Seal-testable backflow-preventing bridge type water distributor, underground separated layer water injection system and application

Abstract

The invention discloses a seal-examining backflow-preventing bridge type water distributor, an underground separated layer water injection system and application. The water distributor comprises a water distributor body, a seal examining assembly and a blanking plug assembly. Wherein a main channel and a plurality of bypass channels are formed in the axial direction of the water distributor body; a seal examining channel communicated with the main channel is formed in the radial direction of the water distributor body, and the seal examining assembly is located in the seal examining channel; the blanking plug assembly is arranged on the water distributor body and enables the main channel to be communicated with the outer side of the water distributor so as to achieve the backflow prevention function. The seal examining assembly comprises a first piston, an air bag, a fixing bolt and a supporting rod. The fixing bolt is fixed in the seal examining channel and connected with the supporting rod, and the supporting rod penetrates through the air bag in the vertical direction and limits the air bag in the vertical direction. The air bag is in interference fit with the seal examining channel, and the first piston is located in the seal examining channel, away from the main channel and matched with the air bag. According to the water distributor, only pressure conduction is carried out during seal examination, no annular liquid enters the water distributor, and seal examination of the water distributor is guaranteed.

Description

Technical Field

[0001] This invention relates to the field of oilfield water injection well technology, and in particular to a bridge-type water distributor with verifiable sealing and anti-backflow capability, a downhole stratified water injection system, and its application. Background Technology

[0002] The existing third-generation bridge-type wellbore injection technology combined with measurement and control linkage technology has become the main downhole wellbore injection technology, which has good adaptability to medium- and high-permeability reservoirs. However, in some sand-producing wells and oil-laden wells, sand or oil from the wellbore is easily spurted back into the tubing during measurement and control, causing obstruction. To address this, the oilfield developed a bridge-type stratified water distributor to prevent backflow, which allows water to be injected into the formation unidirectionally from the tubing. However, the inventors found in actual production applications that the existing bridge-type stratified water distributor cannot verify packer sealing or the sealing function fails quickly, indicating poor adaptability. Summary of the Invention

[0003] To address the problem of unverifiable backflow prevention packers in existing oilfield stratified water injection technology, and to ensure effective stratified water injection while improving technical reliability and adaptability, this invention provides a verifiable anti-backflow bridge-type water distributor, a downhole stratified water injection system, and its application.

[0004] In a first aspect, embodiments of the present invention provide a bridge-type water distributor with a seal-testable anti-backflow mechanism, which may include: a water distributor body, a seal-testing component, and a blocker component;

[0005] The water distributor body has a main channel and several bypass channels axially; the water distributor body has a sealing channel communicating with the main channel radially, and the sealing component is located in the sealing channel; the blocker component is disposed on the water distributor body and connects the main channel and the outside of the water distributor to achieve the backflow prevention function.

[0006] The sealing assembly may include: a first piston, an airbag, a fixing bolt, and a support rod; the fixing bolt is fixed in the sealing channel and connected to the support rod, the support rod passes vertically through the airbag and limits the vertical position of the airbag; the airbag is interference-fitted with the sealing channel, and the first piston is located in the sealing channel away from the main channel and cooperates with the airbag;

[0007] The first piston compresses the airbag under external force, and the airbag expands towards the main channel to compress the fluid sealed in the main channel. The sealing test is performed by the pressure change in the main channel.

[0008] In one embodiment, the sealing channel is connected to a bypass channel; the fixing bolt and the support rod are located in the bypass channel, and the airbag is located at the intersection of the bypass channel and the sealing channel.

[0009] In another embodiment, the seal verification assembly may further include: a second piston located in the seal verification channel near the main channel and cooperating with the airbag; the airbag inflates toward the main channel to act on the second piston, and the second piston compresses the fluid sealed in the main channel.

[0010] In another embodiment, the water distributor body is provided with an offset hole for accommodating the blocker assembly; the blocker assembly may include: a blocker body, a spring, a steel ball, a ball seat, a first sealing ring, and a second sealing ring;

[0011] The plug body and the ball seat are disposed within the offset hole. The first sealing ring and the second sealing ring are sleeved on the outside of the plug body, located between the inner wall of the plug body and the offset hole. The water distributor body has an inlet hole connecting the main channel and the plug body, and an outlet hole connecting the offset hole and the outside of the water distributor body. The end of the plug body is provided with a sand cap, and the plug body has a water nozzle. One end of the spring is limited on the water distributor body, and the other end cooperates with the steel ball.

