Bidirectional sand washing valve, control assembly and one-way valve structure

Abstract

The invention belongs to the field of valve devices of drilling fluid circulating systems for flushing boreholes, and particularly relates to a two-way sand flushing valve, a control assembly and a one-way valve structure. In order to avoid the high-pressure well kick phenomenon when forward sand washing is conducted through the two-way sand washing valve, the one-way valve structure and the control assembly which are used in cooperation are provided, and the two-way sand washing valve is jointly formed by the one-way valve structure and the control assembly. The one-way valve structure comprises a valve element and a valve seat, an insertion hole is formed in the valve seat, a locking groove is formed in the hole wall of the insertion hole, the control assembly comprises an ejector rod inserted into the insertion hole to eject the valve element open, and an eccentric cam in locking fit with the locking groove and a fishing rod limiting rotation of the eccentric cam are arranged on the ejector rod. During forward sand washing, oil layer liquid can be prevented from flowing back to a well opening through the one-way flow guide function of the one-way valve structure; during reverse sand washing, the control assembly is put in, the fishing rod limits the eccentric cam to be matched with the locking groove in a locking mode, the ejector rod ejects the valve element all the time, and therefore the one-way valve structure loses efficacy and is communicated in a two-way mode.

Description

Technical Field

[0001] The invention belongs to the field of valve devices of drilling fluid circulation systems for flushing wellbores, and in particular relates to a two-way sand flushing valve, a control component and a one-way valve structure. Background Art

[0002] After the oil well is fracturing and gushing, there is a phenomenon of sand burying the oil layer. In order to eliminate this phenomenon, the staff needs to perform sand flushing operations.

[0003] The Chinese utility model patent with the authorization announcement number CN218509456U and the authorization announcement date 2023.02.21 discloses a bidirectional well-washing and unblocking pumping and oil extraction device, which includes a bidirectional well-washing fixed valve. Figure 1 As shown, during the forward sand flushing process, the well washing fluid enters the side cavity through the through hole on the baffle 6 and the upper liquid flow channel on the valve core 1. When the pressure of the well washing fluid is large enough, the well washing fluid pushes the slip ring 4 to compress the spring and open the lower liquid flow channel. The upper liquid flow channel and the lower liquid flow channel are connected to perform forward well washing. After the forward well washing is completed, the spring 3 drives the slip ring 4 to reset. During the reverse sand flushing process, the well washing fluid enters the side cavity through the lower liquid flow channel. The stopper fixed on the valve cylinder 2 or the valve core 1 stops the slip ring 4 to prevent the upper liquid flow channel and the lower liquid flow channel from being connected. At the same time, the valve ball 5 is separated from the valve seat to open the central liquid flow channel for reverse well washing.

[0004] However, for oil wells with high formation pressure, when using the above-mentioned two-way well flushing fixed valve for forward sand flushing, once the sand layer is flushed away, due to the high pressure of the oil layer, a high-pressure well kick phenomenon will occur, that is, the oil, gas and water mixture in the oil layer will be ejected from the wellhead, polluting the environment. Summary of the Invention

[0005] The purpose of the present invention is to provide a bidirectional sand flushing valve to solve the technical problem that when using the existing bidirectional well flushing fixed valve for forward sand flushing, once the sand layer is flushed away, due to the high pressure of the oil layer, a high-pressure well kick phenomenon will occur.

[0006] Another object of the present invention is to provide a control assembly to solve the same technical problems mentioned above when used together with a one-way valve structure.

[0007] The present invention also aims to provide a one-way valve structure to solve the same technical problem mentioned above when used together with a control assembly.

[0008] To achieve the above-mentioned purpose, the technical solution of the bidirectional sand flushing valve provided by the present invention is: A two-way sand flushing valve comprises a one-way valve structure and a control component; The one-way valve structure includes a valve seat with a flow passage and a valve core for opening and closing the flow passage. The valve seat is provided with a plug hole, and a locking groove is provided on the hole wall of the plug hole. The control assembly includes a push rod for inserting into the socket and pushing the valve core to open the valve core, the push rod having a radial mounting hole, an eccentric cam rotatably assembled in the radial mounting hole, the axial direction of the push rod being defined as the up and down direction, the rotation axis of the eccentric cam extending horizontally, one end of the eccentric cam protruding from the radial mounting hole in the initial state and constituting a locking end for locking with the locking groove, the upper end of the push rod is also provided with an axial mounting hole connected to the radial mounting hole, a salvage rod for cooperating with the salvage mechanism to salvage the entire control assembly is installed in the axial mounting hole, the salvage rod and the axial mounting hole are movably matched in the axial direction, a limiting protrusion is provided on the hole wall of the axial mounting hole for limiting the lowest position of the downward movement of the salvage rod, and the movement stroke of the salvage rod also has a state switching position above the lowest position, and an elastic member for applying a downward elastic force to the salvage rod is provided between the salvage rod and the axial mounting hole; The eccentric cam is provided with a torsion spring for returning the eccentric cam to its initial state, or the eccentric cam can return to its initial state under its own weight; When the fishing rod is lower than the state switching position, the locking end can rotate forward into the radial mounting hole, but the fishing rod is used to cooperate with the eccentric cam stopper before the locking end rotates reversely into the radial mounting hole, so as to ensure that the locking end is locked with the locking groove when the locking end is in the locking groove and the valve core is always opened by the push rod; When the salvage rod is not lower than the state switching position, the locking end can be rotated in the opposite direction to the radial mounting hole to unlock the locking end and the locking groove, thereby enabling the push rod to exit the socket and separate from the valve core when the salvage mechanism salvages the control component.

