A pressure-opened floating screen tube

Abstract

The present invention discloses a pressure-opened floating screen pipe, which relates to the technical field of oil and gas extraction. The filtering mechanism includes a coupling, a base pipe, an upper end ring, a filter sleeve and a lower end ring. A first flow channel is formed between the filter sleeve and the base pipe, and a first flow groove extending in the axial direction is arranged on the inner wall of the lower end ring; the floating mechanism includes an outer protective sleeve, a connector, a center pipe, a gasket, a sealing sleeve, a lower joint, a blind pipe short section and a plurality of switching components. A second flow channel is formed between the connector and the outer protective sleeve, an annular protrusion is arranged on the center pipe, and a plurality of water-permeable through holes are arranged on the annular protrusion. A third flow channel is formed between the annular protrusion and the outer protective sleeve, and a plurality of axial through holes are arranged on the sealing sleeve along the circumferential direction, and a switching component is installed in each axial through hole. The device reduces the friction resistance of the screen pipe when it is lowered into a large displacement horizontal well, and solves the problem that the screen pipe is difficult to lower due to the large inclination, long stable inclination section and large friction resistance of the wellbore in the large displacement horizontal well.

Description

Technical Field

[0001] The invention relates to the technical field of oil and natural gas exploitation, in particular to a pressure-opening floating screen pipe. Background Art

[0002] The completion string is lowered to the predetermined depth, which is an important factor for the successful completion of the large-displacement horizontal well screen. The conventional screen running method will lead to greater friction and difficulty in running. There is an urgent need for a completion screen suitable for running in large-displacement horizontal wells to minimize the impact of friction on the string running. Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides a pressure-opened floating screen pipe, which reduces the friction resistance when the screen pipe is lowered into a large-displacement horizontal well, and solves the problem that the large-displacement horizontal well has a large inclination, a long stable inclination section and a large wellbore friction resistance, which causes the screen pipe to be difficult to lower.

[0004] To achieve the above object, the present invention provides the following solutions:

[0005] The present invention provides a pressure-opening floating screen pipe, comprising a filtering mechanism and a floating mechanism, wherein the filtering mechanism comprises a coupling, a base pipe, an upper end ring, a filter sleeve and a lower end ring, wherein the coupling is connected to the upper end of the base pipe, the upper end ring, the filter sleeve and the lower end ring are sequentially connected from top to bottom, the upper end ring and the lower end ring are fixed on the base pipe, a first flow channel is formed between the filter sleeve and the base pipe, and a first flow groove extending in an axial direction is arranged on the inner wall of the lower end ring; the floating mechanism comprises an outer protective sleeve, a connector, a center pipe, a gasket, a sealing sleeve, a lower joint, a blind pipe short section and a plurality of switching components, the lower end of the base pipe is connected to the center pipe through the connector, and the lower end of the center pipe is sequentially connected to the The lower joint and the blind pipe short section, the upper end and the lower end of the outer protective sleeve are respectively connected to the lower end ring and the lower joint, a second flow channel is formed between the connecting head and the outer protective sleeve, an annular protrusion is provided on the center tube, a plurality of water-permeable through holes are provided on the annular protrusion, a third flow channel is formed between the annular protrusion and the outer protective sleeve, the gasket and the sealing sleeve are sequentially sleeved on the center tube from top to bottom, the upper end of the gasket contacts with the connecting head, the lower end of the sealing sleeve contacts with the annular protrusion, a plurality of axial through holes are circumferentially provided on the sealing sleeve, each of the axial through holes is installed with a switching component, and the switching component is used to close or connect the second flow channel with the third flow channel.

[0006] Preferably, the filter sleeve comprises an outer sleeve, a filter screen, a guide screen and an inner support sleeve which are arranged in sequence from the outside to the inside, the filter screen, the guide screen and the inner support sleeve are fixedly connected in sequence, a first annular mounting portion is arranged at the lower end of the outer wall of the upper end ring, a second annular mounting portion is arranged at the upper end of the outer wall of the lower end ring, the filter screen is fixed on the inner walls of the first annular mounting portion and the second annular mounting portion, and the outer sleeve is fixed on the outer walls of the first annular mounting portion and the second annular mounting portion.

