Downhole tool with guiding function

Abstract

The invention provides a downhole tool with a guiding function, and relates to the technical field of petroleum drilling, the downhole tool comprises a shell assembly which can be driven by a top driving device to rotate and is internally provided with a screw assembly, one end of the screw assembly extends out of the shell assembly to be connected with a drill bit, and the screw assembly is internally provided with a first circulation cavity; a push block corresponding to the telescopic cavity is arranged on the shell assembly, and the push block can move in the radial direction of the shell assembly; the flow limiting assembly can be communicated with the telescopic cavity and the first circulation cavity; by arranging the push block, when the telescopic cavity communicates with the first circulation cavity, high-pressure liquid enters the telescopic cavity to push out the push block, the push block acts with the well wall to make the drill bit move laterally, the position of the push block can be adjusted by rotating the shell assembly, directional drilling is achieved, and compared with a traditional mode, the push block can be flush with the shell assembly outside the directional drilling stage; the drilling tool is prevented from being subjected to lateral force for a long time, abrasion of related structures of the drill bit is effectively reduced, and the service life is prolonged.

Description

Technical Field

[0001] The present application relates to the technical field of oil drilling, and in particular to a downhole tool with a guiding function. Background Art

[0002] With the maturity of horizontal well drilling technology, in order to save costs and improve efficiency, most construction wells, except for a few exploration wells, use horizontal well technology. At present, there are two main horizontal well drilling technologies, one is the traditional bent screw drill directional drilling technology, and the other is the rotary steerable drilling technology. The rotary steerable technology is currently mainly imported products with high costs; and the core of the bent screw drill directional technology is to use a screw drill with a geometric bend to ensure that the wellbore trajectory can change the well inclination angle in the specified direction, and finally drill the desired directional well or horizontal well. However, the existence of the geometric bend causes the PDC drill bit to generate periodic alternating stress during the drilling process. Under the action of alternating stress, the cutting teeth wear faster, the uneven wear between the cutting teeth increases, the drill bit matrix is ​​locally worn and deformed, the damage risk increases, the wear of the gauge teeth increases, and the gauge structure is deformed and damaged. Summary of the invention

[0003] The purpose of this application is to provide a downhole tool with a steering function in order to solve the above problems, including: A housing assembly, wherein the housing assembly can rotate around its own axis when driven by a top drive device; A screw assembly, wherein the screw assembly is arranged inside the housing assembly, one end of the screw assembly extends out of the housing assembly and is connected to a drill bit, the screw assembly has a first flow cavity inside, and a telescopic cavity is provided between the screw assembly and the housing assembly, and the screw assembly can rotate relative to the housing assembly under the action of high-pressure liquid; A push block, which is arranged on the outer shell component at a position corresponding to the telescopic cavity and can move radially along the outer shell component; A flow limiting assembly, the flow limiting assembly has a first state and a second state. When in the first state, the telescopic chamber is connected to the first flow chamber, and the push block extends out of the shell assembly. When in the second state, the telescopic chamber is separated from the first flow chamber, and the push block is flush with the shell assembly.

[0004] According to the technical solution provided in certain embodiments of the present application, the current limiting assembly also includes a driving member and a current limiting mechanism, the driving member and the current limiting mechanism are both arranged inside the first circulation chamber, the current limiting mechanism has a first channel inside, the two ends of the first channel are respectively connected to the first circulation chamber and the telescopic chamber, a mushroom head is fixed to the driving end of the driving member, and the mushroom head can be moved along the axial direction of the housing assembly under the drive of the driving member to control the opening and closing of the first channel, thereby switching the current limiting assembly between the first state and the second state.

[0005] According to the technical solution provided in certain embodiments of the present application, the housing assembly includes a stator and a first housing connected to each other, the screw assembly includes a rotor and a core shaft connected to each other, the end of the core shaft away from the rotor is connected to the drill bit, the telescopic cavity is formed between the core shaft and the first housing, and a first through hole is also provided thereon, the two ends of the first through hole are respectively connected to the first channel and the telescopic cavity, the stator and the rotor cooperate to drive the core shaft and the drill bit to rotate relative to the housing assembly under the action of high-pressure liquid.

[0006] According to the technical solution provided in certain embodiments of the present application, flow-limiting bearing groups are provided between both ends of the first shell and the core shaft, and the first shell, the core shaft and the two flow-limiting bearing groups together form the telescopic cavity.

