A flexible lateral drilling tool

Abstract

The present application belongs to the technical field of exploration or exploitation drilling tools, and particularly relates to a flexible branch drilling tool, which comprises a drill bit and a flexible section, the flexible section comprising multiple power segments and multiple turning segments driven by hydraulic pressure, the adjacent power segments being connected through the turning structure, and the flexible section being installed at the front end of the rigid drill string, so that the flexible branch drilling tool is applied with the drilling pressure from the rigid drill string to the transmission segment, and further applied with the drilling pressure from each power segment to the drill bit; the rotary torque is generated by the power segment and applied to the drill bit; the drilling pressure and the rotary torque are independently applied to the drill bit, so that the drilling pressure and the rotary torque applied to the drill bit are well controllable; when the turning structure is the turning segment, the turning segment is arranged between the multiple power segments, and each turning segment and the power segment are relatively short and small, so that the length of the rigid section of the whole drilling tool is greatly shortened, and the drilling tool can be used to perform the construction on the small curvature radius borehole which is difficult to be constructed by the conventional power drilling tool.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of exploration drilling tools, and particularly relates to a flexible branch drilling tool. BACKGROUND

[0002] In oil and gas exploitation, the development efficiency of oil and gas reservoirs can be significantly improved by drilling branch wells. The branch well is a branch borehole connected to the main borehole, which increases the oil or gas extraction channel and naturally improves the development efficiency, having obvious economic benefit advantages. However, the branch well needs to reach the location of the oil and gas reservoir, and the branch well must be bent during drilling, which makes it difficult to drill and requires special drilling equipment that can drive the drill bit to rotate and drill and turn.

[0003] The guided drilling technology can control the borehole trajectory to drill towards the pre-designed target layer, which enables the drill bit to bypass obstacles to reach the reservoir and explore scattered and heavy oil reservoirs, having more advantages than traditional straight well exploration. For example, the Chinese patent document with publication number CN2135055Y discloses a flexible articulated guided power drilling tool, the Chinese patent document with publication number CN2548742Y discloses a ball joint in a multi-axis hole drill, and the Chinese patent document with publication number CN112814568A discloses a flexible guided drilling tool, all of which can be used for guided drilling and are suitable for drilling branch wells.

[0004] However, the current guided drilling tools still have the following deficiencies: first, the rigid section of the existing conventional guided drilling tool is relatively long, making it difficult to drill a small radius of curvature well section with a large turning amplitude during drilling; second, the power of the existing guided drilling tool decays, making it difficult to meet the drilling power for long distance branch wells. SUMMARY

[0005] The present application aims to provide a flexible branch drilling tool to solve the technical problems of small turning amplitude and low drilling power in the prior art.

[0006] To solve the above technical problems, the present application adopts the following technical solutions:

[0007] A flexible branch drilling tool is provided, comprising:

[0008] A flexible section, the flexible section comprising a plurality of power segments and a plurality of turning segments, adjacent power segments being connected by a turning structure, the plurality of power segments being connected in front of the plurality of turning segments;

[0009] A transmission segment, the transmission segment also being connected in front of the foremost power segment by a turning structure;

[0010] The drill bit is provided with a power shaft in the power sub, a universal joint transmission device in the turning structure, and an output shaft in the transmission sub, which are connected in sequence, and the drill bit is installed at the front end of the output shaft.

[0011] Each of the power sub, the turning structure, the transmission sub and the drill bit is provided with a hydraulic flow channel in communication, and each of the power shafts is provided with a rotor capable of being driven by hydraulic pressure, so as to apply a rotary torque to the drill bit.

[0012] Preferably, the turning structure is a turning sub, the universal joint transmission device is a universal ball shaft, each of the turning subs includes a first housing and a second housing, the front end of the first housing is correspondingly inserted into the rear end of the second housing, and a first gap for turning is arranged between the front end of the first housing and the rear end of the corresponding second housing, and a sealing ring is arranged in the first gap; one end of the universal ball shaft is correspondingly located in the first housing, and the other end is correspondingly located in the second housing.

