Universal joint for transmitting torque
By designing a universal joint structure, using the universal rotation of spherical projections and grooves and the elastic parts to transmit torque, the problem of difficulty in downhole pipe columns at the steering position is solved, and the smooth transmission of torque and the improvement of construction progress is achieved.
Patent Information
- Application Number
- CN202422046247.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-22
- Publication Date
- 2025-07-08
- Estimated Expiration
- 2034-08-22
AI Technical Summary
It is difficult to enter the well pipe string at the steering position for underground operation, resulting in damage to the casing and drill string, making it difficult to transmit torque, affecting the construction progress.
A universal joint structure is designed, including an upper joint, a lower joint and a guard cap. Using the matching of spherical protrusions and grooves, combined with elastic members and sealing structure, the universal rotation and torque transmission of the upper joint and the lower joint are realized, and adapted to the steering of the wellbore trajectory.
It effectively solves the difficulty of downhole pipe strings at the steering position, prevents frictional damage between the casing and drill strings, ensures smooth torque transmission, and improves construction efficiency.
Smart Images
Figure CN223075492U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to a universal joint for transmitting torque and belongs to the technical field of oilfield workover and drilling Background Technique
[0002] With the oilfield development entering the middle and late stages, the workover of highly deviated wells, horizontal wells and casing window sidetracking increases day by day. Compared with the workover operation of conventional vertical wells, due to the wellbore trajectory turning in highly deviated wells, horizontal wells and sidetracked wells, it is difficult to lower the downhole operation string at the turning point. The string rubs against the casing or the wellbore wall, causing damage to the casing and drill string. At the same time, it is difficult to transmit torque during operation, affecting the operation progress. Content of the Utility Model
[0003] The purpose of the utility model is to provide a universal joint for transmitting torque to solve the problem that it is difficult to lower the downhole operation string at the turning point.
[0004] To achieve the above purpose, the solution of the utility model includes:
[0005] A universal joint for transmitting torque of the utility model includes a lower joint for connecting the lower string, an upper joint for connecting the upper string and a protective cap. The lower joint includes a rod portion and a spherical protrusion arranged above the rod portion. A groove is opened at the bottom of the upper joint, and the concave spherical surface of the groove is adapted to the outer spherical surface of the spherical protrusion. The protective cap is sleeved on the lower joint, and a concave surface adapted to the spherical protrusion is arranged on the inner side wall of the protective cap. When the protective cap is connected to the upper joint, the concave surface and the concave spherical surface form a space for the spherical protrusion to rotate within a certain range. A plurality of concave spherical grooves are opened on the outer peripheral surface of the rod portion, and a plurality of mounting holes corresponding to the positions of the concave spherical grooves are opened on the outer side wall of the protective cap. A plug is arranged at the orifice of the mounting hole, and the plug presses the sphere for transmitting torque into the concave spherical groove through an elastic member. Transmitting torque means transmitting the torque of the upper joint to the lower joint.
[0006] When assembling the universal joint for torque transmission of the present utility model, the protective cap is sleeved on the lower joint from the rod part of the lower joint and connected to the upper joint. The concave spherical surface of the groove of the upper joint and the concave surface on the inner side wall of the protective cap form a space for the spherical protrusion to rotate within a certain range. When the present utility model is at the turning point of the wellbore trajectory in a highly deviated well, horizontal well or sidetrack well, the lower joint rotates inward towards the inner arc of the wellbore trajectory under the action of the turning centripetal force. At this time, if the sphere is squeezed by the turning of the lower joint, the sphere will squeeze the elastic member inward and retract into the installation hole, realizing the universal rotation of the lower joint relative to the upper joint within a certain angle range, ensuring the smooth entry of the pipe string into the well, and effectively preventing rigid hard friction between the casing and the drill string. When rotating the operation, under the action of the elastic member, the sphere is always located in the concave spherical groove on the outer circumference of the lower joint and the installation hole on the protective cap at the same time. Depending on the load-bearing connection of the sphere, the torque transmission between the upper joint and the lower joint is realized, so as to ensure that the torque of the upper pipe string above the upper joint is transmitted to the lower pipe string below the lower joint, and the operation is carried out smoothly.
