A pressure-relieving tool and a sliding directional drilling method

Abstract

This application proposes a pressure mitigation tool and a sliding directional drilling method. The pressure mitigation tool includes a clutch control mechanism, a primary clutch mechanism, a secondary clutch mechanism, and a torque transmission inner spline cylinder. The clutch control mechanism includes a piston stroke unit and a switch key unit arranged sequentially from top to bottom. The piston stroke unit is used to drive the switch key unit to switch to different positions through reciprocating motion, so that the drive shaft and the primary clutch inner spline cylinder can be engaged or disengaged. The primary clutch mechanism includes a primary clutch inner spline cylinder, a drive shaft, and a primary clutch reset assembly. The drive shaft is axially located inside the primary clutch inner spline cylinder. The primary clutch reset assembly is used to drive the drive shaft to return axially. The secondary clutch mechanism includes a centrifugal friction torque adjusting block and a secondary centrifugal torque adjusting clutch sleeve. The torque transmission inner spline cylinder is connected to the drive shaft. This application can alleviate the pressure drag phenomenon generated during sliding directional drilling.

Description

Technical Field

[0001] This application relates to the field of drilling technology, specifically to a pressure-relieving tool and a sliding directional drilling method. Background Technology

[0002] In directional and horizontal well drilling, a sliding drill string with a bent screw and directional measuring instruments are typically used to adjust the wellbore inclination and azimuth. Changes in the plane containing the bend of the screw—the tool face—within the 0-360° range correspond to changes in the wellbore inclination and azimuth. In sliding directional drilling, to maintain tool face stability, the upper drill string cannot rotate for drilling, easily leading to high drilling friction and difficulty in cuttings return. Near-bit measured data shows that under certain conditions, the effective bit pressure near the bit in directional drilling is only 2-4t, with a 4-10t pull pressure above. Therefore, the sliding directional drilling rate is extremely low. When the pull pressure is severe, the instantaneous release of the screw's counter-torque can cause tool face instability, and frequent tool face adjustments can lead to a large dogleg in the wellbore, further reducing the mechanical rate of drilling in directional drilling.

[0003] Currently, there are three main methods to improve directional drilling speed: rotary steerable drilling technology, torsion pendulum drilling technology, and hydraulic oscillator technology. However, due to the complexity of three-dimensional wellbore trajectories, the long open hole sections in the large displacement / horizontal sections, and the fact that some wells are prone to instability, block collapse, and wellbore necking due to factors such as formation mechanics, mud properties, and directional drilling, the use of rotary steerable drilling with large outer diameters is limited. Wellhead oscillating technology has a limited number of oscillations. On the one hand, exceeding the limit poses a risk of backtracking; on the other hand, the friction reduction effect decreases with increasing well depth and is greatly affected by the well structure. It is not effective for long horizontal wells or wells with large reach, and the drill string rotation speed is slow, affecting the mud's rock-carrying capacity. All of these factors seriously affect drilling operations. Hydraulic oscillators relieve pressure and improve drilling pressure transmission efficiency by causing the drill string to move longitudinally in the wellbore. However, their creep space is within 10mm, limiting their effective range within the total drill string. Therefore, the installation position must be determined according to the wellbore trajectory to ensure the best results. Summary of the Invention

[0004] To alleviate the pressure build-up phenomenon during sliding directional drilling, this application proposes a pressure-relieving tool and a sliding directional drilling method, and adopts the following technical solution:

[0005] In the first aspect, this application discloses a pressure relief tool, including a clutch control mechanism, a primary clutch mechanism, a secondary clutch mechanism, and a torque transmission mechanism;

[0006] The primary clutch mechanism includes a primary clutch inner spline cylinder, a drive shaft, and a primary clutch reset assembly;

[0007] The drive shaft is axially disposed inside the inner spline of the first-stage clutch and can engage or disengage with the inner spline of the first-stage clutch.

[0008] The primary clutch reset assembly is used to drive the drive shaft to return to its axial position.

[0009] The clutch control mechanism includes a piston stroke unit and a switch key unit arranged sequentially from top to bottom;

[0010] The piston stroke unit is used to drive the switch key unit to switch to different positions through reciprocating motion, so that the drive shaft and the first-stage clutch inner spline cylinder can be engaged or disengaged.

[0011] The secondary clutch mechanism includes a centrifugal friction torque adjusting block and a secondary centrifugal torque adjusting clutch sleeve. Both the centrifugal friction torque adjusting block and the secondary centrifugal torque adjusting clutch sleeve are located between the lower end of the transmission shaft and the inner spline cylinder of the primary clutch.

[0012] The secondary centrifugal torque-adjusting clutch sleeve is connected to the primary clutch inner spline sleeve, and the centrifugal friction torque-adjusting block is connected to the drive shaft and is set close to the secondary centrifugal torque-adjusting clutch sleeve to generate friction torque;

[0013] The torque transmission mechanism includes a torque transmission inner spline cylinder, which is connected to the transmission shaft.

[0014] Optionally, the secondary clutch mechanism further includes an elastic support member disposed between the drive shaft and the centrifugal friction torque adjusting block, which is used to provide preload to the centrifugal friction torque adjusting block.

[0015] Optionally, the switch key unit includes a switch housing, a switch key, and a lower lock cylinder;

[0016] The switch housing is located at the upper end of the inner spline cylinder of the torque transmission;

[0017] The lower lock cylinder is disposed inside the switch housing, and the lower lock cylinder is provided with long slots and short slots spaced apart along the circumference;

[0018] The piston stroke unit can drive the switch key to move into the long or short slot of the lower lock cylinder, so that the drive shaft and the first-stage clutch inner spline cylinder can be disconnected or engaged.

[0019] Optionally, the switch key unit further includes an upper lock cylinder;

[0020] The upper lock cylinder is provided with a reset groove, and the switch key can be reset into the reset groove so that the drive shaft and the inner spline cylinder of the first-stage clutch can engage with each other.

[0021] Optionally, the switch key unit further includes a lock cylinder positioning sleeve;

[0022] The lock cylinder positioning sleeve is connected to the switch housing, and both the upper and lower lock cylinders are connected to the lock cylinder positioning sleeve. The upper lock cylinder, lower lock cylinder, and lock cylinder positioning sleeve form a sealed oil cavity for the switch key to rotate circumferentially.

[0023] Optionally, the switch key unit further includes a switch adjustment spindle and a switch key bearing cap;

[0024] The switch adjusting spindle is axially disposed inside the switch housing, and the switch key is connected to the switch adjusting spindle via a switch thrust ball bearing;

[0025] The bearing cap of the switch key is located at the bottom of the switch key.

