Plunger catcher

Abstract

The present invention relates to the technical field of natural gas and oil extraction, and discloses a plunger catcher. The plunger catcher provided by the embodiment of the present invention has a simple structure and low cost. When the plunger catcher provided by the embodiment of the present invention is in operation, the end of the plunger can enter the tubular component from the open first end and be caught by the hook. This enables the plunger catcher provided by the embodiment of the present invention to be arranged in the wellhead pipeline, which is easy to install and has a lower risk of leakage than the existing installation form of the plunger catcher being connected to the wellhead pipeline. The plunger catcher provided by the embodiment of the present invention can be combined with the fishing head at the end of the plunger to capture the plunger, and there is no need to design a capture groove on the circumference of the plunger, thereby reducing the processing cost and design difficulty of the plunger.

Description

Technical Field

[0001] The invention relates to the technical field of natural gas and oil exploitation, and in particular to a plunger catcher. Background Art

[0002] During the production process of oil or gas wells, there is liquid accumulation at the bottom of the well. When there is too much liquid at the bottom of the well, the pressure formed by the liquid at the bottom of the well will hinder the oil or gas from flowing upward along the well, eventually leading to a reduction in the production capacity of the oil or gas well, or even a complete shutdown.

[0003] In order to solve the problem of liquid accumulation, some oil wells or natural gas wells use plunger lifting technology for drainage. The plunger is a component that moves upward and reciprocates in an oil well or natural gas well. After the plunger descends to the bottom of the well, the plunger is located below the liquid level of the liquid at the bottom of the well. When the plunger moves upward, the liquid above the plunger is lifted upward by the plunger, and the liquid at the bottom of the well is discharged out of the well. In this way, the pressure generated by the liquid accumulation at the bottom of the well can be reduced, achieving the purpose of increasing the production of oil wells or natural gas wells.

[0004] An oil well or natural gas well using plunger lifting technology has a plunger catcher at the wellhead, which is used to catch the plunger when it moves up to the wellhead, thereby positioning the plunger and facilitating the removal of the plunger from the well.

[0005] The existing plunger catcher has the problem of complex structure and high cost. The existing plunger catcher can only be connected to the wellhead pipeline, which is difficult to install and has the risk of leakage. The existing plunger catcher is combined with the plunger from the side of the plunger to capture the plunger. It is necessary to open a capture groove combined with the plunger catcher on the circumference of the plunger, which increases the processing cost and design difficulty of the plunger. Summary of the invention

[0006] The object of the present invention is to provide a plunger catcher with a simple structure and low cost. The plunger catcher can be arranged in a wellhead pipeline, is easy to install, and has a low risk of leakage. The plunger catcher can be directly combined with a fishing head of a plunger, and further, there is no need to design a catching groove on the circumference of the plunger, thereby reducing the processing cost and design difficulty of the plunger.

[0007] The embodiments of the present invention are implemented by the following technical solutions:

[0008] The plunger catcher comprises: a tubular component extending along a preset axis, the tubular component having a first end and a second end opposite to each other, the first end being open; and a hook portion arranged at the first end and protruding radially inward; wherein the first end is constructed to expand radially outward when subjected to a radially outward force, and to recover after the radially outward force disappears.

[0009] Furthermore, the end surface of the hook portion close to the first end is a first pressure-bearing surface; along the direction from the first end to the second end, the first pressure-bearing surface gradually approaches the preset axis.

[0010] Furthermore, the end surface of the hook portion close to the second end is a second pressure-bearing surface; along the direction from the second end to the first end, the second pressure-bearing surface gradually approaches the preset axis.

[0011] Furthermore, a plurality of elongated holes are formed on the tubular component; the elongated holes extend from the first end surface to the second end, a plurality of expansion strips are separated on the wall of the tubular component, and the hooks are arranged on the expansion strips.

[0012] Furthermore, the expansion strip is constructed to undergo a recoverable deformation and expand radially outward when subjected to a radially outward force, and to recover after the radially outward force disappears.