[0007] According to the technical solution provided in certain embodiments of the present application, a thrust bearing group is further provided in the telescopic cavity, and two ends of the thrust bearing group respectively abut against the two flow-limiting bearing groups to withstand the axial pressure generated when the drill bit is drilling.

[0008] According to the technical solution provided in certain embodiments of the present application, a second flow chamber is provided between the rotor and the housing assembly, a second through hole is provided on the rotor, the flow limiting mechanism separates the first flow chamber into a first part and a second part, the second flow chamber is connected to the first part through the second through hole, and the second part can be connected to the first channel.

[0009] According to the technical solution provided in certain embodiments of the present application, a communication component is also included, which includes a second shell, the second shell is connected to an end of the shell component away from the drill bit, and a transmitting assembly and a receiving assembly electrically connected to each other are provided in the second shell, and the transmitting assembly and the receiving assembly are used for control interaction with a ground controller.

[0010] According to the technical solutions provided in certain embodiments of the present application, a battery assembly is further provided in the first circulation cavity, and two ends of the battery assembly are respectively fixed and electrically connected to the receiving assembly and the current limiting assembly.

[0011] According to the technical solutions provided in certain embodiments of the present application, a well inclination unit is further provided between the driving end of the driving member and the mushroom head, and the well inclination unit is used to detect the well inclination angle when the drill bit is drilling.

[0012] Compared with the prior art, the present application has the following beneficial effects: the present application provides a downhole tool with a guiding function, including a housing assembly, which can rotate around its own axis under the drive of a top drive device, a screw assembly is arranged inside the housing assembly, one end of the screw assembly extends out of the housing assembly and is connected to a drill bit, a first flow chamber is arranged inside the screw assembly, a telescopic chamber is arranged between the screw assembly and the housing assembly, the screw assembly can rotate relative to the housing assembly under the action of high-pressure liquid, a push block is arranged at a position corresponding to the telescopic chamber on the housing assembly, and the push block can move radially along the housing assembly; the present application also includes a flow limiting assembly, the flow limiting assembly has a first state and a second state, when in the first state, the telescopic chamber is connected to the first flow chamber, the push block extends out of the housing assembly, and when in the first state In the second state, the telescopic chamber is separated from the first flow chamber, and the push block is flush with the shell assembly; by arranging a push block that can move radially along the shell assembly on the shell assembly, a flow limiting assembly is used to control the connection and disconnection of the telescopic chamber and the first flow chamber. When the two are connected, high-pressure liquid enters the telescopic chamber to make the push block extend out of the shell assembly, and acts on the well wall to cause the drill bit to produce lateral displacement. At the same time, the shell assembly can be driven to rotate by the top drive device to control the specific direction of the drill bit displacement, thereby realizing directional drilling. Compared with traditional bent screw drilling tools, the push block can be retracted into the telescopic chamber outside the directional drilling stage to keep it flush with the shell assembly, thereby avoiding the drill tool from being subjected to lateral force for a long time during drilling, effectively reducing the wear of the drill bit related structures, and greatly extending its service life.

[0013] It should be understood that the description of technical features, technical solutions, beneficial effects or similar language in this application does not imply that all features and advantages can be realized in any single embodiment. On the contrary, it is understood that the description of features or beneficial effects means that specific technical features, technical solutions or beneficial effects are included in at least one embodiment. Therefore, the description of technical features, technical solutions or beneficial effects in this specification does not necessarily refer to the same embodiment. Furthermore, the technical features, technical solutions and beneficial effects described in the present embodiment can also be combined in any appropriate manner. Those skilled in the art will understand that the embodiment can be realized without one or more specific technical features, technical solutions or beneficial effects of a specific embodiment. In other embodiments, additional technical features and beneficial effects can also be identified in a specific embodiment that does not embody all embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0015] Figure 1 A schematic diagram of the structure of a downhole tool with a guiding function close to a drill bit provided in an embodiment of the present application; Figure 2 A schematic diagram of the structure of the middle part of a downhole tool with a guiding function provided in an embodiment of the present application; Figure 3 A schematic diagram of the structure of a downhole tool with a guiding function away from the drill bit provided in an embodiment of the present application; Figure 4 for Figure 1 A magnified view of part A; Figure 5 for Figure 1 Enlarged view of part B.

