A double-layer tube internal and external fluid conversion and unification check valve

Abstract

The present invention discloses a double-layer tube internal and external fluid conversion and different-direction communication check valve, which belongs to the field of downhole operation equipment for oil and gas wells, and includes an upper outer tube joint, an upper inner tube joint, a lower outer tube joint, and a lower inner tube joint; a fourth channel is arranged in the upper inner tube joint, and a seventh channel is arranged in the lower inner tube joint; a third channel is formed between the upper outer tube joint and the upper inner tube joint, and an eighth channel is formed between the lower outer tube joint and the lower inner tube joint; a reversing valve body is fixed between the upper outer tube joint and the lower outer tube joint, and a valve core assembly is slidably arranged in the reversing valve body; when the valve core assembly moves in the reversing valve body, it can synchronously realize the one-way conversion of the first fluid from the fourth channel to the eighth channel, and the one-way conversion of the second fluid from the seventh channel to the third channel. The present invention can synchronously realize the one-way conversion of the first fluid in the inner tube of the concentric continuous tubing to the annulus of the sand flushing tool, and the one-way conversion of the second fluid in the inner tube of the sand flushing tool to the annulus of the concentric continuous tubing.

Description

Technical Field

[0001] The invention belongs to the technical field of downhole operation equipment of oil and gas wells, and in particular relates to a double-layer tube internal and external fluid conversion and different-direction communication check valve. Background Art

[0002] When the concentric coiled tubing is put into the well for negative pressure sand flushing, part of the liquid carries the sand accumulated in the wellbore and returns through the inner tube of the sand flushing tool. In order to avoid conflict with the flow direction of the sand flushing fluid in the inner tube of the concentric coiled tubing, it is necessary to convert the flow direction of the fluid between the inner tube and the annulus. At the same time, the operation occasionally encounters an emergency situation that causes the concentric coiled tubing to be damaged or broken. At this time, the oil and gas pressure in the well is greater than the ground pressure. The oil and gas in the well spray out from the ruptured and broken parts of the tubing through the inner tube of the concentric coiled tubing and the annulus, causing a blowout accident.

[0003] Based on this, the present application proposes a double-layer tube internal and external fluid conversion asymmetrical connecting one-flow valve, which can perform one-way conversion of fluid from the inner tube to the annulus, and at the same time can form a seal for the inner tube and annulus of the concentric continuous oil tubing when the concentric continuous oil tubing breaks or ruptures due to unexpected circumstances, thereby preventing high-pressure fluid and gas from spraying out from the inner tube and annulus of the concentric continuous oil tubing, and reducing the risk of well control. Summary of the invention

[0004] The purpose of the present invention is to overcome the deficiencies of the prior art and to provide a double-layer tube internal and external fluid conversion and different-direction communication check valve.

[0005] To achieve the above object, the present invention adopts the following technical solution:

[0006] A double-layer tube internal and external fluid conversion and unifying check valve, comprising an upper external tube joint, an upper internal tube joint, a lower external tube joint, and a lower internal tube joint;

[0007] A first through passage is provided inside the upper outer pipe joint, a fourth through passage is provided inside the upper inner pipe joint, a ninth through passage is provided inside the lower outer pipe joint, and a seventh through passage is provided inside the lower inner pipe joint; a third annular passage is formed between the upper outer pipe joint and the upper inner pipe joint, and an eighth annular passage is formed between the lower outer pipe joint and the lower inner pipe joint;

[0008] A reversing valve body is coaxially fixed between the upper outer pipe joint and the lower outer pipe joint, and a valve core assembly is slidably arranged in the reversing valve body;

[0009] When the valve core assembly moves downward in the reversing valve body, the one-way conversion of the first fluid from the fourth channel to the eighth channel and the one-way conversion of the second fluid from the seventh channel to the third channel can be realized synchronously.

