A downhole tool with a guiding function

Abstract

The present application provides a downhole tool with a guiding function, which relates to the technical field of oil drilling. The downhole tool includes a housing assembly that can rotate driven by a top drive device. A screw assembly is provided inside the housing assembly. One end of the screw assembly extends out of the housing assembly and is connected to a drill bit. The inside of the screw assembly has a first flow cavity, and there is a telescopic cavity between the screw assembly and the housing assembly. A push block is provided on the housing assembly corresponding to the telescopic cavity, and the push block can move radially along the housing assembly. The downhole tool further includes a flow-limiting assembly, and the flow-limiting assembly can communicate the telescopic cavity with the first flow cavity. By providing the push block, when the telescopic cavity is communicated with the first flow cavity, high-pressure liquid enters the telescopic cavity to push out the push block, and the interaction between the push block and the wellbore wall causes the lateral displacement of the drill bit. Rotating the housing assembly can adjust the position of the push block to achieve directional drilling. Compared with the traditional method, the push block can be flush with the housing assembly outside the directional drilling stage, avoiding the drill string being subjected to lateral force for a long time, effectively reducing the wear of the relevant structures of the drill bit, and extending the service life.

Description

Technical Field

[0001] This application relates to the technical field of oil drilling, and particularly 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, except for a few exploration wells, most construction wells adopt horizontal well technology. At present, there are mainly two types of horizontal well drilling technologies. One is the traditional bent screw drill bit directional drilling technology, and the other is the rotary steerable drilling technology. Currently, the rotary steerable technology mainly relies on imported products, with a very high cost. The core of the bent screw drill bit directional technology is to use a screw drill bit with a geometric bend angle to ensure that the wellbore trajectory can change the well inclination angle towards the specified azimuth, and finally drill the desired directional well or horizontal well. However, the existence of the geometric bend angle causes periodic alternating stress on the PDC bit during drilling. Under the action of the alternating stress, the cutting teeth are accelerated in wear, the uneven wear between the cutting teeth is aggravated, local wear and deformation occur on the bit matrix, the damage risk increases, the gauge protection teeth are worn more severely, and the gauge protection structure is deformed and damaged. Summary of the Invention

[0003] The purpose of this application is to address the above problems and provide a downhole tool with a guiding function, including:

[0004] A housing assembly that can rotate around its own axis under the drive of a top drive device;

[0005] A screw assembly disposed inside the housing assembly, one end of which extends out of the housing assembly and is connected to a drill bit. The screw assembly has a first flow cavity inside, and there is a telescopic cavity between it and the housing assembly. The screw assembly can rotate relative to the housing assembly under the action of high-pressure liquid;

[0006] A push block disposed on the housing assembly corresponding to the telescopic cavity and capable of moving radially along the housing assembly;

[0007] A flow-limiting assembly having a first state and a second state. When in the first state, the telescopic cavity is in communication with the first flow cavity, and the push block extends out of the housing assembly. When in the second state, the telescopic cavity is separated from the first flow cavity, and the push block is flush with the housing assembly.

[0008] According to the technical solutions provided by certain embodiments of the present application, the current limiting component further includes a driving member and a current limiting mechanism. Both the driving member and the current limiting mechanism are disposed inside the first flow cavity. The current limiting mechanism has a first channel inside, and both ends of the first channel communicate with the first flow cavity and the telescopic cavity respectively. A mushroom head is fixed to the driving end of the driving member, and the mushroom head can move along the axis direction of the housing assembly under the drive of the driving member to control the on-off of the first channel, thereby enabling the current limiting component to switch between the first state and the second state.

[0009] According to the technical solutions provided by 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. One end of the core shaft away from the rotor is connected to the drill bit. A telescopic cavity is formed between the core shaft and the first housing, and a first through hole is further opened thereon. Both ends of the first through hole communicate with the first channel and the telescopic cavity respectively. The stator cooperates with the rotor and can drive the core shaft and the drill bit to rotate relative to the housing assembly under the action of high-pressure liquid.

[0010] According to the technical solutions provided by certain embodiments of the present application, current limiting bearing groups are provided between both ends of the first housing and the core shaft. The first housing, the core shaft and the two current limiting bearing groups jointly enclose the telescopic cavity.

