Double-layer pipe internal and external fluid conversion different-direction communication check valve

Abstract

The invention discloses a double-layer pipe internal and external fluid conversion different-direction communication check valve, which belongs to the field of oil and gas well downhole operation equipment and comprises an upper outer pipe joint, an upper inner pipe joint, a lower outer pipe joint and a lower inner pipe joint. A fourth channel is arranged in the upper inner pipe joint; a seventh channel is arranged in the lower inner pipe joint; a third channel is formed between the upper outer pipe joint and the upper inner pipe joint, and an eighth channel is formed between the lower outer pipe joint and the lower inner pipe joint; a reversing valve body is fixedly arranged between the upper outer pipe connector and the lower outer pipe connector, and a valve element assembly is arranged in the reversing valve body in a sliding mode. When the valve element assembly moves in the reversing valve body, one-way conversion of the first fluid from the fourth channel to the eighth channel and one-way conversion of the second fluid from the seventh channel to the third channel can be synchronously achieved. One-way conversion from the first fluid in the inner pipe of the concentric continuous oil pipe to the annulus of the sand washing tool and one-way conversion from the second fluid in the inner pipe of the sand washing tool to the annulus of the concentric continuous oil pipe can be synchronously achieved.

Description

Technical Field

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

[0002] When negative pressure sand flushing is performed through concentric coiled tubing (CCTU), some fluid, carrying accumulated sand from the wellbore, flows upward through the inner tube of the sand flushing tool. To avoid conflict with the flow of the flushing fluid in the concentric coiled tubing, the fluid must be redirected between the inner tube and the annulus. Furthermore, if an unexpected event causes the concentric coiled tubing to break or fracture, the oil and gas pressure in the wellbore, exceeding the surface pressure, can cause the oil and gas in the wellbore to spurt out through the concentric coiled tubing inner tube and the annulus, out of the rupture or fracture, resulting in a blowout.

[0003] Based on this, the present application proposes a double-layer tube internal and external fluid conversion and interconnecting one-way 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 being ejected from the inner tube and annulus of the concentric continuous oil tubing, thereby reducing the well control risk. Summary of the Invention

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

[0005] To achieve the above object, the present invention adopts the following technical solutions: 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; A first through-going passage is provided inside the upper outer pipe joint, a fourth through-going passage is provided inside the upper inner pipe joint, a ninth through-going passage is provided inside the lower outer pipe joint, and a seventh through-going passage is provided inside the lower inner pipe joint; a third through-going passage is formed between the upper outer pipe joint and the upper inner pipe joint, and an eighth through-going passage is formed between the lower outer pipe joint and the lower inner pipe joint; 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; When the valve core assembly moves downward in the reversing valve body, it can simultaneously 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.

[0006] Preferably, a fifth channel and a sixth channel are sequentially provided 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; An upper outer tube connecting ring connected to an upper outer tube joint is provided 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 provided on the radial inner side of the upper outer tube connecting ring; 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; A first combined 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 combined channel is connected to the third channel, 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 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; 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, as well as the seventh channel, the sixth channel, the first combined channel, and the third channel can be connected simultaneously.

[0007] Preferably, a second combination communicating hole penetrating to the second combination channel is provided on the side wall of the fifth channel, and a first combination communicating hole penetrating to the first combination channel is provided on the side wall of the sixth channel; When the valve core assembly moves downward in the reversing valve body, the fourth channel, the fifth channel, the second combined communicating hole, the second combined channel, and the eighth channel can be connected, as well as the seventh channel, the sixth channel, the first combined communicating hole, the first combined channel, and the third channel can be connected synchronously.

[0008] Preferably, the first combination channel includes the eleventh channel and the twelfth channel, and the second combination channel includes the thirteenth channel and the fourteenth channel; The first combined communication hole includes a seventeenth channel and an eighteenth channel, wherein the seventeenth channel enables communication between the sixth channel and the eleventh channel, and the eighteenth channel enables communication between the sixth channel and the twelfth channel; The second combined communicating 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.