[0012] When the pressure in the main channel is greater than the pressure outside the water distributor body, the fluid is ejected through the inlet hole, the sand cap, the blocker body and the water nozzle and acts on the steel ball to compress the steel ball. The steel ball separates from the ball seat and the fluid flows into the outside of the water distributor body through the outlet hole.

[0013] When the pressure in the main channel is less than the pressure outside the water distributor body, the steel ball abuts against the ball seat under the action of the spring to achieve the anti-backflow function.

[0014] In another embodiment, the water distributor may further include: a first sealing cup, a second sealing cup, a first pressure gauge, and a second pressure gauge;

[0015] The first sealing cup and the second sealing cup are located between the inlet and outlet of the bypass channel and on both sides of the sealing channel; the first pressure gauge is located in the area where the oil pipe connected to the water distributor is located, and the second pressure gauge is located between the first sealing cup and the second sealing cup;

[0016] The first sealing cup and the second sealing cup are used to seal the main channel; the first pressure gauge is used to detect the pressure inside the oil pipe, and the second pressure gauge is used to detect the annular pressure outside the oil pipe.

[0017] In another embodiment, the sealing assembly may further include a third sealing ring fitted over the outside of the support rod.

[0018] In a second aspect, embodiments of the present invention provide a downhole stratified water injection system, comprising: at least one verifiable anti-backflow bridge-type water distributor as described in the first aspect.

[0019] In another embodiment, the downhole stratified water injection system may further include: tubing, a first packer, and a second packer; the first packer, a water distributor, and the second packer are sequentially connected through the tubing.

[0020] In another embodiment, the downhole stratified water injection system may further include: a screen pipe and a test cable; the screen pipe is connected to the lower end of the tubing, and the first sealing cup, second sealing cup, first pressure gauge, and second pressure gauge in the water distributor are connected to a ground controller via the test cable.

[0021] Thirdly, embodiments of the present invention provide an application of the verifiable and anti-backflow bridge-type water distributor as described in the first aspect in a downhole stratified water injection system.

[0022] The beneficial effects of the above-mentioned technical solutions provided in the embodiments of the present invention include at least the following:

[0023] This invention provides a seal-testable anti-backflow bridge-type water distributor, a downhole stratified water injection system, and their applications. This water distributor utilizes the incompressible nature of liquids and the compressibility of gases to ensure that only pressure is transmitted during seal testing, preventing annular liquid from entering the water distributor. This guarantees the water distributor's sealability while avoiding blockage of the seal testing channel from affecting subsequent seal testing, resulting in higher reliability. Furthermore, it does not increase additional processing costs, making it highly economically feasible.

[0024] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description and the accompanying drawings.

[0025] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0026] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0027] Figure 1 This is one of the structural diagrams of the bridge-type water distributor with verifiable sealing and anti-backflow provided in the embodiments of the present invention;

[0028] Figure 2 This is the second structural diagram of the bridge-type water distributor with verifiable sealing and anti-backflow provided in the embodiments of the present invention;

[0029] Figure 3 This is a schematic diagram of the downhole layered water injection system provided in an embodiment of the present invention;

[0030] Figure 4 This is a horizontal cross-sectional view of the water distributor provided in an embodiment of the present invention;

[0031] 1-Water distributor; 2-Oil pipe; 3-First packer; 4-Second packer; 5-Screen pipe; 6-Test cable; 7-Hydraulic anchor;

[0032] 11-Water distributor body; 12-Seal verification assembly; 13-Blocker assembly; 14-First sealing cup; 15-Second sealing cup; 16-First pressure gauge; 17-Second pressure gauge;

[0033] 111-Main channel; 112-Bypass channel; 113-Seal inspection channel; 114-Offset hole; 115-Liquid inlet; 116-Liquid outlet;

[0034] 121-First piston; 122-Airbag; 123-Fixing bolt; 124-Support rod; 125-Second piston; 126-Third sealing ring;

[0035] 131-Blocker body; 132-Spring; 133-Steel ball; 134-Ball seat; 135-First sealing ring; 136-Second sealing ring; 137-Sand cap; 138-Water nozzle; 1121-Liquid inlet; 1122-Liquid outlet. Detailed Implementation

[0036] 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.