[0007] Preferably, the outer sheath is a cylindrical plate on which a plurality of circular holes are arranged; the filter net and the guide net are both mat-type woven nets; the inner support sleeve includes a plurality of transverse ribs evenly distributed along the axial direction and a plurality of longitudinal ribs spirally wound along the circumferential direction, and the plurality of longitudinal ribs are welded to the inside of the plurality of transverse ribs.

[0008] Preferably, a plurality of the first flow grooves are circumferentially arranged on the inner wall of the lower end ring, a plurality of the second flow grooves are circumferentially arranged on the outer wall of the connector, and the second flow grooves are extended along the axial direction of the connector.

[0009] Preferably, the switching assembly includes a locking claw ball seat, a steel ball and a shear pin, the locking claw ball seat is installed in the axial through hole, the locking claw ball seat includes a cylindrical rod and a locking claw, the upper end of the cylindrical rod is provided with a first radial hole, the shear pin is used to be installed in the first radial hole, an axial mounting groove is provided inside the cylindrical rod, the axial mounting groove passes through the bottom surface of the cylindrical rod, the axial mounting groove includes a first circular groove, a conical groove and a second circular groove connected in sequence from top to bottom, the inner diameter of the first circular groove is smaller than the diameter of the steel ball, the inner diameter of the second circular groove is larger than the diameter of the steel ball, a liquid inlet hole is provided on the cylindrical rod, the liquid inlet hole is connected to the first circular groove, and the lower end of the cylindrical rod is connected to the locking claw.

[0010] Preferably, a second radial hole is provided at the upper end of the axial through hole, the shear pin is used to be installed in the second radial hole, a locking groove is provided in the middle of the inner wall of the axial through hole, an annular groove is provided on the upper part of the inner wall of the axial through hole, the annular groove is provided between the second radial hole and the locking groove, and the annular groove is used to install a sealing ring.

[0011] Preferably, a strong magnetic component is installed on the outer side of the upper end of the lower joint.

[0012] Preferably, a plurality of the water-permeable through holes are evenly arranged along the circumference of the annular protrusion, and the water-permeable through holes are waist-shaped holes, and the width of the waist-shaped holes is smaller than the diameter of the steel ball.

[0013] Preferably, the base pipe is threadedly connected to the upper end inside the connector, and the center pipe is threadedly connected to the lower end inside the connector; the lower end of the outer protective sleeve is fixed to the lower joint, and the upper end of the outer protective sleeve is sleeved on the outside of the lower end ring, a sealing ring is provided between the outer protective sleeve and the lower end ring, and a sealing ring is provided between the outer protective sleeve and the sealing sleeve.

[0014] Compared with the prior art, the present invention has achieved the following technical effects:

[0015] The pressure-opened floating screen provided by the present invention comprises a filtering mechanism and a floating mechanism, wherein the filtering mechanism comprises a coupling, a base pipe, an upper end ring, a filtering sleeve and a lower end ring, and the floating mechanism comprises an outer protective sleeve, a connector, a central pipe, a gasket, a sealing sleeve, a lower joint, a blind pipe short section and a plurality of switching components, wherein a plurality of axial through holes are arranged circumferentially on the sealing sleeve, and a switching component is installed in each axial through hole, and the switching component is used to close or connect the second flow channel with the third flow channel. The floating mechanism is connected with the filtering mechanism as a sealing mechanism, so as to ensure that the external drilling fluid cannot enter the base pipe during the lowering process of the screen, and the air or low-density drilling fluid pre-placed in the base pipe is used to increase the lowering buoyancy and reduce the lowering gravity of the screen during the lowering, thereby greatly reducing the friction resistance of the screen when it is lowered in a large displacement horizontal well, and solving the problem that the conventional screen is difficult to lower due to the large inclination, long stable inclination section and large borehole friction resistance of the large displacement horizontal well. After it is in place, the floating mechanism is activated by pressing, that is, the switching component is moved by pressing, the second flow channel and the third flow channel are connected, and the production fluid can enter the interior of the base pipe through the filtering mechanism and the floating mechanism. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 A schematic diagram of the structure of a pressure-opening floating screen tube provided by the present invention;

