A tubing outer packer

Abstract

The utility model discloses a kind of pipe outer packer, it includes sleeve arbor, the sleeve arbor inside hollow, the sleeve arbor is opened with injection hole;Expansion element, the expansion element is sleeved in the sleeve arbor outside, annular cavity is formed between the expansion element and the sleeve arbor;Valve system, set on the sleeve arbor, for control whether the injection hole and the annular cavity are communicated, the valve system includes open valve and close valve;The utility model is combined under the state of open valve and close valve at different hydrostatic pressure difference, accurately control injection hole and the communication condition of annular cavity, to further accurately control the expansion and stop expansion timing of expansion element to adapt to the well wall of different shape and size, ensure that packer can be reliably packed and sealed under various working conditions, improve the working stability and reliability of tool.

Description

TECHNICAL FIELD

[0001] The utility model relates to oilfield downhole tool technical field, concretely relates to a pipe external packer. BACKGROUND

[0002] The casing external packer is a kind of well cementing or completion tool for oil and gas well in petroleum industry, is the important means of using mechanical way to prevent or control oil, gas, water mutual channeling, it is mainly composed of expansion cylinder, intermediate connecting pipe and valve system etc., when going down into well, it is connected to the proper position of casing string, and expansion cylinder is expanded by the rise of casing internal hydraulic pressure, to reach the purpose of controlling pipe external annulus.

[0003] The conventional packer is expanded outwardly by the deformation of mechanical or hydraulic compression rubber cylinder to adhere to casing wall or open hole wall, realizes packer sealing, and the length and size of the rubber cylinder of this packer are limited, can ensure sealing effect for casing setting, but for open hole section, well wall is irregular, well diameter expansion rate is large, often cannot realize good sealing effect. UTILITARY MODEL CONTENTS

[0004] The utility model aims at providing a pipe external packer to solve the problems mentioned in the above background.

[0005] To solve the above technical problems, the utility model provides a pipe external packer, which comprises:

[0006] Casing mandrel, the casing mandrel is hollow inside, and the casing mandrel is provided with liquid injection hole;

[0007] Expansion element, the expansion element is sleeved outside the casing mandrel, and annular cavity is formed between the expansion element and the casing mandrel;

[0008] Valve system, which is arranged on the casing mandrel and is used to control whether the liquid injection hole and the annular cavity are communicated, the valve system comprises opening valve and closing valve;

[0009] When the inside and outside static liquid column pressure difference of the casing mandrel is the same, the opening valve is in the closing position, the closing valve is in the opening position, and the liquid injection hole and the annular cavity are not communicated;

[0010] When the inside and outside static liquid column pressure difference of the casing mandrel reaches the first predetermined value, the opening valve is in the opening position, the closing valve is in the opening position, and the liquid injection hole and the annular cavity are communicated;

[0011] When the inside and outside static liquid column pressure difference of the casing mandrel reaches the second predetermined value, the opening valve is in the opening position, the closing valve is in the closing position, and the liquid injection hole and the annular cavity are not communicated.

[0012] Further, the opening valve and the closing valve are installed on the casing mandrel through a mounting sleeve, a fluid passage is formed in the mounting sleeve to communicate the liquid injection hole and the annular cavity, the opening valve is installed at the liquid inlet end of the fluid passage, and the closing valve is installed at the liquid outlet end of the fluid passage.

[0013] Further, the opening valve comprises an opening valve sleeve and an opening valve core, the opening valve sleeve is installed on the mounting sleeve, the opening valve core is installed at the first end of the opening valve sleeve, the second end of the opening valve core is fixed to the mounting sleeve through the opening shear pin, and the second end of the opening valve core is adapted to the fluid passage; the closing valve comprises a closing valve sleeve and a closing valve core, the closing valve sleeve is installed on the mounting sleeve, the closing valve core is installed at the first end of the closing valve sleeve, the second end of the closing valve core is fixed to the mounting sleeve through the closing shear pin, and the second end of the closing valve core is adapted to the fluid passage; and a communication hole is formed in the middle of the closing valve core and is adapted to the fluid passage.

[0014] Further, a spring is arranged in the middle of the opening valve core, so that the opening valve core has a tendency to move towards the fluid passage.

[0015] Further, a sealing element is arranged at the bottom of the expansion element and is sleeved outside the casing mandrel to prevent fluid leakage in the expansion element, and the valve system is installed at the top of the expansion element.

[0016] Further, a stop rod is installed in the liquid injection hole.

[0017] Further, a casing pin is arranged at each end of the casing mandrel.