[0009] Furthermore, a section of the jack located at the upper end forms a jack expansion section, the inner diameter of the jack expansion section gradually decreases from top to bottom, and the hole wall of the jack expansion section forms a jack guide surface for guiding the push rod and the eccentric cam.

[0010] Furthermore, the one-way valve structure also includes a valve body, a valve seat is installed in the inner cavity of the valve body, and an axial side flow channel is formed between the valve seat and the valve body, and the flow channel includes a socket and a radial connecting channel connecting the socket and the axial side flow channel.

[0011] Furthermore, the push rod includes a rod body and a pressure cap detachably mounted on the upper end of the rod body, the pressure cap and the rod body are both provided with axial holes, and the axial holes on the pressure cap and the rod body together constitute the axial mounting hole; the salvage rod has a radial boss, the elastic member is a compressed elastic member compressed between the pressure cap and the radial boss, and the limiting protrusion is used to cooperate with the radial boss stop to limit the lowest position of the downward movement of the salvage rod.

[0012] Furthermore, the one-way valve structure also includes a valve body, a valve seat is installed in the inner cavity of the valve body, and a spring seat is also installed in the inner cavity of the valve body. The spring seat has a compression spring installation cavity extending in the up and down directions, a compression spring is installed in the compression spring installation cavity, and the valve core is fixedly connected to the upper end of the compression spring; the spring seat is provided with a radial through hole connecting the compression spring installation cavity and the space between the spring seat and the valve body, and the spring seat is also provided with an axial through hole connecting the compression spring installation cavity and the space below the spring seat.

[0013] The bidirectional sand flushing valve provided by the present invention offers the following beneficial effects: This invention is a groundbreaking creation. When forward sand flushing is required, the control assembly is first ensured to be clear of the one-way valve structure (including both situations where the control assembly has not yet been deployed and where it has been removed). Then, flushing fluid is injected from the tubing, the valve core opens, and the flushing fluid, carrying sand and gravel, returns to the surface through the casing annulus. During forward sand flushing, if the reservoir pressure becomes high (specifically, when encountering high-pressure oil and gas flows), the flushing fluid injection is temporarily stopped, and the valve core closes to prevent the high-pressure oil and gas flow from carrying the oil, gas, and water mixture out of the wellhead.

[0014] After forward sand washing, when reverse sand washing is required, you can follow the steps below: Step S1: Place the control assembly into the one-way valve structure. The specific process of the control assembly descending is as follows: the lower end of the push rod is first inserted into the socket. After the locking end contacts the hole wall of the socket, the locking end rotates forward into the radial mounting hole. When the push rod continues to descend until the locking end is aligned with the locking groove, the eccentric cam automatically returns to its initial state, and the push rod pushes the valve core to open the valve core (i.e., the one-way valve structure is bidirectional). In step S2, a flushing fluid is injected into the annulus of the casing. The flushing fluid carries gravel and is discharged from the oil pipe through the flow channel. During this process, since the flow direction of the flushing fluid is opposite to the flow direction of the one-way valve structure when it is normally one-way, the valve core always wants to close, so the valve core always applies an upward force to the push rod. At this time, the elastic member applies a downward force to the fishing rod, and the fishing rod prevents the eccentric cam from rotating in the opposite direction to the radial mounting hole. The eccentric cam is locked with the locking groove. On the surface, the eccentric cam directly applies a downward force to the push rod to prevent the push rod from moving. In essence, the elastic force of the elastic member is the force that prevents the valve core from closing.

[0015] After reverse sand flushing, when forward sand flushing is required, the control assembly can be fished out. The specific process for fishing out the control assembly is as follows: the fishing mechanism is lowered from the wellhead. After the fishing mechanism and the fishing rod are engaged, the fishing mechanism applies an upward force to the fishing rod to overcome the elastic force of the elastic member and move the fishing rod upward. After the fishing rod moves up to a position not lower than the state switching position, the locking end rotates in the opposite direction into the radial mounting hole, unlocking the locking end and the locking groove. After that, the fishing mechanism is further lifted to fish out the control assembly.