[0013] Furthermore, the plunger catcher also includes a contraction portion which is arranged on the inner wall of the tubular component and protrudes radially inward, and the contraction portion is located between the first end and the second end; the plunger catcher also includes a pressure component which is arranged in the tubular component; the pressure component is constructed to move along a preset axis in the tubular component and to slidably cooperate with the contraction portion; when the pressure component is constructed to slidably cooperate with the contraction portion, it applies a radially outward force to the contraction portion and drives the first end to expand radially outward.

[0014] Furthermore, the plunger catcher also includes an actuating component, which passes through the second end along the direction of the preset axis and is connected to the pressure-applying component.

[0015] Furthermore, the end surface of the contraction portion close to the first end is a first contraction surface, and along the direction from the first end to the second end, the first contraction surface gradually approaches the preset axis; the end surface of the contraction portion close to the second end is a second contraction surface, and along the direction from the second end to the first end, the second contraction surface gradually approaches the preset axis; the trend of the second contraction surface approaching the preset axis along the direction from the second end to the first end is smoother than the trend of the first contraction surface approaching the preset axis along the direction from the first end to the second end.

[0016] Furthermore, a plurality of elongated holes are formed on the tubular component; the elongated holes extend from the first end surface to the second end, and a plurality of expansion strips are separated on the wall of the tubular component, and the hook portion and the contraction portion are both arranged on the expansion strips.

[0017] Furthermore, the expansion strip is constructed to undergo a recoverable deformation and expand radially outward when subjected to a radially outward force, and to recover after the radially outward force disappears.

[0018] The technical solution of the present invention has at least the following advantages and beneficial effects:

[0019] The plunger catcher provided in the embodiment of the present invention has a simple structure and low cost. When the plunger catcher provided in the embodiment of the present invention is working, the end of the plunger can enter the tubular component from the open first end and be caught by the hook. This allows the plunger catcher provided in the embodiment of the present invention to be set in the wellhead pipeline, which is easy to install. Compared with the existing installation form of the plunger catcher connected to the wellhead pipeline, the risk of leakage is smaller. The plunger catcher provided in the embodiment of the present invention can be combined with the fishing head at the end of the plunger to capture the plunger, and there is no need to design a capture groove on the circumference of the plunger, which reduces the processing cost and design difficulty of the plunger. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required to be used in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and should not be regarded as limiting the scope of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0021] Figure 1 A schematic diagram of the external structure of the plunger catcher provided in Example 1 of the present invention;

[0022] Figure 2 A schematic diagram of the cross-sectional structure of a plunger catcher provided in Example 1 of the present invention;

[0023] Figure 3a A state diagram of the plunger catcher provided in Example 1 of the present invention when catching the plunger;

[0024] Figure 3b A state diagram of the plunger catcher provided in Example 1 of the present invention when catching the plunger;

[0025] Figure 3c A state diagram of the plunger catcher provided in Example 1 of the present invention when catching the plunger;

[0026] Figure 4 A schematic diagram of the internal structure of a plunger catcher provided in Example 2 of the present invention;

[0027] Figure 5 A schematic diagram of the internal structure of a plunger catcher provided in Example 3 of the present invention;

[0028] Figure 6 Schematic diagram of the internal structure of the plunger catcher provided in Example 4 of the present invention.

[0029] In the figure: 010- plunger catcher; 100- tubular component; 100a- preset axis; 110- first end; 120- second end; 130- hook; 131- first pressure-bearing surface; 132- second pressure-bearing surface; 140- long hole; 150- expansion strip; 160- contraction part; 161- first contraction surface; 162- second contraction surface; 170- pressure-applying component; 180- actuating component; 020- plunger; 021- neck; 022- fishing head; 030- wellhead pipe. DETAILED DESCRIPTION

[0030] To make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be described clearly and completely in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them.

[0031] Therefore, the following detailed description of the embodiments of the present invention is not intended to limit the scope of the invention claimed for protection, but merely represents some embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features and technical solutions in the embodiments may be combined with each other.

