Double-layer reinforced filter screen pipe

Abstract

The present application relates to sand control screen pipe technical field, especially in kind of double layer reinforced filter screen pipe. Including: pipe body, the outer side of pipe body is limited sliding connection with upper fixed part and is fixed with lower fixed part, a plurality of first elastic strips and a plurality of second elastic strips are fixed between upper fixed part and lower fixed part, symmetric and equidistant distribution of embedding groove are arranged on the first elastic strip and the second elastic strip, in vertical direction, the arc-shaped part is arranged between the adjacent two embedding grooves on the first elastic strip and the second elastic strip.Between the adjacent two embedding grooves, the length of the first elastic strip and the second elastic strip in the vertical direction can be changed, that is, the gap width of the two arc-shaped parts corresponding to each other on the first elastic strip and the second elastic strip can be changed, so that the filtering accuracy is changed, the filtering precision of the filter hole is adjusted, the difficulty of screen selection and management is reduced, the number of screen pipes equipped for single well is reduced, and the production cost is reduced.

Description

Technical Field

[0001] This invention relates to the field of sand control screen pipe technology, and in particular to a double-layer reinforced filter screen pipe. Background Technology

[0002] Filter screens, also known as sand filters or oil well sand filters, are key downhole tools installed in the reservoir section of wells during oil and gas extraction. They effectively block the intrusion of formation sand and gravel while ensuring the smooth flow of crude oil into the wellbore through physical filtration. Traditional slotted screens and wire-wound screens have fixed filtration precision after production. However, the median sand particle size varies in different oil wells within the same area, resulting in different filtration precision requirements for different wells. Therefore, it is necessary to select screens based on the actual operating conditions of each well, which undoubtedly increases the difficulty of screen selection and management. In addition, for oil wells where the sand and gravel distribution of the formation is prone to change, the required filtration precision will also change at different stages of production. This leads to the need to equip the same oil well with screens of various filtration precisions, increasing production costs. Summary of the Invention

[0003] This invention provides a double-layer reinforced filter screen tube to overcome the shortcomings of traditional screen tubes, which have high selection and management difficulties due to fixed filtration accuracy, and high production costs in actual use.

[0004] The technical solution is as follows: a double-layer reinforced filter screen tube, comprising: a tube body, on which uniformly distributed filter holes are provided; an upper fixing member is slidably connected to the outer side of the tube body and a lower fixing member is fixedly connected thereto; a plurality of first elastic strips and a plurality of second elastic strips are fixedly connected between the upper fixing member and the lower fixing member; the number of first elastic strips and second elastic strips are the same and they are staggered; symmetrical and equidistantly distributed interlocking grooves are provided on both the first elastic strips and the second elastic strips; the interlocking grooves on the first elastic strips interlock with the interlocking grooves on adjacent second elastic strips; in the vertical direction, arc-shaped portions are provided between two adjacent interlocking grooves on the first elastic strip and between two adjacent interlocking grooves on the second elastic strip; the arc-shaped portions on the first elastic strip and the arc-shaped portions at the same height on the second elastic strip protrude in opposite directions; the gap between two corresponding arc-shaped portions on the first elastic strip and the second elastic strip is used to filter sand and gravel in the fluid; an adjustment component is provided inside the tube body for adjusting the width of the gap between two corresponding arc-shaped portions.

[0005] Furthermore, the tube body is slidably connected with equidistantly distributed positioning rings. The number of positioning rings is half the number of fitting grooves on a single first elastic strip. All the positioning rings are located between the upper fixing member and the lower fixing member. The positioning ring is fixed with two symmetrically distributed support rings. The two support rings on the same positioning ring respectively limit the circumferential movement of all the first elastic strips and all the second elastic strips.

[0006] Furthermore, the adjustment component includes: a positioning member fixed to the upper fixing member; a sliding groove is provided on the tube body near the positioning member; the positioning member slides within the sliding groove; a trigger ring is provided inside the tube body; the trigger ring is provided with a positioning rod slidably connected to the positioning member; two nuts are threadedly connected to the positioning rod near the positioning member; the two nuts are respectively located on both sides of the positioning member.