[0010] Preferably, a fifth channel and a sixth channel are sequentially arranged in the middle of the reversing valve body from top to bottom, the fifth channel passes through the upper end surface of the reversing valve body, the sixth channel passes through the lower end surface of the reversing valve body, and the fifth channel and the sixth channel are separated by a limit plate;

[0011] An upper outer tube connecting ring connected to an upper outer tube joint is disposed at the upper end of the reversing valve body, and an upper inner tube connecting ring connected to an upper inner tube joint is coaxially disposed on the radial inner side of the upper outer tube connecting ring;

[0012] The lower end of the reversing valve body is provided with a lower outer tube connecting ring connected to the lower outer tube joint, and the radial inner side of the lower outer tube connecting ring is coaxially provided with a lower inner tube connecting ring connected to the lower inner tube joint;

[0013] A first combination channel extending in the axial direction is provided on the annular end surface between the upper outer tube connecting ring and the upper inner tube connecting ring, the upper end of the first combination channel is connected to the third channel, and the lower end of the first combination channel is blocked;

[0014] A second combined channel extending in the axial direction is provided on the annular end surface between the lower outer tube connecting ring and the lower inner tube connecting ring, the lower end of the second combined channel is connected to the eighth channel, and the upper end of the second combined channel is blocked;

[0015] When the valve core assembly moves downward in the reversing valve body, the fourth channel, the fifth channel, the second combined channel, and the eighth channel can be connected, and the seventh channel, the sixth channel, the first combined channel, and the third channel can be connected simultaneously.

[0016] Preferably, a second combination communication hole penetrating to the second combination channel is provided on the side wall of the fifth channel, and a first combination communication hole penetrating to the first combination channel is provided on the side wall of the sixth channel;

[0017] When the valve core assembly moves downward in the reversing valve body, the fourth channel, the fifth channel, the second combined connecting hole, the second combined channel, the eighth channel, and the seventh channel, the sixth channel, the first combined connecting hole, the first combined channel, and the third channel can be connected synchronously.

[0018] Preferably, the first combination channel includes an eleventh channel and a twelfth channel, and the second combination channel includes a thirteenth channel and a fourteenth channel;

[0019] The first combined communication hole includes a seventeenth channel and an eighteenth channel, the seventeenth channel realizes the communication between the sixth channel and the eleventh channel, and the eighteenth channel realizes the communication between the sixth channel and the twelfth channel;

[0020] The second combined communication hole includes a fifteenth channel and a sixteenth channel. The fifteenth channel enables communication between the fifth channel and the thirteenth channel, and the sixteenth channel enables communication between the fifth channel and the fourteenth channel.

[0021] Preferably, the eleventh channel, the twelfth channel, the thirteenth channel, and the fourteenth channel are evenly distributed along the circumferential direction;

[0022] The eleventh channel and the twelfth channel are arranged opposite to each other, and the thirteenth channel and the fourteenth channel are arranged opposite to each other.

[0023] Preferably, the lower end of the eleventh channel is sealed and plugged by a first annulus sealing piece, the lower end of the twelfth channel is sealed and plugged by a second annulus sealing piece, the upper end of the thirteenth channel is sealed and plugged by a third annulus sealing piece, and the upper end of the fourteenth channel is sealed and plugged by a fourth annulus sealing piece.

[0024] Preferably, a third groove for assembling a third annular space sealing sheet and a fourth groove for assembling a fourth annular space sealing sheet are provided on the annular end surface between the upper outer tube connecting ring and the upper inner tube connecting ring; the lower ends of the upper outer tube joint and the upper inner tube joint are pressed against the third annular space sealing sheet and the fourth annular space sealing sheet to achieve sealing and plugging of the upper ends of the thirteenth channel and the fourteenth channel;

[0025] A first groove for assembling a first annular space sealing sheet and a second groove for assembling a second annular space sealing sheet are provided on the annular end surface between the lower outer tube connecting ring and the lower inner tube connecting ring; the upper ends of the lower outer tube joint and the lower inner tube joint are pressed against the first annular space sealing sheet and the second annular space sealing sheet to achieve sealing and plugging of the upper end of the eleventh channel and the lower end of the twelfth channel.

[0026] Preferably, the valve core assembly includes an upper valve core and a lower valve core;

[0027] The upper valve core is a cylindrical structure with an upper end blocked, and the outer side wall of the upper valve core is slidably matched with the fifth channel;

[0028] The lower valve core is a cylindrical structure with its upper end blocked, the outer side wall of the lower valve core is slidably matched with the sixth channel, and a through hole is provided on the upper end plate of the lower valve core;

[0029] A valve stem extending downward is fixedly arranged in the middle of the upper end plate of the upper valve core, and the valve stem passes downward through the limit plate and is fixedly connected to the upper end plate of the lower valve core;

[0030] When the upper valve core, the valve stem and the lower valve core move downward in the reversing valve body, the fifteenth channel, the sixteenth channel, the seventeenth channel and the eighteenth channel can be fully opened or closed synchronously.

