity fluid is injected into the sealing annulus 4, when the central shaft 2 rotates, the viscosity fluid is driven to rotate in the sealing annulus 4 through the rotor impeller 6, so as to drive the stator impeller 5 and the tool housing 1 to rotate. Furthermore, the blades 10 are arranged obliquely relative to the inner sleeve 8 so as to better bear the shear stress of the viscosity fluid. In order to facilitate the injection of viscous fluid into the sealing annulus 4, the tool housing 1 is provided with an injection hole, and the injection hole is connected to the sealing annulus 4 to inject viscous fluid into the sealing annulus 4, and a detachable plugging member 11 is provided in the injection hole. In this embodiment, the plugging member 11 adopts a sealing screw to facilitate disassembly. In addition, it should be noted that the number of stator impellers 5 and rotor impellers 6 and the viscosity of the fluid can be adjusted in the preliminary design according to actual production needs, and no specific restrictions are made here. In order to facilitate the transmission of shear stress, the stator impeller 5 and the rotor impeller 6 are arranged at radial intervals along the central axis 2. Therefore, the above-mentioned structure can, on the one hand, transmit rotational force through viscous fluid, significantly reduce the occurrence of drilling accidents such as drill bit stuck during drilling, and can realize the conversion of "off" state and "on" state according to the comparison of the torque generated by itself and the generated counter torque. Specifically, when the device is used in a specific way, when the torque F obtained by driving the viscous fluid is t Greater than the friction resistance F between the drilling tool and the well wall f and the reaction torque F b When the sum of t >F f +F b , the center shaft 2 and the lower drill bit are in a "closed" state, that is, the center shaft 2 drives the lower drill bit to rotate, so that the drill bit as a whole performs composite drilling and rock breaking. When the torque F is obtained by driving the viscosity fluid t Greater than the reaction torque F b and friction resistance F f The difference is less than the counter torque F b and friction resistance F f When the sum of b -F f <F t <F f +F b, it is in the "off" state, and the drill bit is directional drilling to break the rock. In addition, there is a situation when the torque F is obtained by driving the viscosity fluid. t Less than the reaction torque F b and friction resistance F f , the central shaft is prone to idle rotation. In order to avoid this situation, the central shaft 2 is provided with a lower flow channel 12 that penetrates along its axial direction. The end of the central shaft 2 close to the drill bit is provided with a friction block 13 that slides along the tool housing 1. The friction block 13 is provided with a liquid hole 15 along the extension direction of the lower flow channel 12. An elastic member 14 is connected to the end of the friction block 13 and the central shaft 2. A friction layer 16 is provided on the inner periphery of the tool housing 1. The friction block 13 is located between the central shaft 2 and the friction layer 16. Therefore, when the central shaft idles, the amount of flowing liquid entering through the lower flow channel 12 and the liquid hole 15 can be increased. Exemplarily, the flowing liquid can be drilling fluid. Therefore, the elastic member 14 is stretched under the impact of the flowing liquid, so that the friction block 13 contacts the friction layer 16. The friction force △F is increased through the contact between the friction block 13 and the friction layer 16. ff , thereby increasing the F driving the rotation in disguise b； That is F b -F f <F t +△F ff , thereby providing additional rotational driving force by increasing the friction effect, maintaining the rotation speed of the lower drill bit stable to avoid idling. In addition, when the central axis 2 fails to rotate, the drill bit can be prevented from producing harmful reverse rotation due to the counter torque. Specifically, the friction block 13 is provided with a spherical groove 17, the spherical groove 17 faces the central axis 2, and the liquid hole 15 is provided through the spherical groove 17. Through the setting of the spherical groove 17, the flowing liquid can first enter the spherical groove 17, and then pass through the liquid hole 15 to better receive the impact of the flowing liquid, and then adjust the friction block 13 up and down through the flowing liquid. Furthermore, the diameter of the liquid hole 15 is smaller than the diameter of the lower flow channel 12, so that the flowing liquid can enter the spherical groove 17 first to the greatest extent.

[0040] In order to drive the central shaft 2 to rotate, the hydraulic torque conversion directional drilling tool also includes a drive shaft assembly 18, which includes a drive shaft 181. The drive shaft 181 is provided with an upper flow channel 182 that runs through the central shaft 2 along its axial direction. The drive shaft 181 is sealed and plugged into the end of the central shaft 2 away from the friction block 13, so that the upper flow channel 182 is connected to the lower flow channel 12 to enable the above-mentioned flowing liquid to flow. It can be understood that the upper drill string of the drill string system can be connected to the drive shaft 181 to drive the central shaft 2. In order to maintain the stability of the connection, a limiting boss is provided on the outer wall of the end of the drive shaft 181, and a limiting groove that matches and plugs with the limiting boss is provided on the inner wall of the end of the central shaft 2 away from the drilling tool. In order to make the connection more stable, the central shaft 2 and the drive shaft 181 can be threaded. In order to better protect the drive shaft 181, the drive shaft assembly 18 also includes a drive housing 183, the drive shaft 181 is inserted into the drive housing 183, and a drive bearing group 184 is arranged between the drive housing 183 and the drive shaft 181. When the drive shaft 181 is inserted into the central shaft 2, the drive housing 183 is inserted into the tool housing 1, and the two are connected by setting matching threads. Specifically, the drive bearing group 184 includes two TC bearings 1841 arranged at intervals and a series bearing 1842 arranged between the two TC bearings 1841, so that the drive shaft 181 can better rotate in contact with the drive housing 183.

