Anti-blocking oil drain device for oil fields
By designing the fixed ring, sliding block and rotary frame structure of the anti-blocking oil drainer, the problem of oil drainer blockage caused by wax solidification is solved, and the continuity and efficiency of oil well production is achieved, reducing maintenance difficulty and cost.
Patent Information
- Application Number
- CN202510602755.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-12
- Publication Date
- 2025-08-12
- Estimated Expiration
- 2045-05-12
AI Technical Summary
In crude oil wells containing a higher proportion of waxy components, wax solidification causes blockage of the oil drainer, affecting the production process of the well, reducing oil production efficiency and increasing maintenance costs.
An anti-blocking oil drainer is designed to block the waxy components through a fixed ring, and a turbulent disturbance wax deposition is formed using the first annular chamber. The sliding block contacts the casing to maintain the stability of the device, the sliding shell prevents crude oil from flowing backwards, and the rotating frame guides crude oil flow to reduce the adhesion of impurities in the filter screen.
Effectively prevent wax clogging, ensure continuous and smooth oil drainage process, reduce maintenance costs, extend equipment life, and improve oil production efficiency.
Smart Images
Figure CN120100373B_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of oil drainers, in particular to an anti-blocking oil drainer used in oil fields. Background Art
[0002] In current oilfield production technology, drainpipes, as key components ensuring the effective drainage of fluids from oil wells, play a vital role in maintaining continuous and efficient production. However, in practice, this process presents unique challenges, particularly in wells with crude oil containing a high proportion of wax. As the temperature drops, the wax tends to solidify and adhere to the inner surface of the drainpipe, gradually forming a thick wax film. This wax film not only reduces the flow area and causes oil blockage, but also seriously affects the normal production process of the oil well, reducing oil recovery efficiency, and increasing maintenance costs and operational difficulties.
[0003] This problem becomes particularly acute in mature oilfields, particularly as production progresses to deeper strata or geological conditions change. Temperature and pressure fluctuations, as well as altered reservoir properties, caused by long-term production, increase the risk of wax deposition, making traditional production methods inadequate for modern, efficient production. Therefore, effectively addressing or mitigating the problem of wax-induced drain blockage has become crucial for improving production efficiency in mature oilfields, particularly those located in complex geological conditions. Summary of the Invention
[0004] In order to overcome the problems raised in the above background technology, the present invention provides an anti-blocking oil drainer for oil fields.
[0005] The technical solution is as follows: An anti-blocking oil drain device for oil fields, comprising an oil unloading pipe and a sliding sleeve, the oil unloading pipe is provided with an oil unloading port, the inner side of the oil unloading pipe is provided with a threaded groove, the outer side of the sliding sleeve is provided with an external thread, the external thread of the sliding sleeve is located in the threaded groove of the oil unloading pipe and slides, the sliding sleeve is provided with a first through hole for installing a filter screen, when the sliding sleeve moves, the communication state between the first through hole and the oil unloading port is changed, the end of the oil unloading pipe close to the sliding sleeve is provided with a first threaded cover, the first threaded cover and the sliding sleeve slide in a sealed manner, the end of the sliding sleeve away from the oil unloading pipe is provided with an upper joint, the end of the oil unloading pipe away from the first threaded cover is provided with a sleeve, the sliding sleeve and the sleeve slide in a sealed manner, the sleeve is used to cover the first through hole, a fixing ring is fixed in the sleeve, the fixing ring and the sliding sleeve slide in a sealed manner, and the fixing ring is used to cover the first through hole.
[0006] Preferably, the oil unloading pipe and the sliding sleeve form a first annular chamber, and the first annular chamber is used to communicate with the first through hole and the oil unloading port.
[0007] Preferably, the length of the thread groove on the oil unloading pipe is greater than the length of the external thread on the sliding sleeve.
[0008] Preferably, the sleeve is provided with a first sliding sleeve for sealing and sliding, the first sliding sleeve is threadedly mounted with a second threaded cover, the second threaded cover and the sleeve are sealingly slidable, and a spring is installed between the sleeve and the second threaded cover, the first sliding sleeve is provided with a sliding block for limiting sliding, the sliding block is provided with a first inclined surface, the oil unloading pipe is provided with a second inclined surface, the second inclined surface on the oil unloading pipe is used to squeeze the first inclined surface on the sliding block, the sleeve and the first sliding sleeve form a second annular chamber, the sleeve is provided with a second through hole, and the second through hole is communicated with the second annular chamber.