[0037] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," "outer," "far," "near," "front," and "rear," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this invention 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 invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0038] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" 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 of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0039] In view of the existing anti-backflow bridge-type stratified water distributors' inability to verify packer sealing or the rapid failure of the sealing function, and their poor adaptability, this invention is proposed to provide a sealable anti-backflow bridge-type water distributor, a downhole stratified water injection system, and its application that overcomes or at least partially solves the above problems.

[0040] This invention provides a bridge-type water distributor with verifiable sealing and backflow prevention, as described in the following embodiment. Figures 1-4 As shown, the water distributor 1 may include: a water distributor body 11, a sealing assembly 12, and a plugging assembly 13; wherein, the water distributor body 11 has a main channel 111 and several bypass channels 112 axially; the water distributor body 11 has a sealing channel 113 communicating with the main channel 111 radially, and the sealing assembly 12 is located in the sealing channel 113; the plugging assembly 13 is disposed on the water distributor body 11 and connects the main channel 111 to the outside of the water distributor 1 to achieve the anti-backflow function; the sealing assembly 12 may include: a first piston 121, an air bladder 122, a fixing bolt 123, and A support rod 124 and a fixing bolt 123 are fixed in the sealing channel 113 and connected to the support rod 124. The support rod 124 vertically penetrates the airbag 122 and limits the vertical movement of the airbag 122. The airbag 122 is interference-fitted with the sealing channel 113. The first piston 121 is located in the sealing channel 113 away from the main channel 111 and cooperates with the airbag 122. The first piston 121 compresses the airbag 122 under the action of external force. The airbag 122 expands towards the main channel 111 to compress the fluid sealed in the main channel 111. The sealing test is carried out by the pressure change in the main channel 111.

[0041] The water distributor provided in this embodiment of the invention utilizes the incompressible properties of liquids and the compressibility of gases to achieve pressure transmission only during seal testing, without any annular liquid entering the water distributor. This ensures the water distributor can be sealed while preventing blockage of the seal testing channel from affecting subsequent seal testing, resulting in higher reliability. Furthermore, it does not increase additional processing costs, making it highly economically feasible.

[0042] It should be noted that the sealing channel in this embodiment of the invention is a channel that is radially connected to the main channel and has some axial space. In specific implementations, the sealing channel may have a certain space in its axial direction to accommodate the fixing bolts and support rods, and its axial direction may not necessarily be connected to the main channel. The aforementioned airbag (compressible) is made of an elastic material, which has high temperature and high pressure resistance and is interference-sealed with the interior of the sealing channel. In this embodiment, the first piston can be an integral structure with the airbag or a separate structure, as long as the first piston can compress the airbag and expand it towards the main channel under external force. This embodiment of the invention does not specifically limit the specific structure and connection relationship of the first piston and the airbag. It should also be noted that the water distributor in this embodiment has too many bypass channels; for example, a common water distributor has three bypass channels.

[0043] The working process (packer sealing verification process) of the packer provided in this embodiment of the invention is described in detail below:

[0044] Reference Figure 3As shown, a two-stage, two-section well is used as an example for explanation. After the injection well operation is completed, the packer of the whole well needs to be checked after a period of trial injection to determine whether each layer has been injected separately. The test cable 6 is connected to the sealing component 12 and lowered into the wellbore to connect with the water distributor body 11. After successful connection, the ground transmits a signal to open the first sealing cup 14 and the second sealing cup 15, sealing the water outlet part of the water distributor body 11 from top to bottom. Since the water nozzle 138 of the plug assembly 13 is in the open state, the data recorded by the second pressure gauge 17 can be identified as the external pressure data, that is, the annular pressure data between the first packer 3 and the second packer 4, while the first pressure gauge 16 records the pressure data inside the tubing. When the pressure is increased through the wellhead, that is, when the pressure is increased into the tubing 2, water can enter from the inlet 1121 of the bypass channel 112 of the water distributor body 11, and the liquid from the outlet 1122 of the bypass channel 112 continues to flow into the lowered main channel 111, without affecting the normal injection of other layers. When the wellhead is pressurized, the pressure inside tubing 2 increases. Consequently, the pressure of water exiting from distributor 1 also increases. If the second packer 4 is not sealed, water will seep into the upper layers after passing through it. The pressure will be transmitted to the second pressure gauge 17 via distributor 1, causing the pressure in the second pressure gauge 17 to rise synchronously, indicating that the second packer 4 is not sealed. If the second packer 4 is sealed, the pressure inside tubing 2 will increase, meaning the pressure in the first pressure gauge 16 will increase, while the pressure in the second pressure gauge 17 will remain unchanged. Similarly, packer sealing tests can be performed on multiple sections. Whether the casing packer (first packer 3) is sealed can be determined by observing the casing pressure at the wellhead. Absence of casing pressure indicates that the first packer 3 is not sealed; conversely, absence of casing pressure indicates it is sealed.