[0007] Further, the protective cap is threadedly connected to the upper joint, and the thread helix direction is opposite to the torque transmission direction to prevent the upper joint from disengaging from the protective cap.
[0008] The protective cap of the present utility model is threadedly connected to the upper joint, and the thread helix direction is opposite to the torque transmission direction to prevent the upper joint from disengaging from the protective cap.
[0009] Further, half of the sphere is located in the concave spherical groove.
[0010] Half of the sphere of the present utility model is located in the concave spherical groove. At this time, the present utility model achieves the best effect of realizing the universal rotation of the lower joint relative to the upper joint within a certain angle range and realizing the torque transmission between the upper joint and the lower joint.
[0011] Further, both the lower joint and the upper joint are hollow, and the hollow hole of the upper joint is communicated with the hollow hole of the lower joint.
[0012] According to actual needs, the present utility model can select the universal joint with a hollow interior for torque transmission. Generally, pipe fittings communicated with it are connected to both ends of the universal joint to achieve the required functions.
[0013] Further, sealing members are provided at the connection between the upper joint and the protective cap and at the connection between the spherical protrusion and the concave surface to realize the sealing of the upper joint and the lower joint with the protective cap respectively.
[0014] Sealing members are provided at the connection between the upper joint and the protective cap and at the connection between the spherical protrusion and the concave surface of the present utility model to realize the sealing of the upper joint and the lower joint with the protective cap respectively, and to prevent the fluid in the pipe string from leaking during the circulating flushing operation.
[0015] Further, the elastic member is a leaf spring.
[0016] The elastic member of the present utility model is a leaf spring, which is convenient for maintenance, easy to install, and reliable in operation.
[0017] Furthermore, a thread for connecting the upper pipe string is provided on the upper part of the upper joint.
[0018] The upper joint of the present utility model is used for screwing and connecting the upper pipe string, which is convenient for installation and disassembly.
[0019] Furthermore, a thread for connecting the lower pipe string is provided on the lower part of the lower joint.
[0020] The lower joint of the present utility model is used for screwing and connecting the lower pipe string, which is convenient for installation and disassembly.
[0021] Furthermore, the plug and the mounting hole are screwed together.
[0022] The plug of the present utility model is screwed with the mounting hole, which is convenient for the installation, disassembly and replacement of the plug. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Figure 1 is a schematic structural view of the universal joint for transmitting torque of the present utility model;
[0024] Figure 2 is a schematic structural view of the upper joint of the present utility model;
[0025] Figure 3 is a schematic structural view of the lower joint of the present utility model;
[0026] Figure 4 is a schematic structural view of the protective cap of the present utility model.
[0027] DESCRIPTION OF THE REFERENCE NUMERALS:
[0028] 1. Upper joint; 101. Upper pipe string connection thread; 102. Lower connection thread; 103. Concave spherical surface; 2. Lower joint; 201. Convex spherical surface; 202. Concave spherical groove; 203. Lower pipe string connection thread; 3. Protective cap (sheath); 301. Concave surface; 302. Threaded hole; 4. Ball locking mechanism; 401. Plug; 402. Leaf spring; 403. Steel ball; 5. First sealing ring; 6. Second sealing ring. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0029] To make the objectives, technical solutions and advantages of the present utility model clearer and more understandable, the present utility model will be further described in detail below with reference to the drawings and embodiments.
[0030] An embodiment of a universal joint for transmitting torque:
[0031] A universal joint for transmitting torque, as Figures 1 to 4As shown, it mainly consists of an upper joint 1, a lower joint 2, a protective cap 3, a ball locking mechanism 4, a first sealing ring 5, a second sealing ring 6, etc.
