Jamming releasing jar knocker

Abstract

The utility model belongs to the technical field of workover operation tools, and particularly relates to an unfreezing jar. The jam releasing jar comprises an inner cylinder and an outer cylinder arranged outside the inner cylinder in a sleeving mode, the lower portion of the inner cylinder is provided with an annular jarring part protruding outwards, the upper portion of the outer cylinder is provided with a jarred part which is matched with the jarring part and protrudes inwards, and the lower portion of the outer cylinder is provided with a reducing section matched with the jarring part in a sealing mode. A keeping structure for keeping the inner cylinder and the outer cylinder relatively fixed is arranged between the inner cylinder and the outer cylinder, and an energy storage cavity is defined by the inner cylinder and the jarring part and the outer cylinder and the jarred part; the outer cylinder is further provided with a constant-pressure channel used for communicating the energy storage cavity with the oil sleeve annulus. When the inner cylinder is separated from the retaining structure and moves towards the jarred part, the energy storage cavity stores energy; and when the jarring part of the inner cylinder moves into the energy storage cavity, the pressure of the energy storage cavity is released instantly, so that the jarring part moves quickly and generates jarring. Compared with a jar in the prior art, the structure is simplified, and the reliability is improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of downhole tools for well repair operations, and in particular relates to a jam-releasing jar. Background Art

[0002] In the middle and late stages of oilfield development, the production tubing of oil and water wells needs to be lowered into the wellbore for long-term use. Some oil and water well production tubings are equipped with large-diameter downhole tools such as packers. Long-term water injection development accelerates the reduction of the formation bonding strength in the development well section, which is easy to cause sand or collapse of the formation. As the time of the production tubing in the well increases, the phenomenon of the original well tubing getting stuck during operation increases. In this regard, downhole hydraulic force enhancement or shock release is often used. Among them, shock release is achieved by connecting the jar to the ground through the tubing, relying on the ground equipment to give the stuck point an upward or downward shock force through the jar to loosen the stuck point, thereby achieving the purpose of releasing the jam. At present, common shock release processes mainly include two forms: mechanical shock and hydraulic shock. Among them: mechanical shock relies on lifting the tubing to store energy, and the energy is released instantly to form a shock. For example, a Chinese utility model patent with the authorization announcement date of CN202689986U and the authorization announcement date of January 23, 2013 discloses a high-temperature hydraulic impactor, including a splined spindle, an oil chamber spindle and a lower spindle threadedly connected in sequence, and a splined outer cylinder sleeved outside the splined spindle, a connecting outer cylinder and a valve outer cylinder threadedly connected to the spline outer cylinder in sequence, an annular cavity is arranged between the connecting outer cylinder and the oil chamber spindle, and a pressure balance hole communicating with the annular cavity is arranged on the connecting outer cylinder.

[0003] However, the above-mentioned jar has a delay valve arranged between the valve outer tube and the oil chamber core shaft, and a balance piston arranged between the valve outer tube and the lower core shaft, which results in a relatively complex internal structure of the jar and a relatively high internal pressure of the jar. After long-term use, if the internal components are damaged, problems such as failure to pull open or failure to jar may occur, resulting in failure of the jar. Utility Model Content

[0004] The utility model aims to provide a jam-releasing jar to solve the problem that the existing jar has a complicated structure and the jar fails if the internal components are damaged after long-term use.

[0005] In order to achieve the above-mentioned purpose, the jam-releasing jar in the utility model adopts the following technical solutions:

[0006] A jam-releasing jar comprises an inner cylinder and an outer cylinder sleeved outside the inner cylinder, wherein the lower portion of the inner cylinder has an annular jarring portion protruding outward; the upper portion of the outer cylinder has an inwardly protruding jarred portion cooperating with the jarring portion, and the lower portion of the outer cylinder has a reduced diameter section sealingly cooperating with the jarring portion; a retaining structure for keeping the inner cylinder and the outer cylinder relatively fixed is provided between the inner cylinder and the jarring portion and the outer cylinder and the jarred portion form an energy storage chamber; the outer cylinder is also provided with a constant pressure channel for connecting the energy storage chamber and the annulus of the oil casing.