[0009] Preferably, the sliding block is provided with a groove, and an elastic pad is provided on the groove side of the sliding block.
[0010] Preferably, the sleeve is sealed and slidably provided with a second sliding sleeve, the second sliding sleeve is used to block the second through hole, a spring is installed between the second sliding sleeve and the sleeve, the second sliding sleeve is slidably provided with a limiting member, a spring is installed between the limiting member and the second sliding sleeve, the sleeve is provided with a guide groove, and the limiting member slides in the guide groove of the sleeve.
[0011] Preferably, the sleeve is provided with a limiting hole, and the limiting hole is communicated with the guide groove on the sleeve. When the limiting member is inserted into the limiting hole, the limiting hole is used to limit the movement of the limiting member and the second sliding sleeve.
[0012] Preferably, it also includes:
[0013] a fixing seat, installed in the oil unloading port and in contact with the sliding sleeve;
[0014] The sliding shell is slidably arranged in the oil discharge port, the fixing seat is used to limit the movement of the sliding shell, and the sliding shell is provided with a rectangular hole.
[0015] Preferably, a spring is installed between the sliding housing and the oil unloading pipe to reset the sliding housing and block the oil unloading port.
[0016] Preferably, a first rotating frame and a second rotating frame are rotatably arranged in the oil unloading pipe, the first rotating frame and the second rotating frame are both located in the first annular chamber, the second rotating frame is closer to the first through hole than the first rotating frame, and the first rotating frame and the second rotating frame are fixedly connected.
[0017] The present invention has the following advantages: the present invention prevents the wax components precipitated from the crude oil from blocking the first through hole and affecting the normal progress of the oil unloading operation through the blocking of the fixed ring; the discharged crude oil is caused to flow in a curved manner through the first annular chamber to form turbulence, wherein the flow of the crude oil will disturb and destroy the deposition of the wax components, that is, delay waxing and ensure the continuity and smoothness of the oil discharge process; the sliding block is moved to contact the oil field casing, so that the oil unloading pipe is in a fixed state, which is convenient for the subsequent rotation of the sliding sleeve to adjust the connectivity size of the first through hole, thereby improving the applicability of the device; the second sliding sleeve blocks the second through hole, thereby preventing the sliding block from being triggered incorrectly, thereby improving the working stability of the device; and the limiting relationship between the limiting member and the limiting hole facilitates the repeated use of the device, thereby reducing costs and enhancing the adaptability and safety of the equipment; the movement of the sliding shell prevents the crude oil from flowing back and leaking; the rotation of the first rotating frame and the second rotating frame guides the crude oil to backwash the filter screen at the first through hole, thereby reducing the amount of impurities attached to the filter screen at this location. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention;
[0019] Figure 2 A cross-sectional view of the oil unloading pipe and the first sliding sleeve of the present invention;
[0020] Figure 3 It is a schematic diagram of the three-dimensional structure of the fixing ring and the second sliding sleeve of the present invention;
[0021] Figure 4 This is a cross-sectional view of the oil unloading pipe and the sliding sleeve of the present invention;
[0022] Figure 5 is a cross-sectional view of the second sliding sleeve and the limiting member of the present invention;
[0023] Figure 6 It is a schematic diagram of the three-dimensional structure of the fixing seat and the sliding shell of the present invention.
[0024] The meanings of the reference numerals in the figure are: 1. oil unloading pipe, 101. oil unloading port, 2. sliding sleeve, 201. first through hole, 202. first annular chamber, 3. first threaded cover, 4. upper joint, 5. sleeve, 501. fixing ring, 6. first sliding sleeve, 7. second threaded cover, 8. sliding block, 9. second annular chamber, 10. second through hole, 15. second sliding sleeve, 16. limiting member, 17. limiting hole, 18. fixing seat, 19. sliding shell, 20. first rotating frame, 21. second rotating frame. DETAILED DESCRIPTION
[0025] To make the purpose, technical solutions and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention.