[0026] Optionally, the piston stroke unit includes a piston stroke outer cylinder, a thrust stroke piston, and a piston reset assembly;

[0027] The thrust stroke piston and piston reset assembly are both disposed inside the piston stroke outer cylinder, and the thrust stroke piston is connected to the switch adjustment spindle;

[0028] The piston reset assembly is located below the thrust stroke piston and is used to drive the thrust stroke piston to reset axially.

[0029] Optionally, the piston reset assembly includes a piston reset elastic element and a force adjusting ring;

[0030] The piston reset elastic element is disposed in the inner cavity of the piston stroke outer cylinder, and the force adjusting ring is disposed at the bottom of the piston reset elastic element.

[0031] Optionally, the pressure relief tool also includes a filtering mechanism, which is disposed on the piston stroke outer cylinder and is used to separate the inner cavity of the piston stroke outer cylinder from the well wall annulus to filter the drilling fluid.

[0032] Optionally, the drive shaft includes a first meshing portion and a second meshing portion distributed sequentially from bottom to top;

[0033] The first engagement portion has a first external spline for engaging with the first-stage clutch inner spline cylinder;

[0034] The second engagement portion has a second external spline for engaging with the inner spline cylinder of the torque transmission.

[0035] Optionally, the primary clutch mechanism further includes a guide ring, which is connected to the inner wall of the inner spline cylinder of the primary clutch.

[0036] The inner circumference of the guide ring is provided with guide splines that correspond to the inner splines of the first-stage clutch inner spline cylinder, which are used to guide the first outer spline to the inner spline keyway of the first-stage clutch inner spline cylinder when the drive shaft moves upward.

[0037] The second external spline has sufficient circumferential movement space within the spline groove of the inner spline cylinder to allow the first external spline to rotate circumferentially into the guide spline keyway of the guide ring.

[0038] Optionally, the lower end of the guide spline and the upper end of the first external spline of the drive shaft are both provided with rounded corners to guide the first external spline of the drive shaft into the guide spline keyway of the guide ring.

[0039] Optionally, the primary clutch mechanism further includes a first throttling ring and a second throttling ring arranged opposite each other.

[0040] The first throttle ring is connected to the switch adjusting spindle, and the second throttle ring is connected to the upper end of the drive shaft and is located below the first throttle ring;

[0041] The first throttling ring has a through hole, and the first throttling ring can be moved down to fit against the second throttling ring to block the through hole.

[0042] Optional, the pressure relief tool may also include an anti-drop mechanism;

[0043] The anti-drop mechanism includes an anti-drop ring and an anti-drop bearing cap;

[0044] The anti-drop ring is connected to the inner spline cylinder of the torque transmission, and the anti-drop bearing cap is connected to the inner spline cylinder of the first-stage clutch, forming an annular groove between it and the protruding part of the inner sidewall of the inner spline cylinder of the first-stage clutch.

[0045] The lower side wall of the anti-drop ring has a protrusion, which is embedded in the annular groove.

[0046] Optionally, a first guide groove is provided at the upper end of the drive shaft, and the first guide groove connects the inner cavity of the drive shaft with the inner cavity of the inner spline cylinder of the transmission shaft.

[0047] The lower end of the drive shaft is provided with a second guide groove, which connects the inner cavity of the drive shaft with the inner cavity of the first-stage clutch inner spline cylinder.

[0048] Optionally, the inner wall of the anti-drop ring is provided with a third guide groove along the axial direction, and the third guide groove connects the inner cavity of the first-stage clutch inner spline cylinder and the inner cavity of the torque transmission inner spline cylinder.

[0049] Optionally, the primary clutch reset assembly includes a primary clutch elastic reset element and a pressure ring;

[0050] The primary clutch elastic reset component is disposed between the inner spline cylinder of the transmission and the transmission shaft, and the pressure ring is connected to the transmission shaft and located between the primary clutch elastic reset component and the switch key bearing pressure cap;

[0051] A fourth guide groove is provided axially inside the pressure ring, and the fourth guide groove connects the inner cavity of the transmission inner spline cylinder and the inner cavity of the switch housing.

[0052] Secondly, this application also discloses a sliding directional drilling method using a pressure-relieving tool as described in the first aspect.

[0053] Based on the above technical solution, the beneficial effects of this application compared with the prior art are as follows:

[0054] The pressure-reducing tool described in this application, during sliding directional drilling, uses a primary clutch mechanism to connect and disconnect the drill string torque transmission, enabling rotary feed during composite drilling, tool face adjustment, and sliding drilling. The drive shaft is adjusted to its optimal speed, and a secondary clutch mechanism generates torque to balance the screw reverse torque, stabilizing the tool face during rotary feed in sliding drilling and ensuring effective cuttings return. Specifically, when the primary clutch is engaged, the secondary clutch is inactive; the upper and lower torques of the tool are transmitted through the internal spline of the torque transmission sleeve, the drive shaft, and the internal spline of the primary clutch, allowing for composite drilling. When the primary clutch is disengaged, the upper and lower parts of the tool can rotate relative to each other; the upper drill string rotates under the drive of the surface power unit, while the lower drill string does not rotate. The secondary clutch mechanism generates additional torque on the lower drill string, which, together with the frictional torque generated between the lower drill string and the wellbore, balances the screw drill string reverse torque, ensuring tool face stability during relative rotary drilling. This tool has an outer diameter that is more than 15% smaller than that of a rotary guide tool, and its outer diameter is comparable to that of the drill pipe joint. It is less prone to jamming, has a large bore diameter, and has minimal pressure loss at high displacement. Its all-mechanical structure design allows for fast state switching response and low manufacturing cost, meeting the requirements for efficient and low-cost directional drilling. Attached Figure Description

[0055] Figure 1 This is an overall schematic diagram of the pressure-relieving tool in the embodiments of this application;

[0056] Figure 2 This is a schematic diagram of the piston stroke unit in an embodiment of this application;

[0057] Figure 3 yes Figure 2 Enlarged view of region A in the middle;

[0058] Figure 4 This is a schematic diagram of the switch key unit in an embodiment of this application;

[0059] Figure 5 This is a schematic diagram of the primary clutch mechanism in an embodiment of this application;

[0060] Figure 6 This is a schematic diagram of the anti-drop mechanism in the embodiments of this application;

[0061] Figure 7 This is a schematic diagram of the second clutch mechanism in the embodiments of this application;