[0018] Figure 2 A schematic diagram of the structure of the filtering mechanism in the pressure-opening floating screen tube provided by the present invention;

[0019] Figure 3 A schematic diagram of the structure of the floating mechanism in the pressure-opening floating screen tube provided by the present invention;

[0020] Figure 4 A schematic diagram of the structure of a filter sleeve in a pressure-opened floating screen tube provided by the present invention;

[0021] Figure 5 A schematic diagram of the structure of an inner support sleeve in a pressure-opening floating screen provided by the present invention;

[0022] Figure 6 A cross-sectional view of an inner support sleeve in a pressure-opening floating screen provided by the present invention;

[0023] Figure 7 A schematic diagram of the structure of the lower end ring in the pressure-opening floating screen tube provided by the present invention;

[0024] Figure 8 for Figure 7 Sectional view along AA direction;

[0025] Fig. 9 A schematic diagram of the structure of a connector in a pressure-opening floating screen tube provided by the present invention;

[0026] Fig.10 for Fig. 9 Sectional view along CC direction;

[0027] Fig.11 A schematic diagram of the structure of a locking claw ball seat in a pressure-opening floating screen tube provided by the present invention;

[0028] Fig.12 A schematic diagram of the structure of a sealing sleeve in a pressure-opening floating screen tube provided by the present invention;

[0029] Fig.13 for Fig.12 Cross-sectional view along the BB direction;

[0030] Fig.14 A schematic diagram of the flow state of the pressure-opening floating screen tube provided by the present invention after the floating mechanism is activated;

[0031] Fig.15 A schematic diagram of the state of the locking claw ball seat when the floating mechanism of the pressure-opening floating screen tube provided by the present invention is not activated;

[0032] Fig.16 A schematic diagram of the state of the locking claw ball seat after the floating mechanism of the pressure-opening floating screen tube provided by the present invention is activated.

[0033] Description of reference numerals: 100, pressure-opened floating screen; 1, coupling; 2, base pipe; 3, upper end ring; 4, filter sleeve; 401, outer sleeve; 402, filter screen; 403, guide net; 404, inner support sleeve; 4041, transverse rib; 4042, longitudinal rib; 5, lower end ring; 501, first flow groove; 6, outer protective sleeve; 7, connector; 701, second flow groove; 8, center pipe; 801, annular protrusion; 802, water-permeable through hole; 9, gasket; 10, shear pin; 11, sealing sleeve; 1101 , axial through hole; 1102, second radial hole; 1103, locking groove; 12, locking claw ball seat; 1201, cylindrical rod; 1202, first radial hole; 1203, locking claw; 1204, first circular groove; 1205, conical groove; 1206, second circular groove; 1207, liquid inlet hole; 13, steel ball; 14, lower joint; 1401, strong magnetic component; 15, blind pipe short section; 16, first flow channel; 17, second flow channel; 18, third flow channel; 19, first annular mounting portion; 20, second annular mounting portion. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] The purpose of the present invention is to provide a pressure-opened floating screen pipe, which reduces the friction resistance when the screen pipe is lowered into a large-displacement horizontal well, and solves the problem that the large-displacement horizontal well has a large inclination, a long stable inclination section and a large wellbore friction resistance, which causes the screen pipe to be difficult to lower.

