A downhole multi-stage filtering anti-blocking device for water injection wells

Abstract

The utility model discloses a kind of downhole multistage filtering anti-blocking devices of injection well, belong to injection downhole tool technical field, including water pipe, upper adapter disc, lower adapter disc and sliding ring etc., the inner wall of the upper adapter disc is equipped with L type groove, the outer wall of the sliding ring is fixedly connected with clamping block, the sidewall inside of the upper adapter disc is provided with the elastic locking mechanism consisting of spring, limit disc and clamping ball, the clamping ball elastically abuts at the sidewall of the clamping block, by rotating pull rod, clamping block is slid and rotated in L type groove, so that clamping block and clamping ball realize quick unlocking and locking, to be able to quickly take out and replace filter core.The utility model is through the combination of L type groove and clamping ball, solved the existing downhole filtering assembly dismounting cumbersome, maintenance efficiency low problem, realized the quick replacement of multistage filtering structure and the convenient cleaning of bottom impurity.

Description

Technical Field

[0001] This utility model relates to the field of downhole tools for water injection wells, and in particular to a multi-stage downhole filtration and anti-clogging device for water injection wells. Background Technology

[0002] In the oil extraction industry, water is typically injected into oil wells to maintain reservoir pressure or for secondary oil displacement; this is known as water injection. The quality of the injected water is crucial to the reservoir's health. If the water contains excessive amounts of suspended solids, silt, or particulate matter, it can cause reservoir blockage, severely impacting the effectiveness of water injection and the lifespan of the oilfield.

[0003] Most existing water injection well filtration technologies employ surface filtration systems or simple screens or mesh cylinders for filtration downhole. However, surface filtration systems cannot completely eliminate secondary contaminants generated within the tubing or wellbore. For downhole filtration devices, the core challenge lies in achieving efficient, multi-stage filtration within the confined space of the wellbore, while ensuring ease of maintenance and replacement of filter elements in the downhole environment. Traditional downhole filtration devices typically use fixed threaded connections or complex mechanical locking mechanisms to secure the internal filter elements or screens. This necessitates lifting the entire device to the surface for cumbersome disassembly when filter elements become clogged or require replacement, resulting in time-consuming and costly maintenance. This is especially true in multi-stage filtration structures, where the increased number of components and structural complexity exponentially increase the difficulty of assembly and disassembly.

[0004] Therefore, this utility model proposes a downhole multi-stage filtration anti-clogging device for water injection wells to overcome the shortcomings of the prior art. Utility Model Content

[0005] To overcome the above shortcomings, this utility model provides a downhole multi-stage filtration anti-clogging device for water injection wells, aiming to improve the problems of cumbersome disassembly and assembly of internal filter elements, difficult replacement and maintenance, and inconvenient collection and cleaning of bottom impurities in existing downhole multi-stage filtration anti-clogging devices for water injection wells.

[0006] To achieve the above objectives, this utility model provides a downhole multi-stage filtration anti-clogging device for water injection wells, comprising: a water pipe, an upper receiving plate, a lower receiving plate and a sliding ring, as well as a tie rod, a filter element, an L-shaped groove, a locking block, a spring, a limiting plate and a locking ball.

[0007] The upper receiving plate is fixedly connected to the top of the water pipe, the lower receiving plate is fixedly connected to the bottom of the water pipe, and the sliding ring is slidably connected to the inner wall of the upper receiving plate. A filter element is fixedly installed inside the sliding ring, and a pull rod is fixedly connected to the top of the sliding ring.

[0008] The inner wall of the upper receiving plate has an L-shaped groove, and a locking block is fixedly connected to the outer wall of the sliding ring. The locking block slidably engages with the interior of the L-shaped groove. A blind hole is formed inside the side wall of the upper receiving plate. A spring, a limiting plate, and a locking ball are arranged sequentially from the inside to the outside inside the blind hole. A portion of the locking ball protrudes from the blind hole and abuts against the side wall of the locking block. The two ends of the spring abut against the bottom of the groove of the blind hole and the side wall of the limiting plate, respectively.