[0007] Furthermore, the constant pressure channel is a flow limiting hole penetrating through the wall of the outer cylinder.

[0008] Furthermore, the constant pressure channel includes a pressure regulating chamber formed by the inner tube, the outer tube and the impacted part, and also includes a flow limiting hole arranged on the impacted part for connecting the pressure regulating chamber and the energy storage chamber, and a flow guide hole arranged on the outer tube for connecting the pressure regulating chamber.

[0009] Furthermore, a constant pressure structure is arranged on the constant pressure channel.

[0010] Furthermore, the constant pressure structure is a one-way valve for opening or closing the constant pressure channel.

[0011] Furthermore, the one-way valve is arranged in the pressure regulating chamber, and comprises an elastic member and a pressure regulating member used for closing or opening the flow limiting hole and the flow guiding hole through the elastic member.

[0012] Furthermore, the elastic member is a disc spring with one end abutting against the inner wall of the pressure regulating chamber and the other end abutting against the pressure regulating member.

[0013] Further, the retaining structure includes a first retaining structure connecting the lower part of the inner tube and the lower part of the outer tube and / or a second retaining structure connecting the upper part of the inner tube and the upper part of the outer tube.

[0014] Furthermore, the end of the inner cylinder has a guide structure.

[0015] Furthermore, a sealing structure is provided on the outer cylinder and the inner cylinder, and the sealing structure includes a sealing member provided between the outer cylinder and the inner cylinder.

[0016] The beneficial effects of the utility model are as follows: the utility model is improved based on the prior art, by arranging an annular shocking part protruding outward at the lower part of the inner cylinder and an annular shocking part protruding inward at the upper part of the outer sleeve, and arranging a reduced diameter section cooperating with the shocking part on the outer sleeve, and arranging a retaining structure between the inner cylinder and the outer cylinder so that the inner cylinder and the outer cylinder are relatively fixed, so that an energy storage chamber is formed between the inner cylinder and the shocking part and the outer cylinder and the shocking part, and at the same time, the energy storage chamber is connected to the outside of the cylinder body through a constant pressure channel arranged on the outer cylinder. When the shocking part of the inner cylinder overcomes the retaining structure and breaks away from the relative fixation with the outer cylinder and moves toward the shocked part under the action of the lifting load, the inner cylinder moves upward so that the energy storage chamber converts the lifting load into elastic potential energy for storage; when the shocking part of the inner cylinder moves into the energy storage chamber, the pressure in the energy storage chamber is instantly released through the annular space gap between the outer cylinder and the shocking part, and the shocking part moves rapidly toward the shocked part under the action of the lifting load and generates shock with the shocked part; compared with the jar in the prior art, the structure is simplified and the reliability of the jar is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of an embodiment of a jam-releasing jar in the utility model;

[0018] Figure 2 This is a usage diagram of an embodiment of the jam-releasing jar in the utility model.

[0019] In the figure: 1, inner tube; 2, outer tube; 3, pin; 4, lower joint; 11, upper joint; 12, connecting short section; 13, shoulder; 131, outer peripheral surface; 21, first annular platform; 211, first sealing member; 22, pressure regulating chamber; 221, disc spring; 222, flow guide hole; 223, annular pressure relief block; 23, second annular platform; 231, flow limiting hole; 232, second sealing member; 24, second cylinder section; 25, energy storage chamber; 26, third cylinder section; 261, third sealing member. DETAILED DESCRIPTION

[0020] The features and performance of the present invention are further described in detail below in conjunction with the embodiments.

[0021] The utility model provides a jam-releasing jar, which is provided with a jarring part protruding outwards on the inner cylinder and a jarred part protruding inwards on the outer cylinder, and the inner cylinder and the outer cylinder are relatively fixed by a retaining structure, so that an energy storage chamber is formed between the inner cylinder and the jarring part and the outer cylinder and the jarred part. When the jarring part of the inner cylinder is separated from the retaining structure and moves toward the jarred part, the energy storage chamber stores energy. When the jarring part of the inner cylinder moves into the energy storage chamber, the pressure of the energy storage chamber is released instantly, and the jarring part quickly moves toward the jarred part and jars the jarred part. Compared with the jars in the prior art, the structure of the jar of the utility model is simplified, and the reliability of the jar is improved.

