Underground temporary plugging safety valve

Abstract

The utility model belongs to the technical field of oil and gas development, and particularly relates to an underground temporary plugging safety valve. The underground temporary plugging safety valve comprises a connecting sleeve; the check valve is arranged in the connecting sleeve, and the check valve is configured to allow fluid to flow from top to bottom; the sliding sleeve is arranged in the connecting sleeve through a pin, and an overflowing channel is arranged along the central axis of the sliding sleeve; in the first state, the sliding sleeve is located above the check valve. And in the second state, the sliding sleeve extends into the check valve, so that the fluid can flow through the check valve without being limited.

Description

Technical Field

[0001] The utility model belongs to the technical field of oil and gas development, and particularly relates to a downhole temporary plugging safety valve. Background Technique

[0002] With the acceleration of the development pace of unconventional natural gas such as tight gas and shale gas, in order to reduce the pollution of gas wells caused by well killing operations, the operation of running tubing under pressure in gas wells has become the core technology for the development of unconventional gas wells and has been widely implemented.

[0003] The operation of running tubing under pressure in gas wells is a method of running tubing or coiled tubing into the designed depth in the well under the condition of not killing the well with the help of a pressure control service unit. When running tubing under pressure in a gas well, in order to prevent high-pressure gas in the well from overflowing, a temporary plugging device needs to be installed on the first tubing.

[0004] In the prior art, a common temporary plugging device is to install a ceramic rupture disk on the tubing. After the tubing is run to the required position, high-pressure fluid is injected into the tubing through surface equipment such as a surface pump truck or a nitrogen generation vehicle, and the ceramic rupture disk is broken under high pressure to establish a tubing passage.

[0005] Using a ceramic rupture disk as a temporary plugging device has some deficiencies. For example, due to factors such as tool impact and vibration during transportation and running-in, the ceramic rupture disk may be broken in advance. In addition, the fragments formed after the ceramic rupture disk breaks fall into the well, forming downhole debris, which brings risks to the safe production of gas wells.

[0006] In view of the above deficiencies, the utility model provides a downhole temporary plugging safety valve for preventing overflow during running tubing under pressure. Content of the Utility Model

[0007] Aiming at the above technical problems, the utility model aims to provide a downhole temporary plugging safety valve, which can achieve the technical effect of temporary plugging during the operation of running tubing under pressure in a gas well.

[0008] According to the utility model, there is provided a downhole temporary plugging safety valve, comprising:

[0009] A connecting sleeve;

[0010] A check valve arranged in the connecting sleeve, the check valve being configured to allow fluid to flow unidirectionally from top to bottom; and

[0011] A sliding sleeve arranged in the connecting sleeve by a pin, and an over-flow channel is arranged along the central axis of the sliding sleeve;

[0012] In a first state, the sliding sleeve is located above the check valve;

[0013] In a second state, the sliding sleeve extends into the check valve, enabling fluid to flow through the check valve without restriction.

[0014] According to the present utility model, in a specific embodiment, the check valve includes:

[0015] A valve seat coaxially arranged inside the connecting sleeve, with a valve hole provided at the central axis of the valve seat, and the size of the valve hole is larger than the outer size of the sliding sleeve; and

[0016] A valve plate hingedly arranged on the valve seat,

[0017] In the first state, the valve plate seals the valve hole,

[0018] In the second state, the sliding sleeve extends into the valve hole and pushes the valve plate, thereby releasing the sealing of the valve hole by the valve plate.

[0019] According to the present utility model, in a specific embodiment, the edge of the valve plate is hinged to the valve seat through a pin shaft, and a torsion spring is sleeved on the pin shaft. The torsion spring provides a pre-tightening force for the valve plate, so that the valve plate abuts against the valve seat in the first state, and further seals the valve hole.

[0020] According to the present utility model, in a specific embodiment, the check valve further includes a valve body coaxially arranged inside the connecting sleeve. The valve body is located at one end of the valve seat away from the sliding sleeve, and a receiving cavity is provided on the side surface of the valve body. The receiving cavity is configured to be able to receive the valve plate in the second state.

[0021] According to the present utility model, in a specific embodiment, the connecting sleeve includes a first sleeve and a second sleeve coaxially arranged from top to bottom. The inner diameter of the first sleeve is smaller than the inner diameter of the second sleeve. The check valve is arranged inside the second sleeve, and the end of the check valve contacts the end of the first sleeve.

[0022] According to the present utility model, in a specific embodiment, a lower joint is provided at the lower end of the connecting sleeve.