[0009] Preferably, a limiting ring is fixedly connected to the inner wall of the water pipe, and a filter screen ring is overlapped on the top surface of the limiting ring. The filter screen ring is located below the sliding ring, and the bottom end of the sliding ring abuts against the top surface of the filter screen ring, forming a two-stage filtration structure and ensuring the stable fixation of the filter screen ring.

[0010] Preferably, the bottom inner wall of the lower receiving plate is provided with an internal thread, the interior of the lower receiving plate is provided with a collection frame, the top outer wall of the collection frame is provided with an external thread that mates with the internal thread, and the collection frame is threadedly connected to the lower receiving plate through the external thread, which facilitates the independent disassembly and cleaning of the impurity collection frame.

[0011] Preferably, an intercepting mesh ring is fixedly connected to the inner wall of the bottom end of the collection frame, and the intercepting mesh ring is used to perform preliminary filtration of the fluid before it enters the water pipe.

[0012] Preferably, an auxiliary handle is fixedly connected to the outside of the bottom surface of the collection frame. The auxiliary handle is used to drive the collection frame to rotate relative to the lower receiving plate to assist in the thread engagement or disengagement operation.

[0013] Preferably, the L-shaped groove includes a vertical sliding groove extending along the axial direction and a transverse locking groove extending along the circumferential direction connected to the bottom end of the vertical sliding groove. The locking block can slide along the vertical sliding groove and rotate into the transverse locking groove, thus defining the specific path for locking and unlocking.

[0014] Preferably, the diameter of the limiting plate is larger than the outer diameter of the spring, and the limiting plate has an arc-shaped groove on the side facing the ball to accommodate the ball, thus ensuring the stability of the elastic thrust transmission.

[0015] Preferably, the outer diameter of the filter element is adapted to the inner diameter of the sliding ring, and the filter element is fixed inside the sliding ring by an interference fit, ensuring reliable installation of the filter element and sealing of the filter.

[0016] This utility model has the following beneficial effects: 1. In this utility model, by setting a quick locking and unlocking mechanism consisting of a sliding ring, a locking block, an L-shaped groove, a spring, a limiting plate, and a locking ball, the problem of cumbersome disassembly and assembly and low cleaning and replacement efficiency of the internal filter element components in the existing filter device is solved, and the effect of quickly replacing the multi-stage filter structure is achieved.

[0017] 2. This utility model solves the problem of filter ring loosening or side-flow leakage that may occur under the action of fluid by setting a limiting ring in the water pipe to support the filter ring and using the bottom end of the sliding ring to press against the filter ring in the locked state, thus achieving the effect of ensuring the stability and reliability of the filtration structure.

[0018] 3. This utility model solves the problems of insufficient filtration efficiency and easy clogging of a single filter layer by setting a multi-stage filtration structure consisting of an interception mesh ring, a filter mesh ring, and a filter element, thereby extending the service life of the filter element and enhancing the filtration and anti-clogging effect. Attached Figure Description

[0019] Figure 1 This is a three-dimensional schematic diagram of a multi-stage downhole filtration and anti-clogging device for a water injection well, as proposed in this utility model. Figure 2 This is an exploded structural diagram of the filter ring of a downhole multi-stage filtration anti-clogging device for a water injection well, as proposed in this utility model. Figure 3 for Figure 2 Enlarged view of point A in the middle; Figure 4 This is a schematic diagram of the collection frame structure of a downhole multi-stage filtration anti-clogging device for a water injection well, as proposed in this utility model.

[0020] Legend: 1. Water pipe; 101. Lower receiving plate; 102. Upper receiving plate; 103. L-shaped groove; 104. Spring; 105. Limiting plate; 106. Ball clamp; 2. Sliding ring; 201. Filter element; 202. Pull rod; 203. Clamping block; 3. Filter screen ring; 4. Limiting ring; 5. Collection frame; 501. Interception net ring; 502. Power handle. Detailed Implementation

[0021] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0022] Reference Figures 1-4This utility model provides a downhole multi-stage filtration anti-clogging device for water injection wells, which aims to solve the problems of cumbersome disassembly and assembly of internal filter elements in existing downhole filtration devices, difficulty in quick cleaning and replacement, and inconvenience in removing sedimented impurities at the bottom.