[0062] Figure 8 This is a three-dimensional structural diagram of the upper lock cylinder in the embodiment of this application;

[0063] Figure 9 This is a three-dimensional structural diagram of the lower lock cylinder in an embodiment of this application;

[0064] Figure 10 This is a three-dimensional schematic diagram of the clutch control mechanism in the embodiments of this application;

[0065] Figure 11 This is a three-dimensional structural diagram of the drive shaft in an embodiment of this application;

[0066] Figure 12 This is a three-dimensional structural diagram of the guide wreath in an embodiment of this application;

[0067] Figure 13 This is a schematic diagram of the connection between the second external spline and the torque-transmitting internal spline cylinder in an embodiment of this application;

[0068] Figure 14 This is a partial three-dimensional structural diagram of the anti-ring dropping mechanism in an embodiment of this application;

[0069] Figure 15 This is a three-dimensional structural diagram of the pressure ring in the embodiments of this application;

[0070] Figure 16 This is a three-dimensional structural schematic diagram of the first throttling ring in the embodiments of this application;

[0071] Figure 17 This is a three-dimensional structural schematic diagram of the second throttling ring in an embodiment of this application;

[0072] Figure 18 This is a partial schematic diagram of the switch key entering the long slot in an embodiment of this application;

[0073] Explanation of reference numerals in the attached figures:

[0074] 1. Clutch control mechanism; 11. Piston stroke unit; 111. Piston stroke outer cylinder; 112. Thrust stroke piston; 113. Piston reset assembly; 1131. Piston reset elastic element; 1132. Adjusting ring; 12. Switch key unit; 121. Switch housing; 122. Switch adjusting spindle; 123. Switch key; 124. Switch key bearing cap; 125. Switch thrust ball bearing; 126. Wear-resistant sleeve; 127. Upper lock cylinder; 1271. Reset groove; 128. Lower lock cylinder; 1281. Long groove; 1282. Short groove; 129. Lock cylinder positioning sleeve; 130. Sealing screw;

[0075] 2. First-stage clutch mechanism; 21. First-stage clutch inner spline cylinder; 22. Drive shaft; 221. First external spline; 222. Second external spline; 223. First guide groove; 224. Second guide groove; 23. First-stage clutch reset assembly; 231. First-stage clutch elastic reset component; 232. Pressure ring; 2321. Fourth guide groove; 24. Guide spline; 241. Guide spline; 242. Lug; 25. First throttling ring; 251. Through hole; 26. Second throttling ring;

[0076] 3. Two-stage clutch mechanism; 31. Centrifugal friction torque adjusting block; 32. Two-stage centrifugal torque adjusting clutch sleeve; 33. Elastic support component; 4. Torque transmission mechanism; 41. Torque transmission inner spline cylinder; 42. Upper variable snap joint; 43. Lower variable snap joint; 5. Filtration mechanism; 51. Screen plate washer ring; 52. Snap ring; 53. Erosion-resistant screen plate;

[0077] 6. Anti-drop mechanism; 61. Anti-drop ring; 611. Protrusion; 612. Third guide groove; 62. Anti-drop bearing cap; 63. Anti-drop thrust bearing; 64. Radial bearing;

[0078] 7. Dynamic sealing assembly; 8. Static sealing assembly. Detailed Implementation

[0079] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0080] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this disclosure. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this disclosure as detailed in the appended claims.

[0081] In the description of this disclosure, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this disclosure and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this disclosure. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0082] In the description of this disclosure, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linkage" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this disclosure based on the specific circumstances.

[0083] The inventors discovered that during sliding directional drilling, to maintain tool face stability, the upper drill string cannot rotate for drilling, easily leading to high drilling friction and difficulty in cuttings return. Due to the large frictional torque between the drill string and the wellbore, the drilling pressure cannot be transmitted to the drill bit within a specified time, resulting in pressure build-up and affecting drilling speed. When pressure build-up is severe, the instantaneous release of the screw counter-torque can cause tool face instability, and frequent tool face adjustments can lead to a large dogleg in the wellbore, further reducing the mechanical drilling rate in directional drilling. Therefore, to alleviate the pressure build-up generated during sliding directional drilling, this application provides a pressure-relieving tool and a sliding directional drilling method. The following provides detailed descriptions of various embodiments of the anti-clogging filter device, system, and method in this application.

[0084] In a first aspect, embodiments of this application provide a pressure-relieving tool, referring to... Figures 1-7 It includes a clutch control mechanism 1, a primary clutch mechanism 2, a secondary clutch mechanism 3, and a torque transmission mechanism 4. The primary clutch mechanism 2 includes a primary clutch inner spline cylinder 21, a drive shaft 22, and a primary clutch reset assembly 23. The drive shaft 22 is axially disposed within the primary clutch inner spline cylinder 21 and can engage or disengage with it. The primary clutch reset assembly 23 drives the drive shaft 22 to return to its axial position. The clutch control mechanism 1 includes a piston stroke unit 11 and a switch key unit 12 arranged sequentially from top to bottom. The piston stroke unit 11 drives the switch key unit 12 to switch to different positions via reciprocating motion, so that the drive shaft 22 and the primary clutch inner spline cylinder 21 engage or disengage.

[0085] The torque transmission mechanism 4 includes a torque transmission inner spline cylinder 41, which is located above the primary clutch inner spline cylinder 21. The drive shaft 22 is connected to the torque transmission inner spline cylinder 41 and is used to transmit the torque of the upper part of the tool to the primary clutch inner spline cylinder 21 through the drive shaft 22. The secondary clutch mechanism 3 includes a centrifugal friction torque adjusting block 31 and a secondary centrifugal torque adjusting clutch sleeve 32. Both the centrifugal friction torque adjusting block 31 and the secondary centrifugal torque adjusting clutch sleeve 32 are located between the lower end of the drive shaft 22 and the primary clutch inner spline cylinder 21. The secondary centrifugal torque adjusting clutch sleeve 32 is connected to the primary clutch inner spline cylinder 21, and the centrifugal friction torque adjusting block 31 is connected to the drive shaft 22 and is set close to the secondary centrifugal torque adjusting clutch sleeve 32 to generate friction torque to transmit to the lower part of the tool to balance the counter-torque of the lower part of the tool.

