Hydraulic setting packer

Abstract

The invention discloses a hydraulic setting packer, and belongs to the field of oil exploration. The packer comprises a central pipe, a sleeve, a packing mechanism and a pressure control mechanism. A liquid filling cavity is formed in the inner pipe wall of the center pipe, and a liquid inlet is formed in the pipe wall. And the sleeve is sleeved outside the central pipe, and an annulus is reserved between the sleeve and the central pipe and is communicated with the liquid inlet. The packing mechanism comprises a packing assembly and a driving assembly. The pressure control mechanism is arranged in the annulus and positioned at an initial position through the temporary locking piece, the temporary locking piece is released when the pressure in the annulus exceeds a threshold value, and the pressure control mechanism moves in the annulus to reduce the pressure in the annulus. The hydraulic packer provided by the invention is provided with the pressure control mechanism, so that the strength and thickness requirements of pressure-bearing components near the hydraulic cavity are reduced, the reliability of the packer is improved, meanwhile, the risk that the packer breaks down due to high pressure is also reduced, and the operation safety is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of oil exploration, and more particularly to a hydraulic setting packer. Background Art

[0002] The packer is one of the main downhole tools for implementing production, water injection, fracturing, acidizing, and mechanical water shutoff processes, etc. It can provide an effective mechanical means for the normal production of oil and water wells and the smooth progress of various downhole processes. During the exploration and development of oil and gas fields, the packer is mainly used to achieve the following purposes: isolating well fluid and pressure to protect the casing from being affected, thereby improving the working conditions of the casing; sealing the production formation or the target formation for construction to prevent the mutual interference of formation fluids and pressures, to meet the needs of various stratified production techniques, or to facilitate workover operations such as plugging and sealing off channeling; preserving and making full use of formation energy (including dissolved gas energy) to improve the production efficiency of oil wells and extend the production life; facilitating the implementation of various artificial lift methods (such as providing a necessary production channel for gas lift and hydraulic piston pump production, or dividing the casing into an intake and a discharge part to facilitate tubingless pumping); being used in gas wells (the liner is lowered below the perforated section) can slow down the premature rise of the liquid level in the gas well.

[0003] When a hydraulic packer is in use, liquid enters the annulus of the packer to exert pressure on the sealing component, causing the sealing component to deform, and using the sealing component to seal the annulus between the packer and the external casing. However, the high pressure that occurs during wellbore operations may increase the wear of the internal components of the packer. Moreover, in some cases, the liquid pressure may be significantly greater than the pressure required for setting, which poses higher strength requirements for the pressure-bearing components of the packer, and the risk of accidents during operation at such high pressures also increases greatly.

[0004] Therefore, there is still a great room for improvement in the internal pressure control of existing hydraulic setting packers. Summary of the Invention

[0005] The purpose of the present invention is to provide a hydraulic setting packer to solve the above problems existing in the prior art.

[0006] To achieve the above technical purpose, the technical solution adopted by the present invention is as follows:

[0007] According to one aspect of the present invention, there is provided a hydraulic setting packer, comprising:

[0008] A central tube, the inner wall of the central tube forms a liquid filling cavity and there is a liquid inlet on the tube wall;

[0009] A sleeve, the sleeve is sleeved outside the central tube and there is an annulus between the sleeve and the central tube, and the annulus is communicated with the liquid inlet;

[0010] Packing mechanism, the packing mechanism comprising:

[0011] A packing assembly capable of switching between a first state and a second state. In the first state, the packing assembly deforms and extends into the gap between the sleeve and the wellbore to seal the gap. In the second state, the packing assembly contracts to be adjacent to the sleeve to open the gap;

[0012] A driving assembly disposed in the annulus and driven by the liquid flowing into the annulus to cause the packing assembly to switch from the second state to the first state;

[0013] A pressure control mechanism disposed in the annulus and positioned at an initial position by a temporary locking member. The temporary locking member is released when the pressure in the annulus exceeds a threshold value, and the pressure control mechanism moves in the annulus to reduce the pressure in the annulus.

[0014] According to an embodiment of the present invention, the driving assembly is disposed between the packing assembly and the pressure control mechanism, and the driving assembly and the pressure control mechanism form a sealed hydraulic cavity in the annulus. The hydraulic cavity is communicated with a liquid inlet, and the pressure control mechanism moves to expand the volume of the hydraulic cavity.