[0023] The downhole multi-stage filtration and anti-clogging device for the injection well includes a water pipe 1, an upper receiving plate 102 fixedly connected to the top of the water pipe 1, and a lower receiving plate 101 fixedly connected to the bottom of the water pipe 1. The water pipe 1 serves as the main body and core carrier of the entire device, used to carry the filtration components and guide the downhole fluid through. The upper receiving plate 102 and the lower receiving plate 101 serve as the connection and support structures at both ends of the device, integrating the various functional components together.

[0024] It also includes a sliding ring 2, which is slidably fitted onto the inner wall of the upper receiving plate 102, allowing the sliding ring 2 to move up and down and rotate in the axial direction of the water pipe 1. A filter element 201, serving as the main filter medium, is fixedly installed inside the sliding ring 2. A pull rod 202 is fixedly connected to the top of the sliding ring 2, extending upwards for external operation and lifting, thereby driving the sliding ring 2 to move and be disassembled.

[0025] To enable rapid locking and unlocking of the filter element 201 assembly, an L-shaped groove 103 is crucially provided on the inner wall of the upper receiving plate 102. Simultaneously, a locking block 203 is fixedly connected to the outer wall of the sliding ring 2 at a position corresponding to the L-shaped groove 103, and the locking block 203 slidably engages within the L-shaped groove 103. This engagement structure is key to achieving axial movement and circumferential locking of the assembly.

[0026] A blind hole for installing an elastic locking mechanism is provided inside the side wall of the upper receiving plate 102 at the position corresponding to the L-shaped groove 103. The internal structure of this blind hole is ingeniously designed, with a spring 104, a limiting plate 105, and a locking ball 106 arranged sequentially from the inside out. The spring 104 provides elastic restoring force, with its two ends abutting against the bottom of the blind hole and the side wall of the limiting plate 105, respectively. The limiting plate 105 is located between the spring 104 and the locking ball 106, transmitting the thrust of the spring 104 and limiting its movement. A portion of the locking ball 106 protrudes from the blind hole and elastically abuts against the side wall of the locking block 203. When the locking block 203 rotates to its position, the locking ball 106 engages with the locking block 203 under the thrust of the spring 104, achieving locking. Conversely, when the locking block 203 presses the locking ball 106, the locking ball 106 drives the limiting plate 105 to compress the spring 104, thereby releasing the locking and realizing the quick disassembly function of the filter assembly.

[0027] The system also includes a filter ring 3 and a collection frame 5. A limiting ring 4 is fixedly connected to the inner wall of the water pipe 1. The limiting ring 4 is circular, and the filter ring 3 overlaps its top surface. The filter ring 3 is the secondary filtration component of the device. It is located below the sliding ring 2, and the bottom end of the sliding ring 2 abuts against the top surface of the filter ring 3. The limiting ring 4 provides axial support and positioning for the filter ring 3. When the sliding ring 2 is locked, it uses its own weight and the locking force of the retaining ball 106 to axially press and fix the filter ring 3, ensuring that the filter ring 3 will not shift or leak under the action of fluid, thus guaranteeing the reliability of the secondary filtration.

[0028] In another preferred embodiment, to facilitate the cleaning of settled impurities, the bottom inner wall of the lower receiving plate 101 is provided with internal threads, and a collection frame 5 is provided inside the lower receiving plate 101. The collection frame 5 is the impurity settling and collection structure of the device, and its top outer wall is provided with external threads that mate with the internal threads. The collection frame 5 is threadedly connected to the lower receiving plate 101 through these external threads. This threaded connection method allows the collection frame 5 to be easily and quickly disassembled from the main structure.

[0029] In another preferred embodiment, an intercepting mesh ring 501 is fixedly connected to the inner wall of the bottom end of the collection frame 5. The intercepting mesh ring 501, as a first-stage coarse filtration structure, is set on the path of the fluid before it enters the water pipe 1, and is used to initially intercept large particulate impurities in the fluid, thereby reducing the filtration burden on the subsequent filter ring 3 and filter element 201.

