Power tool under high-construction inclined shaft

Abstract

The invention relates to the technical field of well drilling, and discloses a high inclined shaft down-hole power tool which comprises a transmission shaft assembly, the transmission shaft assembly comprises a bent shell rotationally arranged on the outer wall of a transmission shaft in a sleeving mode, the bent shell is provided with a first section and a second section which are integrally formed, the first section is close to a drill bit, and an eccentric supporting block is fixedly arranged at the end, close to the drill bit, of the outer wall of the first section; the projection of the side wall, away from the first section, of the eccentric supporting block and the projection of the outer wall of the first section in the first direction form a second included angle with an opening deviating from the drill bit, the supporting face of the eccentric supporting block and the well wall form stable face contact through the design of the second included angle, and the pressure bearing capacity is improved. Bit pressure is efficiently converted into strong lateral deflecting force; the function of the bent shell and the transmission shaft assembly are integrated, the eccentric supporting block is close to the drill bit, the length of an underground power tool is shortened, the fastest slope building rate can be achieved in the shortest well section, and measurement feedback of an upper instrument is more timely and accurate.

Description

Technical Field

[0001] This invention relates to the field of drilling technology, and more specifically to a high-angle well drilling power tool. Background Technology

[0002] As oil and gas exploration and development continue to deepen, large conventional oil reservoirs that are easy to exploit are becoming increasingly scarce. Exploration targets are gradually shifting towards unconventional reservoirs such as thin-layer reservoirs, fractured reservoirs, marginal oil fields, and shale oil and gas. These reservoirs are often characterized by strong concealment, complex distribution, and significant heterogeneity, requiring well trajectories to enter and penetrate the target reservoir with higher precision and shorter paths, thereby maximizing the drainage area and increasing single-well production.

[0003] A screw drill string is a volumetric downhole power drill that uses drilling fluid as its power source, converting fluid pressure energy into mechanical energy. Through a curved housing with a fixed angle on the screw drill string, the direction of the wellbore can be controlled by adjusting the "tool face angle," achieving preliminary and predictable trajectory control. However, it falls short when facing drilling scenarios requiring sharp turns, short radii, or extremely high build-up rates. Conventional tools often require longer adjustment sections, increasing drilling time and costs, and introducing more uncertainty and risk under complex geological conditions. Summary of the Invention

[0004] In view of the above-mentioned defects or deficiencies in the prior art, it is desirable to provide a high-angle well drilling power tool.

[0005] This invention provides a downhole power tool for high-angle well construction, comprising: A drive shaft assembly includes a drive shaft, one end of which is fixedly connected to a drill bit for drilling. The drive shaft assembly also includes a curved housing rotatably sleeved on the outer wall of the drive shaft. The curved housing has an integrally formed first section and a second section. The first section is closer to the drill bit than the second section. An opening is formed between the axes of the first section and the second section, which is at a first included angle away from the drill bit. An eccentric support block is fixedly provided on the outer wall of the first section near the drill bit, for abutting against the well wall and applying a force away from the eccentric support block to the drive shaft assembly. A motor assembly, which is drivenly connected to the end of the drive shaft assembly away from the drill bit, is used to provide power to rotate the drill bit; The projection of the eccentric support block away from the side wall of the first segment in the first direction forms a first angle with the projection of the outer wall of the first segment in the first direction.

[0006] According to the technical solution provided by the present invention, the junction of the first segment and the second segment is the bend point of the curved shell, and the bend point is provided with a bend point groove.

[0007] According to the technical solution provided by the present invention, the drive shaft assembly further includes a bearing structure disposed between the drive shaft and the curved housing, the bearing structure comprising: An angular contact thrust bearing is sleeved on the outer wall of the drive shaft, the inner ring of the angular contact thrust bearing is connected to the outer wall of the drive shaft, and the outer ring of the angular contact thrust bearing is connected to the inner wall of the curved housing. An upper radial bearing is sleeved on the outer wall of the drive shaft and located on the side of the angular contact thrust bearing near the motor assembly. The inner ring of the upper radial bearing is connected to the outer wall of the drive shaft, and the outer ring of the upper radial bearing is connected to the inner wall of the curved housing. The lower radial bearing is sleeved on the outer wall of the drive shaft and located on the side of the angular contact thrust bearing near the drill bit. The inner ring of the lower radial bearing is connected to the outer wall of the drive shaft, and the outer ring of the upper radial bearing is connected to the inner wall of the curved housing.

[0008] According to the technical solution provided by the present invention, the motor assembly includes: A stator housing, one end of which is screwed to the end of the bent housing away from the drill bit, and a stator is fixedly disposed on the inner wall of the stator housing; The rotor is rotatably disposed inside the stator housing and cooperates with the stator, and a first channel is provided through the rotor along its axial direction. A flexible shaft is disposed within the channel, and the outer wall of the end of the flexible shaft away from the drive shaft assembly is screwed to the inner wall of the end of the rotor away from the drive shaft assembly.

[0009] According to the technical solution provided by the present invention, the motor assembly and the transmission shaft assembly are connected by a universal joint structure, the universal joint structure comprising: The connector has one end fixedly sleeved on the outer wall of the drive shaft away from the drill bit, and the other end of the connector is fixedly provided with a ball seat; A first rotating ball is rotatably disposed at the end of the ball seat away from the drive shaft, and the side of the first rotating ball away from the ball seat is rotatably connected to the end of the flexible shaft near the drive shaft assembly. Multiple second rotating balls are evenly distributed circumferentially on the outer wall of one end of the flexible shaft near the drive shaft assembly and are rotatably connected to the flexible shaft. A connecting ring, one end of which is threaded onto the outer wall of the connector away from the drive shaft, and the other end of which is fitted onto the side of the second rotating ball away from the flexural shaft, and is sealed between the connecting ring and the flexural shaft by a sealing assembly.