[0086] The pressure-relief tool described in this application connects to a drive mechanism at the upper end and to the drill string at the lower end during sliding directional drilling. The primary clutch mechanism 2 connects and disconnects the drill string torque transmission, enabling rotary feed during composite drilling, tool face adjustment, and sliding drilling. The surface power system is adjusted to the optimal speed, and a secondary clutch mechanism 3 generates torque to balance the screw reverse torque, stabilizing the tool face and ensuring cuttings return during rotary feed in sliding drilling. Specifically, when the primary clutch 2 is engaged, the secondary clutch mechanism 3 is inactive. The upper and lower torques of the tool are transmitted through the internal spline sleeve 41, drive shaft 22, and the primary clutch internal spline sleeve 21, allowing the tool to perform composite drilling. When the primary clutch is disengaged, the upper and lower parts of the tool can rotate relative to each other. The upper drill string rotates under the drive of the surface power unit, while the lower drill string does not rotate. The secondary clutch mechanism generates additional torque on the lower drill string, which, together with the frictional torque generated between the lower drill string and the wellbore, balances the screw drill string reverse torque, ensuring tool face stability during relative rotary drilling. This tool has an outer diameter that is more than 15% smaller than that of a rotary guide tool, and its outer diameter is comparable to that of the drill pipe joint. It is less prone to jamming, has a large bore diameter, and has minimal pressure loss at high displacement. Its all-mechanical structure design allows for fast state switching response and low manufacturing cost, meeting the requirements for efficient and low-cost directional drilling.

[0087] In an alternative embodiment, refer to Figure 2 The piston stroke unit 11 includes a piston stroke outer cylinder 111, a thrust stroke piston 112, and a piston return assembly 113. Specifically, the piston stroke outer cylinder 111 is cylindrical and located in the upper part of the tool assembly. The thrust stroke piston 112 and the piston return assembly 113 are both disposed inside the piston stroke outer cylinder 111. The thrust stroke piston 112 is connected to the inner wall of the piston stroke outer cylinder 111 by a dynamic seal assembly 7. The piston return assembly 113 is located below the thrust stroke piston 112 and is used to drive the thrust stroke piston 112 to return to its axial position.

[0088] It should be noted that the piston drive unit is connected to the surface drive pump (not shown in the figure). When the drive pump is turned on, under the pressure difference between the tubing and the annulus of the wellbore, the thrust piston 112 compresses the piston reset assembly 113 downwards. When the drive pump is turned off, the thrust piston 112 moves upwards under the thrust of the piston reset assembly 113. Specifically, the drive pump can be a mud pump.

[0089] Specifically, refer to Figure 2 The piston reset assembly 113 includes a piston reset elastic element 1131 and a force adjusting ring 1132. The force adjusting ring 1132 is located on a protruding boss extending inward from the piston stroke outer cylinder 111 and at the bottom of the piston reset elastic element 1131. The piston reset elastic element 1131 can be a disc spring or compression spring, etc., to provide elastic force to reset the thrust stroke piston 112. By replacing different force adjusting rings 1132, the mechanical parameters of the piston reset elastic element 1131 can be adjusted so that when the piston reset elastic element 1131 is compressed to its limit position, it can satisfy the return of the thrust stroke piston 112.

[0090] In an optional embodiment, refer to Figure 2 , Figure 3 The pressure relief tool also includes a filtering mechanism 5, which is installed on the piston stroke outer cylinder 111. The filtering mechanism 5 separates the inner cavity of the piston stroke outer cylinder 111 from the wellbore annulus to filter the drilling fluid. It also serves as a pressure differential communication channel between the piston and the annulus, connecting the lower part of the thrust stroke piston 112 to the wellbore annulus, thus creating a pressure differential between the upper and lower parts of the thrust stroke piston 112. Specifically, the filtering mechanism 5 includes a screen plate gasket 51, a retaining spring 52, and an erosion-resistant screen plate 53. There are two screen plate gaskets 51, distributed on both sides of the erosion-resistant screen plate 53. The retaining spring 52 is located on the outermost side for limiting movement. The screen plate gaskets 51 and retaining spring 52 together fix the erosion-resistant screen plate 53 to the piston stroke outer cylinder 111. The filtering mechanism 5 can filter large solid particles in the annular mud, ensuring smooth operation of the piston stroke unit 11.

[0091] In an optional embodiment, refer to Figure 4 The switch key unit 12 includes a switch housing 121, a switch adjusting spindle 122, a switch key 123, and a switch key bearing cap 124. Specifically, the switch housing 121 is located below the piston stroke outer cylinder 111, and the switch adjusting spindle 122 is axially disposed inside the switch housing 121. The thrust stroke piston 112 is threadedly connected to the upper end of the switch adjusting spindle 122 to drive the switch adjusting spindle 122 to reciprocate axially. A static seal assembly 8 is provided between the thrust stroke piston 112 and the switch adjusting spindle 122 to further seal the tool and isolate the clean drilling fluid inside the drill string from the annular mud.

[0092] Furthermore, refer to Figure 4 The switch key 123 and the switch adjusting spindle 122 are connected by a switch thrust ball bearing 125. Specifically, the switch key 123 is located at the lower end of the switch adjusting spindle 122, and the switch thrust ball bearing 125 is located on the upper and lower sides of the switch key 123 to clamp the switch key 123 and ensure that the switch key 123 can rotate freely in the circumferential direction. The upper switch thrust ball bearing 125 is located at the bottom of the protruding part of the switch adjusting spindle 122, so the switch key 123 can move axially downward under the drive of the switch adjusting spindle 122. The switch key 123 has a hollow annular structure with protrusions on its sidewalls. A wear-resistant sleeve 126 is also provided between the switch key 123 and the switch adjusting spindle 122 to prevent wear on the switch adjusting spindle 122 caused by repeated rotation of the switch key 123.

[0093] In an optional embodiment, refer to Figure 4 The switch key unit 12 also includes an upper lock cylinder 127, a lower lock cylinder 128, and a lock cylinder positioning sleeve 129 located within the switch housing 121. The upper lock cylinder 127 and lower lock cylinder 128 are both connected to the switch housing 121 via a static sealing assembly 8. The upper lock cylinder 127 and lower lock cylinder 128 are connected to the switch adjusting spindle 122 via a dynamic sealing assembly 7. The upper and lower ends of the lock cylinder positioning sleeve 129 are fixedly connected to the upper lock cylinder 127 and lower lock cylinder 128 respectively. Thus, the upper lock cylinder 127, lower lock cylinder 128, and lock cylinder positioning sleeve 129 form a sealed oil cavity for the switch key 123 to rotate circumferentially, used to inject lubricating oil to lubricate the switch key 123. It should be noted that the lock cylinder positioning sleeve 129 has two symmetrically arranged oil filling holes (not shown in the figure), connected by a shallow circumferential groove to ensure that lubricating oil can be injected into the oil cavity through the oil filling holes. Simultaneously, the switch housing 121 is provided with sealing screws 130 to seal the oil filling holes.