[0033] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0034] In the description of the present invention, it should be noted that the orientations or positional relationships indicated by the terms "upper", "lower", "inside", "outside", etc. are based on the orientations or positional relationships shown in the drawings, or are the orientations or positional relationships in which the inventive product is usually placed when used, or are the orientations or positional relationships commonly understood by those skilled in the art. Such terms are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0035] In the description of the present invention, a "natural gas well" may be a natural gas well used to collect conventional natural gas, or a natural gas well used to collect unconventional natural gas (shale gas, coalbed methane, etc.).

[0036] Embodiment 1:

[0037] Figure 1 The external structure diagram of the plunger catcher 010 provided in this embodiment is as follows: Figure 2This is a schematic diagram of the cross-sectional structure of the plunger catcher 010 provided in this embodiment. Figure 1 and Figure 2 The plunger catcher 010 provided in this embodiment includes a tubular component 100. The tubular component 100 extends along a preset axis 100a. The tubular component 100 has a first end 110 and a second end 120 opposite to each other. The first end 110 is an open end. A hook portion 130 protruding radially inward is provided at the first end 110. There are multiple hook portions 130, which are arranged at equal intervals around the preset axis 100a. In other embodiments, there may be two or more hook portions 130, and the hook portion 130 may also be in a ring shape around the preset axis 100a.

[0038] The first end 110 is configured to expand radially outward when subjected to a radially outward force, and to restore after the radially outward force disappears. Specifically, in the present embodiment, the tubular component 100 is made entirely of an elastic material, such as rubber. When the first end 110 is subjected to a radially outward force, the first end 110 is deformed in a radial direction, expands radially outward, and the hook 130 moves radially outward along with the first end 110. When the radially outward force disappears, the first end 110 moves radially inward under the action of its own elastic restoring force, and restores. In other embodiments, the first end 110 may be made of an elastic material, and the tubular component 100 may be made of metal or other materials.

[0039] Further, in the present embodiment, the end surface of the hook portion 130 close to the first end 110 is a first pressure-bearing surface 131; along the direction from the first end 110 to the second end 120, the first pressure-bearing surface 131 gradually approaches the preset axis 110a. When the first pressure-bearing surface 131 is subjected to a force along the direction from the first end 110 to the second end 120, a part of the force is decomposed into a radially outward force, thereby driving the first end 110 to expand radially outward. In the present embodiment, the end surface of the hook portion 130 close to the second end 120 is a second pressure-bearing surface 132. Along the direction from the second end 120 to the first end 110, the second pressure-bearing surface 132 gradually approaches the preset axis 100a. When the second pressure-bearing surface 132 is subjected to a force along the direction from the second end 120 to the first end 110, a part of the force is decomposed into a radially outward force, thereby driving the first end 110 to expand radially outward.

[0040] Figure 3a , Figure 3b and Figure 3c010 is a state diagram of the plunger catcher 010 provided in this embodiment when catching the plunger 020. The plunger catcher 010 is arranged in the wellhead pipe 030, and the first end 110 of the plunger catcher 010 is downward. The plunger 020 moves upward along the wellhead pipe 030 from bottom to top. The upper end of the plunger 020 is provided with a neck 021 and a fishing head 022 connected to the neck 021, and the diameter of the fishing head 022 is larger than the diameter of the neck 021. Please refer to Figure 3a When the plunger 020 moves upward to the position of the plunger catcher 010, the fishing head 022 contacts the first pressure-bearing surface 131 of the hook 130. Figure 3b As the plunger 020 continues to move upward, the fishing head 022 applies a force along the direction from the first end 110 to the second end 120 to the first pressure-bearing surface 131, and a part of the force is decomposed into a radially outward force, thereby driving the first end 110 to expand radially outward. As the first end 110 expands radially outward, the fishing head 022 passes over the hook 130 and enters the first end 110. Please refer to Figure 3c After the fishing head 022 passes over the hook 130 and enters the first end 110, the radial outward force acting on the first end 110 disappears, and the first end 110 moves radially inward under the elastic restoring force of itself and recovers. At this time, the hook 130 hooks the fishing head 022, preventing the plunger 020 from falling, and achieving the capture of the plunger 020.