[0016] In summary, the one-way valve structure's single-flow function enables forward sand flushing. When reservoir pressure is high, well flushing fluid injection is stopped and the valve core closes to prevent reverse flow, thereby avoiding high-pressure well kicks. By inserting a control component into the one-way valve structure, the one-way valve structure can be disabled and bidirectionally conducted, ensuring reverse flow for reverse sand flushing.

[0017] To achieve the above objectives, the technical solution of the control component provided by the present invention is: A control assembly includes a push rod for pushing open a valve core of a one-way valve structure, the push rod having a radial mounting hole, an eccentric cam rotatably mounted in the radial mounting hole, the axial direction of the push rod being defined as the up and down direction, the rotation axis of the eccentric cam extending horizontally, one end of the eccentric cam protruding from the radial mounting hole in an initial state and constituting a locking end, the upper end of the push rod is also provided with an axial mounting hole communicating with the radial mounting hole, a salvage rod for cooperating with a salvage mechanism to salvage the entire control assembly is installed in the axial mounting hole, the salvage rod and the axial mounting hole are movably matched in the axial direction, a limiting protrusion is provided on the hole wall of the axial mounting hole for limiting the lowest position of the downward movement of the salvage rod, the movement stroke of the salvage rod also has a state switching position above the lowest position, and an elastic member for applying a downward elastic force to the salvage rod is provided between the salvage rod and the axial mounting hole; The eccentric cam is provided with a torsion spring for returning the eccentric cam to its initial state, or the eccentric cam can return to its initial state under its own weight; When the fishing rod is lower than the state switching position, the locking end can be rotated forward into the radial mounting hole, but the fishing rod is used to cooperate with the eccentric cam stopper before the locking end is rotated reversely into the radial mounting hole; When the fishing rod is not lower than the state switching position, the locking end can be rotated in the reverse direction into the radial mounting hole.

[0018] Furthermore, the push rod includes a rod body and a pressure cap detachably mounted on the upper end of the rod body, the pressure cap and the rod body are both provided with axial holes, and the axial holes on the pressure cap and the rod body together constitute the axial mounting hole; the salvage rod has a radial boss, the elastic member is a compressed elastic member compressed between the pressure cap and the radial boss, and the limiting protrusion is used to cooperate with the radial boss stop to limit the lowest position of the downward movement of the salvage rod.

[0019] The control assembly provided by the present invention has the following beneficial effects: The present invention is a groundbreaking invention. When the control assembly is used in conjunction with a one-way valve structure, inserting the control assembly into the one-way valve structure enables the one-way valve structure to conduct in both directions, thereby enabling reverse sand flushing. Removing the control assembly from the one-way valve structure restores the one-way valve structure to conduct in one direction, thereby enabling forward sand flushing and preventing backflow of liquid when reservoir pressure is high.

[0020] To achieve the above-mentioned purpose, the technical solution of the one-way valve structure provided by the present invention is: When the valve body is opened, the cam is rotated in the eccentric cam, and the eccentric cam is rotated in the eccentric cam, and the eccentric cam is rotated in the eccentric cam. When the eccentric cam is opened, the eccentric cam is rotated in the eccentric cam, and the eccentric cam is rotated in the eccentric cam. When the eccentric cam is opened, the eccentric cam is rotated in the eccentric cam, and the eccentric cam is rotated in the eccentric cam. When the eccentric cam is opened, the eccentric cam is rotated in the eccentric cam. When the eccentric cam is opened, the eccentric cam is rotated in the eccentric cam. When the eccentric cam is opened, the eccentric cam is rotated in the eccentric cam, and the eccentric cam is rotated in the eccentric cam. The eccentric cam is provided with a torsion spring for returning the eccentric cam to its initial state, or the eccentric cam can return to its initial state under its own weight; When the fishing rod is lower than the state switching position, the locking end can be rotated forward into the radial mounting hole, but the fishing rod is used to cooperate with the eccentric cam stopper before the locking end is rotated reversely into the radial mounting hole; When the fishing rod is not lower than the state switching position, the locking end can be rotated in the reverse direction into the radial mounting hole; The valve seat is provided with an insertion hole for inserting a push rod in the control assembly, and a locking groove for locking and cooperating with an eccentric cam in the control assembly is provided on the hole wall of the insertion hole.

[0021] Furthermore, the push rod includes a rod body and a pressure cap detachably mounted on the upper end of the rod body, the pressure cap and the rod body are both provided with axial holes, and the axial holes on the pressure cap and the rod body together constitute the axial mounting hole; the salvage rod has a radial boss, the elastic member is a compressed elastic member compressed between the pressure cap and the radial boss, and the limiting protrusion is used to cooperate with the radial boss stop to limit the lowest position of the downward movement of the salvage rod.

[0022] Furthermore, a section of the jack located at the upper end forms a jack expansion section, the inner diameter of the jack expansion section gradually decreases from top to bottom, and the hole wall of the jack expansion section forms a jack guide surface for guiding the push rod and the eccentric cam.