[0015] According to an embodiment of the present invention, the pressure control mechanism includes a pressure control sleeve located above the liquid inlet, and the driving assembly is located below the liquid inlet.

[0016] According to an embodiment of the present invention, the radial dimension of the pressure control sleeve is consistent with the radial dimension of the annulus.

[0017] According to an embodiment of the present invention, the sleeve is further provided with a pressure relief hole, which is blocked by the pressure control sleeve of the pressure control mechanism in the initial position, and when the pressure in the annulus exceeds the threshold value and the pressure control sleeve moves, the pressure relief hole is communicated with the hydraulic cavity.

[0018] According to an embodiment of the present invention, the hydraulic setting packer further includes a limiting member for limiting the maximum moving distance of the pressure control mechanism in the annulus.

[0019] According to an embodiment of the present invention, the limiting member is a limiting protrusion, which is connected to the central pipe or the sleeve and extends into the annulus to prevent the pressure control mechanism from moving beyond the limiting member.

[0020] According to an embodiment of the present invention, the pressure control mechanism includes a pressure control sleeve, which includes an expansion section and a contraction section. The radial dimension of the expansion section is consistent with the radial dimension of the annulus, the radial dimension of the contraction section is smaller than the radial dimension of the annulus, and the contraction section is closer to the driving assembly than the expansion section.

[0021] According to an embodiment of the present invention, the pressure control sleeve is provided with a second liquid inlet at the connection between the contraction section and the expansion section. In the initial position, the second liquid inlet is aligned with the liquid inlet. When the pressure control mechanism moves in the annulus, the second liquid inlet moves away from the liquid inlet and the liquid inlet is blocked by the contraction section.

[0022] According to an embodiment of the present invention, the sleeve is further provided with a pressure relief hole. When the pressure control mechanism is in the initial position, the pressure relief hole is blocked by the expansion section. After the pressure control mechanism moves in the annulus, the pressure relief hole communicates with the hydraulic chamber.

[0023] According to an embodiment of the present invention, the pressure control mechanism further includes an elastic support mechanism for supporting the pressure control sleeve at the maximum displacement position.

[0024] According to an embodiment of the present invention, the elastic support mechanism includes a base and a spring. The base is fixedly connected to the central tube. The lower end of the spring is installed on the base, and the upper end of the spring is connected to the lower part of the contraction section.

[0025] According to an embodiment of the present invention, the lower part of the contraction section is provided with a spring receiving groove on the side close to the central tube. In the initial position, the spring is received in the spring receiving groove in a compressed state.

[0026] According to an embodiment of the present invention, the sleeve is movably connected to the central tube.

[0027] According to an embodiment of the present invention, the drive assembly is fixedly connected to the sleeve, and the drive assembly closes one end of the annulus to form a hydraulic chamber.

[0028] According to an embodiment of the present invention, the pressure control mechanism and the drive assembly are arranged on both sides of the liquid inlet. The pressure control mechanism includes:

[0029] A sealing sleeve having a first state and a second state. In the first state, the sealing sleeve is away from the liquid inlet to communicate the liquid inlet with the hydraulic chamber. In the second state, the sealing sleeve blocks the liquid inlet to disconnect the liquid inlet from the hydraulic chamber;

[0030] An actuator that drives the sealing sleeve to switch from the first state to the second state after the temporary locking member is released.

[0031] According to an embodiment of the present invention, the hydraulic chamber includes a wide section and a narrow section. The wide section is close to the pressure control mechanism, and the narrow section is close to the drive assembly. There is an inner step between the wide section and the narrow section. The inner step is closer to the drive assembly than the liquid inlet and the inner step can prevent the sealing sleeve from moving towards the drive assembly.

[0032] According to an embodiment of the present invention, the temporary locking member is a shear pin.

[0033] According to an embodiment of the present invention, the drive assembly is a piston device.

[0034] According to an embodiment of the present invention, the packer assembly is a rubber cylinder or a rubber block.