[0009] Preferably, the eleventh channel, the twelfth channel, the thirteenth channel, and the fourteenth channel are evenly distributed along the circumferential direction; The eleventh channel and the twelfth channel are arranged opposite each other, and the thirteenth channel and the fourteenth channel are arranged opposite each other.

[0010] Preferably, the lower end of the eleventh channel is sealed and blocked by a first annular space sealing piece, the lower end of the twelfth channel is sealed and blocked by a second annular space sealing piece, the upper end of the thirteenth channel is sealed and blocked by a third annular space sealing piece, and the upper end of the fourteenth channel is sealed and blocked by a fourth annular space sealing piece.

[0011] 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; 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.

[0012] Preferably, the valve core assembly includes an upper valve core and a lower valve core; The upper valve core is a cylindrical structure with its upper end blocked, and the outer side wall of the upper valve core is in sliding engagement with the fifth channel; The lower valve core is a cylindrical structure with its upper end blocked, the outer side wall of the lower valve core is in sliding engagement with the sixth channel, and a through hole is provided on the upper end plate of the lower valve core; A downwardly extending valve stem is fixedly provided 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; When the upper valve core, valve stem and 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.

[0013] Preferably, a return spring is sleeved on the valve stem between the upper end plate of the upper valve core and the limit plate; 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.

[0014] Preferably, threaded connections are made between the outer side wall of the lower end of the upper outer tube joint and the inner side wall of the upper outer tube connecting ring, between the inner side wall of the lower end of the upper inner tube joint and the outer side wall of the upper inner tube connecting ring, between the inner side wall of the lower outer tube connecting ring and the outer side wall of the upper end of the lower outer tube joint, and between the outer side wall of the lower inner tube connecting ring and the inner side wall of the upper end of the lower inner tube joint.

[0015] The beneficial effects of the present invention are: The double-layer tube inner and outer fluid conversion and 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. The overall structure is simple. At the same time, it can form a seal between the inner tube and the annulus of the concentric coiled tubing when the concentric coiled tubing breaks or ruptures due to unexpected circumstances, thereby preventing high-pressure fluid and gas from being ejected from the inner tube and the annulus of the concentric coiled tubing, thereby reducing the risk of well control. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings in the specification, which constitute a part of this application, are used to provide further understanding of this application. The illustrative embodiments of this application and their descriptions are used to explain this application and do not constitute improper limitations on this application.

[0017] Figure 1 This is a schematic structural diagram of a one-way valve for converting fluids inside and outside a double-layer tube according to the present invention; Figure 2 It is a structural schematic diagram of the reversing valve body in the present invention; Figure 3 yes Figure 2 AA section view; Figure 4 yes Figure 2 BB cross-sectional view; Figure 5 yes Figure 2 CC sectional view; Figure 6 yes Figure 2 DD sectional view; Figure 7 It is a structural schematic diagram of the valve core assembly in the present invention; Figure 8 This is a schematic top view of the structure of the lower valve core of the present invention; Figure 9 It is a structural schematic diagram of the upper outer pipe joint in the present invention; Figure 10 It is a structural schematic diagram of the upper inner pipe joint in the present invention; Figure 11 It is a structural schematic diagram of the lower outer pipe joint in the present invention; Figure 12 It is a structural schematic diagram of the lower inner pipe joint in the present invention; in: 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; 1-upper outer pipe joint, 2-upper inner pipe joint, 3-return 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 disc, 12-second annulus sealing disc, 13-third annulus sealing disc, 14-fourth annulus sealing disc. DETAILED DESCRIPTION

[0018] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present application belongs.

[0019] 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, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0020] In the present invention, the directions or positional relationships indicated by terms such as "upper", "lower", "bottom", and "top" 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.

[0021] In the present invention, terms such as "connected" and "connection" should be interpreted broadly to mean a fixed connection, an integral connection, or a detachable connection; a direct connection or an indirect connection through an intermediary. Relevant researchers or technicians in this field may determine the specific meanings of these terms in the present invention based on specific circumstances, and they should not be construed as limitations on the present invention.