[0022] Embodiments of the jam-releasing jar in the utility model:

[0023] like Figure 1 As shown, the jam-releasing jar comprises an inner tube 1 and an outer tube 2 sleeved outside the inner tube 1 .

[0024] The inner tube 1 is a hollow pipe shaft with a channel in the center, specifically including an upper joint part 11 and a shoulder 13 connected in sequence, and a connecting upper joint part 11 and a connecting short-circuit section 12; the upper joint part 11 is provided with an internal thread section for connecting a downhole tool, and the outer diameter of the upper joint part 11 is larger than the outer diameter of the connecting short-circuit section 12, so that a stop surface is formed at the connection between the upper joint part 11 and the connecting short-circuit section 12; the lower part of the connecting short-circuit section 12 has an annular shoulder 13 protruding radially outward, and in this embodiment, the shoulder 13 constitutes a shock part; the upper joint part 11 and the connecting short-circuit section 12 are integrally formed; of course, in other embodiments, the upper joint part can be connected to the connecting short-circuit section 12 by threaded connection. The inner tube 1 formed by the upper joint part 11 and the connecting short-circuit section 12 connected in sequence has a simple structure, convenient processing, and high overall strength; the hollow pipe shaft-shaped structure can prevent the inner tube 1 from affecting the normal production process after the pipe string is connected.

[0025] In this embodiment, the end of the shoulder 13 is a conical guide structure. Specifically, the end of the shoulder 13 away from the upper joint part 11 is a conical surface, that is, the end of the shoulder 13 away from the upper joint part 11 is a conical surface, and the conical surface constitutes a guide cone surface. By setting the conical surface on the shoulder 13 of the inner tube 1, the conical surface can play a guiding role in the process of the shocking part of the inner tube 1 moving away from the shocked part under the action of the external force, thereby facilitating the shoulder 13 to cooperate with the third barrel section 26 of the outer tube 2; at the same time, when the shoulder 13 moves toward the shocked part, that is, toward the second annular platform 23 and enters the energy storage chamber 25, the end structure of the conical surface helps the energy storage chamber 25 to quickly release pressure. In other embodiments, the end of the sealing section can be an arc shape, or other suitable shapes.

[0026] The outer cylinder 2 includes a first cylinder section (not shown in the figure), a second cylinder section 24 and a third cylinder section 26 connected in sequence from top to bottom; the first cylinder section has a first annular platform 21 protruding radially inward at one end away from the third cylinder section 26, and the first cylinder section is provided with a second annular platform 23 protruding radially inward at intervals along the axial direction of the outer cylinder 2; the inner diameter of the second cylinder section 24 is larger than the inner diameters of the first annular platform 21, the second annular platform 23, and the third cylinder section 26; the third cylinder section 26 is provided with a threaded section adapted to the lower joint 4. In this embodiment, the second annular platform 23 constitutes an annular shocking portion for cooperating with the inner cylinder 1.

[0027] In order to ensure that the inner cylinder 1 has a relatively stable position with respect to the outer cylinder 2 at the initial stage, in this embodiment, a retaining structure for keeping the inner cylinder 1 and the outer cylinder 2 relatively fixed is provided between the inner cylinder 1 and the outer cylinder 2. By providing the retaining structure between the inner cylinder 1 and the outer cylinder 2, the inner cylinder 1 and the outer cylinder 2 are kept in a relatively fixed initial state.

[0028] The retaining structure includes a first retaining structure provided at the first annular platform 21 of the first barrel section and cooperating with the connecting short-circuit section 12 of the inner barrel 1, and a second retaining structure provided on the third barrel section 26 and cooperating with the shoulder 13 of the inner barrel 1. Specifically, the first retaining structure and the second retaining structure are both pins 3, at least two pins 3 are provided, and the two pins 3 are symmetrically arranged on the outer barrel 2.