[0031] Preferably, a return spring is sleeved on the valve stem between the upper end plate of the upper valve core and the limit plate;

[0032] When the upper end of the upper valve core is not subjected to external force, the return spring forces the upper valve core to move upward to completely close the fifteenth and sixteenth channels, and the lower valve core to completely close the seventeenth and eighteenth channels.

[0033] Preferably, threaded connections are made between the outer wall of the lower end of the upper outer tube joint and the inner wall of the upper outer tube connecting ring, between the inner wall of the lower end of the upper inner tube joint and the outer wall of the upper inner tube connecting ring, between the inner wall of the lower outer tube connecting ring and the outer wall of the upper end of the lower outer tube joint, and between the outer wall of the lower inner tube connecting ring and the inner wall of the upper end of the lower inner tube joint.

[0034] The beneficial effects of the present invention are:

[0035] The double-layer tube inner and outer fluid conversion different-direction connecting check valve of the present invention can realize the one-way conversion of the first fluid in the inner tube of the concentric coiled tubing to the annulus of the sand flushing tool and the one-way conversion of the second fluid in the inner tube of the sand flushing tool to the annulus of the concentric coiled tubing simultaneously through the setting of the overall structure, and the overall structure is simple; at the same time, when the concentric coiled tubing is broken or ruptured due to an accident, it can form a seal between the inner tube and the annulus of the concentric coiled tubing, avoid the ejection of high-pressure fluid and gas from the inner tube and the annulus of the concentric coiled tubing, and reduce the risk of well control. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The drawings in the specification, which constitute a part of the present application, are used to provide further understanding of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute improper limitations on the present application.

[0037] Figure 1 It is a structural schematic diagram of a non-directional unifying check valve for converting fluid inside and outside a double-layer tube according to the present invention;

[0038] Figure 2 It is a structural schematic diagram of the reversing valve body in the present invention;

[0039] Figure 3 yes Figure 2 AA section view;

[0040] Figure 4 yes Figure 2 BB section view;

[0041] Figure 5 yes Figure 2 CC section view;

[0042] Figure 6 yes Figure 2 DD section view;

[0043] Figure 7 It is a structural schematic diagram of the valve core assembly in the present invention;

[0044] Figure 8 It is a schematic top view of the structure of the lower valve core in the present invention;

[0045] Fig. 9 It is a structural schematic diagram of the upper outer pipe joint in the present invention;

[0046] Fig.10 It is a structural schematic diagram of the upper inner pipe joint in the present invention;

[0047] Fig.11 It is a structural schematic diagram of the lower outer pipe joint in the present invention;

[0048] Fig.12 It is a structural schematic diagram of the lower inner pipe joint in the present invention;

[0049] in:

[0050] 01-first channel, 02-second channel, 03-third channel, 04-fourth channel, 05-fifth channel, 06-sixth channel, 07-seventh channel, 08-eighth channel, 09-ninth channel, 010-tenth channel, 011-eleventh channel, 012-twelfth channel, 013-thirteenth channel, 014-fourteenth channel, 015-fifteenth channel, 016-sixteenth channel, 017-seventeenth channel, 018-eighteenth channel, 019-nineteenth channel;

[0051] 1-upper outer pipe joint, 2-upper inner pipe joint, 3-reset spring, 4-upper valve core, 5-valve stem, 6-reversing valve body, 61-limiting plate, 62-upper outer pipe connecting ring, 63-upper inner pipe connecting ring, 64-lower outer pipe connecting ring, 65-lower inner pipe connecting ring, 7-nut, 8-lower valve core, 81-through hole, 9-lower outer pipe joint, 10-lower inner pipe joint, 11-first annulus sealing plate, 12-second annulus sealing plate, 13-third annulus sealing plate, 14-fourth annulus sealing plate. DETAILED DESCRIPTION

[0052] It should be noted that the following detailed descriptions are illustrative and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0053] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0054] In the present invention, the directions or positional relationships indicated by terms such as "upper", "lower", "bottom", "top", etc. are based on the directions or positional relationships shown in the accompanying drawings. They are relational words determined only for the convenience of describing the structural relationships of the various parts or elements of the present invention. They do not specifically refer to any part or element in the present invention and cannot be understood as limitations on the present invention.