[0013] Preferably, each of the power subs includes a third housing, the power shaft is correspondingly installed in the third housing through a bearing, the front end of the third housing is connected with the first housing of the previous turning sub, and the rear end of the third housing is connected with the second housing of the next turning sub.

[0014] Each of the power shafts and the output shaft is hollow, and a first flow-through hole is arranged in the drill bit,

[0015] The power shaft is provided with a connecting groove at each end, the universal ball shaft is provided with a ball head at each end, the ball head is installed in the connecting groove, and a second flow-through hole is arranged between the ball head and the connecting groove in the circumferential direction; a sealing sleeve is connected between the rear end of the power shaft and the front end of the corresponding second housing, a second gap is arranged between the universal ball shaft and the corresponding first housing and second housing, and the internal holes of the power shaft, the output shaft and the drill bit, each of the second flow-through holes, each of the second gaps and each of the sealing sleeves are in communication to form the hydraulic flow channel;

[0016] A third gap is arranged between the third housing and the corresponding power shaft, a third flow-through hole is arranged on the wall surface of each of the power shafts, and the third gap is correspondingly connected to the second gap on the rear side, so that the fluid in the hydraulic flow channel can flow into the third gap to drive the rotor to rotate.

[0017] Preferably, a stator is arranged in the third housing, and the stator is matched with the rotor on the corresponding power shaft, so as to define a hydraulic flow space.

[0018] Preferably, the flexible branch drilling tool is provided with a posture measuring module at the front end and a tool face angle measuring module and an information transmission module at the rear end, and the posture measuring module and the tool face angle measuring module are signal connected to the information transmission module.

[0019] Preferably, the posture measuring module comprises an inclination sensor, the tool face angle measuring module comprises a magnetometer and / or an acceleration sensor, and the information transmission module is a mud pulse generator.

[0020] Preferably, the transmission segment comprises a fourth housing, the output shaft is installed in the fourth housing through a radial bearing set and an axial thrust bearing set, the rear end of the fourth housing is connected to the second housing of the adjacent turning segment, the rear end of the output shaft is provided with a connecting groove, and the adjacent universal ball shaft is connected to the connecting groove; the posture measuring module is arranged at the front end inside the fourth housing, and the tool face angle measuring module and the information transmission module are arranged in one of the turning segments.

[0021] Preferably, the fourth housing is provided with eccentric centralizing wings or the fourth housing is a fourth housing with an angle.

[0022] Preferably, the rotor comprises a plurality of flat impellers.

[0023] Preferably, the rigid drill string is hollow, the flexible section is installed at the front end of the rigid drill string, and the rigid drill string is used to apply a drilling pressure to the flexible section.

[0024] Compared with the prior art, the present application has the following beneficial effects:

[0025] 1. The flexible branch drilling tool comprises a flexible section, the flexible section comprises a plurality of power segments driven by hydraulic pressure, adjacent power segments are connected through turning segments, and the flexible section is installed at the front end of a rigid drill string, so that the flexible branch drilling tool is applied with a drilling pressure to a drill bit by the rigid drill string, and a rotating torque is applied to the drill bit by each power segment, the drilling pressure and the rotating torque are independently applied to the drill bit, and the torque of each power segment is accumulated from top to bottom, so that the bottom drill bit obtains a greater torque.

[0026] 2. Since the flexible branch drilling tool is provided with a plurality of turning segments and a plurality of power segments, each turning segment and power segment is relatively short, the length of the rigid section of the whole drilling tool is greatly shortened, and the flexible branch drilling tool can be used to drill a wellbore with a small curvature radius which cannot be drilled by a conventional power drilling tool. BRIEF DESCRIPTION OF DRAWINGS

[0027] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0028] Figure 1 This is a partial cross-sectional view of an embodiment of the flexible branch drilling tool of the present invention.

[0029] Figure 2 This is a cross-sectional view of the front part of the flexible section in one embodiment of the flexible branch drilling tool of the present invention.

[0030] Figure 3 for Figure 2 Enlarged view of part A.

[0031] Figure 4 for Figure 1 Enlarged view of part B.

[0032] Figure 5 This is a schematic diagram of another embodiment of the flexible branch drilling tool of the present invention.