[0035] Due to the above technical solutions, the hydraulic setting packer provided by the present invention has at least the following beneficial effects compared with the prior art: The hydraulic packer provided by the present invention is provided with a pressure control mechanism. When the pressure in the hydraulic cavity exceeds the threshold value, the pressure control mechanism automatically moves to reduce the pressure in the hydraulic cavity, so that the pressure in the hydraulic cavity is maintained at a level lower than the threshold pressure. This not only reduces the requirements for the strength and thickness of the pressure-bearing components near the hydraulic cavity, increases the reliability of the packer, but also reduces the risk of the packer malfunctioning due to high pressure, and further improves the operation safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The drawings are used to provide a further understanding of the present invention, and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present invention, but do not constitute a limitation to the present invention. In the drawings:

[0037] Figure 1 is a schematic diagram of the use environment of the hydraulic setting packer according to the present invention;

[0038] Figure 2 is a schematic diagram of the hydraulic setting packer according to an embodiment of the present invention in an initial state;

[0039] Figure 3 is a schematic diagram of the hydraulic setting packer according to an embodiment of the present invention in a set state;

[0040] Figure 4 is a schematic diagram of the hydraulic setting packer according to an embodiment of the present invention in a pressure control state;

[0041] Figure 5 is a schematic diagram of the hydraulic setting packer according to another embodiment of the present invention in an initial state;

[0042] Figure 6 is a schematic diagram of the hydraulic setting packer according to another embodiment of the present invention in a set pressure control state;

[0043] Figure 7 is Figure 6 a partial enlarged view of the hydraulic setting packer. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0044] The following detailed description of the specific embodiments of the present disclosure will be made with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only for the purpose of illustration and explanation of the present disclosure, and are not intended to limit the present disclosure.

[0045] In addition, the mention of "embodiments" in this document means that the specific features, structures, or characteristics described in connection with the embodiments can be included in at least one embodiment of the present invention. The phrase appears in various places in the specification and does not necessarily refer to the same embodiment each time, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0046] Those skilled in the art can understand that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by those of ordinary skill in the field to which this application belongs. It should also be understood that terms such as those defined in a general dictionary should be understood to have a meaning consistent with their meaning in the context of the prior art, and will not be interpreted in an idealized or overly formal sense unless specifically defined as in the embodiments of this application.

[0047] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by terms such as "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present invention.

[0048] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "a plurality" means two or more unless otherwise specifically defined.

[0049] In the present invention, unless otherwise clearly specified and limited, terms such as "mounted", "connected", "connected to", "fixed" and the like should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal communication of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0050] Figure 1Schematic diagram of the usage environment of a hydraulic setting packer according to the present invention. When conducting oil extraction, it is usually necessary to lower a string into the well, and the string forms a wellbore T. The hydraulic packer 10 is connected to the tubing and lowered into the wellbore T. As shown in the figure, there are still some gaps between the tubing and the wellbore T. In some special cases, it is necessary to use the packer to seal this gap, and in other cases, it may also be necessary to set the packer. To achieve the setting of the packer, liquid is injected into the tubing, and the setting of the packer is achieved by using hydraulic pressure.

[0051] Existing hydraulic setting packers do not have a pressure control function. The high pressure that appears during the wellbore operation may increase the wear of the internal components of the packer. Moreover, in some cases, the liquid pressure may be significantly greater than the pressure required for setting, which poses higher strength requirements for the pressure-bearing components of the packer, and the risk of accidents during operation at such a high pressure also increases significantly.

[0052] Therefore, the present invention provides a hydraulic setting packer with a pressure control function. This hydraulic setting packer generally includes a central tube, a sleeve, a sealing mechanism, and a pressure control mechanism.

[0053] The inner wall of the central tube forms a liquid filling cavity and there is a liquid inlet on the tube wall. The sleeve is sleeved outside the central tube and there is an annulus between the sleeve and the central tube, and the annulus is communicated with the liquid inlet. The sealing mechanism includes a driving assembly and a sealing assembly. The sealing assembly can be converted between a first state and a second state. In the first state, the sealing assembly deforms and extends into the gap between the sleeve and the wellbore T to seal the gap. In the second state, the sealing assembly shrinks to be adjacent to the sleeve to open the gap. The driving assembly is arranged in the annulus and is driven by the liquid flowing into the annulus to prompt the sealing assembly to be converted from the second state to the first state. The pressure control mechanism is arranged in the annulus and is positioned at the initial position by a temporary locking member. The temporary locking member is released when the pressure in the annulus exceeds the threshold value, and the pressure control mechanism moves in the annulus to reduce the pressure in the annulus.