[0010] According to the technical solution provided by the present invention, the sealing assembly includes: A sealing ring is sleeved on the outer wall of one end of the flexible shaft near the drive shaft assembly, and is located on the side of the second rotating ball away from the drive shaft assembly; An oil seal is sleeved on the outer wall of the flexible shaft near the drive shaft assembly and located on the side of the sealing ring away from the drive shaft assembly. The two ends of the oil seal abut against the flexible shaft and the sealing ring, respectively. A locking sleeve is fitted onto the outer wall of the sealing ring and the oil seal, and the outer wall of the locking sleeve is screwed onto the inner wall of the end of the connecting ring away from the drive shaft assembly.

[0011] According to the technical solution provided by the present invention, an anti-drop structure is provided at the end of the motor assembly away from the drive shaft assembly, the anti-drop structure comprising: The anti-drop joint is screwed to the outer wall of the end of the stator housing away from the drive shaft assembly at the end of the stator housing near the motor assembly. The anti-drop joint has a second channel extending through it along its axial direction. An anti-drop bar is provided inside the second channel, and the outer wall of the anti-drop bar near the motor assembly is screwed to the inner wall of the flexible shaft away from the drive shaft assembly. An anti-drop nut is threaded onto the outer wall of the end of the anti-drop rod away from the flexural axis, and the anti-drop nut is provided with a first convex ring in the circumferential direction; The inner wall of the second channel is provided with a second protruding ring corresponding to the first protruding ring, and is located on the side of the first protruding ring close to the drive shaft assembly. The inner diameter of the second protruding ring is smaller than the diameter of the first protruding ring.

[0012] According to the technical solution provided by the present invention, the drive shaft assembly further includes an anti-drop component for preventing the drive shaft from falling off, the anti-drop component comprising: A locking nut is sleeved on the outer wall of the drive shaft and located between the angular contact thrust bearing and the lower radial bearing. The outer wall of the locking nut near the lower radial bearing is connected to the inner wall of the inner ring of the lower radial bearing. The outer wall of the locking nut has an annular protrusion, which is used to contact the outer ring of the lower radial bearing when the connection between the drive shaft and the universal joint structure fails, so as to prevent the drive shaft from falling off. A support ring is rotatably sleeved on the outer wall of the locking nut and located between the angular contact thrust bearing and the lower radial bearing. The outer wall of the support ring is connected to the inner wall of the curved housing. The two ends of the support ring along its axial direction abut against the outer ring of the angular contact thrust bearing and the outer ring of the lower radial bearing, respectively.

[0013] According to the technical solution provided by the present invention, a flow channel is formed between the rotor and the stator for the flow of driving fluid, and the flow channel is connected to the interior of the curved housing; The connector has a communicating cavity inside, and the outer wall of the connector has a communicating hole that connects the communicating cavity with the inner cavity of the curved housing for the flow of the driving fluid. The drive shaft has a flow cavity that communicates with the connecting cavity, and the flow cavity is connected to the drill bit.

[0014] In summary, this invention specifically discloses a high-angle wellbore power tool, including a drive shaft assembly. The drive shaft assembly includes a drive shaft, one end of which is fixedly connected to a drill bit for drilling. A motor assembly is driven to the end of the drive shaft assembly away from the drill bit, providing power to rotate the drill bit. The drive shaft assembly also includes a curved shell rotatably sleeved on the outer wall of the drive shaft. The curved shell has an integrally formed first section and a second section. The first section is closer to the drill bit than the second section. A first included angle with an opening away from the drill bit is formed between the axes of the first section and the second section. An eccentric support block is fixedly provided at the end of the outer wall of the first section near the drill bit, which abuts against the well wall and applies a force away from the eccentric support block to the drive shaft assembly. A second included angle with an opening away from the drill bit is formed between the projection of the side wall of the eccentric support block away from the first section in a first direction and the projection of the outer wall of the first section in a first direction.

[0015] The design of the second included angle enables stable surface contact between the support surface and the wellbore, improving pressure bearing capacity and efficiently converting drilling pressure into a powerful lateral build-up force with controllable direction. Integrating the curved housing function with the drive shaft assembly, and placing the eccentric support block close to the drill bit, shortens the overall length of the downhole power tool. This combination of near-offset point and maximum offset angle allows for the fastest build-up rate in the shortest well section. Furthermore, it shortens the measurement zero length of the upper instrument, resulting in more timely and accurate measurement feedback. This invention integrates high build-up capacity, high drilling speed, high precision, and high reliability, making it suitable for demanding scenarios such as short-radius and ultra-short-radius horizontal wells, complex trajectory obstacle avoidance, and efficient development of marginal oilfields. Attached Figure Description

[0016] Other features, objects, and advantages of the invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 This is a schematic diagram of a high-angle well drilling power tool.

[0017] Figure 2 This is a sectional view of the drive shaft assembly.

[0018] Figure 3 This is a schematic diagram of an eccentric support block.

[0019] Figure 4 This is a schematic diagram of the first included angle.

[0020] Figure 5 Schematic diagram at point B in the middle.

[0021] Figure 6 for Figure 2 Schematic diagram at point A in the middle.

[0022] Figure 7 To prevent the structural sectional view from being lost.