[0033] In the diagram, the labels represent: 1. Rigid drill string; 2. Power sub; 21. Third housing; 22. Power shaft; 221. Connecting groove; 222. Universal ball key; 223. Third flow hole; 23. Third clearance; 24. Rotor; 26. Stator; 27. Bearing; 3. Turning sub; 31. First housing; 311. First outer step; 312. Second outer step; 32. Second housing; 33. Universal ball shaft; 331. Ball head; 34. First clearance; 341. First sealing ring; 342. Second sealing ring. 343. First inner step; 344. Second inner step; 35. Ball seat; 36. Sealing sleeve; 37. Second clearance; 4. Transmission sub; 41. Fourth housing; 42. Output shaft; 421. Connecting shaft; 422. Connecting groove; 43. Radial bearing assembly; 44. Axial thrust bearing assembly; 45. Eccentric centering wing; 5. Drill bit; 51. First flow hole; 6. Hydraulic flow channel; 7. Information transmission module; 71. Tool face angle measurement module; 72. Signal line; 73. Attitude measurement module; 8. Signal sub. Detailed Implementation

[0034] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] A flexible branch drilling tool, please refer to Figures 1 to 5 .

[0036] As Figure 1 shown, the flexible branch drilling tool comprises a rigid drill string 1 and a flexible section installed at the front end of the rigid drill string 1, wherein the rigid drill string 1 is used to apply drilling pressure to the flexible section, the drilling pressure herein refers to the drilling pressure of the flexible branch drilling tool forward in the wellbore, and the flexible section can turn to drill a curved branch well.

[0037] The flexible section comprises a plurality of power joints 2 and a plurality of turning joints 3, the adjacent power joints 2 are connected through a turning structure, the power joints 2 are used to apply power for rotation of the flexible branch drilling tool, and each turning joint 3 can realize turning within a certain angle range. The front end of the flexible section is provided with a transmission joint 4, the rigid drill string 1 is connected with the power joint 2 in front through the flexible drill pipe formed by the last turning joint 3, and the transmission joint 4 is connected to the frontmost power joint 2 through the turning structure. The sum of the axis lengths of the plurality of power joints 2 and the plurality of turning joints 3 is greater than the axis length of the pre-drilled branch well.

[0038] The front end of the transmission joint 4 is connected with a drill bit 5, the transmission joint 4 plays a role of assisting the drill bit 5 to turn on one hand, and plays a role of connecting the drill bit 5 and the power joint 2 behind on the other hand, and the rotating torque applied by each power joint 2 is ultimately transmitted to the drill bit 5 through the transmission joint 4.

[0039] Therefore, the flexible branch drilling tool of the embodiment applies drilling pressure to the drill bit 5 by the rigid drill string 1, applies rotating torque to the drill bit 5 by each power joint 2, and the drilling pressure and the rotating torque are independently applied to the drill bit 5, so that the drilling pressure and the rotating torque applied to the drill bit 5 have good controllability, and the torque of each power joint 2 can be accumulated, and the rotating torque ultimately transmitted to the drill bit 5 is stronger.

[0040] Specifically, as Figure 2 and Figure 3 shown, the turning structure between the power joints is a turning joint, each turning joint 3 comprises a first housing 31 and a second housing 32, a universal ball shaft 33 is arranged in the first housing 31 and the second housing 32, the rear end of the universal ball shaft 33 corresponds to the first housing 31, and the front end corresponds to the second housing 32, and ball heads 331 are arranged at the front end and the rear end of the universal ball shaft 33, which are used to connect the power joints 2 on the front side and the rear side.

[0041] The first shell 31 of the turning sub 3 is tapered at the front end, and the second shell 32 is correspondingly tapered at the rear end, so that the front end of the first shell 31 is inserted into the rear end of the second shell 32, and a first gap 34 for turning is arranged between the front end of the first shell 31 and the rear end of the corresponding second shell 32. The first gap 34 is an annular space, and a sealing ring is arranged in the first gap 34, including a first sealing ring 341 and a second sealing ring 342, so that the first gap 34 is sealed to prevent the leakage of high-pressure liquid medium inside and the entry of hydraulic fluid outside into the first shell 31 and the second shell 32 during drilling.

