A fishing joint with internal blowout prevention function

Abstract

This invention relates to the field of downhole operation tools for oil and gas field development, and particularly to a retrieval connector with internal blowout preventer (BOP) function, aiming to solve the problem that existing retrieval connectors cannot provide internal BOP and safe pressure relief functions for casing self-sealing plugs. The invention includes a retrieval head, a connecting seat, an inner conical valve, a locking connector, an outer cylinder of the retrieval head, and a pressure relief pin. The connecting seat is disposed inside the retrieval head, the inner conical valve is inserted into the connecting seat, the upper end of the locking connector is connected to the lower end of the retrieval head, the locking connector is inserted into the outer cylinder of the retrieval head, and the pressure relief pin passes through the side wall of the outer cylinder of the retrieval head and is inserted into the locking connector. The inner conical valve has a first state and a second state; in the first state, the inner conical valve is closed, separating the outer cylinder of the retrieval head from the inner cavity of the retrieval head; in the second state, the inner conical valve is open, connecting the outer cylinder of the retrieval head and the inner cavity of the retrieval head. This invention achieves the connection and disconnection of the inner cavity of the retrieval head and the inner cavity of the outer cylinder of the retrieval head through the opening and closing of the inner conical valve.

Description

Technical Field

[0001] This invention relates to the field of downhole operation tools for oil and gas field development, and particularly to a retrieval connector with internal blowout prevention function. Background Technology

[0002] The casing self-sealing plug falls freely from the wellhead into the wellbore. The pressure inside the wellbore pushes the piston inside the plug upwards, achieving automatic setting. During setting, the casing self-sealing plug must have an internal blowout preventer to prevent high-pressure fluid from entering the space above the piston, causing pressure imbalance on both sides of the piston and preventing it from moving upwards. Due to the internal blowout preventer, the upward movement of the piston compresses the air above it, creating high pressure. Therefore, during unsealing, the casing self-sealing plug must be safely depressurized before retrieval operations can proceed.

[0003] Existing retrieval joints cannot provide internal blowout prevention and safe pressure relief functions for the casing self-sealing plug. Summary of the Invention

[0004] The purpose of this invention is to provide a retrieval connector with an internal blowout prevention function, which provides internal blowout prevention and safety pressure relief functions for the casing self-sealing plug to assist in the setting and unsealing of the casing self-sealing plug.

[0005] To solve the above-mentioned technical problems, the technical solution provided by the present invention is as follows:

[0006] A retrieval connector with internal anti-spray function includes a retrieval head, a connecting seat, an inner cone valve, a locking connector, an outer cylinder of the retrieval head, and a pressure relief pin. The connecting seat is disposed inside the retrieval head, the inner cone valve is inserted into the connecting seat, the upper end of the locking connector is connected to the lower end of the retrieval head, the locking connector is inserted into the outer cylinder of the retrieval head, and the pressure relief pin passes through the side wall of the outer cylinder of the retrieval head and is inserted into the locking connector.

[0007] The inner conical valve has a first state and a second state; in the first state, the inner conical valve is closed, separating the outer cylinder of the retrieval head from the inner cavity of the retrieval head; in the second state, the inner conical valve is open, connecting the outer cylinder of the retrieval head to the inner cavity of the retrieval head.

[0008] Furthermore, the inner cone valve includes an inner cone valve seat and a retrieval head valve core; the inner cone valve seat is connected to the connecting seat, the lower part of the retrieval head valve core is connected to the outer cylinder of the retrieval head, and the upper part of the retrieval head valve core is inserted into the inner cone valve seat after passing through the locking joint.

[0009] Furthermore, a channel hole is provided on the upper part of the retrieval head valve core, and the channel hole is located on the side of the retrieval head valve core.

[0010] Furthermore, multiple channel holes are evenly distributed around the circumference of the salvage head valve core.

[0011] Furthermore, the internal conical valve also includes a valve core sealing ring; the valve core sealing ring is fitted onto the upper part of the retrieval head valve core and is used to seal the channel hole.

[0012] Furthermore, the inner wall of the inner conical valve seat is provided with an annular groove, and the valve core sealing ring is engaged in the annular groove.