[0007] Furthermore, the tube body is fixedly connected to an installation ring, the positioning rod is in contact with the installation ring, the installation ring limits the trigger ring through the positioning rod, and a ring of constant force springs is installed on the installation ring. The end of the constant force spring is fixedly connected to the trigger ring, and the trigger ring is slidably connected to the tube body.

[0008] Furthermore, the elastic coefficient of the constant force spring is greater than the elastic coefficients of the first elastic strip and the second elastic strip.

[0009] Furthermore, the constant force spring contacts the inner wall of the tube and is used to block the filter holes corresponding in the vertical direction. The positioning rod is slidably connected to the trigger ring, and there is friction between the trigger ring and the positioning rod. A limit ring is provided on the positioning rod, and the positioning rod limits the trigger ring through the limit ring. An arc-shaped flow channel is provided on the trigger ring, and the arc-shaped flow channel is used to connect the inner and outer sides of the trigger ring.

[0010] Furthermore, both the upper and lower fixing members are provided with receiving ring grooves on their opposing sides. A compression ring is provided in the receiving ring groove. The compression ring and the receiving ring groove together compress and fix the first elastic strip and the second elastic strip. The compression ring is threadedly connected to a fixing bolt. The upper and lower fixing members are rotatably connected to the adjacent fixing bolts, respectively.

[0011] Furthermore, both the inner and outer sides of the extrusion ring are provided with uniformly distributed annular positioning grooves, and the positioning grooves on the inner side of the extrusion ring correspond one-to-one with the second elastic strips, and the positioning grooves on the outer side of the extrusion ring correspond one-to-one with the first elastic strips. All the positioning grooves are used to position adjacent first elastic strips and adjacent second elastic strips respectively.

[0012] Furthermore, a limiting spring is fixedly connected in the sliding groove. The limiting spring has two symmetrically distributed curved extrusion parts on the side near the lower fixing member. The minimum distance between the two curved extrusion parts is less than the diameter of the positioning member. The two curved extrusion parts are used together to limit the positioning member.

[0013] Furthermore, the sliding channel is provided with two symmetrically distributed relief grooves, which are used to store the corresponding bending extrusion parts.

[0014] Overall, compared with the prior art, the above-described technical solutions conceived by this invention can achieve the following beneficial effects: By changing the length of the first elastic strip and the second elastic strip in the vertical direction, this invention can change the gap width of the two corresponding arc-shaped parts on the first elastic strip and the second elastic strip, thereby changing the filtration accuracy. Through the filter holes with adjustable filtration accuracy, the difficulty of selecting and managing screen pipes is reduced, while the number of screen pipes equipped in a single well is reduced, thus reducing production costs.

[0015] By using positioning rings and support rings to provide segmented support and limit the first and second elastic strips, the interlocking strength and bending strength of the first and second elastic strips are enhanced, thereby increasing the stability of the gap between the two corresponding arc-shaped parts.

[0016] By sealing the tube body with a pressure ball and a trigger ring, and coordinating with external pressure, the trigger ring drives the fixed part to move downward. At the same time, the fluid inside the tube flows in reverse from the filter holes. While controlling the increase of the gap between the two corresponding arc-shaped parts, the backflow of the fluid helps to dislodge the sand and gravel blocking the gap between the two arc-shaped parts. In this way, the screen tube can be unblocked without removing it, saving the unblocking steps of the screen tube.

[0017] By using a constant force spring to block the filter holes, the backflowing fluid inside the tube is guided to flow back into the filter holes through the arc-shaped flow channel. This concentrates the backflowing fluid on the local filter holes corresponding to the arc-shaped flow channel, enhancing the backflow force on the local filter holes and the gaps in the local arc-shaped section, and improving the unblocking effect of the screen tube. Attached Figure Description

[0018] Figure 1 This is a three-dimensional structural diagram of the present invention; Figure 2 This is a three-dimensional structural diagram of the tube body and upper fixing member of the present invention; Figure 3 Appendix to this invention Figure 2 Enlarged view of point A in the middle; Figure 4 This is a three-dimensional structural diagram of the tube body and support ring of the present invention; Figure 5 This is a three-dimensional structural diagram of the trigger ring and mounting ring of the present invention; Figure 6 This is a three-dimensional structural diagram of the positioning element and positioning rod of the present invention; Figure 7 This is an exploded view of the upper fixing member, lower fixing member, and extrusion ring of the present invention; Figure 8 This is a three-dimensional structural diagram of the tube body and positioning element of the present invention; Figure 9 Appendix to this invention Figure 8 Enlarged view of point B in the middle.

