arrow switch valve

Abstract

The present application relates to a kind of arrow-shaped switch valve, for oil and gas well completion.The present application includes upper joint, valve body and lower joint thread connection in turn, set valve core assembly in valve cavity, assembly includes central tube, main valve and big spring;Upper sealing surface two and upper sealing surface one are formed upper sealing pair respectively in the outer part of the upper end of central tube and the inner hole of the lower end of upper joint;Big spring is installed in the annulus between central tube and valve body;Recycle hole is arranged in the side wall of valve body below inner step one;The lower end of central tube is connected with main valve, the lower part of the outer cone or sphere of main valve is contacted with the inner conical surface two in the inner hole of lower joint, and lower sealing pair is formed;The upper end surface of main valve is provided with counterbore, drain hole is arranged in the side wall of counterbore in the middle of main valve, and the lower sealing pair is below drain hole.Because recycle hole is arranged, well washing operation can be carried out in time, and the switch valve of the present application is reliable in operation and long in service life.

Description

Technical Field

[0001] This invention belongs to the field of downhole tools technology for oilfield development, and in particular relates to an arrow-shaped switching valve for oil and gas well completion. Background Technology

[0002] Downhole check valves are commonly used downhole tools, especially on production tubing strings for electric submersible pumps (ESPs). Generally, a simple check valve, consisting of a ball and a seat, is installed above the ESP to prevent backflow of fluid and damage to the centrifugal pump. During oil production, prolonged fluid erosion can damage the sealing surface between the ball and seat, resulting in a short lifespan for this type of check valve. During production, many wells carry formation mud and sand in their produced fluid. When production is suspended, this sediment can fall onto the check valve and clog the tubing, causing restarting failure. Production tubing strings with this structure cannot perform circulation flushing to remove the sediment above the check valve. To address this flushing issue, some well tubing strings also install a sliding sleeve above the check valve. However, because the sliding sleeve may be too far from the check valve, this still does not completely solve the flushing problem. Summary of the Invention

[0003] To solve the above-mentioned technical problems, an arrow-shaped switching valve was invented, which solves the problem of the lack of a well-washing channel in the current single-flow valve and improves its service life.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] An arrow-shaped on / off valve has an upper connector, valve body, and lower connector sequentially and coaxially threaded together. A valve core assembly is housed in the valve cavity. The valve core assembly includes a central tube, a main valve, and a large spring. A second upper sealing surface is provided on the outer surface of the upper end of the central tube. Correspondingly, a first upper sealing surface is provided in the inner hole of the lower end of the upper connector, forming an upper sealing pair. The central tube is a tube that is smaller at the top and larger at the bottom, and has an outer step. An inner step is provided in the inner hole of the valve body. The annular space between the central tube and the valve body contains the outer step and the inner step. A large spring is installed between the first and second steps; a circulation hole is provided on the side wall of the valve body between the upper connector and the central tube; a breather hole is provided on the side wall of the valve body below the first inner step; the lower end of the central tube is coaxially connected to the main valve, the lower part of the main valve is an outer cone or a sphere; an inner cone surface II is provided in the inner hole of the lower connector; the outer cone or sphere at the lower part of the main valve and the inner cone surface II form a lower sealing pair; a countersunk hole is provided on the upper end face of the main valve, and a drain hole is provided on the side wall of the countersunk hole in the middle of the main valve, the lower sealing pair is located below the drain hole.

[0006] Furthermore, the inner hole of the lower connector is a stepped hole, and its upper part is an enlarged diameter hole. The transition surface between the enlarged diameter hole and the main channel of the lower connector is an inner conical surface. The drain hole is located axially inside the enlarged diameter hole.

[0007] Furthermore, the main valve has an internal thread at the bottom of its countersunk hole; the mandrel is a stepped cylinder that is larger at the top and smaller at the bottom, with an external thread at its lower end that connects to the internal thread in the main valve's countersunk hole; a sand-blocking valve is coaxially fitted in the middle of the mandrel; the lower part of the sand-blocking valve is conical or spherical, and the upper port of the main valve's countersunk hole is an inner cone shape, with a central sealing pair formed at the contact point between the sand-blocking valve and the upper port of the main valve's countersunk hole.