[0018] Further, a casing coupling is installed on the casing pin.

[0019] The pipe external packer of the utility model can adapt to different shapes and sizes of well walls through the expansion of the expansion element, can better fit irregular well walls when being lowered into a bare hole section, effectively solves the poor sealing effect of conventional packers in the bare hole section, and improves the quality of cementing or well completion of oil and gas wells. The valve system is combined in different states under different hydrostatic pressure differences through the opening valve and the closing valve, the communication between the liquid injection hole and the annular cavity is accurately controlled, and then the expansion and expansion stopping time of the expansion element are accurately controlled. The accurate control can reasonably adjust the expansion degree of the expansion element according to the actual downhole pressure, avoids excessive expansion or insufficient expansion, ensures that the packer can realize reliable sealing under various working conditions, and improves the working stability and reliability of the tool. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1It is a structure schematic view of the embodiment of the utility model.

[0021] Figure 2 It is a structure schematic view of the first stage of the embodiment of the utility model.

[0022] Figure 3 It is a structure schematic view of the second stage of the embodiment of the utility model.

[0023] Figure 4 It is a structure schematic view of the third stage of the embodiment of the utility model.

[0024] 1, sleeve mandrel;2, expansion element;3, valve system;4, sealing element;5, stop rod;6, sleeve pin;7, sleeve coupling.

[0025] 31, open valve;32, close valve;33, installation sleeve

[0026] 311, open valve sleeve;312, open valve core;313, open shear pin;314, spring;321, close valve sleeve;322, close valve core;323, close shear pin;324, communication hole DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the utility model will be described clearly and completely below with reference to the drawings in the embodiments of the utility model. Obviously, the described embodiments are only one of the embodiments of the utility model, not all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the utility model.

[0028] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application will be further described in detail below with reference to the drawings and specific embodiments.

[0029] In the following description, the reference to "one embodiment", "an embodiment", "one example", "an example" and the like indicates that the embodiment or example so described can include a particular feature, structure, characteristic, property, element or limitation, but every embodiment or example can not necessarily include the particular feature, structure, characteristic, property, element or limitation. In addition, the repeated use of the phrase "according to one embodiment of the present application" does not necessarily refer to the same embodiment, although it can.

[0030] As Figures 1-4 shown, the utility model discloses a pipe outside packer, it includes:

[0031] Sleeve mandrel 1, the inside hollow of sleeve mandrel 1, be provided with liquid injection hole on sleeve mandrel 1;

[0032] An expansion element 2 is sleeved outside the casing mandrel 1, and an annular cavity is formed between the expansion element 2 and the casing mandrel 1;

[0033] A valve system 3 is arranged on the casing mandrel 1, and is used to control whether the injection hole is communicated with the annular cavity. The valve system 3 comprises an opening valve 31 and a closing valve 32;

[0034] When the pressure difference between the inner and outer static liquid columns of the casing mandrel 1 is the same, the opening valve 31 is in the closed position, the closing valve 32 is in the open position, and the injection hole is not communicated with the annular cavity;

[0035] When the pressure difference between the inner and outer static liquid columns of the casing mandrel 1 reaches a first predetermined value, the opening valve 31 is in the open position, the closing valve 32 is in the open position, and the injection hole is communicated with the annular cavity;

[0036] When the pressure difference between the inner and outer static liquid columns of the casing mandrel 1 reaches a second predetermined value, the opening valve 31 is in the open position, the closing valve 32 is in the closed position, and the injection hole is not communicated with the annular cavity.

[0037] When the packer is lowered, the pressure difference between the inner and outer static liquid columns of the casing mandrel 1 is the same, the opening valve 31 is in the closed position, the closing valve 32 is in the open position, and the outer pipe packer does not expand and set. The casing mandrel 1 is pressurized, and when the pressure difference between the inner and outer static liquid columns of the casing mandrel 1 reaches the first predetermined value, the opening valve 31 is opened, and the closing valve 32 remains in the open state, and the injection hole is communicated with the annular cavity. The liquid in the casing mandrel 1 enters the annular cavity through the injection hole, and as the liquid continues to be injected, the pressure in the annular cavity rises, pushing the expansion element 2 to expand outward, so that it tightly adheres to the well wall (whether it is a casing wall or a bare hole wall), thereby realizing the sealing function. When the packer completes the expansion and setting, the pressure is injected again, so that the pressure difference between the inner and outer static liquid columns of the casing mandrel 1 reaches the second predetermined value, the opening valve 31 remains in the open position, the closing valve 32 is closed, and the injection hole is not communicated with the annular cavity again. At this time, the liquid in the annular cavity stops being injected, the expansion element 2 stops further expanding, and remains in the expanded state, continuously applying pressure to the well wall, realizing stable sealing and sealing effect, and preventing oil, gas and water from intermingling.