[0016] The text annotations in the figure represent: 1. Shell assembly; 2. Screw assembly; 3. Push block; 4. Current limiting assembly; 5. Current limiting bearing group; 6. Thrust bearing group; 7. Drill bit; 11. Stator; 12. First shell; 13. Third shell; 21. Rotor; 22. Mandrel; 41. Drive member; 42. Mushroom head; 43. Well deviation unit; 44. Current limiting ring; 45. Flow channel conversion seat; 51. Second shell; 52. Launching assembly; 53. Receiving assembly; 61. Battery; 62. Battery connector; 63. Wiring unit; 101. Telescopic chamber; 102. Second circulation chamber; 201. First circulation chamber; 211. Second through hole; 221. First through hole; 401. First channel. DETAILED DESCRIPTION

[0017] In order to enable those skilled in the art to better understand the technical solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings. The description in this section is only exemplary and explanatory and should not have any limiting effect on the protection scope of the present application. Specifically, the described embodiments are only embodiments of a part of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work should fall within the scope of protection of the present application.

[0018] It should be noted that similar reference numerals and letters represent similar items in the following figures, so once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0019] As mentioned in the background technology, in order to solve the problems in the prior art, this embodiment provides a downhole tool with a steering function, including: The housing assembly 1 can rotate around its own axis when driven by the top driving device; The screw assembly 2 is arranged inside the housing assembly 1, one end of which extends out of the housing assembly 1 and is connected to the drill bit 7. The screw assembly 2 has a first flow cavity 201 inside, and a telescopic cavity 101 between the screw assembly 2 and the housing assembly 1. The screw assembly 2 can rotate relative to the housing assembly 1 under the action of high-pressure liquid; A push block 3, which is disposed on the housing assembly 1 at a position corresponding to the telescopic cavity 101 and can move radially along the housing assembly 1; The flow limiting component 4 has a first state and a second state. When in the first state, the telescopic cavity 101 is connected to the first flow cavity 201, and the push block 3 extends out of the shell component 1. When in the second state, the telescopic cavity 101 is separated from the first flow cavity 201, and the push block 3 is flush with the shell component 1.

[0020] like Figure 1-4 As shown, one end of the housing component 1 can be connected to the ground drilling rig through a drill string. The top drive device is arranged on the ground and is a supporting equipment of the ground drilling rig. It can drive the housing component 1 to rotate around its own axis. The screw assembly 2 is inserted into the housing component 1, and one end thereof extends out of the housing component 1 to connect with the drill bit 7. The first circulation chamber 201 is the internal space of the screw assembly 2. The telescopic chamber 101 is located between the screw assembly 2 and the housing component 1, and is arranged around the side of the screw assembly 2 close to the drill bit 7. The ground drilling rig is also equipped with a mud pump for pumping high-pressure liquid into the drilling tool. The high-pressure liquid can be respectively filled between the screw assembly 2 and the housing component 1, and into the first circulation chamber 201. When the high-pressure liquid is filled between the screw assembly 2 and the housing component 1, the screw assembly 2 can rotate relative to the housing component 1, thereby driving the drill bit 7 to rotate for drilling.

[0021] A mounting hole is provided on the housing component 1 at a position corresponding to the telescopic cavity 101, and a limiting portion extending toward the center position of the mounting hole is provided at the open end of the mounting hole. The push block 3 is provided in the mounting hole and can move radially along the housing component 1 in the mounting hole. The push block 3 has a protrusion extending radially along the end of the housing component 1 close to the housing component 1, and the protrusion can abut against the limiting portion to limit the movement of the push block 3 away from the screw assembly 2. The axial direction of the protrusion abuts against the inner wall of the mounting hole and can slidably contact the inner wall of the mounting hole; the flow limiting component 4 is provided in the first flow cavity 201, and is used to control the connection and disconnection of the first flow cavity 201 and the telescopic cavity 101. When directional drilling is required, the housing component 1 is driven to rotate by the top drive device, so that the push block 3 is located in the opposite direction of the drilling direction required by the drill bit 7. The first circulation chamber 201 is connected to the telescopic chamber 101 through the flow limiting component 4, and the mud pump pumps high-pressure liquid into the telescopic chamber 101 through the first circulation chamber 201. The push block 3 moves radially away from the screw assembly 2 along the outer shell assembly 1 under the action of liquid pressure until the protrusion abuts against the limiting portion. At this time, the push block 3 extends out of the outer shell assembly 1. When drilling, the drill bit 7 is laterally displaced through the interaction between the push block 3 and the well wall, thereby realizing directional drilling; when composite drilling is required, the first circulation chamber 201 is separated from the telescopic chamber 101 by the flow limiting component 4, and the push block 3 is retracted to be flush with the outer shell assembly 1 under the action of the well wall. The drill bit 7 is no longer subjected to lateral force, and the screw assembly 2 drives the drill bit 7 to perform composite drilling under the action of high-pressure liquid.