[0013] Furthermore, a valve seat through hole is provided at the upper end of the inner conical valve seat.

[0014] Furthermore, the valve core of the retrieval head is provided with a boss, which is inserted into the through hole of the valve seat, and the diameter of the boss is equal to the diameter of the through hole of the valve seat.

[0015] Furthermore, the retrieval connector with internal anti-spray function also includes a retrieval head end cap, which is located at the upper end of the outer cylinder of the retrieval head, and the upper part of the locking connector passes through the retrieval head end cap.

[0016] Furthermore, the lower diameter of the locking joint is larger than the inner diameter of the retrieval head end cap.

[0017] In summary, the technical effects achieved by this invention are as follows:

[0018] This invention provides a retrieval connector with internal anti-spray function, comprising a retrieval head, a connecting seat, an inner conical valve, a locking connector, an outer cylinder of the retrieval head, and a pressure relief pin. The connecting seat is disposed inside the retrieval head, the inner conical valve is inserted into the connecting seat, the upper end of the locking connector is connected to the lower end of the retrieval head, the locking connector is inserted into the outer cylinder of the retrieval head, and the pressure relief pin passes through the side wall of the outer cylinder of the retrieval head and is inserted into the locking connector. The inner conical valve has a first state and a second state: in the first state, the inner conical valve is closed, separating the outer cylinder of the retrieval head from the inner cavity of the retrieval head; in the second state, the inner conical valve is open, connecting the outer cylinder of the retrieval head to the inner cavity of the retrieval head.

[0019] This invention provides a retrieval connector with an internal anti-spray function, which achieves the connection and disconnection between the inner cavity of the retrieval head and the inner cavity of the outer cylinder of the retrieval head by opening and closing an inner conical valve. In the first state, the inner conical valve is closed, separating the outer cylinder of the retrieval head from the inner cavity of the retrieval head, preventing internal spraying caused by increased pressure in the inner cavity of the outer cylinder. In the second state, lifting the retrieval head moves the connecting seat, the inner conical valve seat, and the locking connector upwards, causing the locking connector to shear the pressure relief pin, thereby opening the inner conical valve, connecting the outer cylinder of the retrieval head to the inner cavity of the retrieval head, and allowing the high-pressure fluid in the outer cylinder of the retrieval head to be discharged, achieving safe pressure relief. Attached Figure Description

[0020] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0021] Figure 1 A cross-sectional view of a salvage joint with internal blowout protection provided in an embodiment of the present invention;

[0022] Figure 2 for Figure 1 A magnified view of a portion of the image;

[0023] Figure 3 This is a cross-sectional view of an internal cone valve;

[0024] Figure 4 This is a cross-sectional view of the valve core of the retrieval head.

[0025] Figure 5 A perspective view of a salvage joint with internal blowout protection provided in an embodiment of the present invention;

[0026] Figure 6 This is a schematic diagram of the operation of the salvage joint with internal anti-spray function provided in the embodiment of the present invention.

[0027] Icons: 100-Retrieval head; 200-Connecting seat; 300-Inner cone valve; 400-Locking connector; 500-Retrieval head outer cylinder; 600-Pressure relief pin; 700-Retrieval head end cap; 800-O-ring seal; 310-Inner cone valve seat; 320-Retrieval head valve core; 330-Valve core sealing ring; 311-Annular groove; 312-Valve seat through hole; 321-Channel hole; 322-Boss. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0029] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0030] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0031] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention. In addition, the terms "first," "second," "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0032] Furthermore, terms such as "horizontal," "vertical," and "sag" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0033] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0034] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0035] The casing self-sealing plug falls freely from the wellhead into the wellbore. The pressure inside the wellbore pushes the piston inside the plug upwards, achieving automatic setting. During setting, the casing self-sealing plug must have an internal blowout preventer to prevent high-pressure fluid from entering the space above the piston, causing pressure imbalance on both sides of the piston and preventing it from moving upwards. Due to the internal blowout preventer, the upward movement of the piston compresses the air above it, creating high pressure. Therefore, during unsealing, the casing self-sealing plug must be safely depressurized before retrieval. Current retrieval connectors cannot provide internal blowout preventers or safe depressurization for the casing self-sealing plug.