[0029] In the above embodiment, the pin 3 is used as the retaining structure, the connection structure is simple and easy to assemble; the evenly spaced arrangement of the plurality of pins 3 helps to maintain the force balance of the inner tube 1 and improve the stability and reliability of the connection between the inner tube 1 and the outer tube 2; at the same time, through the first retaining structure and the second retaining structure, the connection between the inner tube 1 and the outer tube 2 can be made more reliable, ensuring that the jamming release jar of this embodiment can be matched with the production pipe string and lowered into the wellbore for a long time.

[0030] In other embodiments, only the first holding structure or only the second holding structure may be provided. The holding structure between the inner tube 1 and the outer tube 2 may be a double holding structure or a single holding structure, which may be reasonably provided according to actual needs, and is not limited in this embodiment.

[0031] In other embodiments, the pins 3 may be three, four or other suitable numbers, and a plurality of pins 3 are evenly spaced and arranged on the wall of the outer cylinder 2. The specific number is reasonably set according to actual needs, and there is no limitation on this in the present embodiment.

[0032] In this embodiment, an energy storage chamber is formed between the inner tube 1 and the shocking part and the outer tube 2 and the shocked part. Specifically, the shoulder 13 is sealed with the inner tube wall of the third tube section 26 of the outer tube 2 through the outer peripheral surface 131; because the inner diameter of the second tube section 24 is larger than the inner diameter of the third tube section 26, an energy storage chamber 25 is formed between the portion above the outer peripheral surface 131 of the shoulder 13 of the inner tube 1 and the second annular platform 23 and the outer tube 2.

[0033] When in use, the inner cylinder 1 moves toward the second annular platform 23. After entering the second cylinder section 24, the outer peripheral surface 131 of the shoulder 13 breaks away from the sealing cooperation with the inner wall of the third cylinder section 26 of the outer cylinder 2. Since the inner diameter of the second cylinder section 24 of the energy storage chamber 25 is larger than the outer diameter of the shoulder 13, an annular gap connecting the energy storage chamber 25 and the inner cavity of the inner cylinder 1 appears between the shoulder 13 and the inner wall of the second cylinder section 24 of the outer cylinder 2. The annular gap forms a pressure relief channel for relieving the pressure of the energy storage chamber 25. The pressure in the energy storage chamber 25 will be discharged to the inner cavity of the inner cylinder 1 along the annular gap.

[0034] In this embodiment, a constant pressure channel for connecting the energy storage chamber 25 with the outside of the outer tube 2 (i.e., the casing annulus) is arranged on the outer tube 2. Through the constant pressure channel, the energy storage chamber 25 can maintain a certain pressure and store energy when the shocking part moves toward the shocked part.

[0035] In this embodiment, a constant pressure structure is disposed on the constant pressure channel. By means of the constant pressure structure disposed on the constant pressure channel, the energy stored in the energy storage chamber 25 can be enhanced, and the shock effect can be improved when the energy is released instantly.

[0036] The constant pressure channel is a flow-limiting hole that penetrates the wall of the outer tube 2, and connects the energy storage chamber 25 and the oil casing annulus through the flow-limiting hole. In this embodiment, the flow-limiting hole constitutes a constant pressure structure; the flow-limiting hole is provided with four or other suitable numbers. By setting the aperture of the flow-limiting hole, a certain pressure difference is formed between the energy storage chamber 25 and the oil casing annulus, so that the energy storage chamber 25 is in an energy storage state.

[0037] When in use, the inner tube 1 of the unblocking jar is connected to the downhole tool through the upper joint part 11, and the lower joint 4 is threadedly connected to the pipe string, and is lowered into the well along with the downhole tool. In this state, the inner tube 1 is fixed relative to the outer tube 2; when the production pipe string of the original well is stuck during operation, the lifting load acts on the upper joint. When the lifting load is greater than the shear force of the pin 3, the inner tube 1 moves along the axial direction of the outer tube 2 toward the second annular platform 23, and energy is continuously accumulated in the energy storage chamber 25; until the outer peripheral surface 131 of the shoulder 13 of the inner tube 1 is completely separated from the seal with the inner tube wall of the third barrel section 26 of the outer tube 2 and completely enters the energy storage chamber 25, the energy in the energy storage chamber 25 is instantly released through the annular gap between the shoulder 13 and the inner wall of the second barrel section 24, and the inner tube 1 quickly moves upward to make the shocking part hit the shocked part of the outer tube 2, generating an impact. After the shock, the relative positions of the inner tube 1 and the outer tube 2 are as shown in FIG. Figure 2 shown.