[0022] By arranging a push block 3 on the shell component 1 that can move radially along the shell component 1, and using the flow limiting component 4 to control the connection and disconnection of the telescopic chamber 101 and the first flow chamber 201, when the two are connected, high-pressure liquid enters the telescopic chamber 101 to make the push block 3 extend out of the shell component 1, and reacts with the well wall to cause the drill bit 7 to produce lateral displacement. At the same time, the shell component 1 can be driven by the top drive device to rotate to control the specific direction of the displacement of the drill bit 7, thereby realizing directional drilling. Compared with traditional bent screw drilling tools, the push block 3 can be retracted into the telescopic chamber 101 outside the directional drilling stage to keep the shell component 1 flush, thereby preventing the drill tool from being subjected to lateral force for a long time during drilling, effectively reducing the wear of the relevant structures of the drill bit 7, and greatly extending its service life.

[0023] In a preferred embodiment, the current limiting component 4 also includes a driving member 41 and a current limiting mechanism, both of which are arranged inside the first flow chamber 201. The current limiting mechanism has a first channel 401 inside, and the two ends of the first channel 401 are respectively connected to the first flow chamber 201 and the telescopic chamber 101. A mushroom head 42 is fixed to the driving end of the driving member 41. The mushroom head 42 can move along the axial direction of the shell component 1 under the drive of the driving member 41 to control the opening and closing of the first channel 401, thereby switching the current limiting component 4 between the first state and the second state.

[0024] like Figure 1 , Figure 2 and Figure 4 As shown, the driving member 41 and the flow limiting mechanism are both arranged in the first circulation chamber 201. The driving member 41 adopts a motor, and its driving end is fixedly connected to the mushroom head 42. The driving member 41 is also provided with a control circuit for controlling the start and stop of the driving member 41. The flow limiting mechanism includes a flow limiting ring 44 and a flow channel conversion seat 45. The flow limiting ring 44 is fixed in the first circulation chamber 201, and the flow channel conversion seat 45 is fixed at the end of the flow limiting ring 44 away from the driving member 41, and the free end of the flow channel conversion seat 45 is connected to the telescopic chamber 101, and the flow limiting ring 44 is connected to the inside of the flow channel conversion seat 45 to form a first channel 401. When the driving member 41 controls the mushroom head 42 to move closer to the flow limiting ring 44, the flow channel conversion seat 45 is connected to the first channel 401. The push block 3 moves sideways until the mushroom head 42 closes the first channel 401. At this time, the first circulation chamber 201 is separated from the telescopic chamber 101. The push block 3 can move radially along the outer shell component 1 toward the screw assembly 2 under the action of the well wall until it is flush with the outer shell component 1, that is, the above-mentioned second state. When the driving member 41 controls the mushroom head 42 to move away from the limiting ring 44 until the first channel 401 connects the first circulation chamber 201 and the telescopic chamber 101, the high-pressure liquid can enter the telescopic chamber 101 through the first channel 401. Under the action of the high-pressure liquid, the push block 3 moves radially along the outer shell component 1 away from the screw assembly 2 until it extends out of the outer shell component 1, that is, the above-mentioned first state.

[0025] In a preferred embodiment, the housing assembly 1 includes a stator 11 and a first housing 12 connected to each other, and the screw assembly 2 includes a rotor 21 and a core shaft 22 connected to each other. The end of the core shaft 22 away from the rotor 21 is connected to the drill bit 7. A telescopic cavity 101 is formed between the core shaft 22 and the first housing 12, and a first through hole 221 is also provided thereon. The two ends of the first through hole 221 are respectively connected to the first channel 401 and the telescopic cavity 101. The stator 11 cooperates with the rotor 21 to drive the core shaft 22 and the drill bit 7 to rotate relative to the housing assembly 1 under the action of high-pressure liquid.