[0011] According to the technical solutions provided by certain embodiments of the present application, a thrust bearing group is further provided in the telescopic cavity. Both ends of the thrust bearing group respectively abut against the two current limiting bearing groups and are used to bear the axial pressure generated during the drilling of the drill bit.

[0012] According to the technical solutions provided by certain embodiments of the present application, a second flow cavity is provided between the rotor and the housing assembly. A second through hole is opened on the rotor. The current limiting mechanism divides the first flow cavity into a first part and a second part. The second flow cavity communicates with the first part through the second through hole, and the second part can communicate with the first channel.

[0013] According to the technical solutions provided by certain embodiments of the present application, a communication component is further included. The communication component includes a second housing, and the second housing is connected to one end of the housing assembly away from the drill bit. A transmitting assembly and a receiving assembly that are electrically connected to each other are provided inside the second housing. The transmitting assembly and the receiving assembly are used for control interaction with a ground controller.

[0014] According to the technical solutions provided by certain embodiments of the present application, a battery component is further provided in the first flow cavity. Both ends of the battery component are fixed to and electrically connected to the receiving assembly and the current limiting component respectively.

[0015] According to the technical solution provided by certain embodiments of the present application, a well deviation unit is further provided between the driving end of the driving member and the mushroom head, and the well deviation unit is used to detect the well deviation angle when the drill bit is drilling.

[0016] Compared with the prior art, the beneficial effects of the present application are as follows: The present application provides a downhole tool with a guiding function, including a housing assembly that can rotate around its own axis under the drive of a top drive device. A screw assembly is provided 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 there is a telescopic cavity between it 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 provided at a position corresponding to the telescopic cavity on the housing assembly, and the push block can move radially along the housing assembly; a flow-limiting assembly is also included. The flow-limiting assembly has a first state and a second state. When in the first state, the telescopic cavity is communicated with the first flow cavity, and the push block extends out of the housing assembly. When in the second state, the telescopic cavity is blocked from the first flow cavity, and the push block is flush with the housing assembly; by providing a push block on the housing assembly that can move radially along the housing assembly and using the flow-limiting assembly to control the on-off of the telescopic cavity and the first flow cavity, when the two are communicated, high-pressure liquid enters the telescopic cavity to make the push block extend out of the housing assembly and act on the wellbore wall to cause the drill bit to generate a lateral displacement. At the same time, the specific direction of the drill bit displacement can be controlled by driving the housing assembly to rotate through the top drive device, thereby realizing directional drilling. Compared with traditional bent screw drill tools, the push block can retract into the telescopic cavity outside the directional drilling stage and remain flush with the housing assembly, avoiding 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, and greatly extending its service life.

[0017] It should be understood that the description of technical features, technical solutions, beneficial effects or similar languages in the present application does not imply that all features and advantages can be achieved in any single embodiment. On the contrary, it can be understood that the description of features or beneficial effects means that at least one embodiment includes specific technical features, technical solutions or beneficial effects. Therefore, the descriptions of technical features, technical solutions or beneficial effects in this specification do not necessarily refer to the same embodiment. Furthermore, the technical features, technical solutions and beneficial effects described in this embodiment can be combined in any appropriate manner. Those skilled in the art will understand that an embodiment can be implemented 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 specific embodiments that do not embody all embodiments. Description of the Drawings

[0018] To more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0019] Figure 1 Schematic diagram of the structure of the part of the downhole tool with a guiding function close to the drill bit provided by the embodiment of the present application;

[0020] Figure 2 Schematic diagram of the structure of the middle part of the downhole tool with a guiding function provided by the embodiment of the present application;

[0021] Figure 3 Schematic diagram of the structure of the part of the downhole tool with a guiding function far from the drill bit provided by the embodiment of the present application;

[0022] Figure 4 is Figure 1 The enlarged view of part A in

[0023] Figure 5 is Figure 1 The enlarged view of part B in

[0024] The text markings in the figure are indicated as:

[0025] 1. Outer shell assembly; 2. Screw assembly; 3. Pusher block; 4. Flow-limiting assembly; 5. Flow-limiting bearing group; 6. Thrust bearing group; 7. Drill bit; 11. Stator; 12. First outer shell; 13. Third outer shell; 21. Rotor; 22. Core shaft; 41. Driving part; 42. Mushroom head; 43. Well deviation unit; 44. Flow-limiting ring; 45. Flow path conversion seat; 51. Second outer shell; 52. Transmitting assembly; 53. Receiving assembly; 61. Battery; 62. Battery connector; 63. Wiring unit; 101. Telescopic cavity; 102. Second flow cavity; 201. First flow cavity; 211. Second through hole; 221. First through hole; 401. First channel. Specific embodiments

[0026] To enable those skilled in the art to better understand the technical solutions of the present application, the following will clearly and completely describe the technical solutions in the embodiments of the present application in conjunction with the drawings. The description in this part is only exemplary and explanatory, and should not have any restrictive effect on the protection scope of the present application. Specifically, the described embodiments are only some embodiments of the present application, rather than all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts should fall within the protection scope of the present application.