[0026] Example 1: An anti-blocking oil drain for oil fields, such as Figures 1-4 As shown, it includes an oil unloading pipe 1 and a sliding sleeve 2. The oil unloading pipe 1 is provided with an oil unloading port 101. The inner side of the oil unloading pipe 1 is provided with a thread groove, and the outer side of the sliding sleeve 2 is provided with an external thread. The external thread of the sliding sleeve 2 is located in the thread groove of the oil unloading pipe 1 and slides. The sliding sleeve 2 is provided with a first through hole 201 for installing a filter. When the sliding sleeve 2 moves, the communication state between the first through hole 201 and the oil unloading port 101 is changed. A first threaded cap 3 is installed at one end of the oil unloading pipe 1 close to the sliding sleeve 2. The first threaded cap 3 slides with the sliding sleeve 2 in a sealed manner. The sliding sleeve 2 is away from the oil unloading pipe 1. An upper joint 4 is installed at the end, and a sleeve 5 is installed at the end of the oil unloading pipe 1 away from the first threaded cover 3. The sleeve 2 and the sleeve 5 are sealed and slided. The sleeve 5 is used to cover the first through hole 201. A fixing ring 501 is fixed inside the sleeve 5. The fixing ring 501 and the sleeve 2 are sealed and slided, and the fixing ring 501 is used to cover the first through hole 201; the oil unloading pipe 1 and the sleeve 2 form a first annular chamber 202, and the first annular chamber 202 is used to connect the first through hole 201 and the oil unloading port 101; the length of the thread groove on the oil unloading pipe 1 is greater than the length of the external thread on the sleeve 2.
[0027] In the above scheme, the first threaded cover 3 is provided with two sealing rings for improving the sealing between the first threaded cover 3 and the sleeve 2, the oil unloading port 101 has three circumferentially equidistantly distributed (this number is the quantity expressed in the accompanying drawings, and the subsequent quantity expressions are all illustrated numbers, and the actual number can be set accordingly according to needs), and the first through hole 201 has four circumferentially equidistantly distributed. The upper side surface of the fixing ring 501 is provided with an annular inclined surface for reducing the retention of impurities. In the process of the external thread on the sleeve 2 rotating from the lower limit of the thread groove on the oil unloading pipe 1 to its upper limit, the first through hole 201 on the sleeve 2 gradually communicates with the first annular chamber 202, and at the same time, the first annular chamber 202 gradually communicates with the oil unloading port 101. The first annular chamber 202 causes the discharged crude oil to flow in a tortuous manner and easily form turbulence, wherein the flow of crude oil will disturb and destroy the deposition of wax components, that is, delay wax formation, and ensure the continuity and smoothness of the oil discharge process.
[0028] Specific working principle: first connect the upper joint 4 to the existing oil pipe, and connect the oil pump to the lower end of the casing 5 through the packer, and then put it into the oil well. After the packer moves to the specified position, it works and contacts the oil well, and then the oil pumping operation is carried out. In the initial state, the first annular chamber 202 is not connected with the first through hole 201 and the oil unloading port 101, and the fixed ring 501 blocks the first through hole 201 to prevent the wax components precipitated from the crude oil from adhering to the first through hole 201 during the working process, ensuring the normal subsequent oil unloading operation, that is, the working stability of the device. When the oil pump needs to be taken out, the oil pipe is rotated first, and the oil pipe drives the sliding sleeve 2 to rotate through the upper joint 4. The sliding sleeve 2 rotates so that the outer thread on it is along the thread of the oil unloading pipe 1 The groove rotates (the casing 5 remains stationary due to the action of the packer), causing the sliding sleeve 2 to move upward relative to the oil unloading pipe 1. At this time, the volume of the first annular chamber 202 gradually increases until the first annular chamber 202 is connected to the first through hole 201 and the oil unloading port 101. Subsequently, the crude oil in the oil pipe passes through the middle part of the upper joint 4, the middle part of the sliding sleeve 2, the first through hole 201, the first annular chamber 202 and the oil unloading port 101 and enters between the oil well and the oil pipe, avoiding leakage of crude oil in the oil pipe during the removal of the oil pump, thereby enhancing environmental protection. Afterwards, the oil pump and other components are cleaned and maintained. During the maintenance process, the sliding sleeve 2 is rotated in the opposite direction to reset the device. When the oil pumping operation needs to be performed again, the above components can be assembled and placed.