[0023] According to the present utility model, in a specific embodiment, the upper end of the lower joint extends into the interior of the connecting sleeve, and the upper end of the lower joint contacts the end of the check valve.

[0024] According to the present utility model, in a specific embodiment, a first sealing ring is provided between the valve seat and the connecting sleeve.

[0025] According to the present utility model, in a specific embodiment, a second sealing ring for sealing with the valve plate is provided on the end face of the valve seat.

[0026] According to the present utility model, in a specific embodiment, a ball seat for throwing a ball is provided inside the sliding sleeve.

[0027] Compared with the prior art, the advantages of the present application are as follows.

[0028] The present utility model can be installed on the tubing. During the process of the tubing being lowered into the well, the check valve allows fluid to flow from top to bottom. That is to say, the fluid below the check valve cannot flow upward across the check valve. Specifically, the valve plate of the check valve is hinged below the valve seat, and the valve plate abuts against the end face of the valve seat under the action of a torsion spring, thereby sealing the valve hole on the valve seat. After the tubing is lowered in place, a downward force is applied to the sliding sleeve to cut the shear pin and move the sliding sleeve downward relative to the connecting sleeve. Then, the sliding sleeve passes through the valve hole of the valve seat and pushes the valve plate to release the sealing of the valve hole. At the same time, the flow-through channel of the sliding sleeve connects the inner cavities of the connecting sleeves on both sides of the check valve, enabling the fluid to flow freely in the downhole temporary plugging safety valve.

[0029] Compared with the ceramic rupture disk in the prior art, the present application will not form fragments falling into the well, thereby avoiding the risk to the safe production of the gas well caused by the formation of downhole debris. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The present utility model will be described below with reference to the accompanying drawings.

[0031] Figure 1 Shows a schematic diagram of a first state of an embodiment of a downhole temporary plugging safety valve according to the present utility model;

[0032] Figure 2 Shows Figure 1 a schematic diagram of an embodiment of the check valve in

[0033] Figure 3 Shows a schematic diagram of a second state of an embodiment of a downhole temporary plugging safety valve according to the present utility model.

[0034] In the figure:

[0035] 1. Connecting sleeve; 11. First sleeve; 12. Second sleeve; 13. Third sleeve; 2. Check valve; 21. Valve seat; 22. Valve hole; 23. Valve plate; 24. Pin shaft; 25. Torsion spring; 26. Valve body; 27. Accommodation cavity; 3. Shear pin; 4. Sliding sleeve; 41. Flow-through channel; 42. Ball seat; 5. Lower joint; 61. First sealing ring; 62. Second sealing ring; 63. Third sealing ring; 64. Fourth sealing ring; 65. Fifth sealing ring; 66. Sixth sealing ring; 67. Seventh sealing ring; 68. Eighth sealing ring; 7. Upper joint; 8. Sealing ball; 100. Downhole temporary plugging safety valve.

[0036] In this application, all the attached drawings are schematic drawings, only used to illustrate the principle of the present utility model and not drawn to actual scale. Detailed implementation mode

[0037] The present utility model will be introduced below with reference to the attached drawings.

[0038] It should be noted that in this application, the direction close to the wellhead after the present utility model is lowered into the well is described as "up" or similar terms, that is Figure 1 above; the direction away from the wellhead after the present utility model is lowered into the well is described as "down" or similar terms, that is Figure 1 below.

[0039] Figure 1 shows the structure of the downhole temporary plugging safety valve 100 according to the present utility model. As Figure 1 shown, the downhole temporary plugging safety valve 100 includes a connecting sleeve 1, a check valve 2 and a sliding sleeve 4.

[0040] Among them, the connecting sleeve 1 is configured to be generally in the shape of a cylindrical barrel, and the upper and lower ends of the connecting sleeve 1 are configured to be able to be connected to other downhole tools or tubing.

[0041] The check valve 2 is coaxially and sealingly arranged in the inner cavity of the connecting sleeve 1. The check valve 2 is configured to allow fluid to flow from top to bottom. That is to say, the fluid located below the check valve 2 inside the connecting sleeve 1 cannot flow upward through the check valve 2.