[0023] Furthermore, the one-way valve structure also includes a valve body, a valve seat is installed in the inner cavity of the valve body, and an axial side flow channel is formed between the valve seat and the valve body, and the flow channel includes a socket and a radial connecting channel connecting the socket and the axial side flow channel.

[0024] Furthermore, the one-way valve structure also includes a valve body, a valve seat is installed in the inner cavity of the valve body, and a spring seat is also installed in the inner cavity of the valve body. The spring seat has a compression spring installation cavity extending in the up and down directions, a compression spring is installed in the compression spring installation cavity, and the valve core is fixedly connected to the upper end of the compression spring; the spring seat is provided with a radial through hole connecting the compression spring installation cavity and the space between the spring seat and the valve body, and the spring seat is also provided with an axial through hole connecting the compression spring installation cavity and the space below the spring seat.

[0025] The one-way valve structure provided by the present invention has the following beneficial effects: The present invention is a groundbreaking invention. After the control assembly is used in conjunction with the one-way valve structure, inserting the control assembly into the one-way valve structure enables the one-way valve structure to conduct in both directions, thereby enabling reverse sand flushing. Removing the control assembly from the one-way valve structure restores the one-way valve structure to conduct in one direction, thereby enabling forward sand flushing and preventing liquid backflow when reservoir pressure is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a structural diagram of a two-way well flushing fixed valve in the prior art; Figure 2 This is a structural diagram of the one-way valve structure in the specific embodiment 1 of the two-way sand flushing valve of this application; Figure 3 This is a schematic structural diagram of the control assembly in the specific embodiment 1 of the bidirectional sand flushing valve of this application; Figure 4 This is a schematic structural diagram of a specific embodiment 1 of the bidirectional sand flushing valve of the present application during reverse sand flushing; Figure 5 This is a structural diagram of a spring seat in the specific embodiment 1 of the bidirectional sand flushing valve of this application; Figure 6 This is a structural diagram of another spring seat in the specific embodiment 1 of the bidirectional sand flushing valve of this application; Figure 7 This is a structural diagram of the fishing rod in the specific embodiment 2 of the two-way sand flushing valve of this application.

[0027] Description of reference numerals: Figure 1 Middle: 1. Valve core; 2. Valve cylinder; 3. Spring; 4. Slip ring; 5. Valve ball; 6. Baffle; Figure 2-7Middle: 11. Upper joint; 12. Connecting tube; 13. Lower joint; 2. Valve seat; 21. Locking groove; 22. Radial connecting flow channel; 23. Insert hole; 3. Valve core; 4. Spring seat; 41. Radial through hole; 42. First axial through hole; 43. Second axial through hole; 5. Compression spring; 61. Pressure cover; 62. Rod body; 63. Radial mounting hole; 64. Axial mounting hole; 65. Limiting protrusion; 7. Eccentric cam; 71. Locking end; 8. Pin; 9. Salvage rod; 91. Radial boss; 10. Compression elastic member. DETAILED DESCRIPTION

[0028] In order to solve the problems in the background technology, the core inventive concept of the present invention is: using a one-way valve structure to achieve forward well washing. When encountering high-pressure oil and gas flow, the one-way valve structure automatically closes to avoid high-pressure well kick. When reverse well washing, a control component is put into the one-way valve structure to make the one-way valve structure invalid and bidirectional.

[0029] The present invention is described in further detail below with reference to the examples.

[0030] Specific embodiment 1 of the bidirectional sand flushing valve provided by the present invention: like Figure 2-7 As shown, the two-way sand flushing valve includes a one-way valve structure and a control component; The one-way valve structure includes a valve seat 2 with a flow passage and a valve core 3 for opening and closing the flow passage. The valve seat 2 is provided with a plug hole 23, and a locking groove 21 is provided on the hole wall of the plug hole 23. The control assembly includes a push rod for inserting into the socket 23 and pushing the valve core 3 to open the valve core 3, the push rod has a radial mounting hole 63, the radial mounting hole 63 is rotatably mounted with an eccentric cam 7, the axial direction of the push rod is defined as the up and down direction, and the rotation axis of the eccentric cam 7 extends horizontally. In the initial state, one end of the eccentric cam 7 extends out from the radial mounting hole 63 and constitutes a locking end 71 for locking with the locking groove 21. The upper end of the push rod is also provided with an axial mounting hole 64 connected to the radial mounting hole 63, and the axial mounting hole 64 is provided with a salvage rod 9 for cooperating with the salvage mechanism to salvage the entire control assembly. The salvage rod 9 is axially movable in cooperation with the axial mounting hole 64, and a limiting protrusion 65 is provided on the hole wall of the axial mounting hole 64 for limiting the lowest position of the downward movement of the salvage rod 9. The salvage rod 9 also has a state switching position above the lowest position in its moving stroke. An elastic member for applying a downward elastic force to the salvage rod 9 is provided between the salvage rod 9 and the axial mounting hole 64; The eccentric cam 7 is provided with a torsion spring for returning the eccentric cam 7 to its initial state, or the eccentric cam 7 can return to its initial state under its own weight; When the fishing rod 9 is lower than the state switching position, the locking end 71 can rotate forward into the radial mounting hole 63. However, the fishing rod 9 is used to cooperate with the stopper of the eccentric cam 7 before the locking end 71 rotates reversely into the radial mounting hole 63, so as to ensure that the locking end 71 is locked with the locking groove 21 when the locking end 71 is located in the locking groove 21 and the valve core 3 is always opened by the push rod; When the salvage rod 9 is not lower than the state switching position, the locking end 71 can be rotated in the opposite direction to the radial mounting hole 63 to unlock the locking end 71 and the locking groove 21, thereby enabling the push rod to exit the socket 23 and separate from the valve core 3 when the salvage mechanism salvages the control component.