[0042] The front end of the first shell 31 is provided with a first outer step 311 and a second outer step 312, and the rear end of the second shell 32 is provided with a first inner step 343 and a second inner step 344. The first sealing ring 341 is located between the second inner step 344 and the second inner step 344, and the second sealing ring 342 is located between the first outer step 311 and the first inner step 343.

[0043] A ball seat 35 is arranged in the second shell 32, and the front end of the first shell 31 is a spherical surface matched with the ball seat 35, so that the first shell 31 can smoothly swing along the second shell 32. Since the first gap 34 exists, when the second shell 32 turns relative to the first shell 31, one side of the first sealing ring 341 and the second sealing ring 342 can be compressed and deformed. Therefore, the first shell 31 and the second shell 32 can turn within a certain angle range. Since the flexible section includes multiple turning subs 3, each turning sub 3 can turn within a certain angle, so that the flexible section has a large turning range.

[0044] As shown in Figure 4 Each power sub 2 includes a third shell 21, and the front and rear ends of the third shell 21 are tapered threads. The rear end of the first shell 31 and the front end of the second shell 32 are correspondingly tapered threads, so that the front end of the third shell 21 is connected with the first shell 31 of the previous turning sub, and the rear end of the third shell 21 is connected with the second shell 32 of the next turning sub. In this embodiment, the front and rear ends of the third shell 21 are connected with the corresponding first shell 31 and second shell 32 through threads.

[0045] As shown in Figure 4 A power shaft 22 is arranged in each power sub 2, and the power shaft 22 is correspondingly arranged in the third shell 21 through a bearing 27. Hydraulic medium can flow through the bearing 27, and the power shaft 22 is provided with a connecting groove 221 at each end. A ball head 331 of the universal ball shaft 33 is correspondingly arranged in the connecting groove 221 through a universal ball key 222. The universal ball key 222 is connected in the connecting groove 221 through a pin shaft structure, a tooth or a tooth, and is used to transmit torque between the ball head 331 and the connecting groove 221.

[0046] Since the universal ball shaft 33 is arranged inside the first housing 31 and the second housing 32, and both ends of the universal ball shaft 33 are connected to the connecting groove 221 on the adjacent power shaft 22 through the ball head 331 and the universal ball key 222, when the adjacent power shaft 22 deflects, the turning angle of the power shaft 22 is borne by the two ball heads 331, which reduces the wear of the ball head 331 and the connecting groove 221. For example, when the power shaft 22 turns 6°, the deflection angles of the ball heads 331 on both sides of the power shaft 22 are 3° respectively, which greatly reduces the wear of the ball head and the connecting groove 221.

[0047] When the power shaft 22 turns, the first housing 31 of the turning short section 3 swings relative to the second housing 32.

[0048] As shown in Figure 2 , the transmission short section 4 includes a fourth housing 41, the fourth housing 41 is provided with an output shaft 42, the drill bit 5 is arranged at the front end of the output shaft 42, the output shaft 42 is installed in the fourth housing 41 through a radial bearing set 43 and an axial thrust bearing set 44, the radial bearing set 43 includes a plurality of ball bearings, the axial thrust bearing set 44 can be composed of axial sliding bearings or thrust ball bearings. The rear end of the fourth housing 41 is connected to the second housing 32 of the adjacent turning short section in a threaded manner, the output shaft 42 includes a connecting shaft part 421 at the rear end, the connecting shaft part 421 is provided with a connecting groove 422 at the end, the ball head 331 of the universal ball shaft 33 adjacent to the output shaft 42 is connected to the connecting groove 422, thereby realizing the connection between the transmission short section 4 and the flexible section. It can be known that the front end of the rigid drill string 1 is connected to the rear end of the corresponding turning short section in a threaded manner, which will not be described in detail here.