[0041] The plunger 020 can be separated from the plunger catcher 010 under the action of external force. For example, the plunger 020 is pushed downward by a rod (not shown) extending along the preset axis 100a and penetrating the second end 120, and the fishing head 022 applies a force along the direction from the second end 120 to the first end 110 to the second pressure-bearing surface 132, and a part of the force is decomposed into a radially outward force, thereby driving the first end 110 to expand radially outward. The hook 130 moves radially outward with the first end 110, and when the hook 130 is separated from the fishing head 022, the plunger 020 is separated from the plunger catcher 010 and begins to fall.

[0042] It should be noted that, under the working condition where the position of the plunger 020 does not change significantly (for example, the plunger 020 is held by the upward thrust generated by the gas or liquid below it and is suspended in the wellhead pipeline 020), the plunger catcher 010 can be driven to move downward to capture the plunger 020. When the upward movement of the plunger 020 is blocked (for example, the spring in the blowout preventer prevents the plunger 020 from moving upward), the plunger catcher 010 can be driven to move downward to release the plunger 020.

[0043] Embodiment 2:

[0044] Figure 4Schematic diagram of the internal structure of the plunger catcher 010 provided in this embodiment. The plunger catcher 010 provided in this embodiment is basically the same as the plunger catcher described in Example 1, except that a plurality of elongated holes 140 are provided on the tubular member 100; the elongated holes 140 extend from the end surface of the first end 110 to the second end 120. These elongated holes 140 separate a plurality of expansion strips 150 on the wall of the tubular member 100, and the hook portion 130 is disposed on the expansion strips 150. When the tubular member 100 is not subjected to radial force, the elongated holes 140 are parallel to the preset axis 100a. In other embodiments, when the tubular member 100 is not subjected to radial force, the elongated holes 140 may also be non-parallel to the preset axis 100a.

[0045] A plurality of expansion strips 150 are separated on the wall of the tubular component 100 by the long strip holes 140. In the process of capturing the plunger 020, these expansion strips 150 are independently expanded radially outward under the action of the radially outward force. Compared with the overall radial outward expansion of the first end 110, the expansion strips 150 are easier to expand, and the plunger 020 can be better captured and released. Since the expansion strips 150 are easier to expand, in this embodiment, the expansion strips 150 are made of metal, and the plunger 020 can also be captured and released. In this embodiment, the tubular component 100 and the hook portion 130 are both made of metal, and the tubular component 100 and the hook portion 130 are integrated, which greatly increases the durability of the plunger catcher 010.

[0046] In this embodiment, when the expansion strip 150 is subjected to a radially outward force, it undergoes a recoverable elastic deformation and moves radially outward. When the radially outward force disappears, the expansion strip 150 moves radially inward and recovers under the action of its own elastic restoring force.

[0047] It should be pointed out that in other embodiments, the expansion strip 150 can be connected to the tubular component 100 through an elastic reset mechanism (not shown in the figure), and the expansion strip 150 expands radially outward under the drive of the radial outward force to overcome the elastic force of the elastic reset mechanism. After the radial outward force disappears, the expansion strip 150 is reset under the action of the elastic force of the elastic reset mechanism.

[0048] Embodiment 3:

[0049] Figure 5Schematic diagram of the internal structure of the plunger catcher 010 provided in this embodiment. The plunger catcher 010 provided in this embodiment is basically the same as the plunger catcher described in Example 1, except that the plunger catcher 010 further includes a contraction portion 160 disposed on the inner wall of the tubular member 100 and protruding radially inward. The contraction portion 160 is located between the first end 110 and the second end 120. The plunger catcher 010 further includes a pressure member 170 disposed in the tubular member 100. The pressure member 170 can move in the tubular member 100 along a preset axis 100a. The pressure member 170 is slidably matched with the contraction portion 160. When the pressure member 170 is slidably matched with the contraction portion 160, the pressure member 170 applies a radially outward force to the contraction portion 160, thereby driving the first end 110 to expand radially outward.

