A high temperature and high pressure packer for casing change wells

Abstract

This invention provides a high-temperature, high-pressure packer for variable well applications, relating to the field of oil and gas extraction technology. The packer includes an upper connector, a lower connector, a central tube, and a rubber sleeve assembly, a slip assembly, and an outer sleeve assembly arranged sequentially from top to bottom and abutting each other around the central tube. The slip assembly has a radially protruding flange near its lower end. The top of the outer sleeve assembly abuts against the flange. A gap is defined between the outer sleeve assembly and the central tube. Within this gap, a rubber sleeve drive assembly and a slip drive assembly are sequentially arranged from top to bottom. The rubber sleeve drive assembly abuts against the lower end of the slip assembly. The slip drive assembly drives the outer sleeve assembly upwards, thereby moving the lower end of the slip assembly upwards. The central tube has a first water inlet at a position corresponding to the rubber sleeve drive assembly and a second water inlet at a position corresponding to the slip drive assembly. This high-temperature, high-pressure packer for variable well applications, through its multi-stage drive mechanism and other structural features, enables the rubber sleeve to deform sufficiently, resulting in a tight seal.

Description

Technical Field

[0001] This invention relates to the field of oil and gas extraction technology, and more specifically to a high-temperature and high-pressure packer for casing wells. Background Technology

[0002] As oil and gas field development continues, reservoir stimulation is becoming increasingly important, with large-volume fracturing becoming the primary method. While high-intensity fracturing yields substantial oil and gas resources, it also causes damage to oil and gas wells, particularly severe casing deformation, which directly impacts the efficiency and profitability of oil and gas well development.

[0003] To ensure the effective construction of casing deformation wells (hereinafter referred to as casing deformation wells), casing reshaping technology is typically employed. This technology is highly effective for shallow casing within 1000m, as mechanical expansion, casing replacement, and explosive reshaping can essentially reshape the casing to its original dimensions. However, this technology is less effective for deep well sections. Therefore, the development of packers capable of effectively setting and performing high-intensity reservoir stimulation in casing deformation well sections is particularly necessary. Existing casing deformation well setting devices suffer from incomplete setting due to insufficient compression of the rubber sleeve during the setting process.

[0004] Therefore, it is necessary to develop a device that can still seal the casing of the well under high temperature and high pressure conditions. Summary of the Invention

[0005] The purpose of this invention is to provide a high-temperature and high-pressure packer for variable well casing to solve at least one of the aforementioned problems in the prior art. This high-temperature and high-pressure packer for variable well casing, through the inclusion of a multi-stage drive device and other structures, enables the rubber sleeve to deform sufficiently, achieving a tight seal.

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

[0007] According to one aspect of the present invention, a high-temperature and high-pressure packer for variable wells is provided, comprising:

[0008] Cylindrical upper connector;

[0009] Cylindrical lower connector;

[0010] The central tube is connected at its upper end to the upper connector and at its lower end to the lower connector.

[0011] A rubber sleeve assembly, a slip assembly, and an outer sleeve assembly are arranged sequentially from top to bottom and abutting each other around the central tube. The slip assembly has a radially protruding flange near its lower end. The top of the outer sleeve assembly abuts against the flange. A gap is defined between the outer sleeve assembly and the central tube. Within the gap, a rubber sleeve drive assembly and a slip drive assembly are arranged sequentially from top to bottom. The rubber sleeve drive assembly abuts against the lower end of the slip assembly. The slip drive assembly drives the outer sleeve assembly to move upward and also moves the lower end of the slip assembly upward. The central tube has a first water inlet at the position corresponding to the rubber sleeve drive assembly and a second water inlet at the position corresponding to the slip drive assembly.

[0012] According to one embodiment of the present invention, the slip assembly includes a slip cone, a slip, a slip seat, and a slip pin. The slip cone has a cylindrical body disposed along a central tube and a sliding part disposed in a conical shape at the upper end of the body. The radial dimension of the sliding part decreases from top to bottom. The slip seat is installed on the periphery of the cylindrical body via the slip pin and is located at the lower end of the cylindrical body. The slip is installed between the sliding part and the slip seat and abuts against the cylindrical body. The upper end of the slip is provided with an inclined surface adapted to the conical surface of the sliding part.

[0013] According to one embodiment of the present invention, the slip includes a plurality of slip pieces, which are radially and uniformly installed in the slots of the slip seat.