[0032] The lower joint 2 for connecting the lower pipe string, the upper joint 1 for connecting the upper pipe string, and the protective cap 3. The lower joint 2 includes a rod portion and a spherical protrusion provided above the rod portion. A groove is formed at the bottom of the upper joint 1, and the concave spherical surface 103 of the groove is adapted to the outer spherical surface (convex spherical surface 201) of the spherical protrusion. The protective cap 3 is sleeved on the lower joint 2, and a concave surface 301 adapted to the spherical protrusion is provided on the inner side wall of the protective cap 3. When the protective cap 3 is connected to the upper joint 1, the concave surface 301 and the concave spherical surface 103 form a space for the spherical protrusion to rotate within a certain range. A plurality of concave ball grooves 202 are formed on the outer peripheral surface of the rod portion, and a plurality of mounting holes corresponding to the positions of the concave ball grooves are formed on the outer side wall of the protective cap 3. A plug 401 is provided at the orifice of the mounting hole, and the plug 401 presses the ball for transmitting torque into the concave ball groove 202 through an elastic member. Transmitting torque means transmitting the torque of the upper joint 1 to the lower joint 2. The ball is a non-deformable ball under force and can be selected as a steel ball. The elastic member can be selected as a compression spring or a leaf spring, and the two have the same function.
[0033] The upper joint 1 and the lower joint 2 can be rotatably hinged 360 degrees through the cooperation of the concave spherical surface 103 and the convex spherical surface 201. The protective cap 3 is connected to the lower connection thread 102 of the upper joint 1 to limit and fix the convex spherical surface 201 of the lower joint 2. The upper joint 1 and the lower joint 2 are respectively sealed with the protective cap 3 through the first sealing ring 5 and the second sealing ring 6 to prevent the fluid in the pipe string from leaking during the circulating flushing operation. Threaded holes 302 (mounting holes) are distributed on the lower circumference of the protective cap 3, and a ball locking mechanism 4 composed of a plug 401, a leaf spring 402 (elastic member), and a steel ball 403 (ball) is installed inside. The steel ball 403 in the ball locking mechanism 4 is simultaneously located in the concave ball groove 202 on the outer circumference of the lower joint 2 and the threaded hole 302 on the protective cap 3 to achieve the transmission of the torque between the upper joint 1 and the lower joint 2. A first sealing ring is provided at the connection between the upper joint and the protective cap, and a second sealing ring is provided at the connection between the lower joint and the protective cap.
[0034] The upper joint 1 has an upper pipe string connection thread 101 in the hollow structure at the upper part, which is in threaded fit with the lower thread of the lower well pipe string; at the lower part, there is a lower connection thread 102. There is a sealing groove on the outer circle between the lower connection thread 102 and the upper pipe string connection thread 101, and the first sealing ring 5 is installed at the sealing groove; in the inner hole at the lower part of the lower connection thread 102, there is a concave spherical surface 103.
[0035] The lower joint 2 has a convex spherical surface 201 in the hollow structure at the upper part, which is rotatably hinged 360 degrees in cooperation with the concave spherical surface 103 of the upper joint 1; a plurality of concave ball grooves 202 are distributed on the middle circumference, which are in cooperation with the steel balls 403; at the lower part, there is a lower pipe string connection thread 203, which is in threaded connection with the upper thread of the downhole pipe string of the present invention.
[0036] The upper part of the protective cap 3 has a connecting thread, which is connected to the lower connecting thread 102 of the upper joint 1; on the lower circumference, there are threaded holes 302, and a steel ball 403, a leaf spring 402 and a plug 401 are successively installed from the inside out. The outside of the plug 401 has a thread that is threadedly engaged with the threaded hole 302 to fix and limit the leaf spring 402; in the middle inner cavity, there is a concave surface 301, and the concave surface 301 and the concave spherical surface 103 of the upper joint 1 are in consistent arc surface, and are rotationally hinged with the convex spherical surface 201 of the lower joint 2 for 360-degree rotation, and at the same time, the convex spherical surface 201 of the lower joint 2 is fixed and limited; there is a movable gap between the lower inner cavity of the concave surface 301 and the outer circle of the lower part of the convex spherical surface 201 of the lower joint 2, ensuring that the lower joint 2 can rotate universally relative to the upper joint 1 within a certain angle range.
[0037] The ball locking mechanism 4 is composed of a steel ball 403, a leaf spring 402 and a plug 401. The steel ball 403 is simultaneously located in the concave ball groove 202 on the outer circumference of the lower joint 2 and the threaded hole 302 on the protective cap 3, realizing the torque transmission between the upper joint 1 and the lower joint 2. Under the action of an external force, the steel ball 403 can cooperate with the universal rotation and retract into the threaded hole 302, and the retraction distance matches the rotation angle of the lower joint 2 relative to the upper joint 1.