[0049] In this embodiment, the rigid drill string 1 is hollow, and as shown in Figure 2 , each power shaft 22 and the output shaft 42 are hollow, and the drill bit 5 is provided with a first flow-through hole 51, and in this embodiment, a second flow-through hole (not shown in the figure) is arranged between each ball head 331 and the corresponding connecting groove in the circumferential direction, a sealing sleeve 36 is connected between the rear end of the power shaft 22 and the front end of the corresponding second housing 32, the sealing sleeve 36 is flexible, and a second gap 37 is arranged between the universal ball shaft 33 and the corresponding first housing 31 and second housing 32, the second gap 37 is an annular space, therefore, as shown in Figure 2 , the internal holes of the rigid drill string 1, each power shaft 2, the output shaft 42, the drill bit 5, each second flow-through hole, each second gap 37, and each sealing sleeve 36 are connected to form Figure 2 the hydraulic flow channel 6 indicated by the arrow in the middle, and the high-pressure hydraulic medium injected from the end of the rigid drill string 1 can flow forward along the hydraulic flow channel 6.

[0050] In combination with Figure 4As shown, each power shaft 22 is provided with a rotor 24 capable of being driven by hydraulic pressure, the rotor 24 is fixedly connected with the power shaft 22 or integrally formed with the power shaft 22, and during the flushing of the high-pressure liquid medium, the rotor 24 can drive the power shaft 22 to rotate to apply a rotary torque to the drill bit 5. The rotor 24 includes a plurality of blade groups, each blade group includes a plurality of flat impellers, which is beneficial to shorten the length of each power section, thereby greatly reducing the turning radius of the flexible branch drilling tool, and the impellers are arranged at a certain angle, so that the high-pressure drilling fluid flows along the flow direction to produce an oblique flushing to the impellers. Since the impeller is fixed with the power shaft 22, under the action of the flushing force, the impeller will rotate around the power shaft 22 and drive the power shaft 22 to rotate, and the high-pressure fluid energy is converted into mechanical energy available for drilling.

[0051] Further, as shown in Figure 4 The third gap 23 is an annular space, and the third flow-through hole 223 is arranged on the wall surface of each power shaft 22, so that the high-pressure liquid medium flowing in the hydraulic flow channel 6 can enter the third gap 23 through the third flow-through hole 223 to drive the rotor 24 to rotate, and the end of the third gap 23 corresponds to the second gap 37 on the rear side, so that the fluid in the hydraulic flow channel 6 can continuously flow into the third gap 23 to drive the rotor to rotate.

[0052] Further, as shown in Figure 4 The third housing 21 is provided with a stator 26, which is matched with the rotor 24 on the power shaft 22 inside, for defining a hydraulic flow space, the flow space includes a plurality of flow channels between the stator 26 and the rotor 24, so that the limited space between the stator and the rotor is defined to concentrate flushing to the rotor 24, and the torque of the rotor 24 is greater.

[0053] As shown in Figure 2 The flexible branch drilling tool is provided with eccentric stabilizing wings 45 on the outer wall of the transmission section 4, and when the flexible branch drilling tool is drilled, the eccentric stabilizing wings 45 will exert an eccentric thrust on the drill bit 5, so that when the drilling pressure is applied through the rigid drill string 1, the need for build-up drilling can be met, and when building up, the drill bit 5 will be deflected with the front-end turning section as the deflection center and the contact point between the eccentric stabilizing wings 45 and the well wall as the fulcrum.

[0054] When the flexible branch drilling tool is drilled, the flexible branch drilling tool is rotated at the wellhead end, and the tool face direction of the flexible branch drilling tool is adjusted, so that the turning direction is realized. In other embodiments, the fourth housing of the transmission section can also be designed with an angle at the front end for turning direction.

[0055] Since the output shaft 42 is hingedly connected with the corresponding ball head, when the drill bit 5 deflects, the bending moment generated by the drill bit 5 is prevented from being transmitted to the upper part of the drilling tool, so that the drill bit 5 can more easily deflect to the steering direction with the eccentric stabilizing wing 45 as the fulcrum. At the same time, since the drill bit 5 eliminates the transmission of the bending moment, when the drill bit 5 deflects, the radius of the circular arc formed by the deflection center point of the frontmost turn sub and the fulcrum point of the eccentric stabilizing wing 45 is as short as possible, achieving the purpose of improving the build-up performance.