[0027] 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.

[0028] 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:

[0029] The housing assembly 1 can rotate around its own axis when driven by the top driving device;

[0030] 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;

[0031] 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;

[0032] 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.

[0033] 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.

[0034] An installation hole is provided in the housing assembly 1 at a position corresponding to the telescopic cavity 101. The opening end of the installation hole has a limiting portion extending towards its central position. The push block 3 is disposed in the installation hole and can move radially in the installation hole along the housing assembly 1. One end of the push block 3 close to the housing assembly 1 has a protruding portion extending along its radial direction. The protruding portion can abut against the limiting portion to limit the movement of the push block 3 in a direction away from the screw assembly 2. The axial direction of the protruding portion abuts against the inner wall of the installation hole and is in slidable contact with the inner wall of the installation hole. The flow-limiting assembly 4 is disposed in the first flow cavity 201 and is used to control the on-off of the first flow cavity 201 and the telescopic cavity 101. When directional drilling is required, the housing assembly 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 of the drill bit 7. The flow-limiting assembly 4 is used to connect the first flow cavity 201 and the telescopic cavity 101. The mud pump pumps high-pressure liquid into the telescopic cavity 101 through the first flow cavity 201. The push block 3 moves radially along the housing assembly 1 in a direction away from the screw assembly 2 under the action of the liquid pressure until the protruding portion abuts against the limiting portion. At this time, the push block 3 extends out of the housing assembly 1. When the drill tool is drilling, the drill bit 7 generates a lateral displacement through the interaction between the push block 3 and the well wall, thereby realizing directional drilling. When compound drilling is required, the flow-limiting assembly 4 is used to cut off the connection between the first flow cavity 201 and the telescopic cavity 101. The push block 3 retracts flush with the housing assembly 1 under the action of the well wall. The drill bit 7 is no longer affected by the lateral force. The screw assembly 2 drives the drill bit 7 to perform compound drilling under the action of high-pressure liquid.

[0035] By providing a push block 3 on the housing assembly 1 that can move radially along the housing assembly 1, and using the flow-limiting assembly 4 to control the on-off of the telescopic cavity 101 and the first flow cavity 201. When the two are connected, high-pressure liquid enters the telescopic cavity 101 to make the push block 3 extend out of the housing assembly 1, and interacts with the well wall to make the drill bit 7 generate a lateral displacement. At the same time, the top drive device can be used to drive the housing assembly 1 to rotate to control the specific direction of the displacement of the drill bit 7, thereby realizing directional drilling. Compared with the traditional bent screw drill tool, the push block 3 can retract into the telescopic cavity 101 outside the directional drilling stage, keeping the housing assembly 1 flush, avoiding the drill tool 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.

[0036] In a preferred embodiment, the flow-limiting assembly 4 further includes a driving member 41 and a flow-limiting mechanism. Both the driving member 41 and the flow-limiting mechanism are disposed inside the first flow cavity 201. The flow-limiting mechanism has a first channel 401 inside. The two ends of the first channel 401 are respectively connected to the first flow cavity 201 and the telescopic cavity 101. A mushroom head 42 is fixed to the driving end of the driving member 41. The mushroom head 42 can move along the axis direction of the housing assembly 1 under the drive of the driving member 41 to control the on-off of the first channel 401, thereby enabling the flow-limiting assembly 4 to switch between a first state and a second state.