[0054] The hydraulic packer of the present invention is equipped with a pressure control mechanism. When the pressure in the hydraulic cavity exceeds the threshold value, the pressure control mechanism automatically moves to reduce the pressure in the hydraulic cavity, so that the pressure in the hydraulic cavity is maintained at a level lower than the threshold pressure. This not only reduces the strength and thickness requirements for the pressure-bearing components near the hydraulic cavity, increases the reliability of the packer, but also reduces the risk of the packer malfunctioning due to high pressure, and further improves safety.

[0055] The following will exemplarily illustrate the hydraulic packer of some embodiments of the present invention with reference to specific drawings.

[0056] Figure 2 The schematic diagram shows the hydraulic setting packer according to an embodiment of the present invention in the initial state. Figure 3The schematic diagram when the hydraulic setting packer according to an embodiment of the present invention is in the set state is shown. Figure 4 The schematic diagram when the hydraulic setting packer according to an embodiment of the present invention is in the pressure control state is shown.

[0057] As shown in the figure, the central tube 100 has opposite inner and outer walls, and the area enclosed by its inner wall constitutes a liquid filling cavity for filling pressurized liquid. Figure 2-4 The structure shown only shows part of the structure of the central tube 100 and the packer. However, it can be understood that in the complete structure of the central tube 100, its lower part can be operably closed to form a liquid filling cavity that prevents liquid from flowing out of the central tube 100 and enables liquid to accumulate therein. For example, a structure that can be blocked by dropping a ball is provided at the lower end of the central tube 100. When the lower end of the central tube 100 is blocked, the liquid flowing in from its upper end accumulates in the liquid filling cavity and flows into the area between the central tube 100 and the sleeve 200 through the liquid inlet 110 on the tube wall.

[0058] The sleeve 200 is sleeved outside the central tube 100. The sleeve 200 has an inner wall and an outer wall, and there is a certain gap between the inner wall of the sleeve 200 and the outer wall of the central tube 100, forming an annular space (which can also be called an annulus). This annular space is not only used to place components such as the sealing mechanism 300 and the pressure control mechanism 400, but also used to form a hydraulic drive cavity.

[0059] The sealing mechanism 300 mainly includes a driving component 310 and a sealing component 320. The driving component 310 is used to provide a driving force for the sealing component 320 to move it. In some embodiments, the driving component 310 can adopt a piston. The inner wall of the piston contacts the outer wall of the central tube 100, and the outer wall of the piston contacts the inner wall of the sleeve 200. Thus, the piston divides the annulus into two separated chambers, namely a hydraulic chamber LC located on one side of the piston (for example, above) and a setting chamber BC located on the other side of the piston (for example, below). Compared with the setting chamber BC, the hydraulic chamber LC is located on the side closer to the liquid inlet 110 of the central tube 100, and the hydraulic chamber LC is communicated with the liquid inlet 110. The liquid flowing into the annulus from the liquid inlet 110 can enter the hydraulic chamber LC and increase the pressure in the hydraulic chamber LC. The piston moves towards the sealing component 320 under the hydraulic action, and the sealing component 320 is radially expanded and deformed under the downward pressure of the piston, blocking the gap between the outer wall of the sleeve 200 and the inner wall of the wellbore T to achieve setting.

[0060] In some embodiments, to enhance the sealing performance of the hydraulic chamber LC, a plurality of annular seals, such as O-rings, may be provided on the piston. The annular seals are installed on the sides where the piston contacts the inner wall of the sleeve 200 and the outer wall of the central tube 100 to form a seal. The plurality of annular seals can be used to prevent fluid from flowing from above the piston to below the piston, enabling the piston to seal the hydraulic chamber.

[0061] The packer assembly 320 can be a rubber cylinder or a cup leather, which is installed below the annulus between the sleeve 200 and the central tube 100. As Figure 3 shown, when the driving assembly 310 moves to the lower part of the annulus, it gradually contacts and presses the packer assembly 320. In the example shown in this figure, the packer assembly 320 includes upper and lower parts that can slide obliquely relative to each other. The lower part is fixedly connected to the central tube 100, and the radial dimension of the lower part gradually expands from top to bottom, thereby forming a guiding inclined surface. The upper part is movably connected to the lower part, for example, the two are connected by a keyway. When the upper part is pressed by the driving assembly 310, it moves radially outward along the guiding inclined surface to block the gap between the outer wall of the sleeve 200 and the inner wall of the wellbore T, achieving setting. Optionally, in some other embodiments, a rubber cylinder can be used. Under the extrusion of the packer assembly 320, the axial dimension of the rubber cylinder shrinks and the radial dimension increases, thereby achieving the blocking of the gap.