[0023] The following are the labeling elements in the diagram: 1. Drive shaft; 2. Bent housing; 3. Eccentric support block; 4. Bend groove; 5. Angular contact thrust bearing; 6. Upper radial bearing; 7. Lower radial bearing; 8. Stator housing; 9. Rotor; 10. Flexible shaft; 11. Joint; 12. First rotating ball; 13. Second rotating ball; 14. Connecting ring; 15. Sealing ring; 16. Oil seal; 17. Locking sleeve; 18. Anti-dropping element; 19. Anti-dropping rod; 20. Anti-dropping nut; 21. Second convex ring; 22. Locking nut; 23. Support ring; 24. Ball seat; 25. Stator; 26. First convex ring. Detailed Implementation

[0024] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0025] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0026] Please refer to Figure 1 and Figure 2 A high-angle well drilling power tool, comprising: The drive shaft assembly includes a drive shaft 1, one end of which is fixedly connected to a drill bit for drilling. The drive shaft assembly also includes a curved housing 2 rotatably sleeved on the outer wall of the drive shaft 1. The curved housing 2 has an integrally formed first section and a second section. The first section is closer to the drill bit than the second section. An opening is formed between the axes of the first section and the second section, which is away from the drill bit. An eccentric support block 3 is fixedly provided on the outer wall of the first section near the drill bit, which is used to abut against the well wall and apply a force away from the eccentric support block 3 to the drive shaft assembly. The motor assembly is connected to the end of the drive shaft assembly away from the drill bit and is used to provide power to rotate the drill bit. The eccentric support block 3, whose side wall is away from the first section, forms an opening at a second angle away from the drill bit between the projection of the first section's outer wall in the first direction and the projection of the first section's outer wall in the first direction.

[0027] Specifically, a drill bit is fixedly connected to one end of the drive shaft 1, and drilling can be achieved by rotating the drill bit; A curved housing 2 is rotatably fitted onto the outer wall of the drive shaft 1. As the name suggests, the curved housing 2 is a housing with a bend. The bending condition of the curved housing 2 is adapted to the actual required drilling directional rate. The included angle formed between the axes of the two ends of the curved housing 2 is usually selected within the range of 0°-3°. That is, the curved housing 2 has an integrally formed first section and a second section. The first section is closer to the drill bit than the second section. The opening formed between the axes of the first section and the second section is away from the first included angle of the drill bit, which is within the range of 0°-3°. Figure 2 As shown, along the direction from the second segment to the first segment, the bending direction of the curved housing 2 is counterclockwise (not shown in the figure); an eccentric support block 3 is fixedly installed on the outer wall of the curved housing 2 away from its bending direction and near the drill bit, which is used to abut against the well wall during drilling. The interaction force between the eccentric support block 3 and the well wall provides a force to the drive shaft assembly in the bending direction of the curved housing 2, that is, a force away from the direction of the eccentric support block 3, which converts the drilling pressure into a controllable lateral directional force tilting in the bending direction of the curved housing 2, thereby improving the directional drilling effect.

[0028] The eccentric support block 3 is a protrusion extending from the outer wall of the first section and capable of contacting the well wall. Its sidewall surface away from the first section serves as the support surface, which is curved (e.g., ...). Figure 3 To achieve contact and fit with the well wall, the outer diameter of the eccentric support block 3 gradually increases along the direction from the drill bit to the motor assembly, resembling part of a frustum.

[0029] Unlike conventional tools, the high-angle drilling downhole power tool of this invention integrates a large-angle curved housing 2 directly onto the drive shaft assembly, extremely close to the drill bit. This design significantly shortens the force arm, causing a significant and rigid offset between the drill bit axis and the wellbore axis. Integrating the traditional curved housing function into the drive shaft assembly, forming a curved drive shaft assembly with an eccentric support block 3, optimizes the layout. The traditional split drive shaft assembly of screw drills is integrated with the curved housing into a single curved housing drive shaft assembly, meaning the bend point is closer to the drill bit. This allows for the fastest well inclination angle change rate within the shortest well section, achieving a "maximum offset angle" effect. Furthermore, it shortens the overall length, significantly reducing the measurement zero length of the upper instrument, resulting in more timely and accurate measurement feedback. This leads to higher efficiency, a shorter path, and more precise control in directional drilling.

[0030] Traditional screw drills are relatively long, and the drive shaft assembly, curved housing, and motor assembly are connected in series, resulting in a measurement zero length of uplink instruments that can reach tens of meters or even longer. This means that the data measured by the uplink instruments cannot reflect the real-time status of the drill bit. This invention, by integrating the curved housing 2 into the drive shaft assembly, significantly shortens the length of the downhole power tool itself, thereby physically reducing the measurement zero length. The measurement point of the uplink instrument is closer to the drill bit, and the measurement information obtained by the operator is more real-time and accurate. This greatly improves the downhole power tool's ability to perform high-precision, rapid-response trajectory control in complex formations.

[0031] An eccentric support block 3 is disposed on the outer wall of the first section, specifically on the outer wall of the first section facing away from the bending direction of the curved shell 2. The projection of the side wall of the eccentric support block 3 away from the first section in the first direction and the projection of the outer wall of the first section in the first direction form a second included angle with respect to the drill bit. This second included angle can be selected as 2°, and the specific angle can be calculated based on the actual required inclination rate. The first direction is... Figure 2 The center is perpendicular to the plane of the paper.

[0032] Therefore, during the drilling and directional drilling process, the support surface can form a surface contact with the well wall to achieve full support, effectively disperse the drilling pressure bending moment, enhance support stability, and avoid stress concentration and instability caused by point contact or line contact. The design of the first included angle makes the support force of the well wall on the support surface form a thrust in the bending direction of the bent shell 2, which can improve the directional drilling effect.