[0030] In a preferred embodiment, an auxiliary handle 502 is fixedly connected to the outside of the bottom surface of the collection frame 5. The auxiliary handle 502 protrudes outward, which makes it convenient for the operator to rotate the collection frame 5 circumferentially when disassembling and assembling it underground or on the ground, thereby driving the collection frame 5 to rotate relative to the lower receiving plate 101, realizing the operation of thread engagement or disengagement, and making it convenient to remove the collection frame 5 for impurity cleaning.

[0031] In a preferred embodiment, the L-shaped groove 103 specifically includes a vertical sliding groove extending axially and a transverse locking groove extending circumferentially, connected to the bottom end of the vertical sliding groove. The vertical sliding groove guides the locking block 203 as it moves up and down axially, while the transverse locking groove positions and locks the locking block 203 during circumferential rotation. The locking block 203 can first slide along the vertical sliding groove, and then rotate circumferentially into the transverse locking groove to achieve final locking and positioning.

[0032] In a preferred embodiment, the diameter of the limiting plate 105 is designed to be larger than the outer diameter of the spring 104, ensuring that the limiting plate 105 can effectively transmit the compressive force of the spring 104 to the retaining ball 106. An arc-shaped groove is provided on the side of the limiting plate 105 facing the retaining ball 106 to accommodate a portion of the retaining ball 106, ensuring stable contact and force transmission between the limiting plate 105 and the retaining ball 106.

[0033] In a preferred embodiment, the outer diameter of the filter element 201 is matched with the inner diameter of the sliding ring 2. The filter element 201 is fixed inside the sliding ring 2 by an interference fit. This fit ensures that the filter element 201 will not loosen under fluid pressure, and the fluid can only pass through the filter holes of the filter element 201 without bypass leakage, thus ensuring the filtration effect.

[0034] Working principle: The main body of the device is composed of a water pipe 1, a lower receiving plate 101, and an upper receiving plate 102 integrated together. When it is necessary to remove and replace the filter element 201 inside the sliding ring 2 or the filter screen ring 3 below, the pull rod 202 connected to the top of the sliding ring 2 is rotated first, causing the sliding ring 2 and the locking block 203 fixedly connected to the outer wall of the sliding ring 2 to rotate circumferentially. During the rotation, the side wall of the locking block 203 applies a squeezing force to the locking ball 106 that protrudes into the blind hole. The locking ball 106 retracts inward and drives the limiting plate 105 to compress the spring 104, thereby releasing the locking state between the locking block 203 and the locking ball 106, allowing the locking block 203 to be diverted from the transverse slot of the L-shaped groove 103. Subsequently, pull the lever 202 upwards, causing the locking block 203 to slide upwards along the vertical groove of the L-shaped groove 103, thus removing the sliding ring 2, along with the internal filter element 201 and the overlapping filter screen ring 3 below, from the inside of the water pipe 1 as a whole. When the sliding ring 2 and filter screen ring 3 need to be reset, the limiting ring 4 fixedly connected to the inner wall of the water pipe 1 provides axial support and positioning for the bottom surface of the filter screen ring 3. The operator presses the lever 202 downwards, causing the locking block 203 to slide into place along the vertical groove. Then, the lever 202 is rotated, and the locking block 203 rotates into the horizontal locking groove. At this time, the locking ball 106 protrudes again under the reset thrust of the spring 104 and engages the locking block 203, locking the sliding ring 2. At the same time, the bottom end of the sliding ring 2 presses against the top surface of the filter screen ring 3, completing the quick replacement and reliable locking of the multi-layer filter structure. When the device is in use, the well water first undergoes a first-stage coarse filtration through an intercepting mesh ring 501 fixedly connected to the inner wall of the bottom of the collection frame 5. After this initial interception, the water flows into the water pipe 1 and passes through the filter mesh ring 3 overlapping the top surface of the limiting ring 4 for a second-stage filtration. It then passes through the filter element 201 fixedly installed inside the sliding ring 2 for a third-stage fine filtration. During the filtration process, the intercepted impurities settle under gravity and eventually fall and accumulate inside the collection frame 5 below.