[0094] Furthermore, refer to Figures 8-9 The lower lock cylinder 128 has a long groove 1281 and a short groove 1282 sequentially formed along its circumference upwards. Both the long groove 1281 and the short groove 1282 communicate with the sealing oil cavity. Specifically, there are two sets of each of the long groove 1281 and the short groove 1282, and they are distributed alternately along the circumference. Correspondingly, the upper lock cylinder 127 has a reset groove 1271 formed along its circumference downwards, and there are three sets of reset grooves 1271. The relative positions of the reset grooves 1271, the long grooves 1281, and the short grooves 1282 along their circumference are fixed by the lock cylinder positioning sleeve 129.

[0095] Therefore, refer to Figure 10The piston stroke unit 11 can drive the switch key 123 to move into the long slot 1281 or short slot 1282 of the lower lock cylinder 128, so that the drive shaft 22 and the first-stage clutch inner spline cylinder 21 are disengaged or engaged; or, the switch key 123 is driven by the clutch reset assembly to return to the reset slot 1271 of the upper lock cylinder 127, so that the disengaged drive shaft 22 and the first-stage clutch inner spline cylinder 21 are re-engaged. The number of long slots 1281, short slots 1282 and reset slots 1271 can be adjusted according to actual needs. It should be understood that, in order to facilitate the switching position of the switch key 123, the corners of the long slots 1281, short slots 1282 and reset slots 1271 are all rounded.

[0096] Furthermore, refer to Figure 5 The switch key bearing cap 124 is connected to the switch adjusting spindle 122 via a static seal assembly 8 and is located at the bottom of the switch key 123. Simultaneously, the switch key bearing cap 124 is connected to the drive shaft 22 via a dynamic seal assembly 7.

[0097] Specifically, refer to Figure 5 The primary clutch reset assembly 23 includes a primary clutch elastic reset element 231 and a pressure ring 232. The primary clutch elastic reset element 231 is located between the torque transmission inner spline cylinder 41 and the drive shaft 22, with the torque transmission inner spline cylinder 41 located below the switch housing 121. A force adjusting ring 1132 is also provided at the bottom of the primary clutch elastic reset element 231. The primary clutch elastic reset element 231 and the force adjusting ring 1132 have a partially similar structure to the piston reset assembly 113, which will not be described in detail here. The pressure ring 232 is threadedly connected to the drive shaft 22 and is located between the primary clutch elastic reset element 231 and the switch key bearing cap 124, with a gap between the pressure ring 232 and the switch key bearing cap 124.

[0098] For details, please refer to [reference]. Figure 5 The gap between the pressure ring 232 and the switch key bearing cap 124 should be sufficient to allow the switch key 123 to enter the short groove 1282 of the lower lock cylinder 128. That is, after the drive pump is turned on, the piston stroke unit 11 drives the switch adjusting spindle 122 downwards, and further drives the switch key 123 downwards into the short groove 1282 of the lower lock cylinder 128. At this time, there is still a gap between the pressure ring 232 and the switch key bearing cap 124, and the transmission shaft 22 does not undergo axial displacement, remaining engaged with the inner spline cylinder 21 of the first-stage clutch. When the pump is turned on again after stopping, the piston stroke unit 11 drives the switch key 123 downwards into the long groove 1281 of the lower lock cylinder 128. At this time, the switch key bearing cap 124 drives the pressure ring 232 to compress the elastic reset member 231 of the first-stage clutch. Simultaneously, the pressure ring 232 drives the transmission shaft 22 to move axially downwards and disconnect from the inner spline cylinder 21 of the first-stage clutch, thus finally disengaging the first-stage clutch.

[0099] In an optional embodiment, the torque transmission inner spline sleeve 41 and the first-stage clutch inner spline sleeve 21 are sequentially distributed axially below the switch housing 121, and the drive shaft 22 is axially disposed within the torque transmission inner spline sleeve 41 and the first-stage clutch inner spline sleeve 21. Specifically, refer to... Figure 11 The drive shaft 22 includes a first engagement portion and a second engagement portion arranged sequentially from bottom to top. The first engagement portion is provided with a first external spline 221 along the circumference for engaging with the inner spline sleeve 21 of the first-stage clutch, and the second engagement portion is provided with a second external spline 222 along the circumference for engaging with the inner spline sleeve 41 of the torque transmission. When the drive shaft 22 engages with the inner spline sleeve 41 of the torque transmission and the inner spline sleeve 21 of the first-stage clutch respectively, the torque of the upper part of the tool is transmitted to the drill bit below the tool in sequence through the inner spline sleeve 41 of the torque transmission, the drive shaft 22 and the inner spline sleeve 21 of the first-stage clutch.

[0100] In an optional embodiment, refer to Figure 7 , Figure 12 The first-stage clutch mechanism 2 also includes a guide spline 24, which is connected to the inner wall of the first-stage clutch inner spline cylinder 21. The inner circumference of the guide spline 24 is provided with guide splines 241 that correspond to the inner splines of the first-stage clutch inner spline cylinder 21. When the drive shaft 22 moves upward, the guide splines 221 are guided to the inner spline keyway of the first-stage clutch inner spline cylinder 21.

[0101] Specifically, refer to Figure 12 , Figure 13 The second external spline 222 has sufficient circumferential movement space in the spline groove of the inner spline cylinder 41 to satisfy the first external spline 221 rotating circumferentially into the keyway of the guide spline 241 of the guide ring 24. That is, the spline groove of the inner spline cylinder 41 should have sufficient groove width to ensure that when the first external spline 221 rotates circumferentially into the keyway of the guide spline 241 of the guide ring 24, the second external spline 222 is always located in the spline groove of the inner spline cylinder 41, so that the inner spline cylinder 41 and the transmission shaft 22 are always engaged.

[0102] In an optional embodiment, refer to Figure 12 The guide spline 24 and the first-stage clutch inner spline cylinder 21 are connected by a lug 242 and a groove. Alternatively, the lug 242 may be located on the outer wall of the guide spline 24, and the groove may be located on the inner wall of the first-stage clutch inner spline cylinder 21; or the lug 242 may be located on the inner wall of the first-stage clutch inner spline cylinder 21, and the groove may be located on the outer wall of the guide spline 24. The guide splines 241 on the guide spline 24 correspond one-to-one with the inner splines of the first-stage clutch inner spline cylinder 21, and each guide spline 241 is stacked below its corresponding inner spline. Furthermore, the lower end of the guide spline 241 and the upper end of the first outer spline 221 of the drive shaft 22 are both rounded to guide the first outer spline 221 of the drive shaft 22 into the keyway of the guide spline 241 of the guide spline 241 in the guide spline 244.