[0036] In view of this, the present invention provides a retrieval connector with internal anti-spray function, including a retrieval head 100, a connecting seat 200, an inner cone valve 300, a locking connector 400, an outer cylinder of the retrieval head 500, and a pressure relief pin 600. The connecting seat 200 is disposed inside the retrieval head 100, the inner cone valve 300 is inserted into the connecting seat 200, the upper end of the locking connector 400 is connected to the lower end of the retrieval head 100, the locking connector 400 is inserted into the outer cylinder of the retrieval head 500, and the pressure relief pin 600 passes through the side wall of the outer cylinder of the retrieval head 500 and is then inserted into the locking connector 400. The inner cone valve 300 has a first state and a second state: in the first state, the inner cone valve 300 is closed, separating the inner cavity of the outer cylinder of the retrieval head 500 and the retrieval head 100; in the second state, the inner cone valve 300 is open, connecting the inner cavity of the outer cylinder of the retrieval head 500 and the retrieval head 100.

[0037] This invention provides a retrieval connector with an internal anti-spray function. The opening and closing of the inner conical valve 300 controls the connection and disconnection between the inner cavity of the retrieval head 100 and the inner cavity of the outer cylinder 500. In the first state, the inner conical valve 300 is closed, separating the outer cylinder 500 and the inner cavity of the retrieval head 100 to prevent internal spraying caused by increased pressure within the outer cylinder 500. In the second state, lifting the retrieval head 100 causes the connecting seat 200, the inner conical valve seat 310, and the locking connector 400 to move upwards. This causes the locking connector 400 to shear the pressure relief pin 600, thereby opening the inner conical valve 300 and connecting the outer cylinder 500 and the inner cavity of the retrieval head 100. The high-pressure fluid within the outer cylinder 500 is then discharged, achieving safe pressure relief.

[0038] The following combination Figures 1-6 The structure and shape of the salvage joint with internal blowout prevention function provided in this embodiment are described in detail below:

[0039] In this embodiment, as Figure 5 , Figure 6 As shown, the lower end of the outer cylinder 500 of the retrieval head is provided with an internal thread for connection with the self-sealing plug of the casing. The retrieval head 100 and the connecting seat 200 are threadedly connected, and the lower end of the retrieval head 100 is threadedly connected to the upper end of the locking connector 400.

[0040] In the optional solutions of this embodiment, such as Figure 1 , Figure 2As shown, the inner cone valve 300 includes an inner cone valve seat 310 and a retrieval head valve core 320. The inner cone valve seat 310 is connected to the connecting seat 200. The lower part of the retrieval head valve core 320 is threadedly connected to the outer cylinder 500 of the retrieval head, and the upper part of the retrieval head valve core 320 passes through the locking connector 400 and is inserted into the inner cone valve seat 310. That is, the retrieval head 100 is connected to the inner cone valve seat 310 through the connecting seat 200, and the outer cylinder 500 of the retrieval head is connected to the retrieval head valve core 320. Specifically, the upper end of the retrieval head valve core 320 abuts against the inner cone valve seat 310. Under the action of the high-pressure fluid in the wellbore, the inner cone valve seat 310 is pressed tightly against the retrieval head valve core 320 to ensure a sealing effect.

[0041] Specifically, the upper part of the retrieval head valve core 320 is provided with a channel hole 321, which is located on the side of the retrieval head valve core 320. Figure 4 As shown. Furthermore, multiple channel holes 321 are evenly distributed along the circumference of the retrieval head valve core 320.

[0042] In an optional embodiment, the inner cone valve 300 further includes a valve core sealing ring 330; the valve core sealing ring 330 is fitted onto the upper part of the retrieval head valve core 320 and is used to block the channel hole 321.

[0043] Specifically, such as Figure 2 , Figure 3 As shown, the inner wall of the inner conical valve seat 310 is provided with an annular groove 311, and the valve core sealing ring 330 is engaged in the annular groove 311, so that the valve core sealing ring 330 moves with the inner conical valve seat 310.