[0045] Specifically, refer to Figure 3 As shown, during the sealing test, the packers (first packer 3 and second packer 4) seal the plug assembly 13 from top to bottom. The sealing cups (first sealing cup 14 and second sealing cup 15) are located between the inlet 1121 and outlet 1122 of the bypass channel 112, separating the plug assembly 13 from the bypass channel 112. Water can continue to be injected into the lower layers through the bypass channel 112, and the sealing test does not affect the normal injection of other layers.

[0046] Reference Figure 2As shown, during water injection, the pressure inside the sealing channel 113 is higher than the annular pressure. This pressure, passing through the sealing channel 113, pushes the first piston 121 to compress the airbag 122. The airbag 122 expands towards the main channel 111. With the support rod 124 fixing it, the airbag 122 is confined within the sealing channel 113. If the packer leaks during sealing, water enters the sealing space from the sealing channel 113, pushing the first piston 121 to compress the airbag 122. The airbag 122 expands towards the water distributor 1, pushing the second piston 125 inwards. When the sealing instrument has sealed the sealing channel from top to bottom and the anti-backflow function has been activated, there is a closed space between the sealing cups (first sealing cup 14 and second sealing cup 15). Since water is incompressible, the inward movement of the airbag 122 or the second piston 125 will inevitably increase the pressure value of the second pressure gauge 17. Therefore, the values ​​of the first pressure gauge 16 and the second pressure gauge 17 on the sealing assembly 12 will rise synchronously. Conversely, if the packer is sealed, only the first pressure gauge 16 will rise, and the second pressure gauge 17 will stabilize at a certain value and then stop changing.

[0047] The water distributor described in this embodiment of the invention has the following advantages: First, it has an anti-backflow function after injection is stopped, preventing annular fluid or formation backflow of sand, sticky oil, etc. into the oil pipe, which could cause obstruction or failure of testing and adjustment; second, it has a bypass channel, so that normal water injection in other layers is not affected during normal testing or seal verification; and third, it has a seal verification function, good adaptability, and cannot cause blockage due to excessive liquid, and has a short effective period.

[0048] In an optional embodiment, due to the small size and axial thickness of the water distributor 1, its processing space is limited. In this embodiment, the sealing channel 113 is connected to a bypass channel 112; the fixing bolt 123 and the support rod 124 are located in the bypass channel 112, and the airbag 122 is located at the intersection of the bypass channel 112 and the sealing channel 113. This design ensures the overall structural stability of the water distributor, achieves acceptance functionality, and, since there are other bypass channels, does not affect the continued injection of water to the lower layers.

[0049] In another alternative embodiment, refer to Figure 2 As shown, the sealing assembly 12 may further include a second piston 125, which is located in the sealing channel 113 near the main channel 111 and cooperates with the airbag 122. The airbag 122 expands towards the main channel 111 to act on the second piston 125, and the second piston 125 compresses the fluid sealed in the main channel 111. In this embodiment, by setting the second piston, the limitation of the airbag's movement stroke is overcome. The formation of the sealed fluid by the compression of the second piston is improved, so as to clearly detect the change in the pressure data of the second pressure gauge.

[0050] In another optional embodiment, the water distributor body 11 is provided with an offset hole 114 for accommodating the blocker assembly 13; the blocker assembly 13 may include: a blocker body 131, a spring 132, a steel ball 133, a ball seat 134, a first sealing ring 135, and a second sealing ring 136; the blocker body 131 and the ball seat 134 are disposed within the offset hole 114, and the first sealing ring 135 and the second sealing ring 136 are sleeved on the outside of the blocker body 131 between the inner walls of the blocker body 131 and the offset hole 114; the water distributor body 11 is provided with an inlet hole 115 connecting the main channel 111 and the blocker body 131, and an outlet hole 116 connecting the offset hole 114 and the outside of the water distributor body 11; the blocker body 131... A sand cap 137 is provided at the end of the plug 131, and a water nozzle 138 is provided on the plug body 131. One end of the spring 132 is limited on the water distributor body 11, and the other end cooperates with the steel ball 133. When the pressure in the main channel 111 is greater than the pressure outside the water distributor body 11, the fluid is ejected through the inlet hole 115, the sand cap 137, the plug body 131 and the water nozzle 138 and acts on the steel ball 133 to compress the steel ball 133. The steel ball 133 separates from the ball seat 134, and the fluid flows into the outside of the water distributor body 11 through the outlet hole 116. When the pressure in the main channel 111 is less than the pressure outside the water distributor body 11, the steel ball 133 abuts against the ball seat 134 under the action of the spring 132 to achieve the anti-backflow function.