[0056] Further, as shown in Figure 1 the flexible branch drilling tool is provided with an attitude measurement module 73 at the front end and a tool face angle measurement module 71 and an information transmission module 7 at the rear end, and the attitude measurement module 73 and the tool face angle measurement module 71 are signal connected to the information transmission module 7. In the embodiment, the attitude measurement module 73 is arranged at the front end inside the fourth housing 41, the tool face angle measurement module 71 and the information transmission module 7 are arranged in the signal sub 8 adjacent to the rigid drill string 1, the signal sub 8 is similar in structure to the turn sub, the tool face angle measurement module 71 is connected to the information transmission module 7 through a signal line 72, and the attitude measurement module 73 is also connected to the information transmission module 7 through an internal signal line (not shown in the figure).

[0057] The attitude measurement module 73 includes a hole inclination angle sensor, the tool face angle measurement module 71 includes a magnetometer or an acceleration sensor, and the information transmission module 7 is a mud pulse generator. The hole inclination angle sensor is used to measure the hole inclination angle of the wellbore, the hole inclination angle is the included angle between the central axis of a point in the wellbore and the plumb line of the earth, the magnetometer and the acceleration sensor are used to measure the tool face angle of the flexible branch drilling tool, the tool face angle is the angle of the tool face in the build-up process, and the tool face angle can be used to assist in controlling the steering, and the mud pulse generator can communicate with the surface equipment and is used to transmit the information measured by the attitude measurement module and the tool face angle measurement module to the wellhead end.

[0058] As shown in Figure 5 in another embodiment, the tool face angle measurement module 71 can also be arranged in the turn sub 3 at the middle of the flexible section, and the front end attitude measurement module 73 and the middle tool face angle measurement module 71 are electrically connected to the information transmission module 7 through a signal line 72.

[0059] In the construction, the flexible section of the flexible branch drilling tool is conveyed into the well by the rigid drill string 1, the rigid drill string 1 can transmit the drilling pressure required by the flexible section, the rigid drill string 1, the power shafts 22 in the power short sections 2, the universal ball shafts 33 in the turning short sections 3, the output shafts 42 in the transmission short sections 4 of the flexible branch drilling tool are connected in sequence, and the drill bit 5 is installed at the front end of the output shaft 42, so that the hydraulic flow channels 6 are arranged in the rigid drill string 1, the power short sections 2, the turning short sections 3, the transmission short sections 4 and the drill bit 5, and the rotors 24 capable of being driven by the hydraulic pressure are arranged on the power shafts 22, so that the high-pressure water and other hydraulic mediums can be injected into the rigid drill string 1, the hydraulic mediums flow along the hydraulic flow channels 6, the hydraulic mediums in the hydraulic flow channels 6 enter the third clearances 23 where the rotors 24 are located through the third flow-through holes 223, the rotors 24 are rotated, the torques of the rotors 24 are accumulated to drive the drill bit 5 to rotate, the high-pressure water flows out of the first flow-through holes 51 in the drill bit 5 and washes the working surface of the wellbore, and finally flows out of the wellhead.

[0060] Since the flexible branch drilling tool is provided with the multiple turning short sections 3 and the multiple power short sections 2, and each power short section 2 can provide independent torque, the turning short sections 3 and the power short sections 2 are relatively short under the premise of meeting the drilling power requirement, and the length of the rigid section of the overall drilling tool is greatly shortened. In the oil and gas development, the turning short sections 3 can be conveyed into the high-curvature branch wellbores, or the flexible branch drilling tool can be conveyed into the high-curvature branch well sections to realize the branch well drilling operation, so that the small-curvature radius wellbores which are difficult to be constructed by the conventional power drilling tools can be constructed.

[0061] It should be noted that, in the present document, the terms such as first and second, etc. are used merely to differentiate one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Also, the terms "comprises", "comprising", or any other variations thereof are intended to cover non-exclusive inclusions, so that a process, method, article, or apparatus including a list of elements does not include only those elements, but also includes other elements not explicitly listed, or inherent to such process, method, article, or apparatus.