[0008] Furthermore, the inner hole of the sand-blocking valve is a stepped hole with an inner step three, and the mandrel has an outer step three. A small spring is installed in the annular space between the outer step three and the inner step three.

[0009] Furthermore, the upper outer periphery of the mandrel is provided with an outer step two, the outer diameter of which is larger than the inner diameter of the inner step two in the inner hole of the central tube; the upper large diameter section of the mandrel is provided with an axial flow channel.

[0010] A sand-blocking cap is threaded into the breathing hole, and a filter screen is fixedly installed on the sand-blocking cap.

[0011] An auxiliary sealing ring is provided on the lower side wall of the upper connector at a position below the upper sealing surface.

[0012] The valve body has a groove on its outer periphery, and a countersunk screw thread is provided on the small diameter circumferential surface of the groove. The cable clamp is fixed in the groove with a screw, and the cable clamp has an axial cable groove.

[0013] Furthermore, the upper and lower ends of the cable clip have triangular cross sections, and correspondingly, triangular openings with triangular cross sections are also provided at the upper and lower ends of the card slot, with the upper and lower ends of the cable clip placed inside the triangular openings; cable clip mounting grooves are provided around the triangular openings, and the mounting grooves are arranged vertically opposite each other.

[0014] Furthermore, the mounting slot includes a long mounting slot and a short mounting slot. Two long mounting slots and two short mounting slots are arranged at the triangular openings on both the upper and lower sides. The long mounting slots and short mounting slots are arranged alternately and symmetrical about the center.

[0015] An upper settling step is provided in the inner hole of the upper connector, and a lower settling step is provided in the inner hole of the central tube.

[0016] Compared with the prior art, the advantages of the present invention are as follows:

[0017] 1. Because a circulation hole is provided on the side wall of the arrow-shaped switch valve, when sand settles on the valve and the pump cannot be started, well washing operations can be carried out in time to remove sand blockage and restore oil well production.

[0018] 2. A sand-blocking valve has been added to the valve core assembly inside the valve cavity, so that sand will not fall directly onto the lower sealing surface. This facilitates reopening after sand accumulation and, in particular, reduces the probability of sand falling onto the lower sealing surface, thus improving its sealing life.

[0019] 3. When the drain hole is submerged in the enlarged diameter hole of the lower connector, the erosion of the lower sealing pair by the liquid flow is small when the valve is opened, and the valve has a long service life.

[0020] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0021] When considered in conjunction with the accompanying drawings, the invention will be more fully understood and its many accompanying advantages will become readily apparent from the following detailed description. However, the accompanying drawings, which are provided to further illustrate the invention and form part of this invention, are intended to explain the invention and do not constitute an undue limitation thereof.

[0022] Figure 1 This is a schematic diagram of the arrow-shaped switching valve of the present invention. Because the tool of the present invention is quite long, it has been truncated in the middle; the truncated section is connected by a dashed line in the diagram.

[0023] Figure 2 yes Figure 1 Sectional view at point AA.

[0024] Figure 3 This is a schematic diagram of the cable clip installation structure.

[0025] Figure 4 yes Figure 1 Sectional view at point BB.

[0026] Figure 5 yes Figure 1 Enlarged view of point C in the middle.

[0027] Figure 6 yes Figure 1 Enlarged view of point D in the middle.

[0028] Figure 7 yes Figure 1 Enlarged view of point E in the middle.

[0029] In the picture:

[0030] 1-Upper connector, 101-Upper seat step, 103-Upper sealing surface one, 104-Auxiliary sealing ring;

[0031] 2-Valve body, 201-Circulation hole, 202-Inner step one, 203-Breath hole, 204-Slot, 205-Mounting groove, 206-Screw countersunk thread, 2031-Sand guard cap, 2032-Filter screen, 2041-Triangular bayonet, 2051-Long mounting groove, 2052-Short mounting groove;

[0032] 3-Cable clip, 301-Screw, 302-Cable trough;

[0033] 4-Central tube, 401-Upper sealing surface two, 402-Outer step one, 403-Inner step two, 404-Lower settling step;

[0034] 5-Large springs,

[0035] 6-Mandrel, 601-Outer step two, 602-Flow channel, 603-Outer step three;

[0036] 7-Sand-blocking valve, 701-Inner step three;

[0037] 8-Small spring,

[0038] 9-main valve, 901-drainage hole;

[0039] 10-Lower connector, 1001-Expanded diameter hole, 1002-Inner conical surface II, 1003-Main channel. Detailed Implementation

[0040] The terms "upper" and "lower" used in this application specification and claims refer to the state when the tool is in use. In the drawings, sealing rings are drawn at the points where sealing is required between the parts, as shown in the drawings. They will not be described in detail in the following description.