[0038] If the jam is not released, the downhole tool can be lowered continuously so that the inner tube 1 passes through the guide cone surface at its lower end, through the energy storage chamber 25 and into the third barrel section 26 of the outer tube 2, and the well fluid in the inner tube 1 enters the energy storage chamber 25 from the pressure relief channel between the shoulder 13 of the inner tube 1 and the outer tube 2 until the stop surface of the inner tube 1 contacts the upper surface of the first annular platform 21, and the outer peripheral surface 131 of the shoulder 13 and the inner wall of the third barrel section 26 are sealed again; repeat the above-mentioned jarring and jamming process, and jar upward again. By repeatedly lifting and lowering the inner tube 1, the stuck point is struck multiple times until the jam is successfully released.

[0039] like Figure 1 As shown, as another embodiment, the constant pressure channel includes a pressure regulating chamber 22 formed by the inner tube 1, the outer tube 2 and the impacted part, and also includes a flow limiting hole 231 provided on the impacted part for connecting the pressure regulating chamber 22 and the energy storage chamber 25, and a flow guide hole 222 provided on the outer tube 2 for connecting the pressure regulating chamber 22. Specifically, the pressure regulating chamber 22 is formed between the first annular platform 21, the second annular platform 23, the outer tube 2 and the inner tube 1; the second annular platform 23 is provided with a flow limiting hole 231 for connecting the pressure regulating chamber 22 and the energy storage chamber 25, and the outer tube 2 is provided with a flow guide hole 222 that penetrates the wall of the outer tube 2 and connects the pressure regulating chamber 22 with the outside of the outer tube 2, that is, the flow limiting hole 231, the pressure regulating chamber 22 and the flow guide hole 222 together form a constant pressure channel, and the pressure regulating chamber 22 is connected to the energy storage chamber 25 through the flow limiting hole 231, and is connected to the outside of the outer tube 2 (i.e., the oil casing annulus) through the flow guide hole 222. At least two flow-limiting holes 231 are provided and symmetrically arranged on the second annular platform 23, and the flow-guiding holes 222 are arranged on the wall of the outer cylinder 2 corresponding to the flow-limiting holes 231. Of course, the flow-guiding holes 222 can also be arranged in three, four or other suitable numbers, and the plurality of flow-guiding holes 222 and the flow-limiting holes 231 are evenly spaced and arranged on the wall of the outer cylinder 2. The specific number is reasonably set according to actual needs, and is not limited in this embodiment.

[0040] In this embodiment, the constant pressure structure is a one-way valve for opening or closing the constant pressure channel. By configuring the one-way valve for the constant pressure channel, when the inner cylinder 1 and the outer cylinder 2 are relatively fixed, the constant pressure channel is closed by the one-way valve, so that the energy storage chamber 25 has sufficient pressure to open the constant pressure channel, thereby increasing the energy storage effect of the energy storage chamber 25; when the inner cylinder 1 is separated from the relative fixation with the outer cylinder 2 and moves toward the shocked part, as the inner cylinder 1 moves and before the outer peripheral surface 131 of the shoulder 13 of the inner cylinder 1 completely enters the energy storage chamber 25, the energy in the energy storage chamber 25 overcomes the force of the one-way valve through the flow limiting hole 231 to open the guide hole 222, that is, the energy storage chamber 25 The pressure inside overcomes the force of the one-way valve and opens the constant-pressure channel, so that the energy storage chamber 25 is in an energy storage state; and when the outer peripheral surface 131 of the shoulder 13 of the inner cylinder 1 is completely separated from the outer cylinder 2 and enters the energy storage chamber 25, the energy in the energy storage chamber 25 is instantly released through the annular gap between the shoulder 13 and the inner wall of the second cylinder section 24, and the inner cylinder 1 quickly moves upward to make the shocking part hit the shocked part of the outer cylinder 2, generating an impact; during the upward movement of the shocking part, the pressure in the energy storage chamber 25 drops sharply, and the one-way valve overcomes the pressure of the energy storage chamber 25 and closes the constant-pressure channel again.