[0022] The present invention will be further described below with reference to the accompanying drawings and examples.

[0023] like Figure 1 As shown, a double-layer tube internal and external fluid conversion and unifying check valve includes an upper outer pipe joint 1 for connecting to the outer tube of the concentric coiled tubing, an upper inner pipe joint 2 for connecting to the inner tube of the concentric coiled tubing, a lower outer pipe joint 9 for connecting to the outer tube of the sand flushing tool, and a lower inner pipe joint 10 for connecting to the inner tube of the sand flushing tool; A through first channel 01 is provided inside the upper outer tube joint 1, a through fourth channel 04 is provided inside the upper inner tube joint 2, a through ninth channel 09 is provided inside the lower outer tube joint 9, and a through seventh channel 07 is provided inside the lower inner tube joint 10; a third channel 03 is formed as an annulus between the upper outer tube joint 1 and the upper inner tube joint 2, and an eighth channel 08 is formed as an annulus between the lower outer tube joint 9 and the lower inner tube joint 10; wherein the upper outer tube joint 1, the upper inner tube joint 2, the lower outer tube joint 9, and the lower inner tube joint 10 are all hollow structures, and threads are provided on the side walls of the second channel 02 formed by the expansion of the upper end of the first channel 01 and the upper end of the fourth channel 04, and the tenth channel 010 formed by the expansion of the lower end of the ninth channel 09 and the lower end of the seventh channel 07. Figures 9-12 As shown; 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 .

[0024] Preferably, Figure 2-Figure 6 As shown, the middle part of the reversing valve body 6 is provided with a fifth channel 05 and a sixth channel 06 from top to bottom. The fifth channel 05 passes through the upper end surface of the reversing valve body 6, and the sixth channel 06 passes through the lower end surface of the reversing valve body 6. The fifth channel 05 and the sixth channel 06 are separated by a limit plate 61. 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; 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 a lower inner tube connecting ring 65 connected to the lower inner tube joint 10 is coaxially provided on the radial inner side of the lower outer tube connecting ring 64; 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, it can simultaneously connect the fourth channel 04, the fifth channel 05, the second combined channel, and the eighth channel 08, and the seventh channel 07, the sixth channel 06, the first combined channel, and the third channel 03.

[0025] 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; When the valve core assembly moves downward in the reversing valve body 6, it can simultaneously realize the connection between the fourth channel 04, the fifth channel 05, the second combined connecting hole, the second combined channel, and the eighth channel 08, as well as the seventh channel 07, the sixth channel 06, the first combined connecting hole, the first combined channel, and the third channel 03.

[0026] 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; The first combined communication hole includes a seventeenth channel 017 and an eighteenth channel 018. The seventeenth channel 017 enables communication between the sixth channel 06 and the eleventh channel 011. The eighteenth channel 018 enables communication between the sixth channel 06 and the twelfth channel 012. 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 . The sixteenth channel 016 enables communication between the fifth channel 05 and the fourteenth channel 014 .

[0027] 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; The eleventh channel 011 and the twelfth channel 012 are arranged opposite each other, and the thirteenth channel 013 and the fourteenth channel 014 are arranged opposite each other.

[0028] Preferably, the lower end of the eleventh channel 011 is sealed and blocked by the first annulus sealing piece 11, the lower end of the twelfth channel 012 is sealed and blocked by the second annulus sealing piece 12, the upper end of the thirteenth channel 013 is sealed and blocked by the third annulus sealing piece 13, and the upper end of the fourteenth channel 014 is sealed and blocked by the fourth annulus sealing piece 14.

[0029] Preferably, a third groove for assembling the third annular space sealing piece 13 and a fourth groove for assembling the fourth annular space sealing piece 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 piece 13 and the fourth annular space sealing piece 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 the first annular space sealing piece 11 and a second groove for assembling the second annular space sealing piece 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 piece 11 and the second annular space sealing piece 12 to achieve sealing and plugging of the upper end of the eleventh channel 011 and the lower end of the twelfth channel 012.