[0055] In the present invention, terms such as "connected" and "connection" should be understood in a broad sense, indicating that the connection can be fixed, integral or detachable; it can be directly connected or indirectly connected through an intermediate medium. Relevant scientific research or technical personnel in this field can determine the specific meaning of the above terms in the present invention according to specific circumstances, and they should not be understood as limiting the present invention.

[0056] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0057] like Figure 1 As shown, a double-layer tube internal and external fluid conversion unison check valve comprises an upper external pipe joint 1 for connecting with the outer pipe of the concentric coiled tubing, an upper internal pipe joint 2 for connecting with the inner pipe of the concentric coiled tubing, a lower external pipe joint 9 for connecting with the outer pipe of the sand flushing tool, and a lower internal pipe joint 10 for connecting with the inner pipe of the sand flushing tool;

[0058] The upper outer pipe joint 1 is provided with a through first channel 01, the upper inner pipe joint 2 is provided with a through fourth channel 04, the lower outer pipe joint 9 is provided with a through ninth channel 09, and the lower inner pipe joint 10 is provided with a through seventh channel 07; a third annular channel 03 is formed between the upper outer pipe joint 1 and the upper inner pipe joint 2, and an eighth annular channel 08 is formed between the lower outer pipe joint 9 and the lower inner pipe joint 10; wherein the upper outer pipe joint 1, the upper inner pipe joint 2, the lower outer pipe joint 9, and the lower inner pipe joint 10 are all hollow structures, and threads are provided on the side walls of the second channel 02 formed by the upper end of the first channel 01 and the upper end of the fourth channel 04, and the lower end of the ninth channel 09 and the lower end of the seventh channel 07 are formed by the outward expansion of the lower end. Figure 9-12 As shown;

[0059] A reversing valve body 6 is coaxially fixed between the upper outer pipe joint 1 and the lower outer pipe joint 9, and a valve core assembly is slidably arranged in the reversing valve body 6;

[0060] When the valve core assembly moves downward in the reversing valve body 6 , the one-way conversion of the first fluid from the fourth channel 04 to the eighth channel 08 and the one-way conversion of the second fluid from the seventh channel 07 to the third channel 03 can be realized simultaneously.

[0061] Preferably, Figure 2-Figure 6 As shown, the fifth channel 05 and the sixth channel 06 are sequentially arranged in the middle of the reversing valve body 6 from top to bottom, the fifth channel 05 passes through the upper end surface of the reversing valve body 6, the sixth channel 06 passes through the lower end surface of the reversing valve body 6, and the fifth channel 05 and the sixth channel 06 are separated by a limit plate 61;

[0062] The upper end of the reversing valve body 6 is provided with an upper outer tube connecting ring 62 connected to the upper outer tube joint 1, and the radial inner side of the upper outer tube connecting ring 62 is coaxially provided with an upper inner tube connecting ring 63 connected to the upper inner tube joint 2;

[0063] The lower end of the reversing valve body 6 is provided with a lower outer tube connecting ring 64 connected to the lower outer tube joint 9, and the radial inner side of the lower outer tube connecting ring 64 is coaxially provided with a lower inner tube connecting ring 65 connected to the lower inner tube joint 10;

[0064] A first combination channel extending in the axial direction is provided on the annular end surface between the upper outer tube connecting ring 62 and the upper inner tube connecting ring 63, the upper end of the first combination channel is connected to the third channel 03, and the lower end of the first combination channel is blocked;

[0065] A second combined channel extending in the axial direction is provided on the annular end surface between the lower outer tube connecting ring 64 and the lower inner tube connecting ring 65, the lower end of the second combined channel is connected to the eighth channel 08, and the upper end of the second combined channel is blocked;

[0066] When the valve core assembly moves downward in the reversing valve body 6, the fourth channel 04, the fifth channel 05, the second combined channel, and the eighth channel 08 can be connected, and the seventh channel 07, the sixth channel 06, the first combined channel, and the third channel 03 can be connected simultaneously.

[0067] Preferably, a second combination communication hole penetrating to the second combination channel is provided on the side wall of the fifth channel 05, and a first combination communication hole penetrating to the first combination channel is provided on the side wall of the sixth channel 06;

[0068] When the valve core assembly moves downward in the reversing valve body 6, the fourth channel 04, the fifth channel 05, the second combined connecting hole, the second combined channel, the eighth channel 08 can be connected, and the seventh channel 07, the sixth channel 06, the first combined connecting hole, the first combined channel, and the third channel 03 can be connected simultaneously.