[0103] Therefore, when the ground-driven pump stops again, the drive shaft 22 moves upward under the action of the first-stage clutch elastic reset member 231, and the first external spline 221 of the drive shaft 22 engages with the internal spline of the first-stage clutch inner spline cylinder 21 under the guidance of the guide spline 241 of the guide ring 24.

[0104] In an optional embodiment, refer to Figure 7 The secondary clutch mechanism 3 also includes an elastic support 33, which is located between the drive shaft 22 and the centrifugal friction torque adjusting block 31. The elastic support 33 provides preload to the centrifugal friction torque adjusting block 31, ensuring that the centrifugal friction torque adjusting block 31 and the secondary centrifugal torque adjusting clutch sleeve 32 are in contact. The elastic support 33 can be a disc spring. Furthermore, both the centrifugal friction torque adjusting block 31 and the secondary centrifugal torque adjusting clutch sleeve 32 have a wear-resistant friction coating on their adjacent sides, specifically a chromium plating layer, a zinc plating layer, etc. When the drive shaft 22 rotates, it drives the centrifugal friction torque adjusting block 31 to rotate. Under the thrust of the elastic support 33, the wear-resistant friction coating of the centrifugal friction torque adjusting block 31 adheres tightly to the wear-resistant friction coating of the secondary centrifugal torque adjusting clutch sleeve 32, generating a certain frictional torque that is transmitted to the drill string below the tool. This torque, together with the frictional torque between the lower drill string and the well wall, balances the screw's counter-torque, maintaining tool face stability for directional drilling.

[0105] It should be noted that if the frictional torque is insufficient to balance the counter-torque of the lower screw drill bit, the ground power system can be adjusted to increase the rotational speed of the upper drill bit, so that the centrifugal friction torque adjusting block 31 and the secondary centrifugal torque adjusting clutch sleeve 32 generate a greater frictional torque under the action of centrifugal force to balance the counter-torque of the screw.

[0106] In an optional embodiment, refer to Figure 4 and Figure 5 The primary clutch mechanism 2 also includes a first throttle ring 25 and a second throttle ring 26 arranged opposite each other. The first throttle ring 25 is connected to the switch adjusting spindle 122, and the second throttle ring 26 is connected to the upper end of the drive shaft 22 and is located below the first throttle ring 25. (Refer to...) Figures 16-17 The first throttling ring 25 has a through hole 251, which is specifically a plurality of annular strip holes. The first throttling ring 25 can move down to fit with the second throttling ring 26 to block the through hole 251.

[0107] Specifically, refer to Figure 18When the switch key 123 moves down into the long groove 1281 of the lower lock core 128 under the drive of the piston stroke unit 11, the first throttling ring 25 moves down with the switch adjusting spindle 122 until it is in contact with the end face of the second throttling ring 26. The corresponding position of the second throttling ring 26 is closed, which can block the through hole 251, thereby producing a throttling effect on the drilling fluid. The pressure in the riser rises by 1.5 MPa and remains stable. The disengagement of the first-stage clutch can be determined by observing the pressure change on the surface. Conversely, refer to... Figure 5 When the switch key 123 enters the short groove 1282, the switch key bearing cap 124 descends to the lower limit position and is a certain distance away from the pressure ring 232. The inner spline of the first-stage clutch inner spline cylinder 21 meshes with the first outer spline 221 on the upper part of the drive shaft 22. The first throttling ring 25 and the second throttling ring 26 are also a certain distance apart. The cross-sectional area of ​​the mud flow does not change, and no pressure change occurs at the riser.

[0108] It should be understood that the second throttling ring 26 can partially block the through hole 251 on the first throttling ring 25 to achieve throttling. Specifically, the first throttling ring 25 and the second throttling ring 26 can be hard alloy throttling rings.

[0109] In an optional embodiment, refer to Figure 6 and Figure 14 The pressure relief tool also includes an anti-drop mechanism 6, which includes an anti-drop ring 61 and an anti-drop bearing cap 62. The upper end of the anti-drop ring 61 is threadedly connected to the inner splined cylinder 41 of the torque transmission mechanism. The anti-drop bearing cap 62 is threadedly connected to the inner splined cylinder 21 of the first-stage clutch mechanism. A static seal group 8 is provided between the anti-drop bearing cap 62 and the inner splined cylinder 21 of the first-stage clutch mechanism, and a dynamic seal group 7 is provided between the anti-drop bearing cap 62 and the inner splined cylinder 41 of the torque transmission mechanism. An annular groove is formed between the anti-drop bearing cap 62 and the protruding part of the inner sidewall of the inner splined cylinder 21 of the first-stage clutch mechanism. A protruding part 611 is provided circumferentially on the lower sidewall of the anti-drop ring 61. The protruding part 611 is embedded in the annular groove through an anti-drop thrust bearing 63 and a radial bearing 64, thereby limiting the torque transmission mechanism 4 and the first-stage clutch mechanism 2 axially. The anti-drop ring 61 can be formed by splicing two symmetrically arranged anti-drop half-rings, or it can be integrally formed. The anti-drop thrust bearing 63 can be an anti-drop PDC thrust bearing or an anti-drop thrust roller bearing, and the radial bearing 64 can be a TC radial bearing 64 or a radial needle roller bearing.

[0110] Preferably, in an optional embodiment, the dynamic sealing group 7 used in this application may be composed of a mud ring, a wear-resistant ring and a step seal, and the static sealing group 8 may be composed of a sealing ring, a sealing gasket, etc., to isolate the clean drilling fluid in the drill string from the annular mud.

[0111] In an optional embodiment, refer to Figure 1The torque transmission mechanism 4 also includes an upper variable coupling 42 and a lower variable coupling 43. The upper variable coupling 42 is located at the uppermost end of the tool, and the lower variable coupling 43 is located at the lowermost end of the tool. They are connected to the upper power system and the lower drill bit, respectively, so as to transmit torque together with the torque transmission inner spline cylinder 41.