[0041] Example 1

[0042] See Figure 1 As shown, the arrow-shaped switching valve has an upper connector 1, a valve body 2, and a lower connector 10 connected coaxially and threaded in sequence. A valve core assembly is set in the valve cavity. The valve core assembly includes a central tube 4, a main valve 9, and a large spring 5.

[0043] The upper end of the central tube is provided with an upper sealing surface 401. Correspondingly, the lower end of the upper connector is provided with an upper sealing surface 103. The upper sealing surface 1 and the upper sealing surface 2 form an upper sealing pair.

[0044] The central tube is a tube body that is smaller at the top and larger at the bottom, and is provided with an outer step 402. An inner step 202 is provided in the inner hole of the valve body. A large spring 5 is installed in the annular space between the central tube and the valve body, between the outer step and the inner step.

[0045] The arrow-shaped switching valve of the present invention is a normally closed unidirectional valve, with attachment Figure 1The state shown is the closed state. Based on the positional relationship of the components in the closed state shown in the diagram, a circulation hole 201 is provided on the side wall of the valve body between the upper connector and the central tube;

[0046] A breather hole 203 is provided on the side wall of the valve body below the inner step 202;

[0047] The lower end of the central tube is coaxially connected to the main valve 9. The lower part of the main valve is an outer cone or sphere, or referred to as an outer cone or sphere. An inner cone surface 1002 is provided in the inner hole of the lower connector. The outer cone or sphere at the lower part of the main valve and the inner cone surface 1002 form a lower sealing pair. A countersunk hole is provided on the upper end face of the main valve. A drain hole 901 is provided on the side wall of the countersunk hole in the middle of the main valve. The lower sealing pair is located below the drain hole.

[0048] When closed, the circulation port 201 connects the inside and outside of the valve. If there is sand in or above the valve, it can be flushed through the circulation port to remove the sand blockage.

[0049] During production, the lower liquid flow moves upward and pushes open the valve core assembly. When the production displacement reaches a certain value, the upward thrust generated by the throttling pressure difference on the valve core assembly is greater than the resistance of the large spring 5. The central tube 4 moves upward, and its upper end contacts the lower end of the upper connector 1. The upper sealing surface 103 and the upper sealing surface 401 form an upper sealing pair. At this time, the circulation hole 201 is closed.

[0050] Example 2

[0051] See Figure 1 As shown, Embodiment 2 is an improvement on Embodiment 1. The improvement is that the inner hole of the lower connector is set as a stepped hole, the upper part of which is an enlarged diameter hole 1001. The transition surface between the enlarged diameter hole 1001 and the main channel 1003 of the lower connector is an inner conical surface 1002. The drain hole 901 is axially located inside the enlarged diameter hole.

[0052] In the improved arrow-shaped switch valve, during production, the upward flow of liquid erodes the upper port of the enlarged diameter hole 1001 of the lower connector 10, and the eroded part is far away from the inner conical surface 1002. This improvement protects the lower sealing pair and improves its service life.

[0053] Example 3

[0054] Example 3 is a further improvement on Example 2. The improvements are as follows:

[0055] See Figure 1As shown, the bottom of the countersunk hole of the main valve 9 is provided with an internal thread; the mandrel 6 is a stepped cylinder with a larger upper part and a smaller lower part, and its lower end is provided with an external thread that connects with the internal thread in the countersunk hole of the main valve; the sand-blocking valve 7 is coaxially fitted in the middle of the mandrel 6; the lower part of the sand-blocking valve is conical or spherical, or referred to as a cone or sphere, and the upper port of the countersunk hole of the main valve is an inner cone shape. The sand-blocking valve and the upper port of the countersunk hole of the main valve form a central sealing pair at the contact point.

[0056] The improved arrow-shaped switch valve, with the addition of a sand-blocking valve 7, prevents sand from falling directly onto the lower sealing surface when the well production is suspended. This prevents leakage caused by sand falling onto the sealing surface. This structure, with a small buffer chamber for sand-free areas, also facilitates restarting the submersible pump after sand flushing.