[0036] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0037] like Figure 1-Figure 3As shown, this embodiment provides a pressure-opening floating screen pipe 100, including a filtering mechanism and a floating mechanism, the filtering mechanism includes a coupling 1, a base pipe 2, an upper end ring 3, a filter sleeve 4 and a lower end ring 5, the coupling 1 is connected to the upper end of the base pipe 2, the upper end ring 3, the filter sleeve 4 and the lower end ring 5 are connected in sequence from top to bottom, the upper end ring 3 and the lower end ring 5 are fixed on the base pipe 2, a first flow channel 16 is formed between the filter sleeve 4 and the base pipe 2, and a first flow groove 501 extending in the axial direction is provided on the inner wall of the lower end ring 5. The base pipe 2 in this embodiment adopts a standard oil casing and is not perforated; the floating mechanism includes an outer protective sleeve 6, a connector 7, a center pipe 8, a gasket 9, a sealing sleeve 11, a lower joint 14, a blind pipe short section 15 and a plurality of switching components, the lower end of the base pipe 2 is connected to the center pipe 8 through the connector 7, and the lower end of the center pipe 8 is connected to the lower joints in sequence. 14 and a blind pipe nipple 15, the upper and lower ends of the outer protective sleeve 6 are connected to the lower end ring 5 and the lower joint 14 respectively, a second flow channel 17 is formed between the connector 7 and the outer protective sleeve 6, an annular protrusion 801 is provided on the center pipe 8, a plurality of water-permeable through holes 802 are provided on the annular protrusion 801, a third flow channel 18 is formed between the annular protrusion 801 and the outer protective sleeve 6, a gasket 9 and a sealing sleeve 11 are sequentially sleeved on the center pipe 8 from top to bottom, the upper end of the gasket 9 contacts the connector 7, and the lower end of the sealing sleeve 11 contacts the annular protrusion 801. Specifically, the thickness of the gasket 9 is less than the thickness of the sealing sleeve 11, and a plurality of axial through holes 1101 are provided on the sealing sleeve 11 along the circumferential direction, and a switching assembly is installed in each axial through hole 1101, and the switching assembly is used to close or connect the second flow channel 17 and the third flow channel 18. In the up and down directions defined in this embodiment, one end of the coupling 1 is the upper end, and the blind pipe nipple 15 is the lower end.

[0038] The floating mechanism is connected to the filtering mechanism as a sealing mechanism, ensuring that the external drilling fluid cannot enter the base pipe 2 during the lowering process of the screen. The air or low-density drilling fluid pre-placed in the base pipe 2 is used to increase the lowering buoyancy and reduce the lowering gravity of the screen during lowering, thereby greatly reducing the friction resistance of the screen when lowering in a large displacement horizontal well, solving the problem of difficulty in lowering conventional screens due to the large inclination, long stable inclination section and large borehole friction resistance of large displacement horizontal wells. After being in place, the floating mechanism is activated by pressure, that is, the switching component is moved by pressure, the second flow channel 17 and the third flow channel 18 are connected, and the production fluid can enter the base pipe 2 through the filtering mechanism and the floating mechanism. Specifically, the production fluid enters the first flow channel 16 from the filter sleeve 4, and then enters the central pipe 8 through the first circulation groove 501, the second flow channel 17, the axial through hole 1101 of the sealing sleeve 11, the third flow channel 18 and the water-permeable through hole 802 in sequence, and then enters the base pipe 2 from the central pipe 8.

[0039] like Figure 4As shown, the filter sleeve 4 includes an outer sleeve 401, a filter screen 402, a guide net 403 and an inner support sleeve 404 which are sequentially arranged from the outside to the inside. The filter screen 402, the guide net 403 and the inner support sleeve 404 are sequentially fixedly connected. A first annular mounting portion 19 is arranged at the lower end of the outer wall of the upper end ring 3, and a second annular mounting portion 20 is arranged at the upper end of the outer wall of the lower end ring 5. The filter screen 402 is fixed to the inner walls of the first annular mounting portion 19 and the second annular mounting portion 20, and the outer sleeve 401 is fixed to the outer walls of the first annular mounting portion 19 and the second annular mounting portion 20. Specifically, the filter screen 402 and the outer sleeve 401 are welded to the first annular mounting portion 19 and the second annular mounting portion 20, and the upper end ring 3 and the lower end ring 5 are welded to the base pipe 2.

[0040] In this specific embodiment, the outer sheath 401 is a cylindrical plate with a plurality of circular holes, and the outer sheath 401 is made of 304 stainless steel. The filter net 402 and the guide net 403 are both mat-type woven nets, and the filter net 402 and the guide net 403 are both made of 316L stainless steel. Figure 5 and Figure 6 As shown, the inner support sleeve 404 includes a plurality of transverse ribs 4041 evenly distributed along the axial direction and a plurality of longitudinal ribs 4042 spirally wound along the circumferential direction. The plurality of longitudinal ribs 4042 are welded to the inside of the plurality of transverse ribs 4041 to ensure the flow channel of the fluid along the base pipe 2. The inner support sleeve 404 in this embodiment is a wire-wound skeleton structure, which can support the guide net 403 and the filter net 402.