[0044] In this embodiment, the upper end of the inner conical valve seat 310 is provided with a valve seat through hole 312, such as... Figure 3 As shown, when the inner cone valve 300 is opened, the inner cone valve seat 310 moves upward and disengages from the retrieval head valve core 320, and the retrieval head 100 and the inner cavity of the retrieval head outer cylinder 500 are connected through the valve seat through hole 312 and the channel hole 321.

[0045] Furthermore, the retrieval head valve core 320 is provided with a boss 322, which is inserted into the valve seat through hole 312. The diameter of the boss 322 is equal to the diameter of the valve seat through hole 312, which is used to block the valve seat through hole 312, prevent the high pressure fluid in the wellbore from rapidly entering the inner conical valve seat 310, and reduce the impact on the valve core sealing ring 330.

[0046] In this embodiment, the retrieval connector with internal anti-spray function also includes a retrieval head end cap 700. For example... Figure 1 As shown, the retrieval head end cap 700 is disposed at the upper end of the retrieval head outer cylinder 500, and the upper part of the locking connector 400 passes through the retrieval head end cap 700. The retrieval head end cap 700 is fitted onto the upper side of the retrieval head outer cylinder 500 and is threadedly connected to the retrieval head outer cylinder 500.

[0047] In this embodiment, the lower diameter of the locking connector 400 is larger than the inner diameter of the retrieval head end cap 700 to prevent the locking connector 400 from coming off when the retrieval head 100 is lifted, thus preventing the retrieval head 100 cylinder, the retrieval head end cap 700, and the retrieval head valve core 320 from separating.

[0048] In this embodiment, an O-ring 800 is provided between the lower part of the locking connector 400 and the inner wall of the outer cylinder 500 of the retrieval head to prevent liquid in the wellbore from entering the space below the locking connector 400 in the inner cylinder of the retrieval head 100 through the gap between the end cap 700 of the retrieval head and the locking connector 400. This also prevents liquid in the wellbore from entering the casing self-sealing plugger through the gap between the valve core 320 of the retrieval head and the inner cylinder of the retrieval head 100, thus preventing it from pressing the piston downwards.

[0049] The working process of the salvage connector with internal blowout prevention function provided in this embodiment is as follows:

[0050] After assembly, the fishing connector with internal blowout preventer has its inner conical valve seat 310 pressed against the fishing head valve core 320. During casing self-sealing, the inner conical valve seat 310, valve core sealing ring 330, and fishing head valve core 320 work together to separate the inner cavities of the fishing head 100 and the fishing head outer cylinder 500. Simultaneously, under the dual pressure of high-pressure fluid inside the wellbore and high-pressure fluid inside the fishing head outer cylinder 500, the inner conical valve seat 310 and the fishing head valve core 320 are reliably connected, enhancing the sealing effect. Furthermore, the O-ring 800 seals the lower part of the fishing head 100 inner cylinder and the locking connector 400, preventing high-pressure fluid from entering the inner cavity of the fishing head outer cylinder 500.

[0051] During the setting process of the casing self-sealing plug, the piston moves upward, squeezing the area above the piston, which increases the pressure inside the outer cylinder 500 of the retrieval head. At the same time, since the channel hole 321 is located on the side of the valve core 320 of the retrieval head, the pressure inside the outer cylinder 500 of the retrieval head forces the valve core sealing ring 330 against the inner wall of the inner conical valve seat 310, making it difficult for the valve core sealing ring 330 to shift, ensuring the sealing effect, and preventing the valve core sealing ring 330 from failing. This prevents the inner conical valve 300 from being opened by the high-pressure fluid inside the inner cylinder of the retrieval head 100, causing the liquid in the wellbore to enter above the piston, thereby achieving the internal blowout prevention function.