[0019] In the attached drawings, the following labels are used: 1-pipe body, 101-filter hole, 2-upper fixing component, 3-lower fixing component, 4-first elastic strip, 401-fitting groove, 5-second elastic strip, 6-positioning ring, 7-support ring, 8-positioning component, 801-sliding channel, 9-trigger ring, 901-limiting ring, 902-arc-shaped flow channel, 10-positioning rod, 11-nut, 12-mounting ring, 13-constant force spring, 14-compression ring, 141-accommodating ring groove, 142-positioning groove, 15-fixing bolt, 16-limiting elastic component, 161-bending compression part, 162-relief groove. Detailed Implementation

[0020] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, they are provided so that the invention will be thorough and complete, and the concept of the exemplary embodiments will be fully conveyed to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and therefore their detailed description will be omitted.

[0021] Example 1 This embodiment discloses a double-layer reinforced filter screen tube, which solves the problems of high selection and management difficulty and high production cost in actual use of traditional screen tubes due to the fixed filtration accuracy.

[0022] See Figures 1 to 4A double-layer reinforced filter screen tube includes: a tube body 1, on which uniformly distributed filter holes 101 are provided; an upper fixing member 2 is slidably connected to the outer side of the tube body 1 and a lower fixing member 3 is fixedly connected thereto; a plurality of first elastic strips 4 and a plurality of second elastic strips 5 are fixedly connected between the upper fixing member 2 and the lower fixing member 3; the number of first elastic strips 4 and second elastic strips 5 is the same and they are staggered; each of the first elastic strips 4 and second elastic strips 5 is provided with symmetrically and equidistantly distributed interlocking grooves 401, and the number of interlocking grooves 401 corresponding to the first elastic strip 4 is equal to the number of interlocking grooves 401 corresponding to the second elastic strip 5; the interlocking grooves 401 on the first elastic strip 4 are connected to the adjacent second elastic strips 5. The interlocking grooves 401 on the elastic strip 5 interlock with each other. Through the interlocking of the first elastic strip 4 and the second elastic strip 5, an arc-shaped portion is formed between two adjacent interlocking grooves 401 on the first elastic strip 4 and between two adjacent interlocking grooves 401 on the second elastic strip 5 in the vertical direction. The arc-shaped portion on the first elastic strip 4 and the arc-shaped portion corresponding to the same height on the second elastic strip 5 have opposite protrusion directions. The gap between the two corresponding arc-shaped portions on the first elastic strip 4 and the second elastic strip 5 is used to filter the sand and gravel in the fluid. An adjustment component is provided inside the tube body 1 to adjust the gap width between the two corresponding arc-shaped portions on the first elastic strip 4 and the second elastic strip 5.

[0023] The above setup enables the change of the gap width between the two corresponding arc-shaped parts on the first elastic strip 4 and the second elastic strip 5 by altering the length of the first elastic strip 4 and the second elastic strip 5 in the vertical direction. This changes the filtration accuracy. The adjustable filtration accuracy filter holes 101 reduce the difficulty of selecting and managing the screen pipes, while also reducing the number of screen pipes required per well and lowering production costs.

[0024] See Figure 3 and Figure 4 Positioning rings 6 are slidably connected to the tube body 1 at equal intervals. The number of positioning rings 6 is half the number of fitting grooves 401 on a single first elastic strip 4. All positioning rings 6 are located between the upper fixing member 2 and the lower fixing member 3. Two support rings 7 are fixedly connected to the positioning rings 6 and are symmetrically distributed. The support rings 7 are located between the first elastic strip 4 and the second elastic strip 5 and are used to limit the minimum gap between the arc-shaped part on the first elastic strip 4 and the corresponding arc-shaped part on the second elastic strip 5. The two support rings 7 on the same positioning ring 6 are used to circumferentially limit all the first elastic strips 4 and all the second elastic strips 5 at the fitting points at the same height as the positioning ring 6.

[0025] The above setup enables the positioning ring 6 and the support ring 7 to provide segmented support and limit the first elastic strip 4 and the second elastic strip 5, thereby strengthening the interlocking strength and bending resistance of the first elastic strip 4 and the second elastic strip 5, and thus enhancing the stability of the gap between the two corresponding arc-shaped parts.