[0042] The sliding sleeve 4 is configured to be generally in the shape of a cylindrical barrel, and a flow-through channel 41 is arranged along the central axis of the sliding sleeve 4. In the first state, the sliding sleeve 4 is coaxially arranged in the inner cavity of the connecting sleeve 1 through a pin 3, and the sliding sleeve 4 is located above the check valve 2. In the second state, as Figure 3 shown, the sliding sleeve 4 shears the pin 3 and moves downward relative to the connecting sleeve 1. Finally, the sliding sleeve 4 extends into the check valve 2, and the flow-through channel 41 of the sliding sleeve 4 connects the inner cavities of the connecting sleeve 1 on both sides of the check valve 2, so that the connecting sleeve 1 enables the fluid to flow through the check valve 2 without direction limitation.

[0043] In a specific embodiment, a ball seat 42 is arranged at the upper end of the sliding sleeve 4. When it is necessary to make the sliding sleeve 4 move downward relative to the connecting sleeve 1, a sealing ball 8 is dropped into the connecting sleeve 1 from the ground, so that the sealing ball 8 falls into the ball seat 42, thereby sealing the flow-through channel 41 of the sliding sleeve 4. Then, pressure is applied to the connecting sleeve 1 from the ground, so as to apply a downward pressure to the sliding sleeve 4, making the sliding sleeve 4 move downward relative to the connecting sleeve 1.

[0044] In a preferred embodiment, the upper end of the inner cavity of the connecting sleeve 1 is set as a conical surface, which can play a guiding role for the sealing ball 8.

[0045] In a preferred embodiment, the outer side surface of the lower end portion of the sliding sleeve 4 is provided as a conical surface, which can play a guiding role when it extends into the valve hole 22.

[0046] In a specific embodiment, the check valve 2 includes a valve seat 21 and a valve plate 23.

[0047] As Figure 1 and Figure 2 shown, the valve seat 21 is configured to be generally cylindrical, and a valve hole 22 is provided along the central axis of the valve seat 21. The valve seat 21 is coaxially fixed inside the inner cavity of the connecting sleeve 1. The valve hole 22 of the valve seat 21 can communicate the inner cavities of the connecting sleeve 1 on both the upper and lower sides of the valve seat 21. Moreover, the size of the valve hole 22 is larger than the outer diameter of the sliding sleeve 4, so that the sliding sleeve 4 can extend into the valve hole 22 during the process of moving downward relative to the connecting sleeve 1.

[0048] The valve plate 23 is located below the valve seat 21, and the valve plate 23 is arranged on the valve seat 21 by means of hinge, and the hinge axis of the valve plate 23 is perpendicular to the central axis of the valve seat 21. In the first state, as Figure 1 shown, the valve plate 23 can be in parallel abutment with the end face of the valve seat 21. The size of the valve plate 23 is larger than the size of the valve hole 22. Therefore, in the first state, the valve plate 23 can seal the valve hole 22. In the second state, as Figure 3 shown, the sliding sleeve 4 extends into the valve hole 22 and pushes the valve plate 23 to turn downward relative to the valve seat 21, thereby releasing the seal of the valve hole 22 by the valve plate 23. Moreover, the flow passage 41 of the sliding sleeve 4 can communicate the inner cavities of the connecting sleeve 1 on both the upper and lower sides of the valve seat 21, so that the fluid below the valve seat 21 can flow upward through the flow passage 41 through the valve seat 21, and then the gas production process is implemented.

[0049] As Figure 1 and Figure 3 shown, the valve plate 23 of the check valve 2 can only rotate counterclockwise relative to the valve seat 21. Therefore, when the pressure at the lower part of the valve plate 23 is greater than the pressure at the upper part, the valve plate 23 cannot be opened, and the fluid at the lower part of the valve plate 23 cannot flow upward. After the valve plate 23 is pushed downward from top to bottom by the sliding sleeve 4, the one-way flow restriction of the check valve 2 to the fluid fails, so that the gas production process can be implemented. During this process, the valve plate 23 is always in a connected state with the valve seat 21, and no downhole falling objects will be generated, thus avoiding risks to the safe production of gas wells.

[0050] In a specific embodiment, as Figure 2As shown, the radial edge of the valve plate 23 is hinged to the valve seat 21 through a pin shaft 24. The pin shaft 24 is the hinge shaft of the valve plate 23. The pin shaft 24 is perpendicular to the central axis of the valve plate 23. That is to say, the pin shaft 24 is parallel to the end face of the valve plate 23. A torsion spring 25 is sleeved on the pin shaft 24. The torsion spring 25 provides a pre-tightening force for the valve plate 23, so that the valve plate 23 can maintain the state of abutting against the end face of the valve seat 21 in the first state, and further seal the valve hole 22.