[0112] In an optional embodiment, during drilling operations, drilling fluid enters the outer chamber of the drive shaft 22 and further into the lower chamber to cool and lubricate the anti-dislodgement thrust bearing 63, radial bearing 64, and secondary clutch mechanism 3, before finally flowing into the lower drill string via the drive shaft 22. Specifically, refer to... Figure 8 and Figure 12 The upper end of the drive shaft 22 is provided with a first guide groove 223, which connects the inner cavity of the drive shaft 22 with the inner cavity of the inner spline cylinder 41 of the torque transmission; the lower end of the drive shaft 22 is provided with a second guide groove 224, which connects the inner cavity of the drive shaft 22 with the inner cavity of the first-stage clutch inner spline cylinder 21.

[0113] Furthermore, refer to Figure 14 The inner wall of the anti-drop ring 61 is provided with a third guide groove 612 along the axial direction. The third guide groove 612 connects the inner cavity of the first-stage clutch inner spline cylinder 21 and the inner cavity of the torque transmission inner spline cylinder 41. (Refer to...) Figure 15 The pressure ring 232 has a fourth guide groove 2321 axially formed inside it. The fourth guide groove 2321 connects the inner cavity of the transmission inner spline cylinder 41 and the inner cavity of the switch housing 121. The fourth guide groove 2321 can be a plurality of annular grooves spaced apart along the circumference of the pressure ring 232.

[0114] Therefore, during drilling operations, drilling fluid is pumped into the drive shaft 22. A small portion of the drilling fluid enters the inner cavity of the inner spline cylinder 41 on the outside of the drive shaft 22 through the first guide groove 223 at the upper end of the drive shaft 22. Then, it enters the inner cavity of the first-stage clutch inner spline cylinder 21 on the outside of the drive shaft 22 through the third guide groove 612 in the anti-drop ring 61, and then enters the inner cavity of the switch housing 121 through the fourth guide groove 2321 to completely wet the chamber. The drilling fluid in the chamber is sealed by the dynamic sealing group 7 and the static sealing group 8, and finally flows back into the drive shaft 22 through the second guide groove 224. This diverted drilling fluid serves to lubricate the first-stage clutch inner spline cylinder 21, the anti-drop thrust bearing 63, the radial bearing 64, and the second-stage clutch mechanism 3.

[0115] Secondly, embodiments of this application also disclose a sliding directional drilling method using the pressure-relieving tool described in the first aspect.

[0116] The pressure-relieving tool in this embodiment can quickly adjust the downhole clutch switching state according to the start and stop status of the surface drive pump. Specifically, after the surface drive pump is turned on, the switch key 123 enters the short groove 1282 of the lower lock core 128, and the primary clutch remains engaged for compound rotary drilling. After the surface drive pump stops, the drive shaft 22 moves upward under the action of the primary clutch elastic reset member 231, driving the switch key 123 back into the reset groove 1271 of the upper lock core 127. Guided by the primary clutch engagement guide ring 24, the drive shaft 22 engages with the primary clutch inner spline cylinder 21, the primary clutch is engaged, and the entire drill string transmits torque, allowing the drill to be driven by the surface power system. The tool face is adjusted by rotating the tool; or, the ground drive pump is turned on, stopped, and turned on again. The switch key 123 first enters the short groove 1282 of the lower lock core 128, then returns to the reset groove 1271 of the upper lock core 127, and finally enters the long groove 1281 of the lower lock core 128. The first-stage clutch is finally disengaged, and the upper torque cannot be transmitted to the drill string below the tool. The ground power system drives the drill string to rotate slowly. The upper part of the tool rotates, while the lower part of the tool does not rotate for directional drilling. The second-stage clutch mechanism 3 balances the screw to counter-torque, keeping the tool face stable for directional drilling.

[0117] The foregoing description includes examples of one or more embodiments. It is certainly impossible to describe all possible combinations of components or methods in order to describe the above embodiments, but those skilled in the art will recognize that further combinations and arrangements of the various embodiments are possible. Therefore, the embodiments described herein are intended to cover all such changes, modifications, and variations that fall within the scope of the appended claims. Furthermore, the term "comprising" as used in the specification or claims is interpreted in a manner similar to the term "including," just as "comprising" is interpreted as a conjunction in the claims. Additionally, the use of any term "or" in the specification of the claims is intended to mean "non-exclusive or."

Claims

1. A pressure-relieving tool, characterized in that, It includes a clutch control mechanism (1), a primary clutch mechanism (2), a secondary clutch mechanism (3), and a torque transmission internal spline cylinder (41); The first-stage clutch mechanism (2) includes a first-stage clutch inner spline cylinder (21), a drive shaft (22), and a first-stage clutch reset assembly (23); The drive shaft (22) is axially disposed inside the inner spline cylinder (21) of the first-stage clutch; The first-stage clutch reset assembly (23) is used to drive the transmission shaft (22) to reset axially so as to re-engage with the first-stage clutch inner spline cylinder (21); The clutch control mechanism (1) includes a piston stroke unit (11) and a switch key unit (12) arranged sequentially from top to bottom; The piston stroke unit (11) is used to drive the switch key unit (12) to switch to different positions through reciprocating motion, so that the drive shaft (22) and the first-stage clutch inner spline cylinder (21) can be engaged or disengaged. The secondary clutch mechanism (3) includes a centrifugal friction torque adjusting block (31) and a secondary centrifugal torque adjusting clutch sleeve (32). The centrifugal friction torque adjusting block (31) and the secondary centrifugal torque adjusting clutch sleeve (32) are both located between the lower end of the transmission shaft (22) and the inner spline cylinder (21) of the primary clutch. The secondary centrifugal torque-adjusting clutch sleeve (32) is connected to the primary clutch inner spline sleeve (21), and the centrifugal friction torque-adjusting block (31) is connected to the transmission shaft (22) and is set close to the secondary centrifugal torque-adjusting clutch sleeve (32) to generate friction torque; The torque transmission inner spline cylinder (41) is located above the first-stage clutch inner spline cylinder (21). The torque transmission inner spline cylinder (41) is connected to the drive shaft (22) and is used to transmit the upper torque of the tool to the first-stage clutch inner spline cylinder (21) through the drive shaft (22). The switch key unit (12) includes a switch housing (121), a switch key (123), a lower lock cylinder (128), and an upper lock cylinder (127); The switch housing (121) is disposed at the upper end of the inner spline cylinder (41) of the torque transmission; The lower lock cylinder (128) is disposed inside the switch housing (121), and the lower lock cylinder (128) is provided with long slots (1281) and short slots (1282) spaced apart along the circumference; The piston stroke unit (11) can drive the switch key (123) to move into the long slot (1281) or short slot (1282) of the lower lock cylinder (128) so that the drive shaft (22) and the first-stage clutch inner spline cylinder (21) are disconnected or engaged with each other. The upper lock cylinder (127) is provided with a reset groove (1271), and the switch key (123) can be reset into the reset groove (1271) so that the transmission shaft (22) and the first-stage clutch inner spline cylinder (21) can engage with each other.