[0041] In this embodiment, the one-way valve is arranged in the pressure regulating chamber 22, including an elastic member and a pressure regulating member connected to the elastic member, and the pressure regulating member is used to close or open the flow limiting hole 231 and the flow guide hole 222. Specifically, the elastic member is a disc spring 221 with one end abutting against the first annular platform 21 and the other end abutting against the pressure regulating member. The disc spring 221 has a small axial dimension of the outer cylinder 2 and can bear a large load with a small deformation, which can make the spatial dimension of the pressure regulating chamber 22 more compact, thereby making the overall structure of the unblocking jar in this embodiment compact.

[0042] In the above-mentioned embodiment, by the disc spring 221 arranged in the pressure regulating chamber 22, when the inner cylinder 1 is relatively fixed with the outer cylinder 2, the elastic force of the disc spring 221 pushes the pressure regulating member to close the flow limiting hole 231 and the flow guide hole 222, so that the energy storage chamber 25 forms a closed chamber to prevent the well fluid in the oil casing annulus from entering the energy storage chamber 25; when the inner cylinder 1 is separated from the relative fixation with the outer cylinder 2 and moves toward the second annular platform 23 and the outer peripheral surface 131 of the shoulder 13 of the inner cylinder 1 has not completely entered the energy storage chamber 25, the pressure in the energy storage chamber 25 gradually overcomes the elastic force of the disc spring 221 through the flow limiting hole 231 to compress the disc spring 221 and push the pressure regulating member to move in the direction away from the second annular platform 222 to open the guide hole 222. Flow hole 222, at the same time, under the action of the reverse thrust of the elastic force of the disc spring 221, the guide hole 222 and the flow limiting hole 231 maintain a certain opening, so that the energy storage chamber 25 is kept in the energy storage state; when the outer peripheral surface 131 of the shoulder 13 of the inner cylinder 1 completely enters the energy storage chamber 25, the energy in the energy storage chamber 25 is instantly released through the annular space gap between the shoulder 13 and the inner wall of the second cylinder section 24, and the shocking part of the inner cylinder 1 quickly moves upward and produces a shock with the shocked part of the outer cylinder 2; during the upward process of the shocking part, the pressure in the energy storage chamber 25 drops sharply. When the pressure in the energy storage chamber 25 is less than the spring force of the disc spring 221, the disc spring 221 pushes the pressure regulating component to close the flow limiting hole 231 and the guide hole 222.

[0043] In order to improve the synchronization of closing or opening the flow-limiting hole 231 and the flow-guiding hole 222 by the constant pressure structure, in this embodiment, the pressure regulating member has at least a first closing surface for cooperating with the flow-limiting hole 231 and a second closing surface for cooperating with the flow-guiding hole 222, and an abutting surface for abutting with the disc spring 221. Specifically, the pressure regulating member is an annular pressure relief plate 223 with a rectangular cross section, and the annular pressure relief plate 223 can slide along the inner wall of the pressure regulating chamber 22 under the elastic force of the disc spring 221. The structure of the annular pressure relief plate 223 is simple and easy to manufacture, and it is easy to ensure that a plurality of flow-limiting holes 231 and flow-guiding holes 222 are closed and opened at the same time.

[0044] As another embodiment, the first annular platform is connected to the second annular platform by a connecting portion, and a plurality of installation cavities for installing the set pressure structure are formed between adjacent connecting portions, the first annular platform, the second annular platform and the outer tube and the inner tube, and the plurality of installation cavities are evenly spaced; correspondingly, the plurality of installation cavities are respectively configured with an elastic member and a pressure regulating member for closing or opening the flow limiting hole and the flow guide hole through the elastic member, specifically, the elastic member is a threaded spring, and the pressure regulating member is a block structure at least including a sealing surface for closing the flow limiting hole and the flow guide hole.