[0014] According to one embodiment of the present invention, the rubber sleeve drive assembly includes a rubber sleeve piston, a sealing block and a sealing seat arranged sequentially from top to bottom. The rubber sleeve piston and the sealing block are disposed on both sides of the first water inlet. The sealing block and the sealing seat are fixed on the central tube. The rubber sleeve piston can move upward under the action of water pressure.

[0015] According to one embodiment of the present invention, the central tube includes an upper central tube and a lower central tube that are detachably connected. A setting ball seat is provided at the bottom end of the upper central tube, and the first water inlet and the second water inlet are both located on the upper central tube.

[0016] According to one embodiment of the present invention, the slip drive assembly includes a slip piston, which is adjacent to and above the second water inlet, and the gap below the second water inlet is closed. The inner wall of the outer sleeve assembly is provided with a radially protruding protrusion that abuts against the slip piston.

[0017] According to one embodiment of the present invention, a rubber sleeve shoulder assembly is further included between the upper connector and the rubber sleeve assembly. The rubber sleeve shoulder assembly includes a plurality of sliders and shoulder pins. The lower part of the upper connector has a plurality of grooves evenly arranged circumferentially. Each groove slides in contact with a single slider. The grooves are defined by a ramp extending from the outer wall of the upper connector to the inner wall of the upper connector from top to bottom. Each shoulder pin extends through the slider, the upper connector, and the central tube. When the shoulder pin is sheared, the slider is movable between a contracted position aligned with the sidewall of the upper connector and an expanded position overlapping the radially outer sidewall of the upper connector. In the contracted position, the plurality of sliders are joined together to form a ring. In the expanded position, there is a gap between adjacent sliders.

[0018] According to one embodiment of the present invention, a sleeve shoulder assembly is further included between the upper connector and the sleeve assembly. The sleeve shoulder assembly includes a shoulder body, a plurality of sliders, and shoulder pins. The upper end of the shoulder body is connected to the upper connector, and the lower end of the shoulder body has a plurality of grooves evenly arranged circumferentially. Each groove slides in engagement with a single slider. Each shoulder pin extends through the slider, the shoulder body, and the central tube. When the shoulder pin is sheared, the slider is movable between a contracted position aligned with the sidewall of the shoulder body and an expanded position stacked radially outward of the shoulder body. In the contracted position, the plurality of sliders are joined together to form a ring, and in the expanded position, there is a gap between adjacent sliders.

[0019] According to one embodiment of the present invention, each slider includes a base and a mounting portion arranged axially. The mounting portion has a flange protruding outward in the circumferential direction on its radially inner side. The flange of the mounting portion is engaged in a groove. The circumferential dimension of the base is larger than that of the mounting portion and is configured such that the bases form a complete ring when all sliders are in the retracted position.

[0020] According to one embodiment of the present invention, it further includes an anti-sit lock assembly located within the gap and below the second inlet. The anti-sit lock assembly includes an anti-sit pin, an anti-sit piston, an anti-sit lock block sleeve, and an anti-sit lock block.

[0021] According to one embodiment of the present invention, the anti-sit lock block sleeve is fixedly installed on the lower connector or the central tube. The anti-sit lock block sleeve is provided with an anti-sit lock block mounting hole. The inner wall of the outer sleeve assembly is provided with a recess at a position corresponding to the anti-sit lock block mounting hole. The anti-sit piston includes an upper section and a lower section connected together and extending axially. The upper section is tightly fitted with the outer wall of the central tube and the inner wall of the outer sleeve assembly and is fixed to the central tube by an anti-sit pin near its top. The lower section is located radially inward compared to the upper section. The radial section of the lower section is thicker at both ends and thinner in the middle to form a recess that is radially concave from the outer wall in the middle. The bottom end of the lower section is radially stacked on the inner side of the upper end of the anti-sit lock block sleeve. The anti-sit lock block is received in the anti-sit lock block mounting hole and extends outward to the recess in the inner wall of the outer sleeve assembly. The inner side abuts against the lower end of the anti-sit piston. The size of the recess is set such that when the anti-sit piston moves down, the outer wall of the anti-sit lock block is located radially inward of the inner wall of the outer sleeve assembly after entering the recess.

[0022] According to one embodiment of the present invention, a seat locking assembly is further provided within the gap and located between the rubber sleeve drive assembly and the slip drive assembly, the seat locking assembly including a first locking ring, a second locking ring and a locking pin.

[0023] According to one embodiment of the present invention, a first locking ring and a second locking ring are unidirectionally slidably sleeved on the central tube, with the first locking ring located above the second locking ring. The two are engaged by an inclined surface. The first locking ring is connected to the outer sleeve assembly via a locking pin, and the bottom of the second locking ring is supported by the outer sleeve assembly.