[0069] Preferably, the first combined channel includes an eleventh channel 011 and a twelfth channel 012, and the second combined channel includes a thirteenth channel 013 and a fourteenth channel 014;

[0070] The first combined communication hole includes a seventeenth channel 017 and an eighteenth channel 018, wherein the seventeenth channel 017 enables communication between the sixth channel 06 and the eleventh channel 011, and the eighteenth channel 018 enables communication between the sixth channel 06 and the twelfth channel 012;

[0071] The second combined communication hole includes a fifteenth channel 015 and a sixteenth channel 016 . The fifteenth channel 015 enables communication between the fifth channel 05 and the thirteenth channel 013 , and the sixteenth channel 016 enables communication between the fifth channel 05 and the fourteenth channel 014 .

[0072] Preferably, the eleventh channel 011, the twelfth channel 012, the thirteenth channel 013, and the fourteenth channel 014 are evenly distributed along the circumferential direction;

[0073] The eleventh channel 011 and the twelfth channel 012 are arranged opposite to each other, and the thirteenth channel 013 and the fourteenth channel 014 are arranged opposite to each other.

[0074] Preferably, the lower end of the eleventh channel 011 is sealed and plugged by a first annulus sealing piece 11, the lower end of the twelfth channel 012 is sealed and plugged by a second annulus sealing piece 12, the upper end of the thirteenth channel 013 is sealed and plugged by a third annulus sealing piece 13, and the upper end of the fourteenth channel 014 is sealed and plugged by a fourth annulus sealing piece 14.

[0075] Preferably, a third groove for assembling the third annular space sealing sheet 13 and a fourth groove for assembling the fourth annular space sealing sheet 14 are provided on the annular end surface between the upper outer tube connecting ring 62 and the upper inner tube connecting ring 63; the lower ends of the upper outer tube joint 1 and the upper inner tube joint 2 are pressed against the third annular space sealing sheet 13 and the fourth annular space sealing sheet 14 to achieve sealing and plugging of the upper ends of the thirteenth channel 013 and the fourteenth channel 014;

[0076] A first groove for assembling the first annular space sealing sheet 11 and a second groove for assembling the second annular space sealing sheet 12 are provided on the annular end surface between the lower outer tube connecting ring 64 and the lower inner tube connecting ring 65; the upper ends of the lower outer tube joint 9 and the lower inner tube joint 10 are pressed against the first annular space sealing sheet 11 and the second annular space sealing sheet 12 to achieve sealing and plugging of the upper end of the eleventh channel 011 and the lower end of the twelfth channel 012.

[0077] Preferably, Figure 7As shown, the valve core assembly includes an upper valve core 4 and a lower valve core 8;

[0078] The upper valve core 4 is a cylindrical structure with its upper end blocked, and the outer side wall of the upper valve core 4 is slidably matched with the fifth channel 05;

[0079] The lower valve core 8 is a cylindrical structure with its upper end blocked. The outer wall of the lower valve core 8 is slidably matched with the sixth channel 06. A through hole 81 is provided on the upper end plate of the lower valve core 8. Figure 8 As shown;

[0080] A valve stem 5 extending downward is fixedly arranged in the middle of the upper end plate of the upper valve core 4, and the valve stem 5 passes downward through the limit plate 61 and is fixedly connected to the upper end plate of the lower valve core 8; specifically, the valve stem 5 is connected to the lower valve core 8 through a nut 7, and a nineteenth passage 019 adapted for the valve stem 5 to pass through is arranged on the limit plate 61;

[0081] When the upper valve core 4 , the valve stem 5 , and the lower valve core 8 move downward in the reversing valve body 6 , the fifteenth channel 015 , the sixteenth channel 016 , the seventeenth channel 017 , and the eighteenth channel 018 can be fully opened or fully closed synchronously.

[0082] Preferably, a return spring 3 is sleeved on the valve stem 5 between the upper end plate of the upper valve core 4 and the limit plate 61;

[0083] When the upper end of the upper valve core 4 is not subjected to external force, the return spring 3 causes the upper valve core 4 to move upward to completely close the fifteenth channel 015 and the sixteenth channel 016, and the lower valve core 8 to completely close the seventeenth channel 017 and the eighteenth channel 018.

