A sealing transmission device for improving the pressure bearing capacity of underground water nozzle

Abstract

The present invention relates to the technical field of sealing and adjusting water nozzles for injection and extraction, and specifically discloses a sealing transmission device for improving the pressure bearing capacity of downhole water nozzles, comprising a transmission shaft, wherein the upper and lower ends of the transmission shaft are respectively used to connect a driving mechanism and a water nozzle, the water nozzle is arranged in a water nozzle seat, the upper part of the transmission shaft is connected to a pressure cover through a first bearing, the upper part of the water nozzle seat is provided with a mounting cavity, the lower part of the transmission shaft is rotatably connected to the inner wall of the water nozzle seat through a second bearing, the lower surface of the second bearing presses the upper surface of the water nozzle, the upper surface of the second bearing is pressed against the lower surface of the rigid seal, the upper surface of the rigid seal is pressed against the lower surface of the pressure cover, and the rigid seal is used to seal the cavity between the transmission shaft and the water nozzle seat. The device can improve the pressure bearing capacity of the well without increasing the rotational torque, solve the problem of normal switching operation of the water nozzle under well sealing and high pressure difference conditions, is easy to open, and improves the service life of the water nozzle.

Description

Technical Field

[0001] The invention relates to the technical field of sealing and adjusting separate injection and production water nozzles, in particular to a sealing transmission device for improving the pressure bearing capacity of a downhole water nozzle. Background Art

[0002] In separate injection and production, the stepless water nozzle is the key mechanism for achieving precise control of injection and production flow. It must ensure that it is sealed when closed and can be opened when needed, and the flow can be continuously adjusted. In the existing technology, it is difficult to ensure leakage-free sealing of downhole actuators. Minor leakage of water and gas will form a low-resistance discharge channel in the downhole battery compartment, shortening the downhole working cycle of the actuator; downhole rotary seals all use friction-resistant slip ring structures, and minor leakage is difficult to avoid; increasing the pre-pressure of the friction-resistant slip ring seal will improve the sealing effect, but will also increase the rotational torque between the drive shaft and the friction-resistant slip ring seal structure, resulting in increased energy consumption of the water nozzle, or even abnormal operation, inconvenience in opening, and shortened seal life.

[0003] Downhole water nozzles must ensure high-pressure sealing while also operating at high differential pressures. These differential pressures can reach 35 MPa or even higher. However, due to the radial dimensions of the wellbore, the high-pressure dynamic sealing capabilities (sealing and pressure-bearing) of downhole tools and instruments cannot be met by simply increasing the size or number of seals or pressure-bearing components. Furthermore, when the water nozzle is closed, the existing bearings cannot withstand the pressure requirements and become the weakest link, susceptible to failure due to the high pressure. Summary of the Invention

[0004] The purpose of the present invention is to provide a sealing transmission device for improving the pressure bearing capacity of downhole water nozzles, improving the pressure bearing capacity of the well without increasing the rotational torque, solving the problem of normal switching operation of the water nozzle under well sealing and high pressure difference conditions, making it easy to open and prolong the service life of the water nozzle.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] The cam is connected to the water pump with a push of a button bar, and the push-button bar is connected with the water pump to the water pump end face, and the push-button bar is connected with the water pump end face.

[0007] In a further solution, the rigid seal includes a sealing seat, an outer wall surface of the sealing seat and the faucet seat are sealed by a static sealing structure, and an inner wall surface of the sealing seat and the transmission shaft are sealed by a dynamic sealing structure.

[0008] In a further solution, the static sealing structure includes a sealing ring, and a sealing ring installation groove is provided on the faucet seat and the sealing seat, and the sealing ring is sealingly connected in the installation groove.

[0009] In a further solution, the dynamic sealing structure includes a friction-resistant slip ring, the inner wall surface of the friction-resistant slip ring is in contact with the outer wall surface of the transmission shaft, and the friction-resistant slip ring is pressed onto the transmission shaft through an elastic sealing ring, and the elastic sealing ring is sealed between the inner wall surface of the sealing seat and the outer wall surface of the friction-resistant slip ring.

[0010] In a further solution, the longitudinal section of the friction-resistant slip ring is T-shaped, the upper part of the T is pressed on the inner wall surface of the sealing seat, and the lower part of the T is pressed on the transmission shaft through the elastic sealing ring.

[0011] In a further solution, the dynamic sealing structure further includes an air sealing member arranged between the transmission shaft and the sealing seat.