[0024] According to one embodiment of the present invention, the inner wall of the outer sleeve assembly is provided with a radially protruding flange, and the bottom of the second locking ring is supported by the flange of the outer sleeve assembly.

[0025] According to one embodiment of the present invention, the outer sleeve assembly includes an upper sleeve and a lower sleeve fixedly connected, the bottom end of the upper sleeve is provided with a bottom wall extending radially inward, and the bottom of the second locking ring is supported by the bottom wall.

[0026] According to one embodiment of the present invention, an annular opening is provided between the lower outer wall of the first locking ring and the central tube, the size of the annular opening gradually increases from top to bottom, and a tapered portion is provided at the upper end of the second locking ring, the tapered portion being inserted into the annular opening to form a beveled fit with the first locking ring.

[0027] According to one embodiment of the present invention, the rubber sleeve assembly includes a gauge ring located at the upper part and a rubber sleeve located at the lower part.

[0028] According to one embodiment of the invention, the rubber sleeve is made of a material comprising AFLAS fluororubber and hydrogenated nitrile rubber.

[0029] According to one embodiment of the present invention, the lower connector is fixedly installed on the central tube.

[0030] According to one embodiment of the present invention, both the upper part of the upper connector and the lower part of the lower connector are provided with external threads.

[0031] By adopting the above technical solution, the present invention has at least one of the following beneficial effects:

[0032] (1) A multi-stage drive device is used to drive the slip assembly and the rubber sleeve respectively, which can fully compress the rubber sleeve and deform it to achieve efficient sealing of the annulus.

[0033] (2) Some solutions have a uniquely structured rubber sleeve shoulder assembly. The slider moves with the rubber sleeve. When the rubber sleeve is compressed, the slider moves to the expansion position and sticks to the inner wall of the sleeve, which effectively prevents the deformed part of the rubber sleeve from being squeezed into the annular space of the oil sleeve and avoids the rubber sleeve from tearing.

[0034] (3) Some solutions include an anti-locking assembly to ensure that the packer will not lock prematurely during the lowering process;

[0035] (4) In some schemes, high temperature resistant, corrosion resistant, high strength and high tear resistance rubber sleeves are used to ensure tight sealing;

[0036] (5) This packer can be used in wells where casing deformation occurs during geological and reservoir modification. Taking 5-1 / 2” casing as an example, the outer diameter of this packer can be as small as 98mm. It can be used in an environment with a working pressure of 90MPa and a working temperature of 200℃, which can meet most of the requirements of oil and gas wells for reservoir modification. Attached Figure Description

[0037] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation thereof. In the drawings:

[0038] Figure 1 This is a schematic diagram of the overall structure of a high-temperature and high-pressure packer for casing wells according to an embodiment of the present invention.

[0039] Figure 2 This is a schematic diagram of the rubber sleeve shoulder protector assembly in the retracted position according to an embodiment of the present invention.

[0040] Figure 3 This is a schematic diagram of the rubber sleeve shoulder protector assembly in the expanded position according to an embodiment of the present invention.

[0041] Figure 4 This is an enlarged schematic diagram of an anti-sit lock assembly according to an embodiment of the present invention.

[0042] Figure 5 This is a cross-sectional view of a seat and locking assembly according to an embodiment of the present invention.

[0043] Explanation of reference numerals in the attached figures

[0044] 10 Upper connector, 12 Lower connector, 14 Shoulder pin, 20 Center tube, 22 Upper center tube, 24 Lower center tube, 30 Rubber sleeve shoulder assembly, 32 Shoulder body, 32a Slide groove, 34 Slider, 40 Rubber sleeve assembly, 42 Gauge ring, 44 Rubber sleeve, 50 Collar assembly, 52 Collar cone, 54 Collar, 56 Collar seat, 58 Collar pin, 60 Sleeve assembly, 62 Upper sleeve, 64 Lower sleeve, 7 0. Glue tube drive assembly, 72. Piston, 74. Sealing block and sealing seat, 80. Anti-sit lock assembly, 82. Anti-sit pin, 84. Anti-sit piston, 84a. Upper section of anti-sit piston, 84b. Lower section of anti-sit piston, 86. Anti-sit lock block sleeve, 88. Anti-sit lock block, 90. Sealing lock fixing assembly, 92. First locking ring, 94. Second locking ring, 96. Locking pin, O1. First water inlet, O2. Second water inlet, 100. Slip drive assembly. Detailed Implementation

[0045] The specific embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit this disclosure.