[0062] The pressure control mechanism 400 is used to control the pressure in the hydraulic chamber LC to keep the pressure below a threshold value. The pressure control mechanism 400 is arranged in the annulus and is used to close the second end of the hydraulic chamber LC. The first end of the hydraulic chamber LC is closed by the driving assembly 310. That is to say, the pressure control mechanism 400 and the driving assembly 310 are respectively located at both ends of the hydraulic chamber LC. Moreover, the liquid inlet 110 is arranged on the pipe wall of the central tube 100 between the pressure control mechanism 400 and the driving assembly 310.

[0063] In one embodiment, the pressure control mechanism 400 includes a pressure control sleeve. The pressure control sleeve is located above the liquid inlet 110, and the radial dimension of the pressure control sleeve is suitable for closing the annulus area where it is located. That is to say, the outer wall of the pressure control sleeve contacts the inner wall of the sleeve 200, and the inner wall of the pressure control sleeve contacts the outer wall of the central tube 100. Optionally, sealing rings can be provided on these contact surfaces to enhance the sealing performance of the hydraulic chamber LC. The pressure control sleeve is temporarily fixedly connected to the central tube 100 or the sleeve 200 through a shear pin 500. When the pressure in the hydraulic chamber LC is greater than the threshold value, the shear pin 500 is cut off, and the pressure control sleeve moves in a direction away from the driving assembly 310, the volume of the hydraulic chamber LC increases, and the pressure decreases.

[0064] Optionally, in some embodiments, a pressure relief hole 210 is further provided on the side wall of the sleeve 200 (refer to Figure 3) When the pressure control sleeve is in the initial position, the pressure relief hole 210 is blocked by the pressure control sleeve, and the liquid in the hydraulic chamber LC cannot flow to the pressure relief hole 210. When the pressure in the annulus exceeds the threshold value and the pressure control sleeve moves away from the drive assembly 310, the pressure control sleeve no longer blocks the pressure relief hole 210, and the pressure relief hole 210 communicates with the hydraulic chamber LC. The liquid in the hydraulic chamber LC can be discharged through the pressure relief hole 210 to further reduce the pressure in the hydraulic chamber LC.

[0065] Optionally, the hydraulic setting packer may further include a limiting member 600 for limiting the maximum movement distance of the pressure control mechanism 400 in the annulus. For example, the limiting member 600 can be positioned at a position where the pressure control sleeve moves to expose the pressure relief hole 210 after movement. The limiting member 600 can specifically adopt, for example, a limiting protrusion, which is connected to the central tube 100 or the sleeve 200 and extends into the annulus to prevent the pressure control mechanism 400 from moving beyond the limiting member 600.

[0066] Optionally, in some other embodiments, as Figure 2-4 shown, the pressure control sleeve may include an expansion section 410 and a contraction section 420. The radial dimension of the expansion section 410 is the same as the radial dimension of the annulus to use this section to seal the second end of the hydraulic chamber LC. The radial dimension of the contraction section 420 is smaller than the radial dimension of the annulus. The inner wall of the contraction section 420 contacts the outer wall of the central tube 100, and there is a gap between the outer wall of the contraction section 420 and the inner wall of the sleeve 200. The pressure control sleeve is provided with a second liquid inlet 430 at the connection between the contraction section 420 and the expansion section 410. When the pressure control sleeve is locked in the initial position, the second liquid inlet 430 is aligned with the liquid inlet 110, so that the liquid inlet 110 communicates with the hydraulic chamber LC through the second liquid inlet 430 and the gap between the outer wall of the contraction section 420 and the inner wall of the sleeve 200. When the shear pin 500 is cut off, the contraction section 420 moves in a direction away from the drive assembly 310 and cooperates with the limiting member 600 to stop the contraction section 420 at a position blocking the liquid inlet 110, preventing the liquid from continuing to flow into the hydraulic chamber LC and inhibiting further pressure increase.

[0067] Optionally, in some embodiments, the pressure control mechanism 400 further includes an elastic support mechanism 440 for supporting the pressure control sleeve at the maximum displacement position. As Figure 3 shown, the elastic support mechanism 440 includes a base 441 and a spring 442. The base 441 is fixedly connected to the central tube 100. The lower end of the spring 442 is mounted on the base 441, and the upper end of the spring 442 is connected to the lower part of the contraction section 420. Using the elastic support mechanism 440 to hold the pressure control sleeve at a position capable of blocking the liquid inlet 110 can stabilize the pressure in the hydraulic chamber LC.