[0033] Furthermore, the junction of the first and second segments is the bend point of the curved shell 2, and a bend point groove 4 is provided at the bend point.

[0034] Specifically, the junction of the first and second segments is the bending point of the curved housing 2. Since the opening formed between the axes of the first and second segments is away from the first included angle of the drill bit, the junction of the first and second segments is the bending point of the curved housing 2. A bending point groove 4 is provided at the bending point of the curved housing 2 away from its bending position. The bending point groove 4 and the eccentric support block 3 are located on the same side of the curved housing 2. This forms a local flexible area, so that the bending deformation of the entire shell is mainly concentrated at the bending point groove 4, providing deformation, thereby absorbing and releasing most of the additional bending deformation energy caused by external loads, thus protecting the main structure, releasing deformation stress, and improving the fatigue life and reliability of the entire bending drive shaft assembly.

[0035] Among them, the vertical distance between the midpoint of the support surface of the eccentric support block 3 and the plane at the end of the first section away from the second section is ≤430mm, and the vertical distance between the midpoint of the bend groove 4 and the plane at the end of the first section away from the second section is ≤985mm. This design directly moves the bend position downward, and the center of the eccentric support block 3 is extremely close to the drill bit end face, achieving the effect of "extremely close offset point". This is the geometric basis for achieving a high build-up rate. Combined with the bendable drive shaft assembly, it can complete the rapid change of well inclination angle in a very short well section. The combination of "extremely close offset point" and "extremely large offset angle" enables the rapid change of well inclination angle in the shortest well section, which is suitable for drilling scenarios with sharp turns.

[0036] Furthermore, such as Figure 2 and Figure 5 As shown, the drive shaft assembly also includes a bearing structure disposed between the drive shaft 1 and the curved housing 2. The bearing structure includes: An angular contact thrust bearing 5 is sleeved on the outer wall of the drive shaft 1. The inner ring of the angular contact thrust bearing 5 is connected to the outer wall of the drive shaft 1, and the outer ring of the angular contact thrust bearing 5 is connected to the inner wall of the curved housing 2. The upper radial bearing 6 is sleeved on the outer wall of the drive shaft 1 and located on the side of the angular contact thrust bearing 5 near the motor assembly. The inner ring of the upper radial bearing 6 is connected to the outer wall of the drive shaft 1, and the outer ring of the upper radial bearing 6 is connected to the inner wall of the curved housing 2. The lower radial bearing 7 is sleeved on the outer wall of the drive shaft 1 and located on the side of the angular contact thrust bearing 5 near the drill bit. The inner ring of the lower radial bearing 7 is connected to the outer wall of the drive shaft 1, and the outer ring of the upper radial bearing 6 is connected to the inner wall of the curved housing 2.

[0037] Specifically, the lower radial bearing 7, the angular contact thrust bearing 5, and the upper radial bearing 6 are arranged sequentially in the direction away from the drill bit. The inner ring of the lower radial bearing 7 and the outer wall of the drive shaft 1 can be connected by a screw thread, and the outer ring of the lower radial bearing 7 and the inner wall of the curved housing 2 can be connected by a screw thread, thereby achieving a stable connection between the lower radial bearing 7, the drive shaft 1, and the curved housing 2.

[0038] The outer rings of both the angular contact thrust bearing 5 and the upper radial bearing 6 are in contact with the inner wall of the curved housing 2, and can be selected as an interference fit. The inner rings of both the angular contact thrust bearing 5 and the upper radial bearing 6 are in contact with the outer wall of the drive shaft 1, and can also be selected as an interference fit, increasing the contact area and achieving effective force transmission. The outer and inner rings of the angular contact thrust bearing 5 abut against the outer and inner rings of the upper radial bearing 6, respectively, to ensure stable force transmission.

[0039] By setting up a bearing structure, stable relative rotation between the curved housing 2 and the drive shaft 1 is ensured, while the curved housing 2 and the drive shaft 1 are subjected to pressure, thus preventing the drive shaft assembly from breaking due to excessive bending.

[0040] It should be noted that a wear-resistant layer is provided between the inner and outer rings of the lower radial bearing 7 and the upper radial bearing 6, which extends the service life of the downhole power tools.

[0041] Furthermore, the driveshaft assembly also includes an anti-drop component to prevent the driveshaft 1 from falling off. The anti-drop component includes: Locking nut 22 is sleeved on the outer wall of the drive shaft 1 and located between the angular contact thrust bearing 5 and the lower radial bearing 7. The outer wall of the locking nut 22 near the lower radial bearing 7 is connected to the inner wall of the inner ring of the lower radial bearing 7. The outer wall of the locking nut 22 has an annular protrusion, which is used to contact the outer ring of the lower radial bearing 7 when the connection between the drive shaft 1 and the universal joint structure fails, so as to prevent the drive shaft 1 from falling off. The support ring 23 is rotatably sleeved on the outer wall of the locking nut 22 and located between the angular contact thrust bearing 5 and the lower radial bearing 7. The outer wall of the support ring 23 is connected to the inner wall of the curved housing 2. The two ends of the support ring 23 along its axial direction abut against the outer ring of the angular contact thrust bearing 5 and the outer ring of the lower radial bearing 7, respectively.