[0041] like Figure 7 and Figure 8 As shown, a plurality of first flow grooves 501 are circumferentially arranged on the inner wall of the lower end ring 5, and the protruding portion relative to the first flow grooves 501 is welded to the base pipe 2, which can both support the lower end ring 5 and ensure the flow channel, so that the first flow channel 16 and the second flow channel 17 can be connected.

[0042] like Fig. 9 and Fig.10 As shown, a plurality of second flow grooves 701 are circumferentially arranged on the outer wall of the connector 7. The second flow grooves 701 are extended along the axial direction of the connector 7 to increase the flow channel between the connector and the outer protective sleeve 6, thereby increasing the flow area and enhancing fluidity.

[0043] The switching assembly includes a claw ball seat 12, a steel ball 13 and a shear pin 10. The claw ball seat 12 is installed in the axial through hole 1101. Fig.11As shown, the locking claw ball seat 12 includes a cylindrical rod 1201 and a locking claw 1203. A first radial hole 1202 is provided at the upper end of the cylindrical rod 1201. The shear pin 10 is used to be installed in the first radial hole 1202. An axial mounting groove is provided inside the cylindrical rod 1201. The axial mounting groove passes through the bottom surface of the cylindrical rod 1201. The axial mounting groove includes a first circular groove 1204, a conical groove 1205 and a second circular groove 1206 connected in sequence from top to bottom. The inner diameter of the first circular groove 1204 is smaller than the diameter of the steel ball 13, and the inner diameter of the second circular groove 1206 is larger than the diameter of the steel ball 13. The conical groove 1205 is the sealing surface of the steel ball 13. A liquid inlet hole 1207 is provided on the cylindrical rod 1201. The liquid inlet hole 1207 is connected to the first circular groove 1204. The lower end of the cylindrical rod 1201 is connected to the locking claw 1203.

[0044] Specifically, the locking claw 1203 includes a plurality of locking plates evenly distributed along the circumference of the cylindrical rod 1201, there are gaps between adjacent locking plates, the upper end of the locking plate is flush with the outer wall of the cylindrical rod 1201, and an arc-shaped plate is provided at the lower end of the locking plate, the middle part of the arc-shaped plate protrudes inward, and the lower end of the arc-shaped plate protrudes outward relative to the outer wall of the cylindrical rod 1201.

[0045] like Fig.12 and Fig.13 As shown, a plurality of axial through holes 1101 are evenly arranged along the circumference of the sealing sleeve 11, a second radial hole 1102 is arranged at the upper end of the axial through hole 1101, the shear pin 10 is used to be installed in the second radial hole 1102, a locking groove 1103 is arranged in the middle of the inner wall of the axial through hole 1101, the locking groove 1103 is used to release the locking claw 1203 and lock the locking claw ball seat 12, and an annular groove is arranged at the upper part of the inner wall of the axial through hole 1101, the annular groove is arranged between the second radial hole 1102 and the locking groove 1103, and the sealing ring is installed in the annular groove. The shear pin 10 is inserted into the second radial hole 1102 of the sealing sleeve 11 and the first radial hole 1202 of the locking claw ball seat 12 to maintain a certain pressure to prevent the floating mechanism from being activated prematurely.

[0046] like Figure 1 and Fig.15 As shown, a steel ball 13 is placed inside the locking claw ball seat 12. After installation, the locking claw 1203 is contracted and tightened, and the steel ball 13 is not easy to flow out. The lower end of the locking claw 1203 is positioned at the upper end surface of the annular protrusion 801 of the central tube 8, thereby ensuring that the locking claw ball seat 12 will not move downward and shear the shear pin 10 when subjected to external pressure during the lowering process. Fig.14 and Fig.16As shown, after the locking claw ball seat 12 is activated by pressure, it moves upward and is positioned on the connector 7. At this time, the locking claw 1203 enters the locking groove 1103 of the sealing sleeve 11 and is released and locked to prevent the locking claw ball seat 12 from moving in the opposite direction. The liquid inlet hole 1207 of the locking claw ball seat 12 is exposed, and the second flow channel 17 is connected with the third flow channel 18 through the liquid inlet hole 1207, the axial mounting groove, and the axial through hole 1101, so that the production fluid can enter and the steel ball 13 can be discharged. In this embodiment, the steel ball 13 cooperates with the locking claw ball seat 12 to realize one-time activation of all the locking claw ball seats 12.