[0057] Example 4

[0058] Example 4 is a further improvement on Example 3. The improvements are as follows:

[0059] See Figure 1 As shown, the inner hole of the sand-blocking valve is a stepped hole with an inner step three 701, and the mandrel has an outer step three 603. A small spring 8 is installed between the outer step three and the inner step three in the annular space between the mandrel and the sand-blocking valve. After the improvement, the added small spring can help the sand-blocking valve to quickly return to its original position.

[0060] Example 5

[0061] Example 5 is a further improvement on Example 4. The improvements are as follows:

[0062] See Figure 1 and Figure 4 As shown, the upper outer periphery of the mandrel is provided with an outer step 601, the outer diameter of which is larger than the inner diameter of the inner step 403 in the inner hole of the central tube; the upper large-diameter section of the mandrel is provided with an axial flow channel 602. After the improvement, the mandrel can be prevented from disengaging under the impact of the fluid flow.

[0063] Example 6

[0064] Example 6 is an improvement upon Example 1. The improvements are as follows:

[0065] See Figure 5 As shown, a sand-blocking cap 2031 is threaded into the breather hole, and a filter screen 2032 is fixedly installed on the sand-blocking cap. Alternatively, the breather hole 203 can be designed as a stepped hole, with the bottom of the thread being a flat surface. The filter screen 2032 is installed on this flat surface at the bottom of the thread and secured with the sand-blocking cap 2031. The advantage of this improvement is that it prevents foreign objects such as mud and sand from entering the large spring cavity, ensuring the long-term reliable operation of the large spring.

[0066] Example 7

[0067] Example 7 is an improvement upon Example 1. The improvements are as follows:

[0068] See Figure 1 and Figure 6 As shown, an auxiliary sealing ring 104 is provided on the lower side wall of the upper connector at a position below the upper sealing surface. This improvement is more conducive to the reliable sealing of the upper sealing pair.

[0069] Example 8

[0070] Example 8 is an improvement upon any of Examples 1-7. The improvement is as follows:

[0071] See Figure 1 and Figure 2 As shown, a groove 204 is provided on the outer periphery of the valve body, and a countersunk screw thread 206 is provided on the small-diameter circumferential surface of the groove. The cable clamp 3 is fixed in the groove with a screw 301, and the cable clamp has an axial cable groove 302. After the improvement, the arrow-shaped switch valve of the present invention can be used on the production line of an electric submersible pump, and the power cable is fixed in the cable groove 302.

[0072] The arrow-shaped switching valve of this invention can be used where needed in oilfield well completion, such as for reservoir protection when placed above the oil layer and packer. It can also be used in production wells with electric submersible pumps. The cable clamp can also be installed on the outer wall of the upper or lower connector.

[0073] Example 9

[0074] Example 9 is an improvement upon Example 8. The improvements are as follows:

[0075] See Figure 1 , Figure 2 and Figure 7 As shown, the upper and lower ends of the cable clip 3 are triangular cross sections. Correspondingly, triangular slots 2041 with triangular cross sections are also provided at the upper and lower ends of the slot. The upper and lower ends of the cable clip are placed inside the triangular slots. Cable clip mounting grooves 205 are provided around the triangular slots, and the mounting grooves are arranged vertically opposite each other.

[0076] The improved design facilitates on-site installation of the cable clips and prevents them from falling off the slot 204 under external force.

[0077] Example 10

[0078] Example 10 is a further improvement on Example 9. The improvements are as follows:

[0079] See Figure 1 , Figure 2 and Figure 3 As shown, after the cable clamp 3 is equipped with the cable groove 302, it forms a structure that is wider on one side and narrower on the other, with the side for mounting screws being the wider side. Correspondingly, to accommodate this structure of the cable clamp, the mounting groove 205 includes a long mounting groove 2051 and a short mounting groove 2052. Two long mounting grooves and two short mounting grooves are arranged at the triangular openings on both the upper and lower sides. The long and short mounting grooves are staggered and symmetrical about the center, meaning that two sets of cable clamp mounting grooves are provided on the circumference of the clamp groove 204, which facilitates on-site installation. Figure 3 The image shows the initial state of the cable clip inserted into the mounting slot. Figure 2 The image shows the angle at which the cable clip can be rotated to install the screw after entering the triangular bayonet. The improved design reduced the amount of machining required.