[0026] See Figures 4 to 6 The adjustment assembly includes: a positioning element 8, which is fixed to the upper fixing element 2. The positioning element 8 can be multiple evenly distributed in a ring to ensure that the upper fixing element 2 is subjected to uniform force in the circumference. Here, there are three evenly distributed positioning elements 8 in a ring. The upper part of the tube body 1 is provided with three evenly distributed sliding grooves 801 in a ring. The positioning element 8 slides within the sliding grooves 801. The upper part of the tube body 1 is provided with a trigger ring 9. The trigger ring 9 is provided with a positioning rod 10 that is slidably connected to the positioning element 8. The upper part of the positioning rod 10 is provided with a thread. Two nuts 11 are threadedly connected to the positioning rod 10 near the positioning element 8. The two nuts 11 are located on both sides of the positioning element 8.

[0027] The above setup enables the adjustment of the filtration accuracy by changing the positional relationship between the nut 11 and the positioning rod 10, thereby changing the relative position between the positioning member 8 and the tube body 1, thus adjusting the distance between the upper fixing member 2 and the lower fixing member 3, and consequently changing the length of the first elastic strip 4 and the second elastic strip 5, as well as the gap width of the two corresponding arc-shaped parts.

[0028] It should be noted that in this embodiment, the setting relationship between the trigger ring 9 and the tube body 1 can be regarded as a fixed connection, and the setting relationship between the positioning rod 10 and the trigger ring 9 can be regarded as a fixed connection. It should also be noted that the first elastic strip 4 and the second elastic strip 5 are straight strips in the free state. When the first elastic strip 4 and the second elastic strip 5 are fitted together, arc-shaped portions are formed on both the first elastic strip 4 and the second elastic strip 5. When the first elastic strip 4 and the second elastic strip 5 are fitted together and are not pulled by the upper fixing member 2 and the lower fixing member 3, the positioning member 8 is located at the lower limit position of the sliding groove 801, and the upper fixing member 2 is also located at the lower limit position. Therefore, the first elastic strip 4 and the second elastic strip 5 in the attached figure are in the state after being pulled vertically.

[0029] The process for adjusting the filtration accuracy is as follows: Before the device is lowered into the well, select the gap width of the arc-shaped part according to the median gravel content in the well. Then, use a tool to rotate the nut 11, causing the nut 11 to move the adjacent positioning part 8 upward. The positioning part 8 moves the upper fixing part 2 upward, increasing the distance between the upper fixing part 2 and the lower fixing part 3. This stretches the first elastic strip 4 and the second elastic strip 5, reducing the gap between the two corresponding arc-shaped parts, thus improving the filtration accuracy. Conversely, the operation to reduce the filtration accuracy is the same.

[0030] Example 2 This embodiment is a further optimization based on Embodiment 1.

[0031] See Figure 5 and Figure 6The tube body 1 is fixedly connected to an installation ring 12. The upper end of the positioning rod 10 contacts the installation ring 12 to limit the upper limit position of the positioning rod 10 and the trigger ring 9. The trigger ring 9 is slidably connected to the tube body 1. The trigger ring 9 slides up and down along the tube body 1 by cooperating with the pressure ball (soluble material). A ring-shaped constant force spring 13 is installed on the installation ring 12. The end of the constant force spring 13 is fixedly connected to the trigger ring 9. The elastic coefficient of the constant force spring 13 is greater than the elastic coefficient of the first elastic strip 4 and the elastic coefficient of the second elastic strip 5. During the normal sand filtration stage, the trigger ring 9 is kept in the upper limit position by the traction of the constant force spring 13 and the limiting of the installation ring 12, thus keeping the distance between the upper fixing part 2 and the lower fixing part 3 stable.

[0032] The above setup enables the tube body 1 to be blocked by the pressure ball and the trigger ring 9, and with the external pressure operation, the trigger ring 9 drives the upper fixing part 2 to move down. At the same time, the fluid in the tube body 1 flows in the reverse direction from the filter hole 101. While controlling the gap between the two corresponding arc-shaped parts to increase, the backflow of the fluid helps to dislodge the sand and gravel blocking the gap between the two arc-shaped parts. In this way, the screen tube can be unblocked without removing the screen tube, saving the unblocking steps of the screen tube.