[0062] Although the embodiments of the present application have been shown and described, it should be understood by those ordinary skilled in the art that various changes, modifications, replacements and variations can be made to the embodiments without departing from the principles and spirits of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A flexible lateral drilling tool, characterized by, The flexible branch drilling tool comprises: a flexible section comprising a plurality of power segments connected by turning structures; a transmission segment connected in front of the foremost power segment by a turning structure; a drill bit, a power shaft is arranged in the power segment, a universal joint transmission device is arranged in the turning structure, and an output shaft is arranged in the transmission segment, the power shaft, the universal joint transmission device, and the output shaft are sequentially connected, and the drill bit is mounted at the front end of the output shaft; a hydraulic flow channel is arranged in each of the power segment, the turning structure, the transmission segment, and the drill bit, and a rotor capable of being driven by hydraulic pressure is arranged on each of the power shafts to apply a rotary torque to the drill bit; the turning structure is a turning segment, the universal joint transmission device is a universal ball shaft, each of the turning segments comprises a first housing and a second housing, the front end of the first housing is correspondingly inserted into the rear end of the second housing, a first gap for turning is arranged between the front end of the first housing and the rear end of the corresponding second housing, and a sealing ring is arranged in the first gap; one end of the universal ball shaft is correspondingly arranged in the first housing, and the other end is correspondingly arranged in the second housing; each of the power segments comprises a third housing, the power shaft is correspondingly mounted in the third housing through a bearing, the front end of the third housing is connected to the first housing of the preceding turning segment, and the rear end of the third housing is connected to the second housing of the following turning segment; each of the power shafts and the output shaft is hollow, a first flow-through hole is arranged in the drill bit, connecting grooves are arranged at the two ends of the power shaft, ball heads are arranged at the two ends of the universal ball shaft, the ball heads are mounted in the connecting grooves, and a second flow-through hole is arranged between the ball heads and the connecting grooves in the circumferential direction; a sealing sleeve is arranged between the rear end of the power shaft and the front end of the corresponding second housing, a second gap is arranged between the universal ball shaft and the corresponding first housing and second housing, and the internal holes of the power shaft, the output shaft, and the drill bit, the second flow-through holes, the second gaps, and the sealing sleeves are connected to form the hydraulic flow channel; a third gap is arranged between the third housing and the corresponding power shaft, a third flow-through hole is arranged on the wall surface of each of the power shafts, and the third gap is correspondingly connected to the second gap on the rear side, so that the fluid in the hydraulic flow channel can flow into the third gap to drive the rotor to rotate.

2. The flexible lateral drilling tool of claim 1, wherein: a stator is arranged in the third housing, and the stator is matched with the rotor on the corresponding power shaft to define a hydraulic flow space.

3. The flexible lateral drilling tool of claim 1, wherein: The front end of the flexible branch drilling tool is provided with an attitude measurement module, the rear end is provided with a tool face angle measurement module and an information transmission module, and the attitude measurement module and the tool face angle measurement module are signal connected to the information transmission module.

4. The flexible lateral drilling tool of claim 3, wherein: The attitude measurement module comprises an inclination sensor, the tool face angle measurement module comprises a magnetometer and / or an acceleration sensor, and the information transmission module is a mud pulse generator.

5. The flexible lateral drilling tool of claim 4, wherein: The transmission segment comprises a fourth housing, the output shaft is installed in the fourth housing through a radial bearing set and an axial thrust bearing set; the rear end of the fourth housing is connected in the second housing of the adjacent turning segment, the rear end of the output shaft is provided with a connecting groove, and the adjacent universal ball shaft is connected in the connecting groove; the posture measuring module is arranged at the front end inside the fourth housing, and the tool face angle measuring module and the information transmission module are arranged in one of the turning segments.

6. The flexible lateral drilling tool of claim 5, wherein: An eccentric centralizing wing is arranged outside the fourth housing, or the fourth housing is a fourth housing with a bend.

7. The flexible lateral drilling tool of claim 1, wherein: The rotor comprises a plurality of flat impellers.

8. The flexible lateral drilling tool of claim 1, wherein: A rigid drill string is further included, the rigid drill string is hollow, the flexible section is installed at the front end of the rigid drill string, and the rigid drill string is used for applying a drilling pressure to the flexible section.

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