[0038] The utility model discloses a pipe outer packer, which is capable of adapting to well walls of different shapes and sizes through expansion of the expansion element 2, and better adheres to irregular well walls when being lowered into a wellbore section, effectively solves the problem of poor sealing effect of conventional packers in wellbore sections, and improves the quality of cementing or completion of oil and gas wells. The valve system 3 is capable of accurately controlling the communication between the liquid injection hole and the annular cavity through the combination of the open valve 31 and the closed valve 32 under different hydrostatic pressure differentials, and further accurately controls the expansion and expansion stop timing of the expansion element 2. The accurate control can reasonably adjust the expansion degree of the expansion element 2 according to the actual downhole pressure, avoids excessive expansion or insufficient expansion, ensures that the packer can reliably seal under various working conditions, and improves the working stability and reliability of the tool.

[0039] The utility model discloses a pipe outer packer, which is capable of adapting to well walls of different shapes and sizes through expansion of the expansion element 2, and better adheres to irregular well walls when being lowered into a wellbore section, effectively solves the problem of poor sealing effect of conventional packers in wellbore sections, and improves the quality of cementing or completion of oil and gas wells. The valve system 3 is capable of accurately controlling the communication between the liquid injection hole and the annular cavity through the combination of the open valve 31 and the closed valve 32 under different hydrostatic pressure differentials, and further accurately controls the expansion and expansion stop timing of the expansion element 2. The accurate control can reasonably adjust the expansion degree of the expansion element 2 according to the actual downhole pressure, avoids excessive expansion or insufficient expansion, ensures that the packer can reliably seal under various working conditions, and improves the working stability and reliability of the tool.

[0040] In one embodiment, the open valve 31 and the closed valve 32 are installed on the casing mandrel 1 through the installation sleeve 33, the installation sleeve 33 is provided with a fluid passage, the fluid passage communicates the liquid injection hole and the annular cavity, the open valve 31 is installed at the liquid inlet end of the fluid passage, and the closed valve 32 is installed at the liquid outlet end of the fluid passage.

[0041] In the initial state, the open valve 31 is in the closed position, the fluid passage liquid inlet end is blocked, and the liquid in the casing mandrel 1 cannot enter the fluid passage through the liquid injection hole. When the hydrostatic pressure differential between the inside and outside of the casing mandrel 1 reaches a first predetermined value, the open valve 31 is opened, at this time, the fluid passage liquid inlet end is unobstructed, and the liquid in the casing mandrel 1 can flow into the fluid passage through the liquid injection hole. The closed valve 32 remains in the open position, the fluid passage liquid outlet end is open, the liquid can smoothly enter the annular cavity from the fluid passage, the expansion element 2 is pushed to expand outward, until tightly adheres to the well wall, and the sealing function is realized. When the hydrostatic pressure differential between the inside and outside of the casing mandrel 1 reaches a second predetermined value, the closed valve 32 is closed, the fluid passage liquid outlet end is blocked, the liquid in the annular cavity stops entering, the expansion element 2 stops expanding and maintains the current state, continuously exerts pressure on the well wall, and maintains the sealing and sealing effect.

[0042] In one embodiment, the opening valve 31 comprises an opening valve sleeve 311 and an opening valve core 312, the opening valve sleeve 311 is installed on the mounting sleeve 33, the opening valve core 312 is installed in the opening valve sleeve 311 at the first end and is fixed to the mounting sleeve 33 at the second end through an opening shear pin 313, the second end of the opening valve core 312 is adapted to the fluid passage, the closing valve 32 comprises a closing valve sleeve 321 and a closing valve core 322, the closing valve sleeve 321 is installed on the mounting sleeve 33, the closing valve core 322 is installed in the closing valve sleeve 321 at the first end and is fixed to the mounting sleeve 33 at the second end through a closing shear pin 323, the second end of the closing valve core 322 is adapted to the fluid passage, and a communication hole 324 is formed in the middle of the closing valve core 322 and is adapted to the fluid passage.

[0043] In the initial state, the opening valve core 312 is fixed to the mounting sleeve 33 through the opening shear pin 313, at this time, the second end of the opening valve core 312 is inserted into and tightly fitted in the liquid inlet end of the fluid passage, blocking the liquid from flowing in. The closing valve core 322 is fixed to the mounting sleeve 33 through the closing shear pin 323, and the communication hole 324 in the middle of the closing valve core 322 is in communication with the fluid passage.