[0026] like Figure 1 , Figure 2 and Figure 4As shown, the stator 11 includes a stator shell and a rubber bushing injected on the inner wall of the stator shell, the rubber bushing has an inner spiral, and the rotor 21 has an outer spiral. The rotor 21 is inserted into and between the rubber bushing to form a spiral sealing chamber. When the high-pressure liquid pumped out by the mud pump enters the spiral sealing chamber, the pressure energy is converted into mechanical energy, so that the rotor 21 rotates relative to the stator 11. At the same time, as the rotor 21 rotates, the high-pressure liquid passes through the spiral sealing chamber; the core shaft 22 is connected to one end of the rotor 21, which is connected to the inside of the rotor 21 to form the above-mentioned first flow chamber 201, and the above-mentioned telescopic chamber 101 is formed between the outer wall of the core shaft 22 and the inner wall of the first shell 12. The push block 3 is arranged on the first shell 12, and a first through hole 221 is opened on the core shaft 22. The free end of the flow channel conversion seat 45 is connected to the telescopic chamber 101 through the first through hole 221. The limiting ring 44 is clamped and fixed at the connection between the core shaft 22 and the rotor 21, and the flow channel conversion seat 45 and the limiting ring 44 can rotate with the rotor 21.

[0027] In a preferred embodiment, flow-limiting bearing groups 5 are provided between both ends of the first housing 12 and the core shaft 22 , and the first housing 12 , the core shaft 22 and the two flow-limiting bearing groups 5 together form a telescopic cavity 101 .

[0028] like Figure 4 As shown, two flow-limiting bearing groups 5 are arranged between the core shaft 22 and the first shell 12 along the length direction of the core shaft 22. The flow-limiting bearing group 5 includes a dynamic bearing and a static bearing. The two static bearings are respectively fixed on the inner walls close to the two ends of the first shell 12, and the two dynamic bearings correspond to the two static bearings fixed on the outer wall of the core shaft 22. The static bearings and the dynamic bearings are filled with hard alloy material so that the two can rotate relative to each other. The two flow-limiting bearing groups 5 form a closed space between the outer wall of the core shaft 22 and the inner wall of the first shell 12, that is, the above-mentioned telescopic cavity 101.

[0029] In a preferred embodiment, a thrust bearing group 6 is further provided in the telescopic cavity 101 , and two ends of the thrust bearing group 6 are respectively against the two flow-limiting bearing groups 5 to withstand the axial pressure generated by the drill bit 7 when drilling.

[0030] like Figure 4 As shown, the thrust bearing group 6 is arranged in the telescopic cavity 101, one end of which abuts against the dynamic bearing of the current limiting bearing group 5 on the side close to the drill bit 7, and the other end abuts against the current limiting bearing group 5 on the side away from the drill bit 7. The thrust bearing group 6 includes a plurality of ball bearings, and the plurality of ball bearings are arranged in series to transmit and withstand the axial pressure generated by the drill bit 7 when drilling.

[0031] In a preferred embodiment, a second flow chamber 102 is provided between the rotor 21 and the housing assembly 1, a second through hole 211 is provided on the rotor 21, and a flow limiting mechanism separates the first flow chamber 201 into a first part and a second part. The second flow chamber 102 is connected to the first part through the second through hole 211, and the second part can be connected to the first channel 401.

[0032] like Figure 4 and Figure 5 As shown, the limiting ring 44 has a limiting portion at one end away from the flow channel conversion seat 45, and the limiting portion separates the first flow chamber 201 into a first part and a second part; a third housing 13 is also fixedly connected between the stator 11 and the first housing 12, and the above-mentioned second flow chamber 102 is formed between the limiting bearing group 5 on the side away from the drill bit 7 and the third housing 13, the rotor 21 and the spiral sealing chamber. The second flow chamber 102 is connected to the first part through the second through hole 211, and the first part can also be connected to the drilling well through the hollow structure of the drill bit 7. The high-pressure liquid flows into the second flow chamber 102 after passing through the spiral sealing chamber, and then is discharged into the drilling well from the first part through the second through hole 211. The high-pressure liquid entering the rotor 21 can enter the telescopic chamber 101 through the second part and the first channel 401.