[0031] When forward sand flushing is required, first ensure that the control assembly is not located within the one-way valve structure (this applies to both situations where the control assembly has not yet been deployed and when it has been removed). Next, flushing fluid is injected from the tubing, valve core 3 opens, and the flushing fluid, carrying gravel, returns to the surface through the casing annulus. During forward sand flushing, if reservoir pressure becomes high (specifically, when encountering high-pressure oil and gas flows), flushing fluid injection is temporarily halted, and valve core 3 closes to prevent the high-pressure oil and gas flow from ejecting the oil, gas, and water mixture from the wellhead. The high-pressure oil and gas flow is then depressurized through the choke tube at the casing outlet. Once the pressure is released, forward sand flushing resumes.

[0032] After forward sand washing, when reverse sand washing is required, you can follow the steps below: Step S1: Place the control assembly into the one-way valve structure. The specific process of the control assembly descending is as follows: the lower end of the push rod is first inserted into the insertion hole 23. After the locking end 71 contacts the hole wall of the insertion hole 23, the locking end 71 rotates forward into the radial mounting hole 63. When the push rod continues to descend until the locking end 71 is aligned with the locking groove 21, the eccentric cam 7 automatically returns to its initial state, and the push rod pushes the valve core 3 to open the valve core 3 (i.e., the one-way valve structure is bidirectional). In step S2, a wash fluid is injected into the annulus of the casing. The wash fluid carries gravel and is discharged from the oil pipe through the flow channel. During this process, since the flow direction of the wash fluid is opposite to the flow direction of the one-way valve structure when it is normally one-way, the valve core 3 always wants to close, so the valve core 3 always applies an upward force to the push rod. At this time, the elastic member applies a downward force to the fishing rod 9, and the fishing rod 9 prevents the eccentric cam 7 from rotating in the opposite direction to the radial mounting hole 63. The eccentric cam 7 is locked with the locking groove 21. On the surface, the eccentric cam 7 directly applies a downward force to the push rod to prevent the push rod from moving. In essence, the elastic force of the elastic member is the force that prevents the valve core 3 from closing.

[0033] After reverse sand flushing, when forward sand flushing is required, the control assembly can be fished out. The specific process of fishing out the control assembly is as follows: the fishing mechanism is lowered from the wellhead. After the fishing mechanism and the fishing rod 9 are engaged, the fishing mechanism applies an upward force to the fishing rod 9 to overcome the elastic force of the elastic member and move the fishing rod 9 upward. After the fishing rod 9 moves up to a position not lower than the state switching position, the locking end 71 rotates in the opposite direction into the radial mounting hole 63, unlocking the locking end 71 and the locking groove 21. After that, the fishing mechanism is further lifted to fish out the control assembly.

[0034] In order to facilitate the insertion of the ejector rod into the insertion hole 23, as a specific embodiment, Figure 2-4 As shown, a section of the jack 23 at the upper end forms a jack expansion section, the inner diameter of which gradually decreases from top to bottom, and the hole wall of the jack expansion section forms a jack guide surface for guiding the push rod and the eccentric cam 7, so as to facilitate the insertion of the rod into the jack 23 when it moves downward.

[0035] However, in other specific embodiments, reference Figure 2-4 As shown, the inner diameter of the upper end of the socket 23 can also be kept constant, and the lower end of the push rod can have a conical section or a frustum section, and the conical surface of the conical section or the frustum section constitutes a guide surface, thereby facilitating the insertion of the push rod into the socket 23.

[0036] The locking groove 21 is located at the upper end of a groove expansion section, and the distance from the groove expansion section to the axis of the socket 23 increases from top to bottom. The hole wall of the socket expansion section forms a groove guide surface for guiding the eccentric cam 7 to facilitate the reverse rotation of the locking end 71 into the radial mounting hole 63.