[0042] Specifically, the universal joint structure is located between the drive shaft assembly and the motor assembly, and the anti-drop component is located between the angular contact thrust bearing 5 and the lower radial bearing 7. It is used to prevent the drive shaft 1 from falling off when the connection between the drive shaft 1 and the universal joint structure fails or breaks. The locking nut 22 is sleeved on the outer wall of the drive shaft 1. The inner wall of the locking nut 22 and the outer wall of the drive shaft 1 form a surface contact, which can be an interference fit. The outer wall of the locking nut 22 near the drill bit and the inner wall of the lower radial bearing 7 away from the drill bit can be screwed together to form a stable connection. The end of the locking nut 22 away from the drill bit abuts against the inner ring sidewall of the angular contact thrust bearing 5 to ensure stable force transmission. The outer wall of the locking nut 22 has an annular protrusion that extends radially and is opposite to the outer ring of the lower radial bearing 7. The corresponding position, that is, the outer diameter of the annular protrusion is larger than the outer diameter of the inner ring of the lower radial bearing 7, so that when the connection between the drive shaft 1 and the universal joint structure fails or breaks, the drive shaft 1 will fall due to gravity. However, the outer ring of the lower radial bearing 7 is screwed to the bent housing 2, and the locking nut 22 is interference-fitted with the drive shaft 1. When the drive shaft 1 falls, it will take the locking nut 22 with it. The annular protrusion contacts the outer ring of the lower radial bearing 7 and is thus supported, thereby preventing the drive shaft 1 from falling completely and improving the safety of downhole operations.

[0043] The support ring 23 is rotatably sleeved on the outer wall of the locking nut 22, and the outer wall of the support ring 23 and the inner wall of the curved housing 2 can be selected as an interference fit. The two ends of the support ring 23 along its axial direction abut against the outer ring side wall of the angular contact thrust bearing 5 and the outer ring side wall of the lower radial bearing 7, respectively. The support ring 23 fills the gap between the angular contact thrust bearing 5 and the lower radial bearing 7, further ensuring stable force transmission.

[0044] Furthermore, the motor assembly includes: The stator housing 8 is screwed to one end of the curved housing 2 away from the drill bit, and the stator 25 is fixedly installed on the inner wall of the stator housing 8. The rotor 9 is rotatably disposed inside the stator housing 8 and cooperates with the stator 25. A first channel is provided inside the rotor 9 along its axial direction. The flexible shaft 10 is disposed in the channel, and the outer wall of the end of the flexible shaft 10 away from the drive shaft assembly is screwed to the inner wall of the end of the rotor 9 away from the drive shaft assembly.

[0045] Specifically, the stator housing 8 has a uniform wall thickness along its length to ensure uniform deformation of the stator housing 8 under high pressure. The inner wall of the stator housing 8 is provided with a stator 25, and the surface of the stator 25 is covered with a rubber layer. The rubber layer is made of hard rubber, which improves the output power of the motor assembly and its high temperature resistance, wear resistance and fatigue resistance, ensuring that the performance of the motor assembly does not degrade under high power output and adapts to the needs of high power operation.

[0046] The rotor 9 has a first channel extending through it along its axial direction. The flexible shaft 10 is disposed inside the first channel, and the outer wall of the end of the flexible shaft 10 away from the drive shaft assembly is screwed to the inner wall of the end of the rotor 9 away from the drive shaft assembly. The flexible shaft 10 is integrated onto the rotor 9. Compared with the traditional series connection of the flexible shaft 10 and the motor assembly, the flexible shaft 10 and the rotor 9 in this embodiment are connected in parallel. On the one hand, this shortens the overall length of the downhole power tool and further reduces the measurement zero length of the upper instrument, making the measurement feedback more timely and accurate. On the other hand, it still ensures the output power of the motor assembly, realizing high-power drilling.

[0047] Furthermore, such as Figure 2 and Figure 6 As shown, the motor assembly and the drive shaft assembly are connected by a universal joint structure, which includes: Connector 11, one end of connector 11 is fixedly sleeved on the outer wall of the end of drive shaft 1 away from drill bit, and the other end of connector 11 is fixedly provided with ball seat 24; The first rotating ball 12 is rotatably disposed at the end of the ball seat 24 away from the drive shaft 1, and the side of the first rotating ball 12 away from the ball seat 24 is rotatably connected to the end of the flexible shaft 10 near the drive shaft assembly. Multiple second rotating balls 13 are evenly distributed circumferentially on the outer wall of one end of the flexible shaft 10 near the transmission shaft assembly and are rotatably connected to the flexible shaft 10. The connecting ring 14 has one end threadedly fitted onto the outer wall of the connector 11 away from the drive shaft 1, and the other end fitted onto the side of the second rotating ball 13 away from the flexible shaft 10, and is sealed between the connecting ring 14 and the flexible shaft 10 through the sealing assembly.

[0048] Specifically, the universal joint structure is a ball cage structure. The ball cage structure can transmit torque and speed more smoothly and efficiently under large deflection angles, thereby improving transmission efficiency and service life.

[0049] The connector 11 is provided with a connecting groove at one end near the drive shaft assembly, corresponding to the drive shaft 1. The inner wall of the connecting groove can be connected to the outer wall of the drive shaft 1 away from the drill bit in a screw-on manner to form a stable connection. A ball seat 24 is fixedly provided at the middle position of the end of the connector 11 away from the drive shaft 1. A first spherical recess is provided on the side wall of the ball seat 24 away from the connector 11. A first rotating ball 12 is rotatably disposed inside the first spherical recess. The flexible shaft 10 has a second spherical recess at one end near the drive shaft assembly, corresponding to the first rotating ball 12, and the second spherical recess is rotatably connected to the first rotating ball 12; when a change of direction occurs during drilling, both the drive shaft assembly and the motor assembly achieve relative deflection based on the first rotating ball 12, and the universal joint structure can provide deformation conditions.