2. The pressure-relieving tool according to claim 1, characterized in that... The secondary clutch mechanism (3) further includes an elastic support member (33); The elastic support (33) is located between the transmission shaft (22) and the centrifugal friction torque adjusting block (31) and is used to provide preload to the centrifugal friction torque adjusting block (31).

3. The pressure-relieving tool according to claim 1, characterized in that, The switch key unit (12) also includes a lock cylinder positioning sleeve (129); Both the upper lock cylinder 127 and the lower lock cylinder 128 are connected to the switch housing 121 through the static sealing assembly 8, and the upper and lower ends of the lock cylinder positioning sleeve 129 are fixedly connected to the upper lock cylinder 127 and the lower lock cylinder 128 respectively. The upper lock cylinder (127), lower lock cylinder (128), and lock cylinder positioning sleeve (129) form a sealed oil cavity for the switch key (123) to rotate circumferentially.

4. The pressure-relieving tool according to claim 1, characterized in that, The switch key unit (12) also includes a switch adjustment spindle (122) and a switch key bearing cap (124); The switch adjusting spindle (122) is axially disposed inside the switch housing (121), and the switch key (123) is connected to the switch adjusting spindle (122); The switch key bearing cap (124) is located at the bottom of the switch key (123).

5. The pressure-relieving tool according to claim 4, characterized in that, The piston stroke unit (11) includes a piston stroke outer cylinder (111), a thrust stroke piston (112), and a piston reset assembly (113); The thrust stroke piston (112) and piston reset assembly (113) are both disposed inside the piston stroke outer cylinder (111), and the thrust stroke piston (112) is connected to the switch adjustment spindle (122); The piston reset assembly (113) is located below the thrust stroke piston (112) and is used to drive the thrust stroke piston (112) to reset axially.

6. The pressure-relieving tool according to claim 5, characterized in that, The piston reset assembly (113) includes a piston reset elastic element (1131) and a force adjusting ring (1132); The piston reset elastic element (1131) is disposed in the inner cavity of the piston stroke outer cylinder (111), and the force adjusting ring (1132) is disposed at the bottom of the piston reset elastic element (1131).

7. The pressure-relieving tool according to claim 5, characterized in that, It also includes a filter mechanism (5), which is disposed on the piston stroke outer cylinder (111) to separate the inner cavity of the piston stroke outer cylinder (111) from the well wall annulus for filtering drilling fluid.

8. The pressure-relieving tool according to claim 1, characterized in that, The drive shaft (22) includes a first meshing part and a second meshing part distributed sequentially from bottom to top; The first engagement portion has a first external spline (221) for engaging with the first-stage clutch inner spline cylinder (21); The second engagement portion has a second external spline (222) for engaging with the inner spline cylinder (41) of the torque transmission.

9. The pressure-relieving tool according to claim 8, characterized in that, The primary clutch mechanism (2) also includes a guide wreath (24); The guide ring (24) is arranged along the inner circumference of the first-stage clutch inner spline cylinder (21); The guide ring (24) has guide splines (241) that correspond to the inner splines of the first-stage clutch inner spline cylinder (21), which are used to guide the first outer spline (221) into the inner spline keyway of the first-stage clutch inner spline cylinder (21) when the drive shaft (22) moves upward; The second external spline (222) has circumferential movement space in the spline groove of the inner spline cylinder (41) of the transmission torsion tube, which satisfies the circumferential rotation of the first external spline (221) into the keyway of the guide spline (241) of the guide ring (24).

10. The pressure-relieving tool according to claim 9, characterized in that, The lower end of the guide spline (241) and the upper end of the first external spline (221) of the drive shaft (22) are both provided with rounded corners to guide the first external spline (221) of the drive shaft (22) into the keyway of the guide spline (241) of the guide ring (24).

11. The pressure-relieving tool according to claim 4, characterized in that, The primary clutch mechanism (2) further includes a first throttling ring (25) and a second throttling ring (26) arranged opposite each other. The first throttle ring (25) is connected to the switch adjusting spindle (122), and the second throttle ring (26) is connected to the upper end of the transmission shaft (22) and is located below the first throttle ring (25); The first throttling ring (25) has a through hole (251) and the first throttling ring (25) can be moved down to fit against the second throttling ring (26) to block the through hole (251).

12. The pressure-relieving tool according to claim 1, characterized in that, It also includes a fall prevention mechanism (6); The anti-drop mechanism (6) includes an anti-drop ring (61) and an anti-drop bearing cap (62); The anti-drop ring (61) is connected to the inner spline cylinder (41) of the torque transmission, and the anti-drop bearing cap (62) is connected to the inner spline cylinder (21) of the first-stage clutch, forming an annular groove between the cap and the inner wall of the inner spline cylinder (21) of the first-stage clutch. The anti-drop ring (61) has a protrusion (611) on the lower side wall, and the protrusion (611) is embedded in the annular groove.

13. The pressure-relieving tool according to claim 1, characterized in that... The upper end of the drive shaft (22) is provided with a first guide groove (223), which connects the inner cavity of the drive shaft (22) with the inner cavity of the inner spline cylinder (41). The lower end of the drive shaft (22) is provided with a second guide groove (224), which connects the inner cavity of the drive shaft (22) with the inner cavity of the first-stage clutch inner spline cylinder (21).

14. The pressure-relieving tool according to claim 12, characterized in that... The inner wall of the anti-drop ring (61) is provided with a third guide groove (612) along the axial direction. The third guide groove (612) connects the inner cavity of the first-stage clutch inner spline cylinder (21) and the inner cavity of the torque transmission inner spline cylinder (41).

15. The pressure-relieving tool according to claim 1, characterized in that... The first-stage clutch reset assembly (23) includes a first-stage clutch elastic reset component (231) and a pressure ring (232); The first-stage clutch elastic reset member (231) is disposed between the inner spline cylinder (41) and the transmission shaft (22), and the pressure ring (232) is connected to the transmission shaft (22); The pressure ring (232) has a fourth guide groove (2321) along the axial direction.

16. A sliding directional drilling method using a pressure-relief tool as described in any one of claims 1-15.

Images