[0045] In order to ensure the sealing performance of the outer cylinder 2 when it cooperates with the shock body 1, a sealing structure is provided on the inner wall of the outer cylinder 2. Specifically, a first sealing structure is provided on the first cylinder of the outer cylinder 2, and the first sealing structure includes a first sealing groove provided on both sides of the pin 3 on the first annular platform 21 and a first sealing member 211 provided in the first sealing groove; a second sealing structure is provided on the second annular platform 23, and the second sealing structure includes a second sealing groove and a second sealing member 232 provided in the second sealing groove; a third sealing structure is provided on the third cylinder section 26 of the outer cylinder 2, and the third sealing structure includes a third sealing groove on both sides of the pin 3 connected to the shoulder 131 and a third sealing member 261 provided in the third sealing groove. In this embodiment, two first sealing grooves, two second sealing grooves and two third sealing grooves are provided, and correspondingly, two first sealing members 211, two second sealing members 232 and three third sealing members 261 are also provided. It should be understood that the specific number of the first sealing structure, the second sealing structure and the third sealing structure is reasonably selected according to actual needs, and this is not limited in this embodiment.

[0046] In this embodiment, the shock release process when a one-way valve is used as the constant pressure structure is consistent with the release process when a flow limiting hole is used as the constant pressure structure, and will not be described in detail here.

[0047] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. The patent protection scope of the present invention shall be based on the claims. All equivalent structural changes made using the description and drawings of the present invention shall be included in the protection scope of the present invention.

Claims

1. A jam-releasing jar, comprising an inner cylinder and an outer cylinder sleeved outside the inner cylinder, characterized in that: The lower part of the inner cylinder has an annular shocking part protruding outward; the upper part of the outer cylinder has an inwardly protruding shocking part cooperating with the shocking part, and the lower part of the outer cylinder has a reduced diameter section sealingly cooperating with the shocking part; a retaining structure for keeping the inner cylinder and the outer cylinder relatively fixed is provided between the inner cylinder and the shocking part and the outer cylinder and the shocking part form an energy storage chamber; the outer cylinder is also provided with a constant pressure channel for connecting the energy storage chamber and the oil casing annulus.

2. The jam-releasing jar according to claim 1, characterized in that: The constant pressure channel is a flow limiting hole that penetrates the wall of the outer cylinder.

3. The jam-releasing jar according to claim 1, characterized in that: The constant pressure channel includes a pressure regulating chamber formed by the inner tube, the outer tube and the impacted part, and also includes a flow limiting hole arranged on the impacted part for connecting the pressure regulating chamber and the energy storage chamber, and a flow guide hole arranged on the outer tube for connecting the pressure regulating chamber.

4. The jam-releasing jar according to claim 3, characterized in that: The constant pressure channel is provided with a constant pressure structure.

5. The jam-releasing jar according to claim 4, characterized in that: The constant pressure structure is a one-way valve used to open or close the constant pressure channel.

6. The jam-releasing jar according to claim 5, characterized in that: The one-way valve is arranged in the pressure regulating chamber, and comprises an elastic member and a pressure regulating member used for closing or opening the flow limiting hole and the flow guiding hole through the elastic member.

7. The jam-releasing jar according to claim 6, characterized in that: The elastic member is a disc spring with one end abutting against the inner wall of the pressure regulating chamber and the other end abutting against the pressure regulating member.

8. The jam-releasing jar according to any one of claims 1 to 3, characterized in that: The retaining structure comprises a first retaining structure connecting the lower part of the inner cylinder with the lower part of the outer cylinder and / or a second retaining structure connecting the upper part of the inner cylinder with the upper part of the outer cylinder.

9. The jam-releasing jar according to any one of claims 1 to 3, characterized in that: The end of the inner cylinder is provided with a guide structure.

10. The jam-releasing jar according to any one of claims 1 to 3, characterized in that: The outer cylinder and the inner cylinder are also provided with a sealing structure, and the sealing structure comprises a sealing member provided between the outer cylinder and the inner cylinder.

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