[0050] The outer wall of the flexible shaft 10 near the transmission shaft assembly has a plurality of third spherical recesses evenly arranged in the circumferential direction, and a second rotating ball 13 is rotatably arranged in the third spherical recess; One end of the connecting ring 14 is threaded onto the outer wall of the end of the connector 11 away from the drive shaft 1, forming a stable connection. The other end is sleeved on the end of the flexible shaft 10 near the drive shaft assembly and on the side of the second rotating ball 13 away from the flexible shaft 10. The inner wall of the end of the connecting ring 14 away from the drive shaft assembly is provided with multiple moving grooves corresponding to the multiple second rotating balls 13. The moving grooves are hemispherical structures and extend along the axial direction of the connecting ring 14. The moving grooves can accommodate the second rotating balls 13. When there is a deflection between the drive shaft assembly and the motor assembly, the second rotating ball 13 that is close to the deflection direction moves along its moving groove toward the drive shaft assembly, and the second rotating ball 13 that is away from the deflection direction moves along its moving groove toward the drive shaft assembly. This enables the relative deflection of the drive shaft assembly and the motor assembly.

[0051] Meanwhile, the flexure shaft 10 rotates under the rotational power of the rotor 9, thereby causing multiple second rotating balls 13 to rotate around the axis of the flexure shaft 10. The interaction force between the second rotating balls 13 and the moving groove causes the connecting ring 14 to rotate, thereby causing the joint 11 and the transmission shaft 1 to rotate, and then causing the drill bit to rotate, thus realizing the drilling operation.

[0052] Furthermore, the sealing assembly includes: The sealing ring 15 is sleeved on the outer wall of the end of the flexible shaft 10 near the drive shaft assembly, and is located on the side of the second rotating ball 13 away from the drive shaft assembly. Oil seal 16 is sleeved on the outer wall of the flexible shaft 10 near the drive shaft assembly and located on the side of the sealing ring 15 away from the drive shaft assembly. The two ends of oil seal 16 abut against the flexible shaft 10 and the sealing ring 15 respectively. Locking sleeve 17 is fitted on the outer wall of sealing ring 15 and oil seal 16, and the outer wall of locking sleeve 17 is screwed to the inner wall of the end of connecting ring 14 away from the drive shaft assembly.

[0053] Specifically, the sealing structure is used to seal the universal joint structure, ensuring that the grease inside the universal joint structure does not leak out.

[0054] The sealing ring 15 is sleeved on the outer wall of the end of the flexible shaft 10 near the drive shaft assembly and is located on the side of the second rotating ball 13 away from the drive shaft assembly. The sealing ring 15 can be made of rubber, its inner wall abuts against the outer wall of the flexible shaft 10, and its end near the drive shaft assembly protrudes radially out of the third spherical recess.

[0055] The oil seal 16 is sleeved on the outer wall of the flexible shaft 10 and is located on the side of the sealing ring 15 away from the drive shaft assembly. The two axial ends of the oil seal 16 abut against the sealing ring 15 and the flexible shaft 10 respectively. The outer wall of the flexible shaft 10 has protrusions that limit the oil seal 16. On the one hand, the oil seal 16 can apply a radial force to the sealing ring 15 and press the sealing ring 15 onto the flexible shaft 10. On the other hand, the oil seal 16 can apply a preload force to the sealing ring 15 in the axial direction towards the drive shaft assembly.

[0056] The locking sleeve 17 is fitted onto the outer wall of the sealing ring 15 and the oil seal 16, and the outer wall of the locking sleeve 17 is screwed to the inner wall of the end of the connecting ring 14 away from the drive shaft assembly. Thus, the inner wall of the locking sleeve 17 abuts against the sealing ring 15 and the oil seal 16, and the locking sleeve 17 applies a radial force to the sealing ring 15 and the oil seal 16, pressing the sealing ring 15 and the oil seal 16 onto the flexible shaft 10, and sealing the moving groove to prevent grease leakage.

[0057] Furthermore, such as Figure 7 As shown, the motor assembly has an anti-drop structure at the end away from the drive shaft assembly. The anti-drop structure includes: Anti-drop 18: The outer wall of one end of the anti-drop 18 near the motor assembly is screwed to the inner wall of the stator housing 8 away from the drive shaft assembly. A second channel is opened through the anti-drop 18 along its axial direction. Anti-drop bar 19 is located inside the second channel. The outer wall of the anti-drop bar 19 near the motor assembly is screwed to the inner wall of the flexible shaft 10 away from the transmission shaft assembly. The anti-drop nut 20 is threaded onto the outer wall of the end of the anti-drop rod 19 away from the flexural shaft 10, and the anti-drop nut 20 is provided with a first protruding ring 26 in the circumferential direction. The inner wall of the second channel is provided with a second protruding ring 21 corresponding to the first protruding ring 26, and is located on the side of the first protruding ring 26 close to the drive shaft assembly. The inner diameter of the second protruding ring 21 is smaller than the diameter of the first protruding ring 26.

[0058] Specifically, the anti-drop joint 18 is screwed onto the inner wall of the stator housing 8 at the end away from the drive shaft assembly, forming a stable connection with the motor assembly. The anti-drop joint 18 has a second channel extending through it along its axial direction. An anti-drop rod 19 is disposed in the second channel, and the end of the anti-drop rod 19 near the motor assembly is screwed to the inner wall of the end of the flexible shaft 10 away from the transmission shaft assembly, forming a stable connection with the flexible shaft 10. An anti-drop nut 20 is screwed to the end of the anti-drop rod 19 away from the flexible shaft 10. A first convex ring 26 is provided on the circumferential outer wall of the anti-drop nut 20. A second convex ring 21 is provided on the inner wall of the second channel corresponding to the first convex ring 26. The second convex ring 21 is located on the side of the first convex ring 26 near the transmission shaft assembly, and the diameter of the first convex ring 26 is larger than the inner diameter of the second convex ring 21. Therefore, when the casing breaks during drilling, the second convex ring 21 can directly support the first convex ring 26, preventing the motor assembly from falling off and improving the safety of downhole operations.