[0037] To simplify the structure, Figure 2-4 As shown in the figure, as a specific embodiment, the one-way valve structure also includes a valve body, a valve seat 2 installed in the inner cavity of the valve body, and an axial side flow channel formed between the valve seat 2 and the valve body. The flow channel includes a socket 23 and a radial communication channel 22 connecting the socket 23 and the axial side flow channel. This simple structure and large flow area facilitate the continued downward flow of well washing fluid. Specifically, the valve body includes an upper connector 11, a connecting tube 12, and a lower connector 13.

[0038] However, in other specific embodiments, reference Figure 2-4 As shown, a communicating hole may also be provided on the valve seat 2 , the lower end of the communicating hole being communicated with the insertion hole 23 , and the upper end of the communicating hole being located on the upper surface of the valve seat 2 .

[0039] To simplify the structure, Figure 2-4As shown, as a specific embodiment, the push rod includes a rod body 62 and a pressure cover 61 detachably mounted on the upper end of the rod body 62, and both the pressure cover 61 and the rod body 62 are provided with axial holes, and the axial holes on the pressure cover 61 and the rod body 62 together constitute the axial mounting hole 64; the salvage rod 9 has a radial boss 91, and the elastic member is a compressed elastic member 10 compressed between the pressure cover 61 and the radial boss 91, and the limiting protrusion 65 is used to cooperate with the radial boss 91 to limit the lowest position of the downward movement of the salvage rod 9, with a simple structure and convenient assembly.

[0040] When the outer diameter of the valve body is small, in order to improve the flow capacity of the two-way sand flushing valve, as a specific implementation method, Figure 2-5 As shown, the one-way valve structure also includes a valve body, a valve seat 2 is installed in the inner cavity of the valve body, and a spring seat 4 is also installed in the inner cavity of the valve body. The spring seat 4 has a compression spring installation cavity extending in the up and down directions, and a compression spring 5 is installed in the compression spring installation cavity. The valve core 3 is fixedly connected to the upper end of the compression spring 5; the spring seat 4 is provided with a radial through hole 41 that connects the compression spring installation cavity and the space between the spring seat 4 and the valve body, and the spring seat 4 is also provided with a first axial through hole 42 that connects the compression spring installation cavity and the lower space of the spring seat 4. Figure 2 The valve core 3 is specifically a valve ball sealed with the conical surface of the valve seat 2. Of course, the valve core 3 can also be a valve plate sealed with the plane of the valve seat 2, or other commonly used valve cores in the prior art.

[0041] When the outer diameter of the valve body is small, the ratio of the inner diameter of the compression spring mounting cavity to the maximum outer diameter of the spring seat 4 is large. By setting the first axial through hole 42, the corresponding parts of the spring seat 4 and the compression spring mounting cavity can be effectively utilized, ensuring that the first axial through hole 42 has a larger flow area.

[0042] However, in other specific embodiments, such as Figure 6 As shown, when the outer diameter of the valve body is large, the ratio of the inner diameter of the compression spring installation cavity to the maximum outer diameter of the spring seat 4 is small, and only a second axial through hole 43 connecting the upper and lower sides of the non-compression spring installation cavity part of the spring seat 4 can be provided on the spring seat 4.

[0043] like Figure 2 As shown, when assembling the one-way valve structure, you can assemble it according to the following steps: Step S1: Assemble the upper connector 11, the connecting tube 12 and the valve seat 2 together. Figure 2 Specifically, the connection between the upper joint 11, the connecting tube 12 and the valve seat 2 is a threaded connection, but the upper joint 11, the connecting tube 12 and the valve seat 2 can also be assembled together by pin connection, welding, etc. Step S2: Assemble the lower connector 13, spring seat 4, compression spring 5 and valve core 3 together. Figure 2The connection between the middle and lower joints 13 and the spring seat 4 is specifically a threaded connection, but the lower joint 13 and the spring seat 4 can also be assembled together by pin connection, welding, etc.; Step S3: Assemble the lower connector 13 and the connecting tube 12 together. Figure 2 The connection between the middle and lower joints 13 and the connecting tube 12 is specifically a threaded connection, but the lower joint 13 and the connecting tube 12 can also be assembled together by pin connection, welding, etc.

[0044] like Figure 3 As shown, when assembling the control components, you can follow the steps below: Step S1: First, the push rod and the eccentric cam 7 are rotated and assembled together using a pin shaft 8. The pin shaft 8 can be integrally formed with the push rod, or the pin shaft 8 can be integrally formed with the eccentric cam 7, or both the push rod and the eccentric cam 7 have pin holes, and a separate pin shaft 8 is used to pass through the pin holes on the push rod and the eccentric cam 7; Step S2: Install the salvage rod 9 and the compression elastic member 10 into the axial mounting hole 64, and then assemble the gland 61 and the rod body 62 together. Figure 2 The connection between the middle pressure cover 61 and the rod body 62 is specifically a threaded connection, but the pressure cover 61 and the rod body 62 can also be assembled together by pin connection, welding, etc.