[0068] To improve the stability of the spring 442, optionally, a spring receiving groove may be provided on one side of the lower part of the contraction section 420 near the outer wall of the central tube 100. When the pressure control mechanism 400 is in the initial position, the spring 442 is received in the spring receiving groove in a compressed state. After the shear pin 500 is cut, the spring extends and supports the pressure control sleeve at an elevated position.

[0069] In Figure 2-4 the configuration shown, the hydraulic setting packer is initially in Figure 2 the state shown, in which the pressure control mechanism 400 is locked in the initial position by the shear pin 500. When liquid is filled into the liquid filling cavity of the central tube 100, the liquid flows into the annulus between the central tube 100 and the sleeve 200 from the liquid inlet 110. As the liquid in the hydraulic cavity LC increases, the pressure in the hydraulic cavity LC increases. The piston moves towards the sealing assembly 320 under the action of the hydraulic pressure, and the sealing assembly 320 is radially outwardly expanded and deformed under the downward pressure of the piston (as shown in Figure 3 ), blocking the gap between the outer wall of the sleeve 200 and the inner wall of the wellbore T to achieve setting. Continuing to inject liquid, the pressure in the hydraulic cavity LC increases and exceeds the threshold value, the shear pin 500 is cut, releasing the pressure control sleeve. The pressure control sleeve moves away from the driving assembly 310, the volume of the hydraulic cavity LC increases, the pressure decreases, and the contraction section 420 stays at the position blocking the liquid inlet 110 (refer to Figure 4 ), preventing the liquid from continuing to flow into the hydraulic cavity LC and suppressing the further increase of the pressure. Moreover, the contraction section 420 rises to the position where the pressure relief hole 210 is located, making the pressure relief hole 210 communicate with the hydraulic cavity LC to achieve pressure relief.

[0070] Figure 5 Schematic diagram of the hydraulic setting packer according to another embodiment of the present invention when in the initial state, Figure 6 Schematic diagram of the hydraulic setting packer according to another embodiment of the present invention when in the setting and pressure control state, Figure 7 For Figure 6 partial enlarged view of the hydraulic setting packer.

[0071] In this embodiment, the hydraulic setting packer generally includes a central tube 100', a sleeve 200', a sealing mechanism 300' and a pressure control mechanism 400'.

[0072] The inner pipe wall of the central tube 100' forms a liquid filling cavity and a liquid inlet 110' is provided on the pipe wall.

[0073] In this embodiment, the sleeve 200' can move relative to the central tube 100'. Specifically, the sleeve 200' can be connected to the central tube 100' through a connecting member, and the bottom end of the sleeve 200' is fixedly connected to the driving assembly 310' of the packer mechanism 300'. Therefore, the sleeve 200' moves together with the driving assembly 310'. There is an annulus between the central tube 100' and the sleeve 200'. The bottom end of the annulus is closed by the driving assembly 310', and the upper end of the annulus is closed by the pressure control mechanism 400'. The outer wall of the central tube 100', the inner wall of the sleeve 200', the driving assembly 310' and the pressure control mechanism 400' together form a hydraulic chamber LC'.

[0074] The packer assembly 320' can adopt a structure similar to that of the Figure 2-4 packer assembly 320 therein.

[0075] The pressure control mechanism 400' of this embodiment includes a seal sleeve 410' and an actuator 420'. The seal sleeve 410' has a first state and a second state. In the first state, the seal sleeve 410' is away from the liquid inlet 110' to communicate the liquid inlet 110' with the hydraulic chamber LC'. In the second state, the seal sleeve 410' blocks the liquid inlet 110' to disconnect the liquid inlet 110' from the hydraulic chamber LC'. The actuator 420' drives the seal sleeve 410' to switch from the first state to the second state after the shear pin 500' is released.

[0076] Specifically, the actuator 420' can adopt a helical spring. When the pressure control mechanism 400' is in the initial position, the helical spring is in a compressed state. The first end of the spring is installed on the base, and the base is fixedly connected to the central tube 100' or the sleeve 200'. The second end of the spring is installed on the support block. In the initial position, the support block is fixedly connected to the central tube 100' through the shear pin 500'. The seal sleeve 410' is connected below the support block. In the initial position, the bottom end of the seal sleeve 410' is located above the liquid inlet 110' to expose the liquid inlet 110' and communicate it with the hydraulic chamber LC'.