[0030] Preferably, Figure 7 As shown, the valve core assembly includes 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 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 in sliding cooperation 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; A downwardly extending valve stem 5 is fixedly disposed in the middle of the upper end plate of the upper valve core 4. The valve stem 5 passes downward through a stop plate 61 and is fixedly connected to the upper end plate of the lower valve core 8. Specifically, the valve stem 5 and the lower valve core 8 are connected by a nut 7. The stop plate 61 is provided with a nineteenth passage 019 adapted to accommodate the passage of the valve stem 5. 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.

[0031] 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; When the upper end of the upper valve core 4 is not subjected to external force, the return spring 3 forces 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.

[0032] Preferably, threaded connections are made between the outer side wall of the lower end of the upper outer tube joint 1 and the inner side wall of the upper outer tube connecting ring 62, between the inner side wall of the lower end of the upper inner tube connecting ring 63, between the inner side wall of the lower outer tube connecting ring 64 and the outer side wall of the upper end of the lower outer tube joint 9, and between the outer side wall of the lower inner tube connecting ring 65 and the inner side wall of the upper end of the lower inner tube joint 10.

[0033] A double-layer tube internal and external fluid conversion and unifying check valve, the specific implementation of which is as follows: Before use, complete the assembly of the double-layer tube internal and external fluid conversion and unison check valve. First, connect the upper valve core 4 to 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 piece 13 and the fourth annular space sealing piece 14 on the corresponding position of 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 piece. 13. The fourth annular space sealing piece 14 is used to achieve sealing and plugging of 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 sealing and plugging of the lower end of the eleventh channel 011 and the lower end of the twelfth channel 012, and the assembly is completed.

[0034] During 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 to the appropriate torque to complete the connection between the double-layer tube internal and external fluid conversion and non-directional connecting check valve and the concentric coiled tubing and sand flushing tool.

[0035] 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 exerts a downward thrust on the upper valve core 4, compressing the return spring 3. The upper valve core 4 drives the valve stem 5 through the nineteenth channel 019 to push the lower valve core 8 to move axially downward along the sixth channel 06, causing the fifteenth channel 015, the sixteenth channel 016, the seventeenth channel 017, and the eighteenth channel 018 to open synchronously, thereby allowing the first fluid to enter 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 enter the annulus of the sand flushing tool through the eighth channel 08, thereby realizing a one-way conversion of the first fluid from the inner tube of the concentric coiled tubing to the annulus of the sand flushing tool.

[0036] At the same time, the second fluid (sand-carrying fluid) in the inner tube of the sand flushing tool sequentially 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, 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.

[0037] 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 drops, the return 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 high-pressure fluid at the bottom hole cannot enter the concentric coiled tubing from the annulus of the sand flushing tool and the inner tube of the sand flushing tool. The fluid inside and outside the double-layer tube is converted into a non-directional connected check valve to achieve the effect of sealing the annulus and inner tube of the concentric coiled tubing, which can effectively prevent the occurrence of blowout accidents.

[0038] Although the above describes the specific embodiments 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 any creative work are still within the scope of protection 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).

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 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.

3. The double-layer tube internal and external fluid conversion and different-direction communication check valve as claimed in claim 2, 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.

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 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).

5. The double-layer tube internal and external fluid conversion and different-direction communication check valve as claimed in claim 4, 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.

6. The double-layer tube internal and external fluid conversion and different-direction communication check valve as claimed in claim 4, 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).

7. The double-layer tube internal and external fluid conversion and different-direction communication check valve as claimed in claim 6, 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).

8. The double-layer tube internal and external fluid conversion and different-direction communication check valve as claimed in claim 4, 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.

9. The double-layer tube internal and external fluid conversion and different-direction communication check valve as claimed in claim 8, 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).

10. The double-layer tube internal and external fluid conversion and different-direction communication check valve as claimed in claim 2, 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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