[0052] During unsealing, the retrieval tool is connected to the retrieval head 100 via coiled tubing. Then, pressure is applied to lift the retrieval head 100, causing the connecting seat 200, inner conical valve seat 310, and locking connector 400 to move upwards. At this time, because the casing self-sealing plug is in a set-sealed state and anchored to the inner wall of the wellbore, the outer cylinder 500 of the retrieval head is fixed. Consequently, the locking connector 400 shears the pressure relief pin 600, allowing the retrieval head 100, inner conical valve seat 310, and locking connector 400 to move upwards smoothly. Since the valve core sealing ring 330 is engaged with the inner conical valve seat 310, it moves upwards along with the inner conical valve seat 310, opening the passage hole 321. At this point, the outer cylinder 500 of the retrieval head and the retrieval head 100 are connected, and the high-pressure fluid inside the outer cylinder 500 of the retrieval head returns to the surface circulation tank through the coiled tubing, completing the safe pressure relief.

[0053] Subsequently, pressure is applied to the retrieval head 100 through the coiled tubing. The pressure enters the outer cylinder 500 of the retrieval head through the channel hole 321 and acts on the piston, completing the unsealing of the casing self-sealing plug. After unsealing, the coiled tubing is pulled up, causing the retrieval joint to move upward, driving the locking joint 400. After the locking joint 400 abuts against the end cap 700 of the retrieval head, it can drive the end cap 700 and the outer cylinder 500 of the retrieval head to move upward. The outer cylinder 500 of the retrieval head then drives the casing self-sealing plug upward, removing the casing self-sealing plug from the wellbore.

[0054] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A salvage joint with internal blowout protection, characterized in that, It includes a retrieval head (100), a connecting seat (200), an inner cone valve (300), a locking connector (400), an outer cylinder of the retrieval head (500), and a pressure relief pin (600); The connecting seat (200) is disposed inside the retrieval head (100), the inner cone valve (300) is inserted into the connecting seat (200), the upper end of the locking connector (400) is connected to the lower end of the retrieval head (100), the locking connector (400) is inserted into the outer cylinder (500) of the retrieval head, and the pressure relief pin (600) passes through the side wall of the outer cylinder (500) of the retrieval head and is then inserted into the locking connector (400); The internal cone valve (300) has a first state and a second state; In the first state, the inner cone valve (300) is closed, separating the outer cylinder (500) of the retrieval head from the inner cavity of the retrieval head (100); In the second state, the inner cone valve (300) is open, and the outer cylinder (500) of the retrieval head and the inner cavity of the retrieval head (100) are connected; The inner cone valve (300) includes an inner cone valve seat (310) and a retrieval head valve core (320); The inner conical valve seat (310) is connected to the connecting seat (200), the lower part of the retrieval head valve core (320) is connected to the outer cylinder of the retrieval head (500), and the upper part of the retrieval head valve core (320) passes through the locking connector (400) and is inserted into the inner conical valve seat (310). The upper part of the retrieval head valve core (320) is provided with a channel hole (321), and the channel hole (321) is opened on the side of the retrieval head valve core (320); The inner cone valve (300) also includes a valve core sealing ring (330); The valve core sealing ring (330) is fitted onto the upper part of the retrieval head valve core (320) to block the channel hole (321).

2. The salvage joint with internal anti-spray function according to claim 1, characterized in that... The multiple channel holes (321) are evenly distributed along the circumference of the retrieval head valve core (320).

3. The salvage joint with internal anti-spray function according to claim 2, characterized in that, The inner wall of the inner conical valve seat (310) is provided with an annular groove (311), and the valve core sealing ring (330) is engaged in the annular groove (311).

4. The salvage joint with internal anti-spray function according to claim 3, characterized in that, The upper end of the inner conical valve seat (310) is provided with a valve seat through hole (312).

5. The salvage joint with internal anti-spray function according to claim 4, characterized in that, The retrieval head valve core (320) is provided with a boss (322), which is inserted into the valve seat through hole (312). The diameter of the boss (322) is equal to the diameter of the valve seat through hole (312).

6. The salvage joint with internal anti-spray function according to claim 5, characterized in that... It also includes a retrieval head end cap (700), which is disposed at the upper end of the retrieval head outer cylinder (500), and the upper part of the locking connector (400) passes through the retrieval head end cap (700).

7. The salvage joint with internal anti-spray function according to claim 6, characterized in that, The lower diameter of the locking connector (400) is larger than the inner diameter of the retrieval head end cap (700).

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