[0033] In a preferred embodiment, a communication component is also included, which includes a second shell 51. The second shell 51 is connected to the end of the shell component 1 away from the drill bit 7. A transmitting assembly 52 and a receiving assembly 53 that are electrically connected to each other are provided in the second shell 51. The transmitting assembly 52 and the receiving assembly 53 are used for control interaction with a ground controller.

[0034] like Figure 3 As shown, the second housing 51 is connected to one end of the stator 11 away from the drill bit 7, and the other end thereof is connected to the drill string. The top drive device can drive the second housing 51, the stator 11, the third housing 13 and the first housing 12 to rotate synchronously through the drill string; the transmitting assembly 52 is arranged at one end of the second housing 51 close to the rotor 21, including a transmitting unit and a transmitting circuit, and the receiving assembly 53 is arranged at one end of the second housing 51 away from the rotor 21, which is electrically connected to the transmitting assembly 52, including a receiving unit and a receiving circuit, and the end of the receiving assembly 53 away from the transmitting assembly 52 is electrically connected to the LWD / MWD; the receiving assembly 53 is used to receive control instructions from the ground controller, and the transmitting assembly 52 is used to transmit the working status of the drilling tool to the ground controller through the LWD / MWD.

[0035] In a preferred embodiment, a battery assembly is further provided in the first flow cavity 201 , and two ends of the battery assembly are respectively fixed and electrically connected to the receiving assembly 53 and the current limiting assembly 4 .

[0036] like Figure 2 and Figure 3As shown, the battery assembly includes a battery 61, which is located on the side of the transmitting assembly 52 away from the receiving assembly 53. The battery 61 is electrically connected to the transmitting assembly 52 through a battery connector 62, and is also electrically connected to the control circuit through a wiring unit 63. The battery 61 is used to power the transmitting assembly 52, the receiving assembly 53, the control circuit and the driving member 41.

[0037] In a preferred embodiment, a well inclination unit 43 is further provided between the driving end of the driving member 41 and the mushroom head 42 , and the well inclination unit 43 is used to detect the well inclination angle of the drill bit 7 during drilling.

[0038] like Figure 2 As shown, the well inclination unit 43 is arranged between the driving end of the driving member 41 and the mushroom head 42, and is electrically connected to the control circuit for detecting the well inclination angle when the drill bit 7 is drilling.

[0039] Working principle: When directional drilling is required, the top drive device drives the housing assembly 1 to rotate, so that the push block 3 is located in the opposite direction of the drilling direction required by the drill bit 7, and the driving member 41 controls the mushroom head 42 to move away from the drill bit 7. The first circulation cavity 201 is connected with the telescopic cavity 101 through the first channel 401. The mud pump pumps high-pressure liquid into the telescopic cavity 101 through the first circulation cavity 201. Under the action of the liquid pressure, the push block 3 moves radially along the first housing 12 away from the core shaft 22 until the protrusion abuts against the limit portion. At this time The push block 3 extends out of the first shell 12. When drilling, the drill bit 7 is laterally displaced through the interaction between the push block 3 and the well wall, thereby realizing directional drilling; when composite drilling is required, the driving member 41 controls the mushroom head 42 to move toward the side close to the drill bit 7, the first channel 401 is closed, the first flow chamber 201 is separated from the telescopic chamber 101, and the push block 3 is retracted and flush with the first shell 12 under the action of the well wall. The drill bit 7 is no longer subjected to lateral force, and the rotor 21 drives the core shaft 22 and the drill bit 7 to perform composite drilling under the action of high-pressure liquid.

[0040] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and its core ideas of this application. The above is only the preferred implementation method of this application. It should be pointed out that due to the limitations of textual expression and the objective existence of infinite specific structures, ordinary technicians in this technical field can make several improvements, modifications or changes without departing from the principles of this application, and can also combine the above technical features in an appropriate manner; these improvements, modifications, changes or combinations, or the direct application of the concept and technical solution of the invention to other occasions without improvement, should be regarded as the scope of protection of this application.