[0045] Of course, when assembling the control assembly, step S1 and step S2 may also be reversed.

[0046] In other specific embodiments, the push rod may not include the gland 61. The upper portion of the push rod has a bent portion. After the fishing rod 9 and the compression elastic member 10 are installed in the axial mounting hole 64, the bent portion is bent inward to allow the compression elastic member 10 to be removed from the axial mounting hole 64. The compression elastic member 10 is specifically a commonly used compression elastic member 10 such as the compression spring 5.

[0047] Specific embodiment 2 of the bidirectional sand flushing valve provided by the present invention: The object of the present invention is to provide a bidirectional sand flushing valve with a tensile elastic member.

[0048] In reference Figure 3-4 On the basis of Figure 7 As shown, the main difference between this embodiment and specific embodiment 1 is that in specific embodiment 1, the elastic member is a compression elastic member 10, while in this embodiment, the elastic member is a commonly used tensile elastic member such as a tension spring and a rubber band.

[0049] like Figure 7As shown, when assembling the control assembly, the ends of the tensile elastic member are first fixedly connected to the rod body 62 and the salvage rod 9, respectively. Then, the salvage rod 9 is installed in the axial mounting hole 64, and finally, the gland 61 is installed. When the salvage rod 9 is lifted, it stops and engages with the gland 61 after moving up a set distance to prevent further deformation of the tensile elastic member. At this time, the salvage rod 9 and the tensile elastic member together apply an upward force to the push rod to remove the push rod.

[0050] However, in other specific embodiments, the mandrel may not include the gland 61. In this case, it is necessary to ensure that the tensile elastic member itself, the connection between the tensile elastic member and the mandrel, and the connection between the tensile elastic member and the salvage rod 9 have sufficient connection strength. When the salvage rod 9 is lifted, the salvage rod 9 causes the tensile elastic member to deform, and the tensile elastic member applies an upward pulling force to the mandrel to fish the mandrel out.

[0051] Specific embodiments of the one-way valve structure provided by the present invention: The specific structure of the one-way valve structure in this embodiment is the same as the specific structure of the one-way valve structure in specific embodiment 1 or 2 of the two-way sand flushing valve of the present invention, and will not be repeated here.

[0052] Specific embodiments of the control component provided by the present invention: The specific structure of the control assembly in this embodiment is the same as the specific structure of the control assembly in specific embodiment 1 or 2 of the two-way sand flushing valve of the present invention, and will not be repeated here.

[0053] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments without inventive effort, or replace some of the technical features therein with equivalents. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A two-way sand flushing valve, characterized in that: Including a one-way valve structure and a control component; The one-way valve structure includes a valve seat with a flow passage and a valve core for opening and closing the flow passage. The valve seat is provided with a plug hole, and a locking groove is provided on the hole wall of the plug hole. The control assembly includes a push rod for inserting into the socket and pushing the valve core to open the valve core, the push rod having a radial mounting hole, an eccentric cam rotatably assembled in the radial mounting hole, the axial direction of the push rod being defined as the up and down direction, the rotation axis of the eccentric cam extending horizontally, one end of the eccentric cam protruding from the radial mounting hole in the initial state and constituting a locking end for locking with the locking groove, the upper end of the push rod is also provided with an axial mounting hole connected to the radial mounting hole, a salvage rod for cooperating with the salvage mechanism to salvage the entire control assembly is installed in the axial mounting hole, the salvage rod and the axial mounting hole are movably matched in the axial direction, a limiting protrusion is provided on the hole wall of the axial mounting hole for limiting the lowest position of the downward movement of the salvage rod, and the movement stroke of the salvage rod also has a state switching position above the lowest position, and an elastic member for applying a downward elastic force to the salvage rod is provided between the salvage rod and the axial mounting hole; The eccentric cam is provided with a torsion spring for returning the eccentric cam to its initial state, or the eccentric cam can return to its initial state under its own weight; When the fishing rod is lower than the state switching position, the locking end can rotate forward into the radial mounting hole, but the fishing rod is used to cooperate with the eccentric cam stopper before the locking end rotates reversely into the radial mounting hole, so as to ensure that the locking end is locked with the locking groove when the locking end is in the locking groove and the valve core is always opened by the push rod; When the salvage rod is not lower than the state switching position, the locking end can be rotated in the opposite direction to the radial mounting hole to unlock the locking end and the locking groove, thereby enabling the push rod to exit the socket and separate from the valve core when the salvage mechanism salvages the control component.

2. The two-way sand flushing valve according to claim 1, characterized in that: The section of the jack located at the upper end forms a jack expansion section, the inner diameter of the jack expansion section gradually decreases from top to bottom, and the hole wall of the jack expansion section forms a jack guide surface for guiding the push rod and the eccentric cam.