[0080] Example 11

[0081] Example 11 is a further improvement on Example 10. The improvements are as follows:

[0082] See Figure 1 As shown, an upper landing step 101 is provided in the inner hole of the upper connector for suspending logging instruments or installing plugs. A lower landing step 404 is provided in the inner hole of the central tube for lowering a forced opening tool and fixing it on the lower landing step 404 to perform forced opening operations after the valve core assembly becomes stuck.

[0083] Obviously, many modifications and variations made by those skilled in the art based on the spirit of this invention fall within the scope of protection of this invention.

Claims

1. An arrow-shaped switching valve, wherein the upper connector (1), valve body (2), and lower connector (10) are sequentially and coaxially threaded together, and a valve core assembly is provided in the valve cavity, characterized in that, The valve core assembly includes a central tube (4), a main valve (9), and a large spring (5); an upper sealing surface two (401) is provided on the outer side of the upper end of the central tube, and correspondingly, an upper sealing surface one (103) is provided in the inner hole of the lower end of the upper connector, the upper sealing surface one and the upper sealing surface two forming an upper sealing pair; the central tube is a tube body that is smaller at the top and larger at the bottom, and is provided with an outer step one (402), and an inner step one (202) is provided in the inner hole of the valve body, and a large spring (5) is installed in the annulus between the outer step one and the inner step one; on the upper connector A circulation hole (201) is provided on the side wall of the valve body between the head and the central tube; a breather hole (203) is provided on the side wall of the valve body below the inner step one; the lower end of the central tube is coaxially connected to the main valve, and the lower part of the main valve is an outer cone or a sphere; an inner cone surface two (1002) is provided in the inner hole of the lower connector; the outer cone or sphere at the lower part of the main valve and the inner cone surface two form a lower sealing pair; a countersunk hole is provided on the upper end face of the main valve, and a drain hole (901) is provided on the side wall of the countersunk hole in the middle of the main valve, and the lower sealing pair is located below the drain hole; The inner hole of the lower connector is a stepped hole, and its upper part is an enlarged diameter hole (1001). The transition surface between the enlarged diameter hole and the main channel (1003) of the lower connector is an inner conical surface (1002). The drain hole (901) is located axially inside the enlarged diameter hole. The main valve has an internal thread at the bottom of the countersunk hole; the mandrel (6) is a stepped cylinder with a larger upper part and a smaller lower part, and its lower end has an external thread that connects with the internal thread in the countersunk hole of the main valve; the sand-blocking valve (7) is coaxially fitted in the middle of the mandrel; the lower part of the sand-blocking valve is conical or spherical, the upper port of the countersunk hole of the main valve is an inner cone, and the sand-blocking valve and the upper port of the countersunk hole of the main valve form a middle sealing pair at the contact point; The inner hole of the sand-blocking valve is a stepped hole with an inner step three (701), and the mandrel has an outer step three (603). A small spring (8) is installed between the outer step three and the inner step three in the annular space between the mandrel and the sand-blocking valve. The upper outer periphery of the mandrel is provided with an outer step two (601), the outer diameter of the outer step two is larger than the inner diameter of the inner step two (403) in the inner hole of the central tube; the upper large diameter section of the mandrel is provided with an axial flow channel (602).

2. The arrow-shaped switching valve according to claim 1, characterized in that, The valve body is provided with a groove (204) on its outer periphery, and a screw countersunk thread (206) is provided on the small diameter circumferential surface of the groove. The cable clamp (3) is fixed in the groove with a screw (301). The cable clamp is provided with an axial cable groove (302). The cable clip has a triangular cross-section at both the top and bottom. Correspondingly, a triangular opening (2041) with a triangular cross-section is also provided at both the top and bottom of the slot. The top and bottom of the cable clip are placed inside the triangular opening. A cable clip mounting groove (205) is provided around the triangular opening. The mounting grooves are arranged vertically opposite each other. The mounting slots include a long mounting slot (2051) and a short mounting slot (2052). Two long mounting slots and two short mounting slots are arranged at the triangular openings on both the upper and lower sides. The long mounting slots and short mounting slots are arranged alternately and symmetrical about the center.

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