[0012] In a further embodiment, the first bearing comprises a thrust bearing.

[0013] In a further embodiment, the second bearing comprises a needle roller bearing.

[0014] In a further solution, the water nozzle includes a fixed water nozzle and a movable water nozzle, the fixed water nozzle is used to be fixedly connected to the water nozzle seat, the movable water nozzle is connected between the fixed water nozzle and the transmission shaft, and the movable water nozzle is used to close or open the liquid flow channel between the fixed water nozzle and the water nozzle seat.

[0015] In a further embodiment, the driving mechanism includes a motor.

[0016] Beneficial effects of the present invention:

[0017] 1. The dual-load channel sealing device of this invention more than doubles the faucet's ability to withstand well-sealing pressure by adding a second bearing and its load channel, without increasing the drive shaft's rotational torque. This solves the problem of opening the faucet during well sealing and under high-pressure differential conditions.

[0018] 2. The present invention distributes the load according to the working conditions, which simplifies the installation structure of the upper ball bearing on the one hand and reduces the difficulty of selecting miniature ball bearings (which require high strength in a miniature size and can withstand a thrust of 3t-5t), thereby providing a more economical design concept for the rotation of the faucet under low pressure difference conditions (when the faucet is open).

[0019] 3. The present invention arranges the two bearings at a certain distance apart, which not only straightens the transmission shaft but also transfers high pressure through the load channel to prevent the transmission shaft from bending due to excessive end load, resulting in increased torque and affecting motor drive.

[0020] 4. The present invention increases the sealing of the airtight parts, strengthens the airtightness of the system, and further increases the service life of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0022] Figure 1 Schematic diagram of a sealing transmission device installed inside a downhole tool according to an embodiment of the present invention;

[0023] Figure 2 2. It is a schematic diagram of the exterior of a downhole tool where a sealing transmission device is installed in an embodiment of the present invention;

[0024] Figure 3 is a schematic diagram of a sealed transmission device according to an embodiment of the present invention;

[0025] Figure 4 Schematic diagram of pressure transmission when the sealed transmission device is under positive pressure from a liquid flow in an embodiment of the present invention;

[0026] Figure 5 2. It is a schematic diagram of pressure transmission when the sealing transmission device is subjected to reverse pressure of liquid flow in an embodiment of the present invention;

[0027] In the figure: 1. Drive shaft; 2. Drive mechanism; 3. Water nozzle; 31. Fixed water nozzle; 32. Movable water nozzle; 4. Water nozzle seat; 41. Mounting cavity; 5. First bearing; 6. Pressure cover; 7. Rigid seal; 71. Sealing seat; 72. Static sealing structure; 73. Dynamic sealing structure; 731. Friction-resistant slip ring; 732. Elastic sealing ring; 733. Air seal; 8. Second bearing. DETAILED DESCRIPTION

[0028] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0029] like Figure 1 As shown, a sealing transmission device for improving the pressure-bearing capacity of a downhole water nozzle comprises a transmission shaft 1, the upper and lower ends of the transmission shaft 1 are respectively used to connect a driving mechanism 2 and a water nozzle 3, the water nozzle 3 is arranged in the water nozzle seat 4, and is used to adjust the water inlet and outlet of the water nozzle seat 4, the upper part of the transmission shaft 1 is connected to a pressure cover 6 through a first bearing 5, and the upper part of the water nozzle seat 4 is provided with a mounting cavity 41, the mounting cavity 41 is used to fix the pressure cover 6, and the pressure cover 6 is used to transmit the axial force of the transmission shaft 1 to the water nozzle seat 4, and the lower part of the transmission shaft 1 is rotatably connected to the inner wall of the water nozzle seat 4 through a second bearing 8, the lower surface of the second bearing 8 presses the upper surface of the water nozzle 3, and the upper surface of the second bearing 8 is pressed against the lower surface of the rigid seal 7, and the second bearing 8 is used to transmit the axial pressure between the rigid seal 7 and the water nozzle seat 4, and the upper surface of the rigid seal 7 is pressed against the lower surface of the pressure cover 6, and the rigid seal 7 is used to transmit the axial pressure between the second bearing 8 and the pressure cover 6, and the rigid seal 7 is used to seal the cavity between the transmission shaft 1 and the water nozzle seat 4.