[0051] In this embodiment, the water distributor is equipped with a plugging component to prevent backflow. Water is injected from the oil pipe, enters the deflector 114 through the inlet 115, passes through the sand cap 137 into the plugging body 131, and is sprayed out from the nozzle 138. This water acts on the steel ball 133, and through the compression spring 132, pushes open the ball seat 134, spraying out from the outlet 116 and into the annular space of the casing, injecting into the formation. When injection stops, if the pressure inside and outside the oil pipe reaches equilibrium or the external pressure is greater than the internal pressure, the spring 132 rebounds, pushing the steel ball 133 back to the ball seat 134, achieving a seal and preventing formation or annular fluid from entering the pipe, thus avoiding difficulties in testing, adjusting, and verifying the seal.

[0052] In another alternative embodiment, refer to Figure 3As shown, the water distributor 1 may further include: a first sealing cup 14, a second sealing cup 15, a first pressure gauge 16, and a second pressure gauge 17; the first sealing cup 14 and the second sealing cup 15 are located between the inlet 1121 and the outlet 1122 of the bypass channel 112, and are located on both sides of the sealing channel 113; the first pressure gauge 16 is located in the area where the oil pipe 2 is connected to the water distributor 1, and the second pressure gauge 17 is located between the first sealing cup 14 and the second sealing cup 15; the first sealing cup 14 and the second sealing cup 15 are used to seal the main channel 111; the first pressure gauge 16 is used to detect the pressure inside the oil pipe 2, and the second pressure gauge 17 is used to detect the annular pressure outside the oil pipe 2.

[0053] In this embodiment of the invention, the main channel is sealed by a first sealing cup and a second sealing cup. The changes in pressure data inside the oil pipe and annular pressure data are detected by a first pressure gauge and a second pressure gauge, respectively, to perform a seal verification test.

[0054] In another alternative embodiment, refer to Figure 2 As shown, the sealing assembly 12 may further include a third sealing ring 126 sleeved on the outside of the support rod 124. In this embodiment, the third sealing ring isolates the sealing channel (bypass channel) from the main channel through an interference seal, ensuring that fluid is not injected into the lowered formation from the bypass channel, thereby preventing damage to the vertical stability of the airbag.

[0055] Based on the same inventive concept, this invention also provides a downhole stratified water injection system, referring to... Figure 3 As shown, the system may include at least one of the above-mentioned verifiable anti-backflow bridge-type water distributors 1.

[0056] In another alternative embodiment, refer to Figure 3 As shown, the downhole stratified water injection system may also include: tubing 2, a first packer 3, and a second packer 4; the first packer 3, a water distributor 1, and the second packer 4 are connected sequentially via tubing 2. For details, please refer to... Figure 3 As shown, the downhole stratified water injection system may further include: a screen pipe 5 and a test cable 6; the screen pipe 5 is connected to the lower end of the tubing 2, and the first sealing cup 14, the second sealing cup 15, the first pressure gauge 16, and the second pressure gauge 17 in the water distributor 1 are connected to a surface controller (not shown in the figure) via the test cable 6. More specifically, the system may also include a hydraulic anchor 7 to secure the tubing 2.

[0057] Based on the same inventive concept, this embodiment of the invention also provides an application of the above-mentioned verifiable anti-backflow bridge-type water distributor 1 in a downhole stratified water injection system.

[0058] The principle by which the downhole stratified water injection system and the verifiable anti-backflow bridge-type water distributor described in the embodiments of the present invention solve the problem in the downhole stratified water injection system is similar to that of the aforementioned verifiable anti-backflow bridge-type water distributor. Therefore, its implementation can refer to the implementation of the aforementioned water distributor, and the repeated parts will not be described again.