[0051] In a preferred embodiment, the check valve 2 further includes a valve body 26 coaxially arranged in the connecting sleeve 1. As Figure 2 shown, the valve body 26 is configured to be generally in the shape of a cylindrical barrel. The valve body 26 is located at the end of the valve seat 21 away from the sliding sleeve 4, that is, the valve body 26 is arranged at the lower end of the valve seat 21. A receiving cavity 27 is arranged on the side of the valve body 26. The receiving cavity 27 is configured to be able to receive the valve plate 23 in the second state. As Figure 3 shown, when the valve body 26 is pushed by the sliding sleeve 4 and turns downward relative to the valve seat 21, the valve body 26 can enter the receiving cavity 27.

[0052] According to the present invention, in a specific embodiment, the connecting sleeve 1 includes a first sleeve 11 and a second sleeve 12 coaxially arranged from top to bottom. The inner diameter of the first sleeve 11 is smaller than the inner diameter of the second sleeve 12, so as to form a step at the connection of the first sleeve 11 and the second sleeve 12. The check valve 2 is arranged in the second sleeve 12, and the end of the check valve 2 contacts the end of the first sleeve 11. Specifically, the upper end face of the valve seat 21 contacts the lower end face of the first sleeve 11.

[0053] According to the present invention, in a specific embodiment, a lower joint 5 is arranged at the lower end of the connecting sleeve 1. The lower end of the lower joint 5 is used to connect with other downhole tools or tubing. Further, the upper end of the lower joint 5 extends into the connecting sleeve 1, and the upper end of the lower joint 5 contacts the end of the check valve 2. Specifically, the lower end face of the valve body 26 contacts the upper end face of the lower joint 5. The upper and lower ends of the check valve 2 respectively contact the lower end face of the first sleeve 11 and the upper end face of the lower joint 5, so as to prevent the check valve 2 from axially moving relative to the connecting sleeve 1.

[0054] In a specific embodiment, the connecting sleeve 1 further includes a third sleeve 13 coaxially arranged at the upper end of the first sleeve 11. The inner diameter of the third sleeve 13 is smaller than the inner diameter of the first sleeve 11. In the first state, as Figure 1 shown, the sliding sleeve 4 is arranged in the first sleeve 11 through a pin 3, and the upper end face of the sliding sleeve 4 abuts against the lower end face of the third sleeve 13.

[0055] According to the present invention, an upper joint 7 is coaxially fixed at the upper end of the connecting sleeve 1. The upper joint 7 is used to connect the upper downhole tools or tubing.

[0056] In a specific embodiment, as Figure 2 shown, a first sealing ring 61 is provided between the valve seat 21 and the connecting sleeve 1. A second sealing ring 62 for sealing with the valve plate 23 is provided on the end face of the valve seat 21.

[0057] In a specific embodiment, as Figure 1 shown, a third sealing ring 63 is provided between the lower joint 5 and the connecting sleeve 1. A fourth sealing ring 64, a fifth sealing ring 65 and a sixth sealing ring 66 are provided between the upper joint 7 and the connecting sleeve 1. Among them, the fourth sealing ring 64 is located at the lower end of the upper joint 7, and the fifth sealing ring 65 and the sixth sealing ring 66 are respectively located on the upper and lower sides of the pin 3. A seventh sealing ring 67 and an eighth sealing ring 68 are provided between the sliding sleeve 4 and the connecting sleeve 1, and the seventh sealing ring 67 and the eighth sealing ring 68 are respectively located on the upper and lower sides of the pin 3.

[0058] The assembly steps of the downhole temporary plugging safety valve 100 are as follows. The sliding sleeve 4 is connected to the connecting sleeve 1 through the pin 3. Sealing rings are provided on both the upper and lower sides of the pin 3 to prevent fluid from leaking from the gaps between the connecting sleeve 1 and the upper joint 7 and between the sliding sleeve 4 and the connecting sleeve 1. The check valve 2 is sleeved upward from the lower end of the connecting sleeve 1. The upper end of the connecting sleeve 1 is provided with the upper joint 7 through threads, and the lower end of the connecting sleeve 1 is connected to the lower joint 5 through threads.