[0030] Its working principle or implementation method is that the driving mechanism 2 drives the transmission shaft 1 to rotate, thereby driving the water spout 3 to adjust the water inlet and outlet of the water spout seat 4 to achieve stepless adjustment. During the adjustment process, when the water spout 3 needs to be in the water-discharging state, that is, when the water spout 3 is under positive pressure and the water spout 3 is in the open state, refer to Figure 4 As shown, the second bearing 8 on the faucet 3 is not sealed and is connected to the water outlet cavity. It is in a floating state in the liquid to maintain high-pressure balance. The high-pressure fluid will generate pressure on the end of the transmission shaft 1 and the rigid seal along the fitting gap. The pressure will then be transmitted to the faucet seat 4 through the pressure cover 6. Figure 2As shown, at this time, because the liquid can flow out from the faucet seat 4, the upward pressure is greatly relieved, the pressure on the end of the transmission shaft 1 will be relatively small, and the impact on the rotational torque of the transmission shaft 1 will be small. The transmission shaft 1 itself will also be easy to rotate under the action of the first bearing 5, so it will not affect the stepless adjustment of the transmission shaft 1 by the driving mechanism 2 under high pressure. Figure 5 As shown, when the faucet seat 4 does not need to be in the water-out state, that is, the faucet 3 is in the closed state, the faucet 3 will withstand the reverse pressure from the downstream channel, such as the pressure of the bottom hole fluid, and generally at this time the bottom hole fluid pressure is generally greater than the inlet pressure, which will push the faucet 3. The pressure on the faucet 3 is transmitted to the faucet seat 4 in sequence by the second bearing 8, the rigid seal 7, and the pressure cover. At this time, the first bearing 5 at the upper end is in a floating state, and the maximum impact pressure at the bottom is basically transmitted directly to the faucet seat 4 through the rigid seal 7. This will reduce the pressure on the drive shaft 1 and prevent the torque on the drive shaft 1 from increasing, solving the problem of opening the faucet 3 when sealing the well and under high pressure difference conditions, and can play a role in timely opening, thereby improving the ability of the faucet 3 to withstand the sealing pressure.

[0031] According to the above working principle, some preferred implementation structures or methods are provided, such as Figure 3 As shown, the rigid seal 7 includes a sealing seat 71. The outer wall of the sealing seat 71 is sealed against the faucet seat 4 shown in the figure by a static sealing structure 72, and the inner wall of the sealing seat 71 is sealed against the drive shaft 1 by a dynamic sealing structure 73. The static sealing structure 72 prevents fluid from passing through the gap between the sealing seat 71 and the faucet seat 4. The dynamic sealing structure 73 also seals the gap between the drive shaft 1 and the sealing seat 71 when the drive shaft 1 rotates. This achieves a complete seal between the faucet seat 4 and the drive mechanism 2, i.e., the actuator, preventing safety issues or pressure shortages caused by leakage.

[0032] The static sealing structure 72 includes a sealing ring, and a sealing ring installation groove is provided on the faucet seat 4 and the sealing seat 71. The sealing ring is sealed and connected in the installation groove. There can be multiple sealing rings.

[0033] The dynamic seal structure 73 includes a friction-resistant slip ring 731, the inner surface of which contacts the outer surface of the transmission shaft 1. The friction-resistant slip ring 731 is pressed against the transmission shaft 1 via an elastic sealing ring 732, which is sealed between the inner surface of the sealing seat 71 and the outer surface of the friction-resistant slip ring 731. This reduces friction on the seal when the transmission shaft 1 drives the faucet 3 for stepless adjustment, thereby increasing the service life of the seal structure.

[0034] The longitudinal section of the friction-resistant slip ring 731 is T-shaped, with the upper portion of the T pressed against the inner wall of the sealing seat 71 and the lower portion of the T pressed against the transmission shaft 1 through the elastic sealing ring 732. This facilitates the arrangement of the elastic sealing ring 732, which can of course also be I-shaped or other shapes.

[0035] The dynamic sealing structure 73 further includes an air seal 733 disposed between the transmission shaft 1 and the sealing seat 71. The addition of the air seal 733 structure can improve the wear resistance between the transmission shaft 1 and the sealing seat 71 and improve the sealing performance.

[0036] The dynamic seal structure 73 can be a simple combined seal consisting of an O-ring and a friction-resistant slip ring 731. The O-ring ensures the seal between the transmission shaft 1 and the seal seat 71, and the friction-resistant slip ring 731 ensures the seal between the transmission shaft 1 and the dynamic seal assembly.