[0077] As Figure 7 shown, the hydraulic chamber LC' of this embodiment includes a wide section LC1' and a narrow section LC2'. The wide section LC1' is close to the pressure control mechanism 400', and the narrow section LC2' is close to the driving assembly 310'. There is an inner step LCS' between the wide section LC1' and the narrow section LC2'. The inner step LCS' is closer to the driving assembly 310' than the liquid inlet 110'. In the Figure 7 example shown, the inner step LCS' is located below the liquid inlet 110'. The inner step LCS' can prevent the seal sleeve 410' from moving towards the driving assembly 310'.

[0078] In Figure 5-7In the configuration shown, the hydraulic setting packer is initially in the Figure 5 state shown, in which the pressure control mechanism 400' is locked in the initial position by the shear pin 500'. When the liquid filling cavity of the central tube 100' is filled with liquid, the liquid flows into the annulus between the central tube 100' and the sleeve 200' from the liquid inlet 110'. As the liquid in the hydraulic cavity LC' increases, the pressure in the hydraulic cavity LC' increases. The piston moves towards the packer assembly 320' under the hydraulic action, and the packer assembly 320' is radially outwardly expanded and deformed under the downward pressure of the piston (as shown in Figure 6 ), blocking the gap between the outer wall of the sleeve 200' and the inner wall of the wellbore T to achieve setting. Continuing to inject liquid, the pressure in the hydraulic cavity LC' increases and exceeds the threshold value, the shear pin 500' is cut off, releasing the seal sleeve 410'. The seal sleeve 410' moves towards the driving assembly 310' under the action of the actuator 420', blocking the liquid inlet 110' (as shown in Figure 6-7 ), and the liquid can no longer flow into the annulus, and the pressure no longer increases.

[0079] In the embodiments of the present invention, the temporary locking member can be a shear pin as described above, or other structures, such as an adhesive portion that breaks when the threshold pressure is reached.

[0080] The hydraulic packer of the present invention is provided with a pressure control mechanism. When the pressure in the hydraulic cavity exceeds the threshold value, the pressure control mechanism automatically moves to reduce the pressure in the hydraulic cavity, so that the pressure in the hydraulic cavity is maintained at a level lower than the threshold pressure. This not only reduces the strength and thickness requirements for the pressure-bearing components near the hydraulic cavity, increases the reliability of the packer, but also reduces the risk of the packer malfunctioning due to high pressure, further improving safety.

[0081] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0082] In addition, it should be noted that, in the various specific technical features described in the above specific embodiments, they can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the present invention will not separately describe various possible combination methods.

[0083] In addition, any combination can be made between various different embodiments of the present invention, as long as it does not violate the idea of the present invention, it should also be regarded as the content disclosed by the present invention.

Claims

1. A hydraulic setting packer, characterized in that, it includes: a central tube, the inner wall of the central tube forms a liquid filling cavity and the tube wall is provided with a liquid inlet; a sleeve, the sleeve is sleeved outside the central tube and there is an annulus between the sleeve and the central tube, and the annulus is communicated with the liquid inlet; a sealing mechanism, the sealing mechanism includes: a sealing component, the sealing component can be converted between a first state and a second state. In the first state, the sealing component deforms and extends into the gap between the sleeve and the wellbore to close the gap. In the second state, the sealing component shrinks to be adjacent to the sleeve to open the gap; a driving component, the driving component is arranged in the annulus and is driven by the liquid flowing into the annulus to cause the sealing component to be converted from the second state to the first state; a pressure control mechanism, the pressure control mechanism is arranged in the annulus and is positioned at an initial position by a temporary locking member. The temporary locking member is released when the pressure in the annulus exceeds a threshold value, and the pressure control mechanism moves in the annulus to reduce the pressure in the annulus.

2. The hydraulic setting packer according to claim 1, characterized in that, the driving component is arranged between the sealing component and the pressure control mechanism, and the driving component and the pressure control mechanism form a sealed hydraulic cavity in the annulus. The hydraulic cavity is communicated with the liquid inlet, and the pressure control mechanism moves to expand the volume of the hydraulic cavity.