[0033] It should be noted that in this embodiment, the trigger ring 9 is located below the filter hole 101, while in subsequent embodiments, the trigger ring 9 is located above the filter hole 101.

[0034] When dredging is required, a soluble pressure-absorbing ball is inserted into the pipe body 1. After the pressure-absorbing ball falls to the upper end face of the trigger ring 9, a seal is formed. Then, pressure is applied through the wellhead, pushing the trigger ring 9 to slide downward against the tension of the constant force spring 13, thereby causing the upper fixing part 2 to move down and increase the filter gap. After the dredging is completed, the pressure-absorbing ball gradually dissolves under the temperature at the bottom of the well or under a specific chemical environment, restoring the internal channel of the pipe body 1. The trigger ring 9, positioning rod 10, positioning part 8 and upper fixing part 2 move upward and reset under the tension of the constant force spring 13.

[0035] Example 3 This embodiment is a further optimization based on embodiment 2.

[0036] See Figure 5 and Figure 6The constant force spring 13 contacts the inner wall of the tube body 1 and is used to block the corresponding filter hole 101 in the vertical direction. The positioning rod 10 is slidably connected to the trigger ring 9, and there is friction between the trigger ring 9 and the positioning rod 10. This friction is sufficient to overcome the sum of the elastic forces of all the first elastic strips 4 and all the second elastic strips 5, so that when the trigger ring 9 moves down, it will first drive the positioning rod 10 down, which will then deform the first elastic strips 4 and the second elastic strips 5. After the positioning member 8 moves to the sliding groove 801, When the trigger ring 9 reaches its lower limit position, it slides relative to the positioning rod 10 as the trigger ring 9 moves downward. A limit ring 901 is provided on the positioning rod 10, which limits the trigger ring 9 to its upper limit position. An arc-shaped flow channel 902 is provided on the trigger ring 9, which connects the inner and outer sides of the trigger ring 9. During the movement of the trigger ring 9 along the tube body 1, the arc-shaped flow channel 902 can connect with the corresponding filter hole 101.

[0037] The above setup enables the constant force spring 13 to block the filter hole 101, guiding the backflowing fluid in the tube body 1 to flow into the filter hole 101 after passing through the arc-shaped flow channel 902. This concentrates the backflowing fluid on the local filter hole 101 corresponding to the arc-shaped flow channel 902, enhancing the backflow force on the local filter hole 101 and the gap of the local arc-shaped part, and improving the unblocking effect of the screen tube.

[0038] Example 4 This embodiment is a further optimization based on embodiment 3.

[0039] See Figures 5 to 7 Both the upper fixing member 2 and the lower fixing member 3 have receiving annular grooves 141 on their opposing sides. The inner diameter of the two receiving annular grooves 141 gradually decreases and the outer diameter gradually increases as they approach each other. A compression ring 14 is provided inside the receiving annular groove 141. The inner diameter of the two compression rings 14 gradually decreases and the outer diameter gradually increases as they approach each other. The compression ring 14 and the receiving annular groove 141 together compress and fix the first elastic strip 4 and the second elastic strip 5. The compression ring 14 is threadedly connected to a fixing bolt 15. The upper fixing member 2 and the lower fixing member 3 are rotatably connected to the adjacent fixing bolts 15, respectively.

[0040] See Figure 7 The inner and outer sides of the compression ring 14 are provided with uniformly distributed annular positioning grooves 142. The positioning grooves 142 on the inner side of the compression ring 14 correspond one-to-one with the second elastic strips 5, and the positioning grooves 142 on the outer side of the compression ring 14 correspond one-to-one with the first elastic strips 4. The positioning grooves 142 on the inner and outer sides are used to position the adjacent second elastic strips 5 and the adjacent first elastic strips 4, respectively. During the process of compression and fixing the first elastic strips 4 and the second elastic strips 5, the positioning grooves 142 help stabilize the position of the first elastic strips 4 and the second elastic strips 5 in the vertical direction.

[0041] Example 5 This embodiment is a further optimization based on embodiment 4.