[0035] When impurities accumulate in the collection frame 5 and need to be cleaned, the collection frame 5 is rotated by turning the auxiliary handle 502, which is fixedly connected to the outside of the bottom surface of the collection frame 5. Since the external thread on the outer wall of the top of the collection frame 5 and the internal thread on the inner wall of the bottom of the lower receiving plate 101 are engaged, the rotation operation allows the collection frame 5 to be unscrewed relative to the threads of the lower receiving plate 101 and removed, realizing convenient cleaning and discharge of settled impurities.

Claims

1. A downhole multi-stage filtration and anti-clogging device for a water injection well, comprising: The water pipe (1), upper receiving plate (102), lower receiving plate (101) and sliding ring (2) are characterized in that the upper receiving plate (102) is fixedly connected to the top end of the water pipe (1), the lower receiving plate (101) is fixedly connected to the bottom end of the water pipe (1), and the sliding ring (2) is slidably connected to the inner wall of the upper receiving plate (102); A filter element (201) is fixedly installed inside the sliding ring (2). A pull rod (202) is fixedly connected to the top of the sliding ring (2). An L-shaped groove (103) is opened on the inner wall of the upper receiving plate (102). A locking block (203) is fixedly connected to the outer wall of the sliding ring (2). The locking block (203) is slidably fitted inside the L-shaped groove (103). A blind hole is opened inside the side wall of the upper receiving plate (102). A spring (104), a limiting plate (105), and a locking ball (106) are arranged sequentially from the inside to the outside inside the blind hole. A part of the locking ball (106) protrudes from the blind hole and abuts against the side wall of the locking block (203). The two ends of the spring (104) abut against the bottom of the groove of the blind hole and the side wall of the limiting plate (105), respectively.

2. The downhole multi-stage filtration and anti-clogging device for water injection wells according to claim 1, characterized in that, A limiting ring (4) is fixedly connected to the inner wall of the water pipe (1). A filter ring (3) is attached to the top surface of the limiting ring (4). The filter ring (3) is located below the sliding ring (2), and the bottom end of the sliding ring (2) is pressed against the top surface of the filter ring (3).

3. The downhole multi-stage filtration and anti-clogging device for water injection wells according to claim 1, characterized in that, The lower receiving plate (101) has an internal thread on its bottom inner wall, and a collection frame (5) is provided inside the lower receiving plate (101). The collection frame (5) has an external thread on its top outer wall that matches the internal thread. The collection frame (5) is threadedly connected to the lower receiving plate (101) through the external thread.

4. The downhole multi-stage filtration and anti-clogging device for water injection wells according to claim 3, characterized in that, An intercepting net ring (501) is fixedly connected to the inner wall of the bottom end of the collection frame (5). The intercepting net ring (501) is used to perform preliminary filtration of the fluid before it enters the water pipe (1).

5. The downhole multi-stage filtration and anti-clogging device for water injection wells according to claim 3, characterized in that, An auxiliary handle (502) is fixedly connected to the outside of the bottom surface of the collection box (5), and the auxiliary handle (502) is used to drive the collection box (5) to rotate relative to the lower receiving plate (101).

6. The downhole multi-stage filtration and anti-clogging device for water injection wells according to claim 1, characterized in that, The L-shaped groove (103) includes a vertical sliding groove extending along the axial direction and a transverse locking groove extending along the circumferential direction connected to the bottom end of the vertical sliding groove. The locking block (203) can slide along the vertical sliding groove and rotate into the transverse locking groove.

7. The downhole multi-stage filtration and anti-clogging device for water injection wells according to claim 1, characterized in that, The diameter of the limiting disk (105) is larger than the outer diameter of the spring (104), and the limiting disk (105) has an arc-shaped groove on the side facing the ball (106) for accommodating the ball (106).

8. The downhole multi-stage filtration and anti-clogging device for water injection wells according to claim 1, characterized in that, The outer diameter of the filter element (201) is adapted to the inner diameter of the sliding ring (2), and the filter element (201) is fixed inside the sliding ring (2) by an interference fit.

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