[0041] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, various obvious changes, readjustments and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A hydraulic torque-variable directional drilling tool, used to connect a drilling tool, characterized in that: include: A tool housing (1), one end of the tool housing (1) being used for connecting the drilling tool, a central shaft (2) being inserted into the tool housing (1), a sealing member (3) being provided between the tool housing (1) and the central shaft (2) to enclose and form a sealing annulus (4), and the central shaft (2) being configured to rotate relative to the tool housing (1); The sealing annulus (4) is provided with a plurality of stator impellers (5) connected to the tool housing (1) and a plurality of rotor impellers (6) connected to the central shaft (2); the stator impellers (5) and the rotor impellers (6) rotate independently of each other; the sealing annulus (4) can accommodate a viscous fluid, and when the central shaft (2) rotates, the viscous fluid is driven to rotate in the sealing annulus (4) through the rotor impellers (6), thereby driving the stator impellers (5) and the tool housing (1) to rotate; The stator impeller (5) and the rotor impeller (6) are arranged at intervals along the radial direction of the central axis (2); The stator impeller (5) and the rotor impeller (6) both include an inner sleeve (8), an impeller ring wall (9) is arranged on the outer periphery of the inner sleeve (8), and a plurality of impellers are arranged between the impeller ring wall (9) and the inner sleeve (8); the central shaft (2) is inserted into the inner sleeves (8) of the stator impeller (5) and the rotor impeller (6), the inner sleeve (8) of the rotor impeller (6) is fixedly connected to the central shaft (2), and the impeller ring wall (9) of the stator impeller (5) is fixedly connected to the tool housing (1).

2. The hydraulic torque variable directional drilling tool according to claim 1, characterized in that: It also includes radial bearings (7), two of which are located at the two ends of the sealing annulus (4), and the central shaft (2) is inserted into the radial bearings (7) to be connected to the tool housing (1) through the radial bearings (7).

3. The hydraulic torque variable directional drilling tool according to claim 2, characterized in that: Two sealing members (3) are arranged at intervals between the two radial bearings (7).

4. The hydraulic torque variable directional drilling tool according to claim 1, characterized in that: The tool housing (1) is provided with a liquid injection hole, the liquid injection hole is connected to the sealing annulus (4) so ​​as to inject the viscosity fluid into the sealing annulus (4), and the liquid injection hole is provided with a detachable blocking member (11).

5. The hydraulic torque variable directional drilling tool according to claim 1, characterized in that: The central shaft (2) is provided with a downflow channel (12) penetrating along its axial direction; the central shaft (2) is provided with a friction block (13) sliding along the tool housing (1) at one end thereof close to the drilling tool; the friction block (13) is provided with a liquid passage hole (15) extending along the extension direction of the downflow channel (12); an elastic member (14) is connected between the friction block (13) and the end of the central shaft (2); a friction plate layer (16) is provided on the inner periphery of the tool housing (1); and the friction block (13) is located between the central shaft (2) and the friction plate layer (16).

6. The hydraulic torque variable directional drilling tool according to claim 5, characterized in that: The friction block (13) is provided with a spherical groove (17), the spherical groove (17) faces the central axis (2), the liquid passage hole (15) is arranged through the spherical groove (17), and the diameter of the liquid passage hole (15) is smaller than the diameter of the lower flow channel (12).

7. The hydraulic torque variable directional drilling tool according to claim 5, characterized in that: The invention also comprises a drive shaft assembly (18), wherein the drive shaft assembly (18) comprises a drive shaft (181), wherein the drive shaft (181) is provided with an upper flow channel (182) penetrating along its axial direction, and wherein the drive shaft (181) is sealably plugged into an end of the central shaft (2) away from the friction block (13) so that the upper flow channel (182) is connected to the lower flow channel (12).

8. The hydraulic torque variable directional drilling tool according to claim 7, characterized in that: A limiting boss is arranged on the outer wall of the end of the driving shaft (181), and a limiting groove which is matched and plugged with the limiting boss is arranged on the inner wall of the end of the central shaft (2) away from the drilling tool.

9. A method for using a hydraulic torque-variable directional drilling tool, for use of the hydraulic torque-variable directional drilling tool as claimed in any one of claims 1 to 8, the method being as follows: Controlling the central shaft (2) to rotate so as to drive the viscosity fluid; When driving the viscosity fluid to obtain a torque F t Greater than the friction resistance F between the drilling tool and the well wall f and the reaction torque F b When the sum of the above values ​​is reached, the drill bit rotates to perform composite drilling and rock breaking; When driving the viscosity fluid to obtain a torque F t Greater than the reaction torque F b The friction resistance F between the drilling tool and the well wall f and is less than the counter torque F b and the friction resistance F between the drilling tool and the well wall f When the sum of the above values ​​is reached, the drilling tool performs directional drilling to break the rock.

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