[0029] During the oil unloading operation by rotating the tubing, the operator can adjust the flow velocity and flow rate to adjust the flow cross-section size of the unloading channel according to the specific production conditions of the oil well and the fluid characteristics to ensure the best discharge efficiency (with the increase of crude oil production, the unloading channel needs to be appropriately enlarged). At the same time, the reasonable configuration of the flow cross-section size of the unloading channel helps to balance the impact force of the fluid on the equipment, reduce wear, and thus extend the service life of the equipment.
[0030] Example 2: Based on Example 1, Figure 1-Figure 3 As shown, the sleeve 5 is provided with a first sliding sleeve 6 for sealing and sliding, and the first sliding sleeve 6 is threadedly installed with a second threaded cover 7. The second threaded cover 7 and the sleeve 5 are sealed and slided, and a spring is installed between the sleeve 5 and the second threaded cover 7. The first sliding sleeve 6 is provided with a sliding block 8 for limited sliding. The sliding block 8 is provided with a first inclined surface, and the oil unloading pipe 1 is provided with a second inclined surface. The second inclined surface on the oil unloading pipe 1 is used to squeeze the first inclined surface on the sliding block 8. The sleeve 5 and the first sliding sleeve 6 form a second annular chamber 9. The sleeve 5 is provided with a second through hole 10, and the second through hole 10 is connected to the second annular chamber 9; the sliding block 8 is provided with a groove, and an elastic pad is provided on the groove side of the sliding block 8.
[0031] In the above scheme, the casing 5 is provided with two sealing rings, and the sealing rings of the casing 5 are used to improve the sealing between it and the first sliding sleeve 6. The sliding blocks 8 have three circumferentially equidistantly distributed, and the second inclined surface on the oil unloading pipe 1 has three circumferentially equidistantly distributed, and the three sliding blocks 8 are respectively located on the lower side of the adjacent second inclined surfaces on the oil unloading pipe 1. The second through holes 10 have four circumferentially equidistantly distributed, and the elastic pad on the sliding block 8 is used to enhance the friction between it and the wellbore.
[0032] like Figure 3 and Figure 5 As shown, the sleeve 5 is sealed and slidably provided with a second sliding sleeve 15, the second sliding sleeve 15 is used to block the second through hole 10, a spring is installed between the second sliding sleeve 15 and the sleeve 5, the second sliding sleeve 15 is slidably provided with a limit member 16, a spring is installed between the limit member 16 and the second sliding sleeve 15, the sleeve 5 is provided with a guide groove, the limit member 16 is located in the guide groove of the sleeve 5 and slides; the sleeve 5 is provided with a limit hole 17, the limit hole 17 is connected to the guide groove on the sleeve 5, when the limit member 16 is inserted into the limit hole 17, the limit hole 17 is used to limit the movement of the limit member 16 and the second sliding sleeve 15.
[0033] In the above scheme, the upper side surface of the second sliding sleeve 15 is set as an annular inclined surface to reduce the retention of impurities and facilitate the second sliding sleeve 15 to move and clean the wax components attached to the sleeve 5. Two limit members 16 are provided. The elastic coefficient of the spring between the limit member 16 and the second sliding sleeve 15 is smaller than the elastic coefficient of the spring between the second sliding sleeve 15 and the sleeve 5, and the spring between the limit member 16 and the second sliding sleeve 15 is in a compressed state, so that the two limit members 16 are in the illustrated state in the initial state.