[0037] AsFigure 1 , Figure 2 and Figure 4 As shown in Figure 1 , Figure 2 and Figure 4 , the driving member 41 and the current limiting mechanism are both arranged in the first flow chamber 201. The driving member 41 is a motor, and its driving end is fixedly connected with a mushroom head 42. A control circuit is also arranged on the driving member 41 to control the start and stop of the driving member 41. The current limiting mechanism includes a current limiting ring 44 and a flow path conversion seat 45. The current limiting ring 44 is fixed in the first flow chamber 201, and the flow path conversion seat 45 is fixed at one end of the current limiting ring 44 away from the driving member 41, and the free end of the flow path conversion seat 45 is communicated with the telescopic chamber 101. The inside of the current limiting ring 44 and the flow path conversion seat 45 is communicated to form a first channel 401. When the driving member 41 controls the mushroom head 42 to move towards the current limiting ring 44 until the mushroom head 42 closes the first channel 401, at this time, the first flow chamber 201 is separated from the telescopic chamber 101, and the push block 3 can move radially towards the screw assembly 2 along the outer shell assembly 1 under the action of the well wall until it is flush with the outer shell assembly 1, that is, the above-mentioned second state. When the driving member 41 controls the mushroom head 42 to move away from the current limiting ring 44 until the first channel 401 communicates the first flow chamber 201 and the telescopic chamber 101, at this time, the high-pressure liquid can enter the telescopic chamber 101 through the first channel 401, and the push block 3 moves radially away from the screw assembly 2 along the outer shell assembly 1 under the action of the high-pressure liquid until it extends out of the outer shell assembly 1, that is, the above-mentioned first state.

[0038] In a preferred embodiment, the outer shell assembly 1 includes a stator 11 and a first outer shell 12 connected to each other. The screw assembly 2 includes a rotor 21 and a core shaft 22 connected to each other. One end of the core shaft 22 away from the rotor 21 is connected to the drill bit 7. A telescopic chamber 101 is formed between the core shaft 22 and the first outer shell 12, and a first through hole 221 is also opened thereon. The two ends of the first through hole 221 communicate with the first channel 401 and the telescopic chamber 101 respectively. The stator 11 and the rotor 21 cooperate with each other and can drive the core shaft 22 and the drill bit 7 to rotate relative to the outer shell assembly 1 under the action of high-pressure liquid.

[0039] As Figure 1 , Figure 2 and Figure 4As shown in the figure, the stator 11 includes a stator housing and a rubber bushing cast on the inner wall of the stator housing. The rubber bushing has an internal helix, and the rotor 21 has an external helix. The rotor 21 is inserted into the rubber bushing to form a spiral seal cavity between them. When the high-pressure liquid pumped out by the mud pump enters the spiral seal cavity, the pressure energy is converted into mechanical energy, causing the rotor 21 to rotate relative to the stator 11. At the same time, as the rotor 21 rotates, the high-pressure liquid passes through the spiral seal cavity; the core shaft 22 is connected to one end of the rotor 21, and it communicates with the inside of the rotor 21 to form the above-mentioned first flow cavity 201. The outer wall of the core shaft 22 and the inner wall of the first housing 12 form the above-mentioned telescopic cavity 101. The push block 3 is arranged on the first housing 12. A first through hole 221 is opened on the core shaft 22. The free end of the flow path conversion seat 45 communicates with the telescopic cavity 101 through the first through hole 221. The flow limiting ring 44 is snap-fitted and fixed at the connection between the core shaft 22 and the rotor 21. The flow path conversion seat 45 and the flow limiting ring 44 can rotate together with the rotor 21.

[0040] In a preferred embodiment, 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 jointly enclose to form the telescopic cavity 101.

[0041] As Figure 4 shown, the two flow limiting bearing groups 5 are arranged between the core shaft 22 and the first housing 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 near both ends of the first housing 12. The two dynamic bearings are correspondingly fixed on the outer wall of the core shaft 22. A cemented carbide material is filled between the static bearing and the dynamic bearing to enable them to rotate relative to each other; the two flow limiting bearing groups 5 form a sealed space between the outer wall of the core shaft 22 and the inner wall of the first housing 12, that is, the above-mentioned telescopic cavity 101.

[0042] In a preferred embodiment, a thrust bearing group 6 is further provided in the telescopic cavity 101. Both ends of the thrust bearing group 6 respectively abut against the two flow limiting bearing groups 5, and are used to bear the axial pressure generated when the drill bit 7 drills.

[0043] As Figure 4 shown, the thrust bearing group 6 is arranged in the telescopic cavity 101. One end of it abuts against the dynamic bearing of the flow limiting bearing group 5 on the side close to the drill bit 7, and the other end abuts against the flow limiting bearing group 5 on the side far 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, and are used to transmit and bear the axial pressure generated when the drill bit 7 drills.