[0050] The pressure member 170 can be moved in the tubular member 100 in a variety of ways, for example, by using a driving mechanism (not shown) disposed in the tubular member 100 to drive the pressure member 170 to move. In this embodiment, an actuating member 180 is provided. The actuating member 180 is rod-shaped, and the actuating member 180 can slide through the second end 120 along the direction of the preset axis 100a. One end of the actuating member 180 is located in the tubular member 100 and connected to the pressure member 170. The other end of the actuating member 180 is located outside the tubular member 100. The actuating member 180 can be driven by manpower or a driving mechanism, thereby driving the pressure member 170 to move in the tubular member 100 along the preset axis 100a.

[0051] In this embodiment, when the first end 110 needs to expand radially outward, the actuating component 180 drives the pressure component 170 to move along the preset axis 100a in the tubular component 100, so that the pressure component 170 and the contraction portion 160 are slidably matched. During the sliding match between the pressure component 170 and the contraction portion 160, the pressure component 170 applies a radially outward force to the contraction portion 160, and the force is transmitted to the first end 110, so that the first end 110 expands radially outward.

[0052] During operation, when the plunger 020 needs to be captured, the pressure component 170 is driven by the actuating component 180 to move downward along the preset axis 100a, and the pressure component 170 cooperates with the contraction portion 160 to make the first end 110 radially open outward, and the fishing head 022 of the plunger 020 enters the first end 110. After the pressure component 170 passes over the contraction portion 160 downward, the radially outward force disappears, the first end 110 recovers, and the hook 130 hooks the fishing head 022 to prevent the plunger 020 from falling, thereby capturing the plunger 020. When the plunger 020 needs to be released, the pressure component 170 is driven by the actuating component 180 to move upward along the preset axis 100a, and the pressure component 170 cooperates with the contraction portion 160 to make the first end 110 radially open outward, and the fishing head 022 of the plunger 020 is separated from the hook 130, and the plunger 020 is released and falls downward.

[0053] In this embodiment, the end surface of the contraction portion 160 close to the first end 110 is a first contraction surface 161, and along the direction from the first end 110 to the second end 120, the first contraction surface 161 gradually approaches the preset axis 100a. The end surface of the contraction portion 160 close to the second end 120 is a second contraction surface 162, and along the direction from the second end 120 to the first end 110, the second contraction surface 162 gradually approaches the preset axis 100a. The trend of the second contraction surface 162 approaching the preset axis 100a along the direction from the second end 120 to the first end 110 is more gentle than the trend of the first contraction surface 161 approaching the preset axis 100a along the direction from the first end 110 to the second end 120. When the plunger 020 needs to be captured, the pressure component 170 moves downward along the preset axis 100a and cooperates with the second contraction surface 162 to cause the first end 110 to expand radially outward. When the plunger 020 needs to be released, the pressure component 170 moves upward along the preset axis 100a and cooperates with the first contraction surface 161 to expand the first end 110 radially outward. Since the trend of the second contraction surface 162 approaching the preset axis 100a along the direction from the second end 120 to the first end 110 is more gentle than the trend of the first contraction surface 161 approaching the preset axis 100a along the direction from the first end 110 to the second end 120, when the pressure component 170 moves downward along the preset axis 100a and cooperates with the second contraction surface 162, the driving force required to be applied to the pressure component 170 is small, which is conducive to capturing the plunger 020. When the pressure component 170 moves upward along the preset axis 100a and cooperates with the first contraction surface 161, a large driving force needs to be applied to the pressure component 170, which is conducive to preventing the plunger 020 from being released by mistake.

[0054] In other embodiments, the shape of the contraction portion 160 is not limited to the above one. For example, the contraction portion 160 may have a semicircular cross-sectional shape, the contraction portion 160 may be hemispherical, etc., as long as the contraction portion 160 can form a sliding fit with the pressure component 170 when it moves upward or downward.