[0037] The first bearing 5 comprises a thrust bearing. This bearing reduces the friction coefficient during the rotational motion of the transmission shaft 1, reducing friction at the shaft end, thereby reducing torque. Of particular note, to enhance the load-bearing capacity of the thrust ball bearing, the bearing utilizes a full ball design.

[0038] Second bearing 8 comprises a needle roller bearing. A needle roller bearing is positioned below seal seat 71. Because needle roller bearings utilize line contact, they significantly increase the device's pressure-bearing capacity. Therefore, needle roller bearings offer greater pressure resistance than ball bearings, improving bearing strength.

[0039] The faucet 3 includes a fixed faucet 31 and a movable faucet 32. The fixed faucet 31 is used to be fixedly connected to the faucet seat 4. The movable faucet 32 ​​is connected between the fixed faucet 31 and the transmission shaft 1. The movable faucet 32 ​​is used to close or open the liquid flow channel between the fixed faucet 31 and the faucet seat 4.

[0040] The drive mechanism 2 includes a motor. This motor is a commonly used actuator with mature control technology and is readily available. Downhole, the motor is connected to the sealing device's transmission shaft 1, the lower end of which is connected to the movable water nozzle 32. The motor drives the movable water nozzle 32 via the transmission shaft 1, thereby adjusting the opening of the water nozzle 3.

[0041] The sealing device is secured to the downhole tool via a pressure-bearing cap at its top, which can be threadedly connected to the faucet holder 4. A sealing seat 71 is located below the drive shaft 1. Multiple O-rings are installed on the outside of sealing seat 71 as static seals, ensuring that liquid does not enter the motor area of ​​the downhole tool from outside the sealing device during downhole operation.

[0042] When used specifically, Figure 4As shown, when the faucet 3 is subjected to positive pressure, the faucet 3 is in the open state. At this time, the movable faucet 32 ​​is connected to the fixed faucet 31, and the high-pressure fluid enters the working chamber of the faucet 3 through the small hole water inlet evenly distributed on the faucet seat 4, and then flows through the faucet 3 connecting channel to the downstream. At this time, because the entire needle roller bearing is not sealed, it is in a balanced state under high pressure, that is, a floating state. The high-pressure fluid acts on the dynamic seal and the end of the transmission shaft 1 along the fitting clearance. The fluid pressure acting on the end of the dynamic seal squeezes and further compacts the dynamic seal, thereby generating a radial clamping force that can increase the rotational torque of the transmission shaft 1; and the fluid pressure acting on the end of the transmission shaft 1 is transmitted to the thrust bearing, and then transmitted to the pressure cover by the thrust bearing, and then transmitted to the faucet seat 4 by the connecting thread between the pressure cover and the faucet seat 4, reducing the pressure and torque on the transmission shaft 1, making it easier for the motor to control its rotation to adjust the faucet 3. The direction of the arrow is the force transmission direction. As shown Figure 5 As shown. When the faucet 3 is subjected to reverse pressure, that is, the faucet 3 is closed, the movable faucet 32 ​​is not connected to the fixed faucet 31, the upstream and downstream channels are blocked, and the inlet and outlet of the faucet 3 form corresponding pressures respectively. Sometimes the pressure on both sides reaches 35MPa, or even higher. Usually, the pressure from the bottom hole fluid, that is, the outlet pressure, will be higher. This pushes the fixed faucet 31, and the pressure is transmitted to the faucet seat 4 in turn by the needle bearing, the sealing seat 71, the pressure cover, and the connecting thread between the pressure cover and the faucet seat 4. The direction of the arrow is the direction of force transmission. At this time, the thrust ball bearing at the upper end is in a floating state. It also reduces the pressure and torque on the drive shaft 1, making it easier for the motor to control its rotation to adjust the faucet 3.

[0043] It should be noted that the terms "first", "second" etc. in this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the application described herein. In this application, the directions or positional relationships indicated by the terms "upper", "lower", "left", "right", "front", "back", "top", "bottom", "inside", "outside", "center", "vertical", "horizontal", "lateral", "longitudinal" etc. are based on the directions or positional relationships shown in the accompanying drawings.

[0044] Throughout this specification, references to terms such as "one embodiment," "example," or "specific example" indicate that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0045] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention, and such changes and modifications fall within the scope of the invention as claimed.