[0047] like Figure 3 As shown, a strong magnetic component 1401 is installed on the outer side of the upper end of the lower joint 14 to absorb the outflowing steel balls 13 to prevent disturbances in the later production process or injection process.

[0048] Specifically, a plurality of water-permeable holes 802 are evenly arranged along the circumference of the annular protrusion 801 . The water-permeable holes 802 are waist-shaped holes, and the width of the waist-shaped holes is smaller than the diameter of the steel ball 13 , which can ensure sufficient flow area and prevent the steel ball 13 from entering the base pipe 2 .

[0049] The base pipe 2 is threadedly connected to the upper end of the connector 7, and the center pipe 8 is threadedly connected to the lower end of the connector 7; the lower end of the outer protective sleeve 6 is fixed to the lower joint 14, and the upper end of the outer protective sleeve 6 is sleeved on the outside of the lower end ring 5. A sealing ring is provided between the outer protective sleeve 6 and the lower end ring 5, a sealing ring is provided between the outer protective sleeve 6 and the sealing sleeve 11, and a sealing ring is provided between the sealing sleeve 11 and the center pipe 8, so as to achieve the sealing between the sealing sleeve 11 and the outer protective sleeve 6 and the center pipe 8. It can be seen that in this embodiment, the lower end ring 5 and the outer protective sleeve 6 are inserted and sealed, and the center pipe 8 and the base pipe 2 are threadedly connected. The insertion seal + threaded connection method ensures the connection strength and overall sealing.

[0050] The specific use process is as follows: during the lowering process of the pressure-opened floating screen tube 100 in this embodiment, since the base pipe 2 is not perforated, the floating mechanism is in a closed state. After the drilling fluid in the well enters the filter sleeve 4, it cannot enter the base pipe 2 from the floating mechanism. In this way, the screen tube can have a certain buoyancy to reduce the friction resistance during lowering. When the screen tube is lowered into place, pressure is applied, and the pressure acts on the locking claw ball seat 12, the shear pin 10 is cut off, the locking claw ball seat 12 moves upward and is positioned on the end face of the connector 7, and the locking claw 1203 is locked in the locking groove 1103 of the sealing sleeve 11. At this time, although the liquid inlet hole 1207 of the locking claw ball seat 12 has been opened, due to the presence of the steel ball 13, it is still The pressure can be maintained, thereby ensuring that all switching components can be opened. After the pressure is released, the external fluid of the screen tube can enter the inner support sleeve 404 through the outer sleeve 401, the filter screen 402 and the guide net 403, and then go down through the bridge flow channel formed by the inner support sleeve 404 and the base pipe 2 using the wire skeleton structure, and then continue to go down through the annular space of the connector 7 and the outer protective sleeve 6, and then enter the liquid inlet hole 1207 of the locking claw ball seat 12, and push the steel ball 13 out, and then enter the base pipe 2 through the water-permeable through hole 802 of the center pipe 8 to establish a production channel. At this time, the steel ball 13 will be adsorbed on the strong magnetic component 1401 of the lower joint 14 to prevent the steel ball 13 from affecting the flow of liquid.

[0051] The present specification uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A pressure-opened floating screen tube, characterized in that: The filter mechanism comprises a coupling, a base pipe, an upper end ring, a filter sleeve and a lower end ring, wherein the coupling is connected to the upper end of the base pipe, the upper end ring, the filter sleeve and the lower end ring are sequentially connected from top to bottom, the upper end ring and the lower end ring are fixed on the base pipe, a first flow channel is formed between the filter sleeve and the base pipe, and a first flow groove extending in an axial direction is arranged on the inner wall of the lower end ring; the floating mechanism comprises an outer protective sleeve, a connector, a center pipe, a gasket, a sealing sleeve, a lower joint, a blind pipe short section and a plurality of switching components, the lower end of the base pipe is connected to the center pipe through the connector, and the lower end of the center pipe is sequentially connected to the lower joint and the blind pipe short section The upper end and the lower end of the outer protective sleeve are respectively connected to the lower end ring and the lower joint, a second flow channel is formed between the connecting head and the outer protective sleeve, an annular protrusion is arranged on the center tube, a plurality of water-permeable through holes are arranged on the annular protrusion, a third flow channel is formed between the annular protrusion and the outer protective sleeve, the gasket and the sealing sleeve are sequentially sleeved on the center tube from top to bottom, the upper end of the gasket contacts with the connecting head, the lower end of the sealing sleeve contacts with the annular protrusion, a plurality of axial through holes are circumferentially arranged on the sealing sleeve, each of the axial through holes is installed with a switching component, the switching component is used to close or connect the second flow channel with the third flow channel.