[0059] Furthermore, a flow channel is formed between the rotor 9 and the stator 25 for the flow of drive fluid, and the flow channel is connected to the interior of the curved housing 2; The connector 11 has a communicating cavity inside, and the outer wall of the connector 11 has a communicating hole that connects the communicating cavity with the inside of the bent housing 2 for the flow of driving fluid. The drive shaft 1 has a flow cavity that communicates with the connecting cavity, and the flow cavity is connected to the drill bit.

[0060] Specifically, a flow channel is formed between the rotor and the stator 25. The driving fluid can be mud. The driving fluid is delivered to the anti-drop joint 18 through the ground through the second channel. The driving fluid can flow into the flow channel from the second channel, thereby driving the rotor 9 to rotate, causing the flexible shaft 10 to rotate, which in turn drives the universal joint structure to rotate, causing the transmission shaft 1 to rotate, and finally causing the drill bit to rotate, thus realizing drilling.

[0061] The connector 11 has a connecting cavity inside, and the outer wall of the connector 11 has a connecting hole that connects the connecting cavity with the inner cavity of the curved housing 2. When the driving fluid flows through the flow channel, it enters the inner cavity of the curved housing 2. Since the connector 11 has a connecting cavity inside and a connecting hole that connects to the connecting cavity on its outer wall, the driving fluid can enter the connecting cavity through the connecting hole, and then enter the flow cavity inside the drive shaft 1 through the connecting cavity, and finally flow to the drill bit and be discharged downhole through the drill bit.

[0062] Working principle: The driving fluid is delivered to the surface and enters the second channel of the anti-drop 18, flowing into the flow channel between the stator 25 and the rotor 9, causing the rotor 9 to rotate. This causes the flexible shaft 10 to rotate, which in turn drives the universal joint structure to rotate, thereby causing the drive shaft 1 to rotate and driving the drill bit to rotate, thus achieving drilling. The flexible shaft 10 is connected in parallel with the motor assembly, and the bending housing function is combined with the drive shaft assembly, which shortens the overall length of the downhole power tool, making the data of the upper instrument closer to the drill bit, achieving high-precision and fast-response trajectory control, and ensuring the output power of the motor assembly. Integrating the bending housing function with the drive shaft assembly to form a "bending drive shaft assembly" and moving the bending point position and eccentric support block 3 downwards can achieve the maximum angle in the shortest well section. The deflection provides a geometric basis for high-angle drilling, and the eccentric support block 3 is located on the outer wall of the curved shell 2 away from its bending direction. At the same time, the 2° design of the support surface achieves stable surface contact between the support surface and the well wall, improving the pressure bearing capacity and making the support more stable. It also efficiently converts drilling pressure into a powerful lateral drilling force with controllable direction. The high-angle drilling downhole power tool provided by this invention integrates high drilling capacity, high drilling speed, high precision, and high reliability. It is suitable for harsh scenarios such as short-radius and ultra-short-radius horizontal wells, complex trajectory obstacle avoidance, and efficient development of marginal oil fields. In addition, the bearing structure can ensure more stable torque transmission and strengthen the structural strength of the drive shaft assembly. The ball cage design of the universal joint structure can transmit torque more smoothly and efficiently under large deflection angles, improving transmission efficiency and service life.

[0063] The above description is merely a preferred embodiment of the present invention and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention is not limited to the specific combination of the above-described technical features, but also includes other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above-described features with (but not limited to) technical features with similar functions disclosed in this invention.

Claims

1. A high-angle well drilling power tool, characterized in that, include: A drive shaft assembly includes a drive shaft (1), one end of which is fixedly connected to a drill bit for drilling. The drive shaft assembly also includes a curved housing (2) rotatably sleeved on the outer wall of the drive shaft (1). The curved housing (2) has an integrally formed first section and a second section. The first section is closer to the drill bit than the second section. An opening is formed between the axes of the first section and the second section, which is away from the drill bit. An eccentric support block (3) is fixedly provided on the outer wall of the first section near the drill bit, which is used to abut against the well wall and apply a force away from the eccentric support block (3) to the drive shaft assembly. A motor assembly, which is drivenly connected to the end of the drive shaft assembly away from the drill bit, is used to provide power to rotate the drill bit; The eccentric support block (3) forms an opening away from the drill bit at a second included angle between the projection of the side wall away from the first segment in the first direction and the projection of the outer wall of the first segment in the first direction.

2. The high-angle well drilling power tool according to claim 1, characterized in that, The junction of the first segment and the second segment is the bend point of the curved shell (2), and the bend point is provided with a bend point groove (4).

3. The high-angle well drilling power tool according to claim 1, characterized in that, The drive shaft assembly further includes a bearing structure disposed between the drive shaft (1) and the curved housing (2), the bearing structure comprising: An angular contact thrust bearing (5) is sleeved on the outer wall of the transmission shaft (1). The inner ring of the angular contact thrust bearing (5) is connected to the outer wall of the transmission shaft (1), and the outer ring of the angular contact thrust bearing (5) is connected to the inner wall of the curved housing (2). Upper radial bearing (6) is sleeved on the outer wall of the transmission shaft (1) and located on the side of the angular contact thrust bearing (5) close to the motor assembly. The inner ring of the upper radial bearing (6) is connected to the outer wall of the transmission shaft (1), and the outer ring of the upper radial bearing (6) is connected to the inner wall of the curved housing (2). The lower radial bearing (7) is sleeved on the outer wall of the transmission shaft (1) and located on the side of the angular contact thrust bearing (5) near the drill bit. The inner ring of the lower radial bearing (7) is connected to the outer wall of the transmission shaft (1), and the outer ring of the upper radial bearing (6) is connected to the inner wall of the curved housing (2).