[0042] See Figure 4 , Figure 8 and Figure 9 A limiting spring 16 is fixedly connected inside the sliding groove 801. A protrusion is provided in the middle of the upper side of the limiting spring 16. The protrusion is embedded in the tube body 1 and fixedly connected to the tube body 1. A bending extrusion part 161 is provided on the opposite side of the lower part of the limiting spring 16. The minimum distance between the two bending extrusion parts 161 is less than the diameter of the positioning part 8. The minimum distance between the two bending extrusion parts 161 after being extruded and deformed is equal to the diameter of the positioning part 8. The two bending extrusion parts 161 are used together to limit the positioning part 8. The elastic coefficient of the constant force spring 13 is greater than the elastic coefficient of the bending extrusion part 161.

[0043] The above configuration enables the positioning member 8 to accumulate elastic potential energy during reset movement by limiting the positioning member 8 through the bending and pressing part 161, thereby enabling the positioning member 8 to reset quickly and drive the first elastic strip 4 and the second elastic strip 5 to vibrate, thereby causing the gravel between the first elastic strip 4 and the second elastic strip 5 to fall off, thus improving the unblocking effect.

[0044] See Figure 9 The sliding channel 801 is provided with two symmetrically distributed relief grooves 162, which are used to store the corresponding bending extrusion part 161.

[0045] During the unblocking operation, the trigger ring 9, under the pressure inside the sleeve and the elastic force of the first elastic strip 4 and the second elastic strip 5, overcomes the tension of the constant force spring 13, causing the positioning member 8 to move downward. When the positioning member 8 contacts the bending extrusion part 161, the positioning member 8 will drive the bending extrusion part 161 to move downward, causing the arc-shaped part on the upper part of the limiting spring 16 to bend. When the bending extrusion part 161 corresponds to the relief groove 162, the positioning member 8 squeezes the bending extrusion part 161 into the corresponding relief groove 162, so that the positioning member 8 can pass over the bending extrusion part 161 without squeezing the bending extrusion part 161 to deform, reducing the resistance of the positioning member 8 moving downward. After the positioning member 8 passes over the bending extrusion part 161, the limiting spring 16 returns to its original state under its own elasticity.

[0046] After the dredging operation is completed, the pressure inside the well casing is reduced, and during the process of the positioning element 8 moving upward and resetting, when the positioning element 8 contacts the bending and squeezing part 161, in this state, the sum of the downward force of the casing pressure on the trigger ring 9, the downward force of the bending and squeezing part 161 on the positioning element 8, and the elastic force of the first elastic strip 4 and the second elastic strip 5 is greater than the tension of all the constant force springs 13. Therefore, at this time, the positioning element 8, the trigger ring 9, and the positioning rod 10 all temporarily stop moving until the casing pressure returns to the state before pressurization. Under the tension of the constant force spring 13, the trigger ring 9 and the positioning element 8 overcome the elastic force of the bending and squeezing part 161 and the elastic force of the first elastic strip 4 and the second elastic strip 5 and move upward. This increases the speed of the positioning element 8 resetting and moving, causing the first elastic strip 4 and the second elastic strip 5 to deform rapidly and vibrate during resetting, thus causing the gravel adhering between the first elastic strip 4 and the second elastic strip 5 to fall off.

[0047] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. A double-layer reinforced filter screen tube, characterized in that it comprises: The tube body (1) is provided with uniformly distributed filter holes (101). An upper fixing member (2) is slidably connected to the outer side of the tube body (1) and a lower fixing member (3) is fixedly connected thereto. A plurality of first elastic strips (4) and a plurality of second elastic strips (5) are fixedly connected between the upper fixing member (2) and the lower fixing member (3). The number of first elastic strips (4) and second elastic strips (5) is the same and they are staggered. Symmetrical and equidistantly distributed interlocking grooves (401) are provided on both the first elastic strips (4) and the second elastic strips (5). The interlocking grooves (401) on the first elastic strips (4) are connected to the adjacent second elastic strips (401). The fitting grooves (401) on the first elastic strip (4) are fitted together. In the vertical direction, there are arc-shaped parts between two adjacent fitting grooves (401) on the first elastic strip (4) and between two adjacent fitting grooves (401) on the second elastic strip (5). The arc-shaped parts on the first elastic strip (4) and the arc-shaped parts corresponding to the same height on the second elastic strip (5) have opposite protrusion directions. The gap between the two corresponding arc-shaped parts on the first elastic strip (4) and the second elastic strip (5) is used to filter the sand and gravel in the fluid. An adjustment component for adjusting the gap width between the two corresponding arc-shaped parts is provided inside the tube body (1).