[0055] It should be noted that, since the radially outward expansion of the first end 110 in this embodiment is achieved through the cooperation between the contraction portion 160 and the pressure-applying component 170 , the first pressure-bearing surface 131 and the second pressure-bearing surface 132 on the hook portion 130 may be eliminated.

[0056] Embodiment 4:

[0057] Figure 6 Schematic diagram of the internal structure of the plunger catcher 010 provided in this embodiment. The plunger catcher 010 provided in this embodiment is basically the same as the plunger catcher described in Example 2, except that the plunger catcher 010 further includes a contraction portion 160 disposed on the inner wall of the tubular member 100 and protruding radially inward. The contraction portion 160 is located between the first end 110 and the second end 120. The contraction portion 160 is disposed on the expansion strip 150. The plunger catcher 010 further includes a pressure member 170 disposed in the tubular member 100. The pressure member 170 can move in the tubular member 100 along a preset axis 100a. The pressure member 170 is slidably matched with the contraction portion 160. When the pressure member 170 is slidably matched with the contraction portion 160, the pressure member 170 applies a radially outward force to the contraction portion 160, thereby driving the expansion strip 150 to expand radially outward.

[0058] The pressure member 170 can be moved in the tubular member 100 in a variety of ways, for example, by using a driving mechanism (not shown) disposed in the tubular member 100 to drive the pressure member 170 to move. In this embodiment, an actuating member 180 is provided. The actuating member 180 is rod-shaped, and the actuating member 180 can slide through the second end 120 along the direction of the preset axis 100a. One end of the actuating member 180 is located in the tubular member 100 and connected to the pressure member 170. The other end of the actuating member 180 is located outside the tubular member 100. The actuating member 180 can be driven by manpower or a driving mechanism, thereby driving the pressure member 170 to move in the tubular member 100 along the preset axis 100a.

[0059] In this embodiment, when the expansion strip 150 needs to expand radially outward, the actuating component 180 drives the pressure component 170 to move along the preset axis 100a in the tubular component 100, so that the pressure component 170 and the contraction portion 160 are slidably matched. During the sliding match between the pressure component 170 and the contraction portion 160, the pressure component 170 applies a radially outward force to the contraction portion 160, and this force causes the expansion strip 150 to expand radially outward.

[0060] During operation, when the plunger 020 needs to be captured, the pressure component 170 is driven by the actuating component 180 to move downward along the preset axis 100a, and the pressure component 170 cooperates with the contraction portion 160 to make the expansion bar 150 radially open outward, and the fishing head 022 of the plunger 020 enters the first end 110. After the pressure component 170 passes over the contraction portion 160 downward, the radial outward force disappears, the expansion bar 150 recovers, and the hook portion 130 hooks the fishing head 022 to prevent the plunger 020 from falling, thereby capturing the plunger 020. When the plunger 020 needs to be released, the pressure component 170 is driven by the actuating component 180 to move upward along the preset axis 100a, and the pressure component 170 cooperates with the contraction portion 160 to make the expansion bar 150 radially open outward, and the fishing head 022 of the plunger 020 is separated from the hook portion 130, and the plunger 020 is released and falls downward.

[0061] In this embodiment, the end surface of the contraction portion 160 close to the first end 110 is a first contraction surface 161, and along the direction from the first end 110 to the second end 120, the first contraction surface 161 gradually approaches the preset axis 100a. The end surface of the contraction portion 160 close to the second end 120 is a second contraction surface 162, and along the direction from the second end 120 to the first end 110, the second contraction surface 162 gradually approaches the preset axis 100a. The trend of the second contraction surface 162 approaching the preset axis 100a along the direction from the second end 120 to the first end 110 is more gentle than the trend of the first contraction surface 161 approaching the preset axis 100a along the direction from the first end 110 to the second end 120. When the plunger 020 needs to be captured, the pressure component 170 moves downward along the preset axis 100a and cooperates with the second contraction surface 162 to cause the expansion strip 150 to expand radially outward. When the plunger 020 needs to be released, the pressure component 170 moves upward along the preset axis 100a and cooperates with the first contraction surface 161, so that the expansion strip 150 expands radially outward. Since the trend of the second contraction surface 162 approaching the preset axis 100a along the direction from the second end 120 to the first end 110 is more gentle than the trend of the first contraction surface 161 approaching the preset axis 100a along the direction from the first end 110 to the second end 120, when the pressure component 170 moves downward along the preset axis 100a and cooperates with the second contraction surface 162, the driving force required to be applied to the pressure component 170 is small, which is conducive to capturing the plunger 020. When the pressure component 170 moves upward along the preset axis 100a and cooperates with the first contraction surface 161, a large driving force needs to be applied to the pressure component 170, which is conducive to preventing the plunger 020 from being released by mistake.