[0034] Specific working principle: After the device is repeatedly placed in the oil well as described above, as the sucker rod slowly enters the oil pipe to work, the sucker rod first squeezes the two limit members 16. At this time, under the limiting action of the limit members 16, the sucker rod moves downward and drives the second sliding sleeve 15 to move downward together through the two limit members 16. The second sliding sleeve 15 compresses the connected spring, and the second sliding sleeve 15 gradually releases the obstruction of the second through hole 10 during the downward movement. After the second sliding sleeve 15 moves to the lower limit position, the limit member 16 is facing the adjacent limit hole 17. Under the elastic force of the spring connected to the limit member 16, the limit member 16 moves and is inserted into the adjacent limit hole 17, and at this time, the facing ends of the two limit members 16 are both located inside the second sliding sleeve 15. The wall, that is, the limit member 16 does not block the up and down reciprocating movement of the sucker rod. In the subsequent oil pumping process, the sucker rod and the oil pump work synchronously to pump crude oil to the ground through this device and the oil pipe. During the oil pumping process, the crude oil pressure in the oil well increases. At this time, the crude oil with increased pressure enters the second annular chamber 9 through the second through hole 10. Subsequently, the crude oil squeezes the first sliding sleeve 6, the second threaded cover 7 and the three sliding blocks 8 to move upward together. The inclined surfaces of the three sliding blocks 8 respectively contact and squeeze the adjacent second inclined surfaces on the oil unloading pipe 1, so that the three sliding blocks 8 are separated and contact the inner wall of the well, ensuring that the first sliding sleeve 6 is located in the middle of the well. At this time, the first sliding sleeve 6 and the oil unloading pipe 1 are in a limited and fixed state, and then the oil pumping operation is continued.
[0035] When the oil pump needs to be removed, the operation of the oil pump and the sucker rod is stopped, and the above-mentioned operation of rotating the oil pipe is repeated. At this time, since the first sliding sleeve 6 and the oil unloading pipe 1 are in a limited and fixed state, the rotation angle of the oil pipe is ensured to be the relative rotation angle between the sliding sleeve 2 and the oil unloading pipe 1, which is convenient for accurately controlling the size of the opened oil unloading channel.
[0036] Example 3: Based on Example 2, Figure 2 and Figure 6 As shown, it also includes: a fixed seat 18, which is installed in the oil unloading port 101 and contacts the sliding sleeve 2; a sliding shell 19, which is slidably arranged in the oil unloading port 101, and the fixed seat 18 is used to limit the movement of the sliding shell 19, and the sliding shell 19 is provided with a rectangular hole; a spring is installed between the sliding shell 19 and the oil unloading pipe 1, which is used to reset the sliding shell 19 and seal the oil unloading port 101.
[0037] In the above solution, in the initial state, the spring connected to the sliding housing 19 is in a compressed state, and when the sliding sleeve 2 rotates to the upper limit position, the sliding sleeve 2 still contacts the fixing seat 18 .
[0038] like Figure 2 and Figure 6As shown, a first rotating frame 20 and a second rotating frame 21 are rotatably arranged in the oil unloading pipe 1. The first rotating frame 20 and the second rotating frame 21 are both located in the first annular chamber 202. The second rotating frame 21 is closer to the first through hole 201 than the first rotating frame 20. The first rotating frame 20 and the second rotating frame 21 are fixedly connected.
[0039] In the above solution, the first turret 20 is used to convert the flow of crude oil into rotational power, and the second turret 21 rotates to drive the crude oil to gather in the middle.
[0040] Specific working principle: During the oil unloading operation, the second rotating frame 21 is facing the connecting part of the first through hole 201. At this time, the crude oil flowing in the first annular chamber 202 first squeezes the sliding shell 19 to move, and the sliding shell 19 simultaneously squeezes the connected spring. The sliding shell 19 moves to release the blockage of the oil unloading port 101, and the subsequent crude oil is discharged between the sliding shell 19 and the oil unloading port 101. During the crude oil discharge process, the crude oil simultaneously impacts the first rotating frame 20 to rotate, and the rotation of the first rotating frame 20 drives the second rotating frame 21 to rotate, so that the second rotating frame 21 rotates to drive the crude oil, causing the crude oil to have an inward flow trend. At this time, the inward flowing crude oil will backwash the filter screen on the first through hole 201, reducing the accumulation of impurities at the filter screen, thereby ensuring the continuous progress of the oil unloading operation.
[0041] It should be noted that the above preferred embodiments are merely illustrative of the technical concepts and features of the present invention. Their purpose is to enable those skilled in the art to understand the contents of the present invention and implement them accordingly. They are not intended to limit the scope of protection of the present invention. Any equivalent changes or modifications made in accordance with the spirit and essence of the present invention are intended to be encompassed within the scope of protection of the present invention.