Claims

1. A downhole tool with a guiding function, characterized in that: include: A housing assembly (1), wherein the housing assembly (1) can rotate around its own axis when driven by a top drive device; A screw assembly (2), the screw assembly (2) being arranged inside the housing assembly (1), one end of the screw assembly (2) extending out of the housing assembly (1) and connected to a drill bit (7), the screw assembly (2) having a first flow chamber (201) inside, a telescopic chamber (101) between the screw assembly (2) and the housing assembly (1), and the screw assembly (2) being capable of rotating relative to the housing assembly (1) under the action of high-pressure liquid; A push block (3), the push block (3) being arranged at a position on the outer shell component (1) corresponding to the telescopic cavity (101) and being movable radially along the outer shell component (1); A flow limiting component (4), the flow limiting component (4) having a first state and a second state, when in the first state, the telescopic cavity (101) is connected to the first flow cavity (201), and the push block (3) extends out of the shell component (1), and when in the second state, the telescopic cavity (101) is separated from the first flow cavity (201), and the push block (3) is flush with the shell component (1).

2. A downhole tool with a guiding function according to claim 1, characterized in that: The current limiting assembly (4) comprises a driving member (41) and a current limiting mechanism, wherein the driving member (41) and the current limiting mechanism are both arranged inside the first circulation chamber (201), wherein the current limiting mechanism has a first channel (401) inside, wherein two ends of the first channel (401) are respectively connected to the first circulation chamber (201) and the telescopic chamber (101), and a mushroom head (42) is fixed to the driving end of the driving member (41), wherein the mushroom head (42) can move along the axial direction of the housing assembly (1) under the drive of the driving member (41) to control the opening and closing of the first channel (401), thereby switching the current limiting assembly (4) between the first state and the second state.

3. A downhole tool with a guiding function according to claim 2, characterized in that: The housing assembly (1) comprises a stator (11) and a first housing (12) which are connected to each other, and the screw assembly (2) comprises a rotor (21) and a core shaft (22) which are connected to each other, the core shaft (22) having an end away from the rotor (21) connected to the drill bit (7), the core shaft (22) and the first housing (12) forming the telescopic cavity (101), the core shaft (22) also having a first through hole (221), the two ends of the first through hole (221) respectively communicating with the first channel (401) and the telescopic cavity (101), the stator (11) and the rotor (21) cooperating to drive the core shaft (22) and the drill bit (7) to rotate relative to the housing assembly (1) under the action of high-pressure liquid.

4. A downhole tool with a guiding function according to claim 3, characterized in that: A flow-limiting bearing group (5) is provided between both ends of the first housing (12) and the core shaft (22); the first housing (12), the core shaft (22) and the two flow-limiting bearing groups (5) together enclose the telescopic cavity (101).

5. A downhole tool with a guiding function according to claim 4, characterized in that: A thrust bearing group (6) is also provided in the telescopic cavity (101), and two ends of the thrust bearing group (6) respectively abut against the two flow-limiting bearing groups (5) to withstand the axial pressure generated by the drill bit (7) during drilling.

6. A downhole tool with a guiding function according to claim 3, characterized in that: A second flow chamber (102) is provided between the rotor (21) and the housing assembly (1); a second through hole (211) is provided on the rotor (21); the flow limiting mechanism divides the first flow chamber (201) into a first part and a second part; the second flow chamber (102) is in communication with the first part via the second through hole (211); and the second part can be in communication with the first channel (401).

7. A downhole tool with a guiding function according to claim 1, characterized in that: The invention also comprises a communication component, wherein the communication component comprises a second housing (51), wherein the second housing (51) is connected to an end of the housing component (1) away from the drill bit (7), and wherein a transmitting assembly (52) and a receiving assembly (53) electrically connected to each other are arranged in the second housing (51), and the transmitting assembly (52) and the receiving assembly (53) are used for performing control interaction with a ground controller.

8. A downhole tool with a guiding function according to claim 7, characterized in that: A battery assembly is also provided in the first circulation cavity (201), and two ends of the battery assembly are respectively fixed to and electrically connected to the receiving assembly (53) and the current limiting assembly (4).

9. A downhole tool with a guiding function according to claim 2, characterized in that: A well inclination unit (43) is also provided between the driving end of the driving member (41) and the mushroom head (42), and the well inclination unit (43) is used to detect the well inclination angle when the drill bit (7) is drilling.

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