[0059] During the process of lowering the tubing under pressure, first install the downhole temporary plugging safety valve 100 at the bottom of the tubing and lower it to the designed well depth position of the oil and gas well. During the lowering process, the check valve 2 is in a one-way cut-off state, and the check valve 2 can prevent the downhole fluid from flowing up inside the tubing, thus ensuring well control safety when lowering the tubing string. After lowering in place, a sealing ball 8 is dropped into the tubing. The sealing ball 8 is preferably a soluble sealing ball, and the material can be soluble magnesium alloy, soluble aluminum alloy, soluble resin, etc. The sealing ball 8 is pumped to the ball seat 42 at the upper end of the sliding sleeve 4. Under the hydraulic action, the sliding sleeve 4 shears the pin 3 and moves downward, as Figure 3 shown. Finally, the sliding sleeve 4 extends into the valve hole 22 and pushes open the valve plate 23, so that the gas production process can be implemented.

[0060] In the description of the present invention, it should be understood that the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "a plurality" means two or more, unless otherwise specifically defined.

[0061] In the present utility model, unless otherwise clearly defined and limited, terms such as "installation", "connection", "attachment", "fixation", etc. shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be a direct connection or an indirect connection through an intermediate medium, and it may be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0062] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "examples", "specific examples", or "some examples", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present utility model. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0063] Finally, it should be noted that the above are only the preferred implementation schemes of the present utility model and do not constitute any limitation to the present utility model. Although the present utility model has been described in detail with reference to the foregoing implementation schemes, for those skilled in the art, it is still possible to modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A downhole temporary plugging safety valve, characterized in that: include: Connecting sleeve (1); A one-way valve (2) disposed in the connecting sleeve (1), the one-way valve (2) being configured to allow a fluid to flow in one direction from top to bottom; and A sliding sleeve (4) is arranged in the connecting sleeve (1) through a pin (3), and a flow passage (41) is arranged along the central axis of the sliding sleeve (4); In a first state, the sliding sleeve (4) is located above the check valve (2); In the second state, the sliding sleeve (4) extends into the one-flow valve (2), allowing the fluid to flow through the one-flow valve (2) without restriction.

2. The underground temporary plugging safety valve according to claim 1, characterized in that: The one-flow valve (2) comprises: A valve seat (21) is coaxially arranged in the connecting sleeve (1), a valve hole (22) is arranged at the central axis of the valve seat (21), and the size of the valve hole (22) is larger than the outer size of the sliding sleeve (4); and a valve plate (23) hingedly arranged on the valve seat (21), In the first state, the valve plate (23) seals the valve hole (22). In the second state, the sliding sleeve (4) extends into the valve hole (22) and pushes the valve plate (23), thereby releasing the sealing of the valve hole (22) by the valve plate (23).

3. The underground temporary plugging safety valve according to claim 2 is characterized in that: The edge of the valve plate (23) is hinged to the valve seat (21) via a pin shaft (24), and a torsion spring (25) is sleeved on the pin shaft (24). The torsion spring (25) provides a pre-tightening force for the valve plate (23), so that the valve plate (23) abuts against the valve seat (21) in a first state, thereby sealing the valve hole (22).

4. The underground temporary plugging safety valve according to claim 2, characterized in that: The one-flow valve (2) further comprises a valve body (26) coaxially arranged in the connecting sleeve (1); the valve body (26) is located at an end of the valve seat (21) away from the sliding sleeve (4); a receiving cavity (27) is arranged on a side of the valve body (26); the receiving cavity (27) is configured to receive the valve plate (23) in the second state.

5. The downhole temporary plugging safety valve according to any one of claims 1 to 4, characterized in that: The connecting sleeve (1) comprises a first sleeve (11) and a second sleeve (12) which are coaxially arranged in sequence from top to bottom, the inner diameter of the first sleeve (11) is smaller than the inner diameter of the second sleeve (12), the one-flow valve (2) is arranged in the second sleeve (12), and the end of the one-flow valve (2) is in contact with the end of the first sleeve (11).

6. The underground temporary plugging safety valve according to claim 5, characterized in that: A lower joint (5) is provided at the lower end of the connecting sleeve (1).

7. The downhole temporary plugging safety valve according to claim 6, characterized in that: The upper end of the lower joint (5) extends to the interior of the connecting sleeve (1), and the upper end of the lower joint (5) contacts the end of the check valve (2).

8. The downhole temporary plugging safety valve according to any one of claims 2 to 4, characterized in that: A first sealing ring (61) is provided between the valve seat (21) and the connecting sleeve (1).

9. The downhole temporary plugging safety valve according to any one of claims 2 to 4, characterized in that: A second sealing ring (62) for sealing with the valve plate (23) is arranged on the end surface of the valve seat (21).

10. The downhole temporary plugging safety valve according to any one of claims 1 to 4, characterized in that: A ball seat (42) for pitching a ball is arranged in the sliding sleeve (4).

Images