[0059] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. This disclosure is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this disclosure is limited only by the appended claims. Thus, if these modifications and variations of the invention fall within the scope of the claims of the invention and their equivalents, the invention is also intended to include these modifications and variations.

Claims

1. A bridge-type water distributor with verifiable sealing and anti-backflow capability, characterized in that, include: Water distributor body, seal verification assembly and blocker assembly; The water distributor body has a main channel and several bypass channels axially; the water distributor body has a sealing channel communicating with the main channel radially, and the sealing component is located in the sealing channel; the blocker component is disposed on the water distributor body and connects the main channel and the outside of the water distributor to achieve the backflow prevention function. The sealing assembly includes: a first piston, an airbag, a fixing bolt, and a support rod; the fixing bolt is fixed in the sealing channel and connected to the support rod, the support rod vertically passes through the airbag and limits the vertical movement of the airbag; the airbag is interference-fitted with the sealing channel, and the first piston is located in the sealing channel away from the main channel and cooperates with the airbag; The first piston compresses the airbag under external force, and the airbag expands towards the main channel to compress the fluid sealed in the main channel. The sealing test is performed by the pressure change in the main channel.

2. The water distributor according to claim 1, characterized in that, The sealing inspection channel is connected to one of the side channels; the fixing bolt and the support rod are located in the side channel, and the airbag is located at the intersection of the side channel and the sealing inspection channel.

3. The water distributor according to claim 1, characterized in that, The sealing assembly further includes a second piston located in the sealing channel near the main channel and cooperating with the airbag; the airbag expands toward the main channel to act on the second piston, and the second piston compresses the fluid sealed in the main channel.

4. The water distributor according to any one of claims 1 to 3, characterized in that, The water distributor body is provided with an offset hole to accommodate the blocker assembly; the blocker assembly includes: a blocker body, a spring, a steel ball, a ball seat, a first sealing ring, and a second sealing ring; The plug body and the ball seat are disposed within the offset hole. The first sealing ring and the second sealing ring are sleeved on the outside of the plug body, located between the inner wall of the plug body and the offset hole. The water distributor body has an inlet hole connecting the main channel and the plug body, and an outlet hole connecting the offset hole and the outside of the water distributor body. The end of the plug body is provided with a sand cap, and the plug body has a water nozzle. One end of the spring is limited on the water distributor body, and the other end cooperates with the steel ball. When the pressure in the main channel is greater than the pressure outside the water distributor body, the fluid is ejected through the inlet hole, the sand cap, the blocker body and the water nozzle and acts on the steel ball to compress the steel ball. The steel ball separates from the ball seat and the fluid flows into the outside of the water distributor body through the outlet hole. When the pressure in the main channel is less than the pressure outside the water distributor body, the steel ball abuts against the ball seat under the action of the spring to achieve the anti-backflow function.

5. The water distributor according to any one of claims 1 to 3, characterized in that, The water distributor also includes: a first sealing cup, a second sealing cup, a first pressure gauge, and a second pressure gauge; The first sealing cup and the second sealing cup are located between the inlet and outlet of the bypass channel and on both sides of the sealing channel; the first pressure gauge is located in the area where the oil pipe connected to the water distributor is located, and the second pressure gauge is located between the first sealing cup and the second sealing cup; The first sealing cup and the second sealing cup are used to seal the main channel; the first pressure gauge is used to detect the pressure inside the oil pipe, and the second pressure gauge is used to detect the annular pressure outside the oil pipe.

6. The water distributor according to any one of claims 1 to 3, characterized in that, The sealing assembly also includes a third sealing ring fitted on the outside of the support rod.

7. A downhole stratified water injection system, characterized in that, include: At least one verifiable anti-backflow bridge-type water distributor as described in any one of claims 1 to 6.

8. The system according to claim 7, characterized in that, The downhole stratified water injection system further includes: tubing, a first packer, and a second packer; the first packer, a water distributor, and the second packer are connected sequentially through the tubing.

9. The system according to claim 8, characterized in that, The downhole stratified water injection system also includes: a screen pipe and a test cable; the screen pipe is connected to the lower end of the tubing, and the first sealing cup, the second sealing cup, the first pressure gauge, and the second pressure gauge in the water distributor are connected to a ground controller via the test cable.

10. The application of a verifiable anti-backflow bridge-type water distributor as described in any one of claims 1 to 6 in a downhole stratified water injection system.

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