Claims
1. An anti-blocking oil drain for oil fields, characterized in that: The invention comprises an oil unloading pipe (1) and a sliding sleeve (2), wherein the oil unloading pipe (1) is provided with an oil unloading port (101), a thread groove is provided on the inner side of the oil unloading pipe (1), and an external thread is provided on the outer side of the sliding sleeve (2), and the external thread of the sliding sleeve (2) slides in the thread groove of the oil unloading pipe (1), and the sliding sleeve (2) is provided with a first through hole (201) for installing a filter screen. When the sliding sleeve (2) moves, the communication state between the first through hole (201) and the oil unloading port (101) is changed. A first threaded cover (3) is installed at one end of the oil unloading pipe (1) close to the sliding sleeve (2). ), the first threaded cover (3) and the sliding sleeve (2) are sealed and slidable, an upper joint (4) is installed on one end of the sliding sleeve (2) away from the oil unloading pipe (1), a sleeve (5) is installed on one end of the oil unloading pipe (1) away from the first threaded cover (3), the sliding sleeve (2) and the sleeve (5) are sealed and slidable, the sleeve (5) is used to cover the first through hole (201), a fixing ring (501) is fixed inside the sleeve (5), the fixing ring (501) and the sliding sleeve (2) are sealed and slidable, and the fixing ring (501) is used to cover the first through hole (201); The oil unloading pipe (1) and the sliding sleeve (2) form a first annular chamber (202), and the first annular chamber (202) is used to communicate with the first through hole (201) and the oil unloading port (101); The sleeve (5) is provided with a first sliding sleeve (6) for sealing and sliding, the first sliding sleeve (6) is threadedly provided with a second threaded cover (7), the second threaded cover (7) and the sleeve (5) are sealed and slidable, and a spring is installed between the sleeve (5) and the second threaded cover (7), the first sliding sleeve (6) is provided with a sliding block (8) for limited sliding, the sliding block (8) is provided with a first inclined surface, the oil unloading pipe (1) is provided with a second inclined surface, the second inclined surface on the oil unloading pipe (1) is used to squeeze the first inclined surface on the sliding block (8), the sleeve (5) and the first sliding sleeve (6) form a second annular chamber (9), the sleeve (5) is provided with a second through hole (10), and the second through hole (10) is communicated with the second annular chamber (9); The sliding block (8) is provided with a groove, and an elastic pad is provided on the groove side of the sliding block (8); The sleeve (5) is provided with a second sliding sleeve (15) for sealing and sliding. The second sliding sleeve (15) is used to block the second through hole (10). A spring is installed between the second sliding sleeve (15) and the sleeve (5). The second sliding sleeve (15) is provided with a limiting member (16) for sliding. A spring is installed between the limiting member (16) and the second sliding sleeve (15). The sleeve (5) is provided with a guide groove. The limiting member (16) is located in the guide groove of the sleeve (5) and slides. The sleeve (5) is provided with a limiting hole (17), and the limiting hole (17) is communicated with the guide groove on the sleeve (5). When the limiting member (16) is inserted into the limiting hole (17), the limiting hole (17) is used to limit the movement of the limiting member (16) and the second sliding sleeve (15).
2. The anti-blocking oil drain device for oil fields according to claim 1, characterized in that: The length of the thread groove on the oil unloading pipe (1) is greater than the length of the external thread on the sliding sleeve (2).
3. The anti-blocking oil drain device for oil fields according to claim 1, characterized in that: Also included are: A fixed seat (18) is installed in the oil unloading port (101) and is in contact with the sliding sleeve (2); The sliding shell (19) is slidably arranged in the oil discharge port (101), the fixing seat (18) is used to limit the movement of the sliding shell (19), and the sliding shell (19) is provided with a rectangular hole.
4. The anti-blocking oil drain device for oil fields according to claim 3, characterized in that: A spring is installed between the sliding shell (19) and the oil unloading pipe (1) for resetting the sliding shell (19) and sealing the oil unloading port (101).
5. The anti-blocking oil drain device for oil fields according to claim 4, characterized in that: A first rotating frame (20) and a second rotating frame (21) are rotatably arranged in the oil unloading pipe (1); the first rotating frame (20) and the second rotating frame (21) are both located in the first annular chamber (202); the second rotating frame (21) is closer to the first through hole (201) than the first rotating frame (20); and the first rotating frame (20) and the second rotating frame (21) are fixedly connected.
Citation Information
Patent Citations
Rotary type tubing drain and use method thereof
CN102797436A
A sliding sleeve drain valve
CN207728345U