[0044] In a preferred embodiment, there is a second flow cavity 102 between the rotor 21 and the housing assembly 1. A second through hole 211 is formed in the rotor 21. The flow limiting mechanism divides the first flow cavity 201 into a first part and a second part. The second flow cavity 102 communicates with the first part through the second through hole 211, and the second part can communicate with the first channel 401.

[0045] As Figure 4 and Figure 5 shown, one end of the flow limiting ring 44 away from the flow path conversion seat 45 has a flow limiting portion, and the flow limiting portion divides the first flow cavity 201 into a first part and a second part; a third housing 13 is fixedly connected between the stator 11 and the first housing 12. The flow limiting bearing group 5 on the side away from the drill bit 7 forms the above-mentioned second flow cavity 102 between the third housing 13, the rotor 21 and the spiral sealing cavity. The second flow cavity 102 communicates with the first part through the second through hole 211. The first part can also communicate with the drilling through the hollow structure of the drill bit 7. The high-pressure liquid flows through the spiral sealing cavity and then enters the second flow cavity 102, and then is discharged into the drilling through the second through hole 211 by the first part. The high-pressure liquid entering the rotor 21 can enter the expansion cavity 101 through the second part and the first channel 401.

[0046] In a preferred embodiment, a communication component is further included. The communication component includes a second housing 51. The second housing 51 is connected to one end of the housing assembly 1 away from the drill bit 7. An emission assembly 52 and a reception assembly 53 which are electrically connected to each other are arranged in the second housing 51. The emission assembly 52 and the reception assembly 53 are used for control interaction with the ground controller.

[0047] As Figure 3 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 emission assembly 52 is arranged at one end of the second housing 51 close to the rotor 21 and includes an emission unit and an emission circuit. The reception assembly 53 is arranged at one end of the second housing 51 away from the rotor 21 and is electrically connected to the emission assembly 52 and includes a reception unit and a reception circuit. One end of the reception assembly 53 away from the emission assembly 52 is electrically connected to the LWD / MWD; the reception assembly 53 is used for receiving the control instructions of the ground controller, and the emission assembly 52 is used for transmitting the working state of the drill tool to the ground controller through the LWD / MWD.

[0048] In a preferred embodiment, a battery assembly is further arranged in the first flow cavity 201. Both ends of the battery assembly are fixedly connected and electrically connected to the reception assembly 53 and the flow limiting assembly 4 respectively.

[0049] As Figure 2 and Figure 3As shown in the figure, 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 supply power to the transmitting assembly 52, the receiving assembly 53, the control circuit, and the driving member 41.

[0050] In a preferred embodiment, an inclination unit 43 is further provided between the driving end of the driving member 41 and the mushroom head 42. The inclination unit 43 is used to detect the well inclination angle when the drill bit 7 is drilling.

[0051] As Figure 2 shown in the figure, the inclination unit 43 is provided between the driving end of the driving member 41 and the mushroom head 42, and is electrically connected to the control circuit, and is used to detect the well inclination angle when the drill bit 7 is drilling.

[0052] 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 direction in which the drill bit 7 needs to drill. The driving member 41 controls the mushroom head 42 to move away from the drill bit 7. The first flow cavity 201 is communicated 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 flow cavity 201. The push block 3 moves radially away from the core shaft 22 along the first housing 12 under the action of the liquid pressure until the convex portion abuts against the limiting portion. At this time, the push block 3 protrudes from the first housing 12. When the drill string is drilling, the drill bit 7 generates a lateral displacement through the interaction between the push block 3 and the wellbore wall, so as to achieve directional drilling; when compound drilling is required, the driving member 41 controls the mushroom head 42 to move towards the drill bit 7. The first channel 401 is closed, and the first flow cavity 201 is separated from the telescopic cavity 101. The push block 3 retracts to be flush with the first housing 12 under the action of the wellbore 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 compound drilling under the action of high-pressure liquid.

[0053] In this article, specific examples are used to elaborate on the principles and implementation methods of this application. The descriptions of the above embodiments are only used to help understand the method and its core idea of this application. The above are only the preferred implementation methods of this application. It should be noted that due to the limited nature of written expression and objectively existing infinite specific structures, for those of ordinary skill in the art, without departing from the principle of this application, several improvements, refinements or changes can be made, or the above technical features can be combined in an appropriate manner; these improvements, refinements, changes or combinations, or directly applying the inventive concept and technical solution to other occasions without improvement, should all be regarded as the protection scope of this application.