2. The pressure-opened floating screen according to claim 1, characterized in that: The filter sleeve includes an outer sleeve, a filter screen, a guide screen and an inner support sleeve which are arranged in sequence from the outside to the inside. The filter screen, the guide screen and the inner support sleeve are fixedly connected in sequence. A first annular mounting portion is arranged at the lower end of the outer wall of the upper end ring, and a second annular mounting portion is arranged at the upper end of the outer wall of the lower end ring. The filter screen is fixed on the inner walls of the first annular mounting portion and the second annular mounting portion, and the outer sleeve is fixed on the outer walls of the first annular mounting portion and the second annular mounting portion.

3. The pressure-opened floating screen according to claim 2, characterized in that: The outer sheath is a cylindrical plate with a plurality of circular holes; the filter net and the guide net are both mat-type woven nets; the inner support sleeve includes a plurality of transverse ribs evenly distributed along the axial direction and a plurality of longitudinal ribs spirally wound along the circumferential direction, and the plurality of longitudinal ribs are welded to the inside of the plurality of transverse ribs.

4. The pressure-opened floating screen according to claim 1, characterized in that: A plurality of first flow grooves are circumferentially arranged on the inner wall of the lower end ring, a plurality of second flow grooves are circumferentially arranged on the outer wall of the connector, and the second flow grooves are extended along the axial direction of the connector.

5. The pressure-opened floating screen according to claim 1, characterized in that: The switching assembly includes a locking claw ball seat, a steel ball and a shear pin, the locking claw ball seat is installed in the axial through hole, the locking claw ball seat includes a cylindrical rod and a locking claw, a first radial hole is provided at the upper end of the cylindrical rod, the shear pin is used to be installed in the first radial hole, an axial mounting groove is provided inside the cylindrical rod, the axial mounting groove passes through the bottom surface of the cylindrical rod, the axial mounting groove includes a first circular groove, a conical groove and a second circular groove connected in sequence from top to bottom, the inner diameter of the first circular groove is smaller than the diameter of the steel ball, the inner diameter of the second circular groove is larger than the diameter of the steel ball, a liquid inlet hole is provided on the cylindrical rod, the liquid inlet hole is connected to the first circular groove, and the lower end of the cylindrical rod is connected to the locking claw.

6. The pressure-opened floating screen according to claim 5, characterized in that: A second radial hole is provided at the upper end of the axial through hole, and the shear pin is used to be installed in the second radial hole. A locking groove is provided in the middle of the inner wall of the axial through hole, and an annular groove is provided on the upper part of the inner wall of the axial through hole. The annular groove is provided between the second radial hole and the locking groove, and a sealing ring is installed in the annular groove.

7. The pressure-opened floating screen according to claim 5, characterized in that: A strong magnetic component is installed on the outer side of the upper end of the lower joint.

8. The pressure-opened floating screen according to claim 5, characterized in that: A plurality of water-permeable through holes are evenly arranged along the circumference of the annular protrusion, and the water-permeable through holes are waist-shaped holes, and the width of the waist-shaped holes is smaller than the diameter of the steel ball.

9. The pressure-opened floating screen according to claim 1, characterized in that: The base pipe is threadedly connected to the upper end inside the connector, and the center pipe is threadedly connected to the lower end inside the connector; the lower end of the outer protective sleeve is fixed to the lower joint, and the upper end of the outer protective sleeve is sleeved on the outside of the lower end ring, a sealing ring is provided between the outer protective sleeve and the lower end ring, and a sealing ring is provided between the outer protective sleeve and the sealing sleeve.

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