[0046] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. For example, terms such as “length,” “width,” “upper,” “lower,” “left,” “right,” “front,” “rear,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” and “outer” indicate orientations or positions based on the orientations or positions shown in the accompanying drawings and are for ease of description only, and should not be construed as limiting the technical solution.

[0047] The terms "comprising" and "having," and any variations thereof, used in the specification, claims, and accompanying drawings of this invention are intended to cover non-exclusive inclusion; the terms "first," "second," etc., used in the specification, claims, and accompanying drawings are used to distinguish different objects, not to describe a particular order. "A plurality of" means two or more, unless otherwise explicitly specified.

[0048] In the description and claims of this invention and the foregoing drawings, when an element is referred to as "fixed to," "mounted to," "disposed on," or "connected to" another element, it can be located directly or indirectly on that other element. For example, when an element is referred to as "connected to" another element, it can be directly or indirectly connected to that other element.

[0049] Furthermore, the reference to "embodiment" herein means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0050] It should be understood that, in the following embodiments, "radial," "axial," and "circumferential" refer to directions with the packer's overall structure or central tube as a reference. "Up," "down," "inner," and "outer" refer to the various orientations when the packer is in an assembled state and placed vertically.

[0051] This invention provides a high-temperature and high-pressure packer for variable wells. Figure 1 A schematic diagram of the overall structure of a high-temperature and high-pressure packer for casing-type wells according to an embodiment of the present invention is shown. The high-temperature and high-pressure packer generally includes an upper connector 10, a lower connector 12, a central tube 20, and a rubber sleeve assembly 40, a slip assembly 50, and an outer sleeve assembly 60 arranged sequentially from top to bottom and abutting each other around the central tube 20. A rubber sleeve drive assembly 70 and a slip drive assembly 100 are also arranged sequentially from top to bottom within the gap between the outer sleeve assembly 60 and the central tube 20.

[0052] The upper connector 10 is cylindrical and has external threads on the top for connection to the downhole tubing string. The external threads can be, for example, 2-7 / 8” TBG tubing threads. The upper connector 10 and the center tube 20 can be connected, for example, by threaded connections.

[0053] The slip assembly 50 has a radially protruding flange near its lower end. The top of the outer sleeve assembly 60 abuts against the flange to push the slip assembly 50 upward. The upper end of the rubber sleeve drive assembly 70 abuts against the lower end of the slip assembly 50. The slip drive assembly 100 drives the outer sleeve assembly 60 upward and also moves the lower end of the slip assembly 50 upward. The central tube 20 has a first water inlet O1 at a position corresponding to the rubber sleeve drive assembly 70 and a second water inlet O2 at a position corresponding to the slip drive assembly 100.

[0054] Most hydraulic packers use a single-piston motion structure, meaning that a single piston provides the power to push the slips for setting and the rubber sleeve for compression. While this structure is simple and reliable for normal casing with small deformations, it has significant drawbacks for wells with large deformation requirements. If the slips and rubber sleeve move simultaneously and with a large amount of movement, the slips may completely engage the casing wall and complete the setting, but the rubber sleeve, due to its elastic rebound force, may not be fully compressed and still have some clearance, resulting in incomplete setting. To solve this problem, the packer of this invention is designed with a slip drive assembly 100 and a rubber sleeve drive assembly 70 to respectively drive the slips for setting and the rubber sleeve for compression.

[0055] In some embodiments, the slip assembly 50 includes a slip cone 52, slips 54, a slip seat 56, and a slip pin 58. The slip cone 50 has a cylindrical body disposed along a central tube 20 and a tapered sliding portion located at the upper end of the body. The radial dimension of the sliding portion decreases from top to bottom to form an inclined surface that can slide with the slip 54. The slip seat 56 is mounted on the periphery of the cylindrical body and located at the lower end of the cylindrical body via the slip pin 58. The slip pin 58 connects the slip seat 56 and the slip cone 52 to prevent the packer from setting midway. The slip 54 is mounted between the sliding portion and the slip seat 56 and abuts against the cylindrical body. The upper end of the slip 56 has an inclined surface adapted to the tapered surface of the sliding portion. The slip 54 may include a plurality of independent slip pieces. The slip seat 56 has a plurality of radially evenly distributed slots. The lower ends of the slip pieces are installed in the slots, and the upper ends of the slip pieces engage with the inclined surface of the sliding portion. When the slip seat 56 is driven upward, it pushes the slip plate upward along the inclined surface of the sliding part. During the upward movement, the upper end of the slip plate expands radially until it jams the inner wall of the sleeve (not shown in the figure). During this process, the relative movement between the slip plate and the slip seat 56 is similar to the opening of flower petals.