4. The high-angle well drilling power tool according to claim 3, characterized in that, The motor assembly includes: A stator housing (8) is provided with a stator (25) fixedly disposed on the inner wall of the stator housing (8), one end of the stator housing (8) is screwed to the end of the bent housing (2) away from the drill bit. The rotor (9) is rotatably disposed inside the stator housing (8) and cooperates with the stator (25). A first channel is provided inside the rotor (9) along its axial direction. A flexible shaft (10) is disposed in the channel, and the outer wall of the end of the flexible shaft (10) away from the drive shaft assembly is screwed to the inner wall of the end of the rotor (9) away from the drive shaft assembly.

5. A high-angle well drilling power tool according to claim 4, characterized in that, The motor assembly and the drive shaft assembly are connected by a universal joint structure, the universal joint structure comprising: The connector (11) is fixedly sleeved on the outer wall of the drive shaft (1) away from the drill bit at one end, and a ball seat (24) is fixedly provided on the other end of the connector (11). The first rotating ball (12) is rotatably disposed at one end of the ball seat (24) away from the drive shaft (1), and the side of the first rotating ball (12) away from the ball seat (24) is rotatably connected to the end of the flexible shaft (10) near the drive shaft assembly; Multiple second rotating balls (13) are evenly distributed circumferentially on the outer wall of one end of the flexible shaft (10) near the drive shaft assembly and are rotatably connected to the flexible shaft (10). A connecting ring (14) is threaded at one end to the outer wall of the connector (11) away from the drive shaft (1), and the other end is sleeved on the side of the second rotating ball (13) away from the flexible shaft (10), and is sealed between the connecting ring (14) and the flexible shaft (10) through a sealing assembly.

6. A high-angle well drilling power tool according to claim 5, characterized in that, The sealing assembly includes: A sealing ring (15) is sleeved on the outer wall of one end of the flexible shaft (10) near the drive shaft assembly and is located on the side of the second rotating ball (13) away from the drive shaft assembly. Oil seal (16) is sleeved on the outer wall of the flexible shaft (10) near the drive shaft assembly and located on the side of the sealing ring (15) away from the drive shaft assembly. The two ends of the oil seal (16) abut against the flexible shaft (10) and the sealing ring (15) respectively. Locking sleeve (17) is fitted on the outer wall of the sealing ring (15) and the oil seal (16), and the outer wall of the locking sleeve (17) and the inner wall of the connecting ring (14) away from the drive shaft assembly are screwed together.

7. A high-angle well drilling power tool according to claim 4, characterized in that, The motor assembly is provided with an anti-drop structure at the end away from the drive shaft assembly, the anti-drop structure comprising: Anti-drop joint (18), the outer wall of the anti-drop joint (18) near the motor assembly is screwed to the inner wall of the stator housing (8) away from the drive shaft assembly, and a second channel is provided inside the anti-drop joint (18) along its axial direction. Anti-drop rod (19), the anti-drop rod (19) is disposed inside the second channel, and the outer wall of the anti-drop rod (19) near the motor assembly is screwed to the inner wall of the flexible shaft (10) away from the transmission shaft assembly; Anti-drop nut (20), the anti-drop nut (20) is threaded onto the outer wall of the end of the anti-drop rod (19) away from the flexural shaft (10), and the anti-drop nut (20) is provided with a first convex ring (26) in the circumferential direction. The inner wall of the second channel is provided with a second protruding ring (21) corresponding to the first protruding ring (26), and is located on the side of the first protruding ring (26) close to the drive shaft assembly. The inner diameter of the second protruding ring (21) is smaller than the diameter of the first protruding ring (26).

8. A high-angle well drilling power tool according to claim 5, characterized in that, The drive shaft assembly further includes an anti-drop component to prevent the drive shaft (1) from falling off. The anti-drop component includes: Locking nut (22), the locking nut (22) is sleeved on the outer wall of the transmission shaft (1) and located between the angular contact thrust bearing (5) and the lower radial bearing (7). The outer wall of the locking nut (22) near the lower radial bearing (7) is connected to the inner wall of the inner ring of the lower radial bearing (7). The outer wall of the locking nut (22) has an annular protrusion, which is used to contact the outer ring of the lower radial bearing (7) when the connection between the drive shaft (1) and the universal joint structure fails, so as to prevent the drive shaft (1) from falling off. The support ring (23) is rotatably sleeved on the outer wall of the locking nut (22) and located between the angular contact thrust bearing (5) and the lower radial bearing (7). The outer wall of the support ring (23) is connected to the inner wall of the curved housing (2). The two ends of the support ring (23) along its axial direction abut against the outer ring of the angular contact thrust bearing (5) and the outer ring of the lower radial bearing (7), respectively.

9. A high-angle well drilling power tool according to claim 5, characterized in that, A flow channel is formed between the rotor and the stator (25) for the flow of driving fluid, and the flow channel is connected to the interior of the curved housing (2); The connector (11) has a communicating cavity inside, and the outer wall of the connector (11) has a communicating hole that communicates with the inner cavity of the curved shell (2) for the flow of the driving fluid. The drive shaft (1) has a flow cavity that communicates with the connecting cavity, and the flow cavity is connected to the drill bit.

Images