3. The two-way sand flushing valve according to claim 1 or 2, characterized in that: The one-way valve structure also includes a valve body, a valve seat installed in the inner cavity of the valve body, and an axial side flow channel is formed between the valve seat and the valve body. The flow channel includes a socket and a radial connecting channel connecting the socket and the axial side flow channel.

4. The two-way sand flushing valve according to claim 1 or 2, characterized in that: The push rod includes a rod body and a pressure cap detachably mounted on the upper end of the rod body. Both the pressure cap and the rod body are provided with axial holes, and the axial holes on the pressure cap and the rod body together constitute the axial mounting hole. The salvage rod has a radial boss, and the elastic member is a compressed elastic member compressed between the pressure cap and the radial boss. The limiting protrusion is used to cooperate with the radial boss stop to limit the lowest position of the downward movement of the salvage rod.

5. The two-way sand flushing valve according to claim 1 or 2, characterized in that: The one-way valve structure also includes a valve body, a valve seat installed in the inner cavity of the valve body, and a spring seat is also installed in the inner cavity of the valve body. The spring seat has a compression spring installation cavity extending in the up and down directions, a compression spring is installed in the compression spring installation cavity, and the valve core is fixedly connected to the upper end of the compression spring; a radial through hole is provided on the spring seat for connecting the compression spring installation cavity and the space between the spring seat and the valve body, and an axial through hole is also provided on the spring seat for connecting the compression spring installation cavity and the space below the spring seat.

6. A control component, characterized in that: The cam is fixed with an eccentric cam which is rotatably mounted in the radial mounting hole, and the axial direction of the cam is defined as the up and down direction. The rotation axis of the eccentric cam extends horizontally. In the initial state, one end of the eccentric cam extends out of the radial mounting hole and constitutes a locking end. The upper end of the cam is also provided with an axial mounting hole which is connected with the radial mounting hole. A salvage rod for cooperating with a salvage mechanism to salvage the entire control assembly is installed in the axial mounting hole. The salvage rod is movably matched with the axial mounting hole in the axial direction. A limiting protrusion is provided on the hole wall of the axial mounting hole for limiting the lowest position of the downward movement of the salvage rod. The salvage rod also has a state switching position which is higher than the lowest position in its moving stroke. An elastic member for applying a downward elastic force to the salvage rod is provided between the salvage rod and the axial mounting hole. The eccentric cam is provided with a torsion spring for returning the eccentric cam to its initial state, or the eccentric cam can return to its initial state under its own weight; When the fishing rod is lower than the state switching position, the locking end can be rotated forward into the radial mounting hole, but the fishing rod is used to cooperate with the eccentric cam stopper before the locking end is rotated reversely into the radial mounting hole; When the fishing rod is not lower than the state switching position, the locking end can be rotated in the reverse direction into the radial mounting hole.

7. The control assembly according to claim 6, wherein: The push rod includes a rod body and a pressure cap detachably mounted on the upper end of the rod body. Both the pressure cap and the rod body are provided with axial holes, and the axial holes on the pressure cap and the rod body together constitute the axial mounting hole. The salvage rod has a radial boss, and the elastic member is a compressed elastic member compressed between the pressure cap and the radial boss. The limiting protrusion is used to cooperate with the radial boss stop to limit the lowest position of the downward movement of the salvage rod.

8. A one-way valve structure, characterized in that: It comprises a valve seat with a flow passage and a valve core for switching the flow passage, the valve seat is provided with a socket for inserting the push rod in the control assembly described in any one of claims 6-7, and the hole wall of the socket is provided with a locking groove for locking with the eccentric cam in the control assembly.

9. The one-way valve structure according to claim 8, characterized in that: The section of the jack located at the upper end forms a jack expansion section, the inner diameter of the jack expansion section gradually decreases from top to bottom, and the hole wall of the jack expansion section forms a jack guide surface for guiding the push rod and the eccentric cam.

10. The one-way valve structure according to claim 8 or 9, characterized in that: The one-way valve structure also includes a valve body, a valve seat installed in the inner cavity of the valve body, and an axial side flow channel is formed between the valve seat and the valve body. The flow channel includes a socket and a radial connecting channel connecting the socket and the axial side flow channel.

11. The one-way valve structure according to claim 8 or 9, characterized in that: The one-way valve structure also includes a valve body, a valve seat installed in the inner cavity of the valve body, and a spring seat is also installed in the inner cavity of the valve body. The spring seat has a compression spring installation cavity extending in the up and down directions, a compression spring is installed in the compression spring installation cavity, and the valve core is fixedly connected to the upper end of the compression spring; a radial through hole is provided on the spring seat for connecting the compression spring installation cavity and the space between the spring seat and the valve body, and an axial through hole is also provided on the spring seat for connecting the compression spring installation cavity and the space below the spring seat.

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