[0056] In some embodiments, the rubber sleeve drive assembly 70 includes a rubber sleeve piston 72, a sealing block, and a sealing seat 74 arranged sequentially from top to bottom. The rubber sleeve piston 72 is located below the slip seat 56. The sealing block and sealing seat 74 are fixed to the central tube 20, and the rubber sleeve piston 72 and the sealing block and sealing seat 74 are disposed on both sides of the first water inlet O1. The space defined by the sleeve assembly 60, the central tube 20, and the sealing block and sealing seat 74 forms a hydraulic chamber for the reciprocating motion of the rubber sleeve piston 72. Under water pressure, the rubber sleeve piston 72 can move upward and push the slip cone 52 upward to compress the rubber sleeve 44.

[0057] In some embodiments, the central tube 20 may include an upper central tube 22 and a lower central tube 24 that are detachably connected (e.g., by threaded connection). The upper central tube 22 is provided with a first water inlet O1 and a second water inlet O2 and a setting ball seat at the bottom.

[0058] In some embodiments, the slip drive assembly 100 includes a slip piston. The slip piston is adjacent to and above the second inlet O2. The gap below the second inlet O2 is closed to form a hydraulic chamber capable of causing the slip piston to move upward. The outer sleeve assembly 60 engages with the slip piston; for example, the inner wall of the outer sleeve assembly 60 has radially protruding protrusions that abut against the slip piston so as to push the outer sleeve assembly 60 upward when the slip piston moves upward. Alternatively, a separate locating block can be used to engage the slip piston and the outer sleeve assembly 60 together.

[0059] In some embodiments, the high-temperature, high-pressure packer for casing wells may further include a sleeve shoulder assembly 30 located between the upper connector 10 and the sleeve assembly 40. The sleeve shoulder assembly 30 may include a plurality of independent sliders 34 and shoulder pins 14. The lower part of the upper connector 10 may be provided with a plurality of grooves evenly arranged circumferentially, each groove slidingly engaging with a single slider 34. The grooves are defined by a ramp extending from top to bottom from the outer wall of the upper connector 10 to the inner wall of the upper connector 10. Each shoulder pin 14 extends through the slider 34, the upper connector 10, and the central tube 20 to secure the slider 34. When the shoulder pin 14 is sheared, the slider 34 is movable between a contracted position aligned with the sidewall of the upper connector 10 and an expanded position overlapping radially outward of the sidewall of the upper connector. In the contracted position, the plurality of sliders 34 are joined together in a ring; in the expanded position, there is a gap between adjacent sliders.

[0060] In some embodiments, such as Figure 2-3 As shown, the rubber sleeve shoulder protector assembly 30 includes a shoulder protector body 32, a plurality of sliders 34, and shoulder protector pins 14. In this embodiment, the rubber sleeve shoulder protector assembly 30 includes six independent sliders 34. Figure 2 This diagram shows the structure of the rubber sleeve shoulder protector assembly 30 in the retracted position. Figure 3 A schematic diagram of the sleeve shoulder protector assembly 30 in the expanded position is shown. The upper end of the shoulder protector body 32 is connected to the upper connector 10. The lower end of the shoulder protector body has a plurality of circumferentially evenly arranged grooves 32a. Each groove 32a slides into a single slider 34. The grooves 34 are defined by a ramp extending from top to bottom from the outer wall of the shoulder protector body 32 to the inner wall of the shoulder protector body 32. Each shoulder protector pin 14 extends through the slider 34, the shoulder protector body 32, and the central tube 20 to secure the three together. When the shoulder protector pin 14 is sheared, the slider 34 is movable between a contracted position aligned with the side wall of the shoulder protector body 32 and an expanded position stacked radially outward of the shoulder protector body 32. In the contracted position, the plurality of sliders 34 are joined together in a ring; in the expanded position, there is a gap between adjacent sliders 34.