[0084] Preferably, threaded connections are made between the outer wall of the lower end of the upper outer tube joint 1 and the inner wall of the upper outer tube connecting ring 62, between the inner wall of the lower end of the upper inner tube joint 2 and the outer wall of the upper inner tube connecting ring 63, between the inner wall of the lower outer tube connecting ring 64 and the outer wall of the upper end of the lower outer tube joint 9, and between the outer wall of the lower inner tube connecting ring 65 and the inner wall of the upper end of the lower inner tube joint 10.

[0085] A double-layer tube internal and external fluid conversion unison check valve, the specific implementation method is as follows:

[0086] Before use, complete the assembly of the double-layer tube internal and external fluid conversion unison check valve. First, connect the upper valve core 4 with the valve stem 5, nest the return spring 3 on the valve stem 5, pass the lower end of the valve stem 5 through the nineteenth channel 019, install the lower valve core 8 and the nut 7 inside the sixth channel 06, install the third annular space sealing sheet 13 and the fourth annular space sealing sheet 14 at the corresponding positions on the upper end surface of the reversing valve body 6, and then install the upper inner pipe joint 2 and the upper outer pipe joint 1 in sequence, so that the lower ends of the upper outer pipe joint 1 and the upper inner pipe joint 2 are pressed tightly against the third annular space sealing sheet. 13. The fourth annular space sealing piece 14 is used to seal the upper end of the thirteenth channel 013 and the upper end of the fourteenth channel 014; the first annular space sealing piece 11 and the second annular space sealing piece 12 are installed at the corresponding positions on the lower end surface of the reversing valve body 6, and then the lower inner pipe joint 10 and the lower outer pipe joint 9 are installed in sequence, so that the upper ends of the lower outer pipe joint 9 and the lower inner pipe joint 10 are pressed tightly on the first annular space sealing piece 11 and the second annular space sealing piece 12 to achieve the sealing of the lower end of the eleventh channel 011 and the lower end of the twelfth channel 012, and the assembly is completed.

[0087] When in use, the inner tube of the concentric coiled tubing is threadedly connected to the second channel 02, the outer tube of the concentric coiled tubing is threadedly connected to the upper end of the first channel 01, the inner tube of the sand flushing tool is threadedly connected to the tenth channel 010, and the outer tube of the sand flushing tool is threadedly connected to the lower end of the ninth channel 09. Tighten them to the appropriate torque to complete the connection between the double-layer tube internal and external fluid conversion anisotropic connecting check valve and the concentric coiled tubing and the sand flushing tool.

[0088] When the concentric coiled tubing is performing downhole operations, the first fluid enters the fourth channel 04 of the upper inner pipe joint 2 through the inner tube of the concentric coiled tubing, the first fluid applies a downward thrust to the upper valve core 4, the return spring 3 is compressed, and the upper valve core 4 drives the valve stem 5 to push the lower valve core 8 to move axially downward along the sixth channel 06 through the nineteenth channel 019, so that the fifteenth channel 015, the sixteenth channel 016, the seventeenth channel 017, and the eighteenth channel 018 are opened synchronously, so that the first fluid enters the thirteenth channel 013 and the fourteenth channel 014 from the fourth channel 04 and the fifth channel 05 through the fifteenth channel 015 and the sixteenth channel 016, and finally enters the annulus of the sand flushing tool through the eighth channel 08, thereby realizing the one-way conversion of the first fluid from the inner tube of the concentric coiled tubing to the annulus of the sand flushing tool.

[0089] At the same time, the second fluid (sand-carrying fluid) in the inner tube of the sand flushing tool successively enters the seventh channel 07, the sixth channel 06, passes through the through hole 81 and the opened seventeenth channel 017 and the eighteenth channel 018, enters the eleventh channel 011, the twelfth channel 012, and finally enters the annulus of the concentric coiled tubing through the third channel 03, thereby realizing the one-way conversion of the second fluid from the inner tube of the sand flushing tool to the annulus of the concentric coiled tubing.

[0090] When an accident occurs and the upper part of the concentric coiled tubing is damaged or broken, the pressure in the inner tube of the concentric coiled tubing decreases, the reset spring 3 pushes up, the upper valve core 4 moves up to the highest position, the side of the upper valve core 4 blocks the fifteenth channel 015 and the sixteenth channel 016, and the lower valve core 8 blocks the seventeenth channel 017 and the eighteenth channel 018. At this time, the bottom hole high-pressure fluid cannot enter the concentric coiled tubing from the annulus of the sand flushing tool and the inner tube of the sand flushing tool. The double-layer tube internal and external fluid conversion and the non-directional connected check valve achieve the effect of sealing the annulus and the inner tube of the concentric coiled tubing, which can effectively prevent the occurrence of blowout accidents.