[0062] In other embodiments, the shape of the contraction portion 160 is not limited to the above one. For example, the contraction portion 160 may have a semicircular cross-sectional shape, the contraction portion 160 may be hemispherical, etc., as long as the contraction portion 160 can form a sliding fit with the pressure component 170 when it moves upward or downward.

[0063] The plunger catcher provided in the embodiment of the present invention has a simple structure and low cost. When the plunger catcher provided in the embodiment of the present invention is working, the end of the plunger can enter the tubular component from the open first end and be caught by the hook. This allows the plunger catcher provided in the embodiment of the present invention to be set in the wellhead pipeline, which is easy to install. Compared with the existing installation form of the plunger catcher connected to the wellhead pipeline, the risk of leakage is smaller. The plunger catcher provided in the embodiment of the present invention can be combined with the fishing head at the end of the plunger to capture the plunger, and there is no need to design a capture groove on the circumference of the plunger, which reduces the processing cost and design difficulty of the plunger.

[0064] The above description is only a partial embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A plunger catcher, characterized in that: include: a tubular member extending along a predetermined axis, the tubular member having opposite first and second ends, the first end being open; as well as A hook portion is disposed at the first end and protrudes radially inward; wherein the first end is configured to expand radially outward when subjected to a radially outward force and to recover after the radially outward force disappears; The plunger catcher further comprises a contraction portion which is arranged on the inner wall of the tubular component and protrudes radially inward, and the contraction portion is located between the first end and the second end; The plunger catcher further comprises a pressure member disposed in the tubular member; the pressure member is configured to move along the preset axis in the tubular member and slidably cooperate with the contraction portion; the pressure member is configured to apply a radially outward force to the contraction portion when slidably cooperate with the contraction portion, and drive the first end to expand radially outward; The plunger catcher further comprises an actuating component, the actuating component passing through the second end along the direction of the preset axis and connected to the pressure applying component; An end surface of the contraction portion close to the first end is a first contraction surface, and along the direction from the first end to the second end, the first contraction surface gradually approaches the preset axis; An end surface of the contraction portion close to the second end is a second contraction surface, and along the direction from the second end to the first end, the second contraction surface gradually approaches the preset axis; The tendency of the second contraction surface approaching the preset axis along the direction from the second end to the first end is gentler than the tendency of the first contraction surface approaching the preset axis along the direction from the first end to the second end.

2. The plunger catcher according to claim 1, characterized in that: The end surface of the hook portion close to the first end is a first pressure-bearing surface; Along the direction from the first end to the second end, the first pressure-bearing surface gradually approaches the preset axis.

3. The plunger catcher according to claim 1, characterized in that: The end surface of the hook portion close to the second end is a second pressure-bearing surface; Along the direction from the second end to the first end, the second pressure-bearing surface gradually approaches the preset axis.

4. The plunger catcher according to claim 1, characterized in that: The tubular component is provided with a plurality of elongated holes, the elongated holes extending from the first end surface to the second end, and a plurality of expansion strips are separated on the wall of the tubular component, and the hook portion and the contraction portion are both arranged on the expansion strips.

5. The plunger catcher according to claim 4, characterized in that: The expansion strip is configured to undergo a recoverable deformation and expand radially outward when subjected to a radially outward force, and to recover after the radially outward force disappears.

Images