2. The double-layer reinforced filter screen tube according to claim 1, characterized in that, The tube body (1) is slidably connected with equidistantly distributed positioning rings (6). The number of positioning rings (6) is half the number of fitting grooves (401) on a single first elastic strip (4). All the positioning rings (6) are located between the upper fixing member (2) and the lower fixing member (3). The positioning rings (6) are fixed with two symmetrically distributed support rings (7). The two support rings (7) on the same positioning ring (6) respectively limit the circumferential movement of all the first elastic strips (4) and all the second elastic strips (5).

3. The double-layer reinforced filter screen tube according to claim 1, characterized in that, The adjustment component includes: A positioning component (8) is fixed to the upper fixing component (2). A sliding groove (801) is provided on the tube body (1) near the positioning component (8). The positioning component (8) slides within the sliding groove (801). A trigger ring (9) is provided inside the tube body (1). The trigger ring (9) is provided with a positioning rod (10) that is slidably connected to the positioning component (8). Two nuts (11) are threadedly connected to the positioning rod (10) near the positioning component (8). The two nuts (11) are located on both sides of the positioning component (8).

4. The double-layer reinforced filter screen tube according to claim 3, characterized in that, The tube body (1) is fixedly connected to an installation ring (12), the positioning rod (10) is in contact with the installation ring (12), the installation ring (12) limits the trigger ring (9) through the positioning rod (10), a ring-shaped constant force spring (13) is installed on the installation ring (12), the end of the constant force spring (13) is fixedly connected to the trigger ring (9), and the trigger ring (9) is slidably connected to the tube body (1).

5. The double-layer reinforced filter screen tube according to claim 4, characterized in that, The elastic coefficient of the constant force spring (13) is greater than that of the first elastic bar (4) and the second elastic bar (5).

6. The double-layer reinforced filter screen tube according to claim 4, characterized in that, The constant force spring (13) contacts the inner wall of the tube (1) and is used to block the filter hole (101) corresponding in the vertical direction. The positioning rod (10) is slidably connected to the trigger ring (9), and there is friction between the trigger ring (9) and the positioning rod (10). A limit ring (901) is provided on the positioning rod (10), and the positioning rod (10) limits the trigger ring (9) through the limit ring (901). An arc-shaped flow channel (902) is provided on the trigger ring (9), and the arc-shaped flow channel (902) is used to connect the inner and outer sides of the trigger ring (9).

7. The double-layer reinforced filter screen tube according to claim 3, characterized in that, The upper fixing member (2) and the lower fixing member (3) are provided with receiving ring grooves (141) on their opposite sides. A compression ring (14) is provided in the receiving ring groove (141). The compression ring (14) and the receiving ring groove (141) together compress and fix the first elastic strip (4) and the second elastic strip (5). The compression ring (14) is threadedly connected to a fixing bolt (15). The upper fixing member (2) and the lower fixing member (3) are respectively rotatably connected to the adjacent fixing bolt (15).

8. The double-layer reinforced filter screen tube according to claim 7, characterized in that, The inner and outer sides of the extrusion ring (14) are provided with uniformly distributed annular positioning grooves (142). The positioning grooves (142) on the inner side of the extrusion ring (14) correspond one-to-one with the second elastic strip (5), and the positioning grooves (142) on the outer side of the extrusion ring (14) correspond one-to-one with the first elastic strip (4). All the positioning grooves (142) are used to position the adjacent first elastic strip (4) and the adjacent second elastic strip (5).

9. The double-layer reinforced filter screen tube according to claim 7, characterized in that, A limiting spring (16) is fixedly connected in the sliding groove (801). The limiting spring (16) has two symmetrically distributed curved extrusion parts (161) on the side near the lower fixing part (3). The minimum distance between the two curved extrusion parts (161) is less than the diameter of the positioning part (8). The two curved extrusion parts (161) are used together to limit the positioning part (8).

10. The double-layer reinforced filter screen tube according to claim 9, characterized in that, The sliding through groove (801) is provided with two symmetrically distributed relief grooves (162), which are used to store the corresponding bending extrusion part (161).

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