[0091] Although the above describes the specific implementation mode of the present invention in conjunction with the accompanying drawings, it is not a limitation of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without creative work are still within the protection scope of the present invention.

Claims

1. A double-layer tube internal and external fluid conversion unison check valve, characterized in that: It comprises an upper outer pipe joint (1), an upper inner pipe joint (2), a lower outer pipe joint (9), and a lower inner pipe joint (10); The upper outer pipe joint (1) is provided with a first through passage (01), the upper inner pipe joint (2) is provided with a fourth through passage (04), the lower outer pipe joint (9) is provided with a ninth through passage (09), and the lower inner pipe joint (10) is provided with a seventh through passage (07); an annular third passage (03) is formed between the upper outer pipe joint (1) and the upper inner pipe joint (2), and an annular eighth passage (08) is formed between the lower outer pipe joint (9) and the lower inner pipe joint (10); A reversing valve body (6) is coaxially fixed between the upper outer pipe joint (1) and the lower outer pipe joint (9), and a valve core assembly is slidably arranged in the reversing valve body (6); When the valve core assembly moves downward in the reversing valve body (6), it can simultaneously realize the one-way conversion of the first fluid from the fourth channel (04) to the eighth channel (08) and the one-way conversion of the second fluid from the seventh channel (07) to the third channel (03); A fifth channel (05) and a sixth channel (06) are sequentially arranged in the middle of the reversing valve body (6) from top to bottom, the fifth channel (05) passes through the upper end surface of the reversing valve body (6), the sixth channel (06) passes through the lower end surface of the reversing valve body (6), and the fifth channel (05) and the sixth channel (06) are separated by a limit plate (61); An upper outer tube connecting ring (62) connected to an upper outer tube joint (1) is disposed at the upper end of the reversing valve body (6), and an upper inner tube connecting ring (63) connected to an upper inner tube joint (2) is coaxially disposed radially inside the upper outer tube connecting ring (62); The lower end of the reversing valve body (6) is provided with a lower outer tube connecting ring (64) connected to the lower outer tube joint (9), and the radial inner side of the lower outer tube connecting ring (64) is coaxially provided with a lower inner tube connecting ring (65) connected to the lower inner tube joint (10); A first combined channel extending in the axial direction is provided on the annular end surface between the upper outer tube connecting ring (62) and the upper inner tube connecting ring (63); the upper end of the first combined channel is connected to the third channel (03), and the lower end of the first combined channel is blocked; A second combined channel extending in the axial direction is provided on the annular end surface between the lower outer tube connecting ring (64) and the lower inner tube connecting ring (65), the lower end of the second combined channel is connected to the eighth channel (08), and the upper end of the second combined channel is blocked; When the valve core assembly moves downward in the reversing valve body (6), the fourth channel (04), the fifth channel (05), the second combined channel, and the eighth channel (08) can be connected synchronously, as well as the seventh channel (07), the sixth channel (06), the first combined channel, and the third channel (03) can be connected.

2. The double-layer tube internal and external fluid conversion and different-direction communication check valve as claimed in claim 1, characterized in that: A second combination communication hole penetrating to the second combination channel is provided on the side wall of the fifth channel (05), and a first combination communication hole penetrating to the first combination channel is provided on the side wall of the sixth channel (06); When the valve core assembly moves downward in the reversing valve body (6), the fourth channel (04), the fifth channel (05), the second combined connecting hole, the second combined channel, and the eighth channel (08) can be connected, and the seventh channel (07), the sixth channel (06), the first combined connecting hole, the first combined channel, and the third channel (03) can be connected simultaneously.

3. The double-layer tube internal and external fluid conversion and different-direction communication check valve as claimed in claim 2, characterized in that: The first combined channel includes an eleventh channel (011) and a twelfth channel (012), and the second combined channel includes a thirteenth channel (013) and a fourteenth channel (014); The first combined communication hole comprises a seventeenth channel (017) and an eighteenth channel (018), wherein the seventeenth channel (017) enables communication between the sixth channel (06) and the eleventh channel (011), and the eighteenth channel (018) enables communication between the sixth channel (06) and the twelfth channel (012); The second combined communication hole comprises a fifteenth channel (015) and a sixteenth channel (016), wherein the fifteenth channel (015) enables communication between the fifth channel (05) and the thirteenth channel (013), and the sixteenth channel (016) enables communication between the fifth channel (05) and the fourteenth channel (014).