[0044] When the pressure difference reaches the first predetermined value, the pressure of the liquid acting on the opening valve core 312 exceeds the shear strength of the opening shear pin 313, the opening shear pin 313 is sheared off, and the opening valve core 312 moves towards the inside of the opening valve sleeve 311 under the action of the liquid pressure, the liquid inlet end of the fluid passage is opened, and since the closing shear pin 323 has not been sheared off at this time, the closing valve core 322 remains in place, and the liquid can flow through the communication hole 324 into the liquid outlet end of the fluid passage. That is, in this embodiment, the opening shear pin 313 is sheared, the opening valve core 312 leaks out of the fluid passage and starts to expand the packer outside the setting tube.

[0045] When the pressure difference reaches the second predetermined value, the opening valve core 312 has been in the open position, keeping the liquid inlet end of the fluid passage unobstructed, at the same time, the pressure of the liquid acting on the closing valve core 322 exceeds the shear strength of the closing shear pin 323, the closing shear pin 323 is sheared off, and the closing valve core 322 moves under the action of the liquid pressure, the communication hole 324 is misaligned with the fluid passage, and the second end of the closing valve core 322 is located in the fluid passage, blocking the liquid from continuing to enter the annular cavity, and the expansion element 2 stops expanding and maintains the current state.

[0046] In one embodiment, the opening valve core 312 is provided with a spring 314 in the middle, which makes the opening valve core 312 have a tendency to move to the fluid passage. After the completion of the setting and pressure relief of the pump, the opening valve core 312 rebounds to the bottom end under the action of the spring 314, that is, the opening valve core 312 is inserted into the fluid passage, and the fluid passage inlet is closed, further preventing the backflow of the liquid in the annular cavity, maintaining the expansion state of the expansion element 2, and ensuring the continuous and stable sealing effect. When the pressure is increased again, neither the opening valve 31 nor the closing valve 32 will be in action, and the pipe forms a whole, which can better withstand various pressures and working condition changes in the subsequent operation process.

[0047] In one embodiment, a sealing member 4 is further included, which is located at the bottom of the expansion element 2 and is sleeved outside the casing mandrel 1, for preventing fluid leakage in the expansion element 2, and the valve system 3 is installed at the top of the expansion element 2. The presence of the sealing member 4 adds an important sealing defense line to the pipe external packer, cooperates with the valve system 3, prevents fluid leakage from different positions and links, greatly improves the sealing reliability of the pipe external packer in the well, and reduces the risk of sealing failure caused by leakage.

[0048] In one embodiment, a stop rod 5 is installed in the liquid injection hole, which ensures that the packer can accurately reach the predetermined position before performing the setting and other operations, avoids the premature setting of the packer or the damage of the components due to accidental action in the complex downhole environment, and ensures the smooth operation. The stop rod 5 is installed in the liquid injection hole through a fixed pin, and by pressing into the casing mandrel 1, the stress borne by the fixed pin exceeds its shear strength, the pin breaks, and the liquid injection hole is exposed.

[0049] In one embodiment, the casing mandrel 1 is provided with a casing pin 6 at both ends, so that the packer can be connected to any section of the casing string or the tail pipe string. Multiple packers can also be used on the same pipe string to isolate different layers. When multiple pipe external packers are lowered, the valve system 3 needs to be adjusted so that each packer can be expanded individually under the appropriate pressure difference.

[0050] In one embodiment, the casing pin 6 is provided with a casing collar 7 for extending the connection length, facilitating replacement and maintenance, and adapting to different specifications of casing connections. That is, in downhole operations, multiple casings are sometimes connected together to reach the required depth. By installing the casing collar 7 on the casing pin 6, casings of different lengths can be conveniently connected together to form a longer casing string, meeting different well depth and operation requirements. When the casing is damaged or needs to be replaced, if cutting and welding operations are directly performed at the casing pin 6, not only time and effort are wasted, but also the overall performance of the casing can be affected. After the casing collar 7 is installed, the damaged casing can be conveniently disassembled and replaced by loosening the connection between the collar and the casing, thereby reducing maintenance costs and operation difficulty. In addition, in actual operations, different specifications (such as outer diameter and wall thickness) of casings may need to be connected. The casing collar 7 can be designed and manufactured according to different connection requirements to achieve reliable connection between casings of different specifications.