3. The hydraulic setting packer according to claim 2, characterized in that, the pressure control mechanism includes a pressure control sleeve, the pressure control sleeve is located above the liquid inlet, and the driving component is located below the liquid inlet.

4. The hydraulic setting packer according to claim 3, characterized in that, the radial dimension of the pressure control sleeve is the same as the radial dimension of the annulus.

5. The hydraulic setting packer according to claim 4, characterized in that, the sleeve is further provided with a pressure relief hole, and the pressure relief hole is blocked by the pressure control sleeve of the pressure control mechanism in the initial position. When the pressure in the annulus exceeds the threshold value and the pressure control sleeve moves, the pressure relief hole is communicated with the hydraulic cavity.

6. The hydraulic setting packer according to claim 1, characterized in that, the hydraulic setting packer further includes a limiting member, and the limiting member is used to limit the maximum moving distance of the pressure control mechanism in the annulus.

7. The hydraulic setting packer according to claim 6, characterized in that, the limiting member is a limiting bump, and the limiting bump is connected to the central tube or the sleeve and extends into the annulus to prevent the pressure control mechanism from moving beyond the limiting member.

8. The hydraulic setting packer according to claim 1, characterized in that, the pressure control mechanism includes a pressure control sleeve, the pressure control sleeve includes an expansion section and a contraction section. The radial dimension of the expansion section is the same as the radial dimension of the annulus, the radial dimension of the contraction section is smaller than the radial dimension of the annulus, and the contraction section is closer to the driving component than the expansion section.

9. The hydraulic setting packer according to claim 8, characterized in that, The pressure control sleeve is provided with a second liquid inlet at the connection between the contraction section and the expansion section. In the initial position, the second liquid inlet is aligned with the liquid inlet. When the pressure control mechanism moves in the annulus, the second liquid inlet moves away from the liquid inlet and the liquid inlet is closed by the contraction section.

10. The hydraulic setting packer according to claim 9, wherein, the sleeve is further provided with a pressure relief hole. When the pressure control mechanism is in the initial position, the pressure relief hole is blocked by the expansion section. After the pressure control mechanism moves in the annulus, the pressure relief hole communicates with the hydraulic chamber.

11. The hydraulic setting packer according to claim 9, wherein, the pressure control mechanism further includes an elastic support mechanism, and the elastic support mechanism is used to support the pressure control sleeve at the maximum displacement position.

12. The hydraulic setting packer according to claim 11, wherein, the elastic support mechanism includes a base and a spring. The base is fixedly connected to the central tube. The lower end of the spring is installed on the base, and the upper end of the spring is connected to the lower part of the contraction section.

13. The hydraulic setting packer according to claim 11, wherein, a spring receiving groove is provided on the side of the lower part of the contraction section close to the central tube. In the initial position, the spring is received in the spring receiving groove in a compressed state.

14. The hydraulic setting packer according to claim 1, wherein, the sleeve is movably connected to the central tube.

15. The hydraulic setting packer according to claim 14, wherein, the drive assembly is fixedly connected to the sleeve, and the drive assembly closes one end of the annulus to form a hydraulic chamber.

16. The hydraulic setting packer according to claim 15, wherein, the pressure control mechanism and the drive assembly are arranged on both sides of the liquid inlet. The pressure control mechanism includes: a sealing sleeve having a first state and a second state. In the first state, the sealing sleeve moves away from the liquid inlet to communicate the liquid inlet with the hydraulic chamber. In the second state, the sealing sleeve blocks the liquid inlet to disconnect the liquid inlet from the hydraulic chamber; an actuator that drives the sealing sleeve to switch from the first state to the second state after the temporary locking member is released.

17. The hydraulic setting packer according to claim 16, wherein, the hydraulic chamber includes a wide section and a narrow section. The wide section is close to the pressure control mechanism, and the narrow section is close to the drive assembly. An inner step is provided between the wide section and the narrow section. The inner step is closer to the drive assembly than the liquid inlet and the inner step can block the sealing sleeve from moving towards the drive assembly.

18. The hydraulic setting packer according to claim 1, wherein, the temporary locking member is a shear pin.

19. The hydraulic setting packer according to claim 1, wherein, the drive assembly is a piston device.

20. The hydraulic setting packer according to claim 1, wherein, The packer assembly is a rubber cylinder or a rubber block.

Images