4. The double-layer tube internal and external fluid conversion and different-direction communication check valve as claimed in claim 3, characterized in that: The eleventh channel (011), the twelfth channel (012), the thirteenth channel (013), and the fourteenth channel (014) are evenly distributed along the circumferential direction; The eleventh channel (011) and the twelfth channel (012) are arranged opposite to each other, and the thirteenth channel (013) and the fourteenth channel (014) are arranged opposite to each other.

5. The double-layer tube internal and external fluid conversion and different-direction communication check valve as claimed in claim 3, characterized in that: The lower end of the eleventh channel (011) is sealed by the first annulus sealing piece (11), the lower end of the twelfth channel (012) is sealed by the second annulus sealing piece (12), the upper end of the thirteenth channel (013) is sealed by the third annulus sealing piece (13), and the upper end of the fourteenth channel (014) is sealed by the fourth annulus sealing piece (14).

6. The double-layer tube internal and external fluid conversion and different-direction communication check valve as claimed in claim 5, characterized in that: A third groove for assembling a third annular space sealing sheet (13) and a fourth groove for assembling a fourth annular space sealing sheet (14) are provided on the annular end surface between the upper outer tube connecting ring (62) and the upper inner tube connecting ring (63); the lower ends of the upper outer tube joint (1) and the upper inner tube joint (2) are pressed against the third annular space sealing sheet (13) and the fourth annular space sealing sheet (14) to achieve sealing and plugging of the upper ends of the thirteenth channel (013) and the fourteenth channel (014); A first groove for assembling a first annular space sealing sheet (11) and a second groove for assembling a second annular space sealing sheet (12) are provided on the annular end surface between the lower outer tube connecting ring (64) and the lower inner tube connecting ring (65); the upper ends of the lower outer tube joint (9) and the lower inner tube joint (10) are pressed against the first annular space sealing sheet (11) and the second annular space sealing sheet (12) to achieve sealing and plugging of the upper end of the eleventh channel (011) and the lower end of the twelfth channel (012).

7. The double-layer tube internal and external fluid conversion and different-direction communication check valve as claimed in claim 3, characterized in that: The valve core assembly comprises an upper valve core (4) and a lower valve core (8); The upper valve core (4) is a cylindrical structure with its upper end blocked, and the outer side wall of the upper valve core (4) is in sliding cooperation with the fifth channel (05); The lower valve core (8) is a cylindrical structure with its upper end blocked, the outer wall of the lower valve core (8) is slidably matched with the sixth channel (06), and a through hole (81) is provided on the upper end plate of the lower valve core (8); A valve stem (5) extending downward is fixedly arranged in the middle of the upper end plate of the upper valve core (4); the valve stem (5) passes downward through the limit plate (61) and is fixedly connected to the upper end plate of the lower valve core (8); When the upper valve core (4), the valve stem (5) and the lower valve core (8) move downward in the reversing valve body (6), the fifteenth channel (015), the sixteenth channel (016), the seventeenth channel (017) and the eighteenth channel (018) can be fully opened or fully closed synchronously.

8. The double-layer tube internal and external fluid conversion and different-direction communication check valve as claimed in claim 7, characterized in that: A return spring (3) is sleeved on the valve stem (5) between the upper end plate of the upper valve core (4) and the limit plate (61); When the upper end of the upper valve core (4) is not subjected to external force, the return spring (3) causes the upper valve core (4) to move upward to completely close the fifteenth channel (015) and the sixteenth channel (016), and the lower valve core (8) to completely close the seventeenth channel (017) and the eighteenth channel (018).

9. The double-layer tube internal and external fluid conversion and different-direction communication check valve as claimed in claim 1, characterized in that: The lower end outer wall of the upper outer tube joint (1) and the inner wall of the upper outer tube connecting ring (62), the lower end inner wall of the upper inner tube joint (2) and the outer wall of the upper inner tube connecting ring (63), the inner wall of the lower outer tube connecting ring (64) and the upper end outer wall of the lower outer tube joint (9), and the outer wall of the lower inner tube connecting ring (65) and the upper end inner wall of the lower inner tube joint (10) are all threadedly connected.

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