[0051] The casing mandrel 1 in the embodiments of the utility model can adopt an integrated mandrel structure, and there is no internal thread, which is not limited. The setting process thereof includes:

[0052] The first stage: the pre-setting stage of running in and setting.

[0053] At this time, the internal and external hydrostatic column pressure difference of the casing mandrel 1 is the same, opening the shear pin 313 will not shear, the opening valve 31 is in the closed state, and the external casing packer does not expand and set.

[0054] The second stage: the external casing packer expansion and setting stage.

[0055] The internal pipe string of the lower part of the external casing packer is blocked, and the pressure is pressed into the casing. When the pressure difference reaches the first predetermined value, that is, the pressure exceeds the shear value of the opening shear pin 313, the opening shear pin 313 is sheared, the opening valve core 312 goes up to leak the fluid passage inlet, and the liquid can flow through the fluid passage inlet, enter the communication hole 324, and then enter the fluid passage outlet to enter the annular cavity, and the external casing packer begins to expand and set.

[0056] The third stage: the setting completion and valve locking stage.

[0057] When the packer completes expansion and setting, the pressure difference reaches the second predetermined value, and there is a sudden rising process of the injection pressure at this time, that is, the injection pressure reaches the shear value of the closing shear pin 323, the closing shear pin 323 is sheared, the closing valve core 322 goes up, the fluid passage outlet is closed, and the packer no longer continues to set and expand, and the setting is completed. After stopping the pump and releasing the pressure, the opening valve core 312 rebounds to the bottom end under the action of the spring 314 and closes the fluid passage inlet. Further pressing, the opening valve 31 and the closing valve 32 are not in action, and the whole pipe is formed.

[0058] The foregoing description of the disclosed embodiments is implemented or used by those of ordinary skill in the art. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the application. Accordingly, the application is not to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An external packer, characterized in that: include: A sleeve mandrel, the sleeve mandrel being hollow inside, and having an injection hole on the sleeve mandrel; An expansion element is sleeved on the outside of the sleeve mandrel, and an annular cavity is formed between the expansion element and the sleeve mandrel; A valve system, mounted on the sleeve mandrel, is used to control whether the injection hole is connected to the annular cavity. The valve system includes an opening valve and a closing valve. When the pressure difference between the internal and external hydrostatic columns of the sleeve mandrel is the same, the valve is in the closed position when the open valve is in the open position, and the injection hole is not connected to the annular cavity when the valve is in the closed position. When the pressure difference between the internal and external hydrostatic columns of the sleeve mandrel reaches a first predetermined value, the valve is opened in the open position and the valve is closed in the open position, and the injection hole is connected to the annular cavity. When the pressure difference between the internal and external hydrostatic columns of the sleeve mandrel reaches the second predetermined value, the valve is opened in the open position and the valve is closed in the closed position, and the injection hole is not connected to the annular cavity. The opening valve and the closing valve are mounted on the sleeve mandrel via an installation sleeve. The installation sleeve has a fluid channel that connects the injection hole and the annular cavity. The opening valve is installed at the inlet end of the fluid channel, and the closing valve is installed at the outlet end of the fluid channel. The opening valve includes an opening valve sleeve and an opening valve core. The opening valve sleeve is installed on the mounting sleeve. The first end of the opening valve core is installed inside the opening valve sleeve, and its second end is fixed to the mounting sleeve by an opening shear pin. The second end of the opening valve core is adapted to the fluid channel. The closing valve includes a closing valve sleeve and a closing valve core. The closing valve sleeve is installed on the mounting sleeve. The first end of the closing valve core is installed inside the closing valve sleeve, and its second end is fixed to the mounting sleeve by a closing shear pin. The second end of the closing valve core is adapted to the fluid channel. The closing valve core has a connecting hole in the middle that is adapted to the fluid channel.

2. The external packer according to claim 1, characterized in that: The opening valve core is provided with a spring in the middle, and the spring causes the opening valve core to tend to move towards the fluid channel.

3. An external packer according to claim 1, characterized in that: It also includes a seal located at the bottom of the expansion element and sleeved on the outside of the sleeve mandrel to prevent fluid leakage in the expansion element, and the valve system is installed on the top of the expansion element.

4. An external packer according to claim 1, characterized in that: A stop lever is installed in the injection hole.

5. An external packer according to claim 1, characterized in that: Both ends of the sleeve mandrel are provided with sleeve male threads.

6. An external packer according to claim 5, characterized in that: The male thread of the sleeve is equipped with a sleeve coupling.

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