[0038] See Figure 1 , when using the present utility model for drilling and workover operations, according to the installation position required by the design, the upper pipe string connecting thread 101 of the present utility model is threadedly connected to the lower thread of the lower well pipe string, and the lower pipe string connecting thread 203 is threadedly connected to the upper thread of the well pipe string below it and runs into the well. When the present utility model is at the turning point of the wellbore trajectory of a highly deviated well, a horizontal well or a sidetrack well, the lower joint rotates towards the inside of the wellbore trajectory arc under the action of the turning centripetal force. At this time, if the steel ball 403 is squeezed by the turning of the lower joint 2, the steel ball 403 will squeeze the leaf spring 402 and retract into the threaded hole 302, realizing the universal rotation of the lower joint 2 relative to the upper joint 1 within a certain angle range, ensuring the smooth running of the pipe string into the well, and effectively preventing the rigid hard friction between the casing and the drill string. When rotating the operation, under the action of the leaf spring 402, the steel ball 403 is always simultaneously located in the concave ball groove 202 on the outer circumference of the lower joint 2 and the threaded hole 302 on the protective cap 3. Relying on the load-bearing connection of the steel ball 403, the torque transmission between the upper joint 1 and the lower joint 2 is realized, so as to ensure that the torque of the upper pipe string of the upper joint 1 is transmitted to the lower pipe string of the lower joint 2, and the operation is carried out smoothly.
[0039] The present utility model is applied in the drilling and workover operations in Henan Oilfield. The application shows that the present utility model adopts a ball lock load-bearing structure, with reliable load-bearing performance, and preferably solves the technical problems existing in highly deviated wells, horizontal wells and sidetracks, such as the difficulty in running the downhole pipe string, the friction between the pipe string and the casing or the well wall, the damage to the casing and the drill string, the difficulty in torque transmission during operation, and the impact on the operation construction progress.
Claims
1. A universal joint for transmitting torque, characterized in that, It includes a lower joint for connecting the lower pipe string, an upper joint for connecting the upper pipe string, and a protective cap. The lower joint includes a rod portion and a spherical bulge provided above the rod portion. A groove is formed at the bottom of the upper joint, and the concave spherical surface of the groove is adapted to the outer spherical surface of the spherical bulge. The protective cap is sleeved on the lower joint, and a concave surface adapted to the spherical bulge is provided on the inner side wall of the protective cap. When the protective cap is connected to the upper joint, the concave surface and the concave spherical surface form a space for the spherical bulge to rotate within a certain range. A plurality of concave spherical grooves are formed on the outer peripheral surface of the rod portion, and a plurality of mounting holes corresponding to the positions of the concave spherical grooves are formed on the outer side wall of the protective cap. A plug is provided at the orifice of the mounting hole, and the plug presses a sphere for transmitting torque into the concave spherical groove through an elastic member. The torque transmission refers to transmitting the torque of the upper joint to the lower joint.
2. The universal joint for transmitting torque according to claim 1, characterized in that, The protective cap is threadedly connected to the upper joint, and the thread helix direction is opposite to the torque transmission direction to prevent the upper joint and the protective cap from disengaging.
3. The universal joint for transmitting torque according to claim 1, characterized in that, Half of the sphere is located in the concave spherical groove.
4. The universal joint for transmitting torque according to claim 1, characterized in that, Both the lower joint and the upper joint are hollow, and the hollow hole of the upper joint is communicated with the hollow hole of the lower joint.
5. The universal joint for transmitting torque according to claim 1, characterized in that, Sealing members are provided at the connection between the upper joint and the protective cap and at the connection between the spherical bulge and the concave surface to achieve sealing between the upper joint and the lower joint and the protective cap respectively.
6. The universal joint for transmitting torque according to claim 1, characterized in that, The elastic member is a leaf spring.
7. The universal joint for transmitting torque according to claim 1, characterized in that, Threads for connecting the upper pipe string are provided at the upper part of the upper joint.
8. The universal joint for transmitting torque according to claim 1, characterized in that, Threads for connecting the lower pipe string are provided at the lower part of the lower joint.
9. The universal joint for transmitting torque according to claim 1, characterized in that, The plug and the mounting hole are screwed together.