Claims

1. A downhole tool with a guiding function, characterized in that, Comprising: A housing assembly (1) that rotates about its own axis under the drive of a top drive device; A screw assembly (2) disposed inside the housing assembly (1), one end of which extends out of the housing assembly (1) and is connected to a drill bit (7). The screw assembly (2) has a first flow cavity (201) inside, and there is a telescopic cavity (101) between the screw assembly (2) and the housing assembly (1). The screw assembly (2) rotates relative to the housing assembly (1) under the action of high-pressure liquid; A push block (3) disposed at a position corresponding to the telescopic cavity (101) on the housing assembly (1) and moving radially along the housing assembly (1); A flow-limiting assembly (4) having a first state and a second state. When in the first state, the telescopic cavity (101) is in communication with the first flow cavity (201), and the push block (3) extends out of the housing assembly (1). When in the second state, the telescopic cavity (101) is cut off from the first flow cavity (201), and the push block (3) is flush with the housing assembly (1); The flow-limiting assembly (4) includes a driving member (41) and a flow-limiting mechanism. Both the driving member (41) and the flow-limiting mechanism are disposed inside the first flow cavity (201). The flow-limiting mechanism has a first channel (401). Both ends of the first channel (401) are respectively in communication with the first flow cavity (201) and the telescopic cavity (101). A mushroom head (42) is fixed to the driving end of the driving member (41). The mushroom head (42) moves along the axis direction of the housing assembly (1) under the drive of the driving member (41) to control the on-off of the first channel (401), thereby enabling the flow-limiting assembly (4) to switch between the first state and the second state; The housing assembly (1) includes a stator (11) and a first housing (12) connected to each other. The screw assembly (2) includes a rotor (21) and a mandrel (22) connected to each other. One end of the mandrel (22) away from the rotor (21) is connected to the drill bit (7). The telescopic cavity (101) is formed between the mandrel (22) and the first housing (12). A first through hole (221) is also provided on the mandrel (22). Both ends of the first through hole (221) are respectively in communication with the first channel (401) and the telescopic cavity (101). The stator (11) cooperates with the rotor (21) to drive the mandrel (22) and the drill bit (7) to rotate relative to the housing assembly (1) under the action of high-pressure liquid; A second flow chamber (102) is provided between the rotor (21) and the housing assembly (1). A second through hole (211) is formed in 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) communicates with the first part through the second through hole (211), and the second part communicates with the first channel (401). The push block (3) retracts into the telescopic chamber (101) outside the directional drilling stage, remaining flush with the housing assembly (1), so as to avoid the drill string being subjected to lateral force for a long time during drilling.

2. The downhole tool with a guiding function according to claim 1, characterized in that, Limiting flow bearing sets (5) are provided between the two ends of the first housing (12) and the mandrel (22). The first housing (12), the mandrel (22) and the two limiting flow bearing sets (5) jointly enclose to form the telescopic chamber (101).

3. The downhole tool with a guiding function according to claim 2, wherein, A thrust bearing set (6) is further provided in the telescopic chamber (101). The two ends of the thrust bearing set (6) respectively abut against the two limiting flow bearing sets (5) and are used for bearing the axial pressure generated when the drill bit (7) drills.

4. A downhole tool with a guiding function according to claim 1, characterized in that, It further includes a communication component. The communication component includes a second housing (51). The second housing (51) is connected to one end of the housing assembly (1) away from the drill bit (7). An emission assembly (52) and a reception assembly (53) which are electrically connected to each other are provided in the second housing (51). The emission assembly (52) and the reception assembly (53) are used for control interaction with a ground controller.

5. The downhole tool with a guiding function according to claim 4, characterized in that, A battery assembly is further provided in the first flow chamber (201). The two ends of the battery assembly are respectively fixed and electrically connected to the reception assembly (53) and the flow limiting component (4).

6. The downhole tool with a guiding function according to claim 1, characterized in that, An inclination unit (43) is further provided between the driving end of the driving member (41) and the mushroom head (42). The inclination unit (43) is used for detecting the well inclination angle when the drill bit (7) drills.

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