Claims

1. A sealed transmission device for improving the pressure bearing capacity of a downhole water nozzle, comprising a transmission shaft (1), wherein the upper and lower ends of the transmission shaft (1) are respectively used to connect a driving mechanism (2) and a water nozzle (3), and the water nozzle (3) is arranged in a water nozzle seat (4) and is used to adjust the water inlet and outlet of the water nozzle seat (4), characterized in that: The upper portion of the transmission shaft (1) is connected to a pressure cover (6) via a first bearing (5), and the upper portion of the faucet seat (4) is provided with a mounting cavity (41), and the mounting cavity (41) is used for fixedly connecting the pressure cover (6), and the pressure cover (6) is used for transmitting the axial force of the transmission shaft (1) to the faucet seat (4), and the lower portion of the transmission shaft (1) is rotatably connected to the inner wall of the faucet seat (4) via a second bearing (8), and the lower surface of the second bearing (8) presses the upper surface of the faucet (3). The upper surface of the second bearing (8) is pressed against the lower surface of the rigid seal (7), and the second bearing (8) is used to transmit the axial pressure between the rigid seal (7) and the faucet seat (4). The upper surface of the rigid seal (7) is pressed against the lower surface of the pressure cover (6), and the rigid seal (7) is used to transmit the axial pressure between the second bearing (8) and the pressure cover (6), and the rigid seal (7) is used to seal the cavity between the transmission shaft (1) and the faucet seat (4); The rigid sealing member (7) includes a sealing seat (71), an outer wall surface of the sealing seat (71) and the faucet seat (4) are sealed via a static sealing structure (72), and an inner wall surface of the sealing seat (71) and the transmission shaft (1) are sealed via a dynamic sealing structure (73); The water nozzle (3) comprises a fixed water nozzle (31) and a movable water nozzle (32), wherein the fixed water nozzle (31) is used for being fixedly connected to the water nozzle seat (4), and the movable water nozzle (32) is connected between the fixed water nozzle (31) and the transmission shaft (1), and the movable water nozzle (32) is used for closing or opening the liquid flow channel between the fixed water nozzle (31) and the water nozzle seat (4); The second bearing (8) on the water nozzle (3) is not sealed and is connected to the water outlet cavity. It is in a floating state in the liquid and maintains high-pressure balance. The high-pressure fluid will generate pressure on the end of the transmission shaft (1) and the rigid seal along the fitting gap; The high-pressure fluid acts on the dynamic sealing structure and the end of the transmission shaft (1) along the fitting gap, and the fluid pressure acting on the end of the dynamic sealing structure squeezes and further compacts the dynamic sealing structure, thereby generating a radially tightening force that increases the rotational torque of the transmission shaft (1).

2. A sealing transmission device for improving the pressure bearing capacity of a downhole water nozzle according to claim 1, characterized in that: The static sealing structure (72) comprises a sealing ring, and a mounting groove for the sealing ring is provided on the faucet seat (4) and the sealing seat (71), and the sealing ring is sealingly connected in the mounting groove.

3. A sealing transmission device for improving the pressure bearing capacity of a downhole water nozzle according to claim 1, characterized in that: The dynamic sealing structure (73) includes a friction-resistant slip ring (731), the inner wall surface of the friction-resistant slip ring (731) contacts the outer wall surface of the transmission shaft (1), and the friction-resistant slip ring (731) is pressed onto the transmission shaft (1) through an elastic sealing ring (732), and the elastic sealing ring (732) is sealingly connected between the inner wall surface of the sealing seat (71) and the outer wall surface of the friction-resistant slip ring (731).

4. A sealing transmission device for improving the pressure bearing capacity of a downhole water nozzle according to claim 3, characterized in that: The longitudinal section of the friction-resistant slip ring (731) is in a "T" shape, the upper portion of the "T" is pressed against the inner wall surface of the sealing seat (71), and the lower portion of the "T" is pressed against the transmission shaft (1) through the elastic sealing ring (732).

5. The sealing transmission device for improving the pressure bearing capacity of a downhole water nozzle according to claim 1, characterized in that: The dynamic sealing structure (73) further comprises an air sealing member (733) arranged between the transmission shaft (1) and the sealing seat (71).

6. The sealing transmission device for improving the pressure bearing capacity of a downhole water nozzle according to claim 1, characterized in that: The first bearing (5) comprises a thrust bearing.

7. The sealing transmission device for improving the pressure bearing capacity of a downhole water nozzle according to claim 1, characterized in that: The second bearing (8) comprises a needle roller bearing.

8. The sealing transmission device for improving the pressure bearing capacity of a downhole water nozzle according to claim 1, characterized in that: The driving mechanism (2) comprises a motor.

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