[0061] The rubber sleeve shoulder assembly 30 is a crucial component that protects the deformed portion of the rubber sleeve 44 from being squeezed into the annular space of the casing after the packer is set, preventing tearing of the rubber sleeve. Generally, rubber sleeve shoulders use a sulfurized copper sheet or a sulfurized spring structure. However, in casing-modified well packers, the deformation of the rubber sleeve is too large, making both copper sheet and spring shoulders ineffective in protecting it. To address this issue, the packer of this invention employs an umbrella-shaped shoulder with a structure similar to an umbrella frame. The slider 34 moves with the rubber sleeve. When the rubber sleeve 44 compresses the slider 34, the slider 34 moves up the inclined surface and opens to adhere to the inner wall of the casing, forming a protective layer and effectively preventing the deformed portion of the rubber sleeve 44 from being squeezed into the annular space of the casing. During unsealing, as the rubber sleeve 44 recovers and springs back, the slider also contracts and recovers.

[0062] In some embodiments, such as Figure 2-3 As shown, each slider 34 includes a base and a mounting portion arranged axially. The mounting portion has a flange protruding outward in the circumferential direction on its radially inner side. The flange of the mounting portion is engaged in a groove, and the groove has U-shaped recesses on both sides for receiving the flange. The circumferential dimension of the base is larger than that of the mounting portion and is configured such that the bases of all sliders form a complete ring when in the retracted position. Thus, when in the retracted position, the bases of adjacent sliders abut against each other, preventing them from moving further down the slope.

[0063] In some embodiments, such as Figure 1 and Figure 4 As shown, the high-temperature and high-pressure packer for casing wells of the present invention may further include an anti-sit lock assembly 80 for preventing the packer from setting midway. The anti-sit lock assembly 80 is located within the gap and below the second inlet O2. The anti-sit lock assembly 80 includes an anti-sit pin 82, an anti-sit piston 84, an anti-sit lock block sleeve 86, and an anti-sit lock block 88.

[0064] The anti-sit locking block sleeve 86 is fixedly installed on the lower connector 12 or the central tube 20. The anti-sit locking block sleeve 86 is provided with an anti-sit locking block mounting hole. The inner wall of the outer sleeve assembly 60 is provided with a recess at a position corresponding to the anti-sit locking block mounting hole. The anti-sit piston 84 includes an upper section 84a and a lower section 84b connected together and extending axially. The upper section 84a is engaged between the outer wall of the central tube 20 and the inner wall of the outer sleeve assembly 60 and is fixed to the central tube 20 by an anti-sit pin 82 near its top. The lower section 84b is located radially inward compared to the upper section 84a. The radial section of the lower section 84b is thicker at both ends and thinner in the middle to form a notch that is radially concave from the outer wall in the middle. The bottom end of the lower section 84b is radially stacked inside the upper end of the anti-sit locking block sleeve 86. The anti-sit locking block 88 is received within the anti-sit locking block mounting hole and extends outward into the inner wall recess of the outer sleeve assembly 60. The inner side of the anti-sit locking block 88 abuts against the end of the lower section of the anti-sit piston 84. The recess is sized such that when the anti-sit piston 84 moves downward, the outer wall of the anti-sit locking block 88 is located radially inward of the inner wall of the outer sleeve assembly 60 after entering the recess. That is, when the anti-sit locking block 88 is supported by the end of the lower section 84b, it is inserted into the inner wall recess of the outer sleeve assembly 60 to prevent the outer sleeve assembly 60 from moving relative to the anti-sit piston 84 and the central tube 20. When the anti-sit piston 84 moves downward, causing the anti-sit locking block 88 to enter the recess, the anti-sit locking block 88 disengages from the inner wall recess of the outer sleeve assembly 60 to release the outer sleeve assembly 60, allowing it to move. When the anti-sit piston 84 descends, it unlocks the anti-sit lock block 88, releasing the outer sleeve assembly 60 into a free state. The slip piston then moves the outer sleeve assembly 60 upwards, pushing the slip seat 56 to shear the slip pin 58. The slip 54 can then move relative to the inclined plane, extending until it locks into the inner wall of the sleeve, completing the slip setting. Only then can the rubber sleeve piston 72 move to fully compress the rubber sleeve 44, thus preventing the rubber sleeve from having excess material under the elastic rebound force, which could lead to incomplete setting.

[0065] In some embodiments, such as Figure 1 and Figure 5 As shown, the high-temperature and high-pressure packer for casing-type wells of the present invention may further include a setting and locking assembly 90 that locks the entire packer after setting. The setting and locking assembly 90 is disposed within the gap between the outer sleeve assembly 60 and the central tube 20 and is located between the rubber sleeve drive assembly 70 and the slip drive assembly 100. Figure 5As shown, the seat locking assembly 90 includes a first locking ring 92, a second locking ring 94, and a locking pin 96. The first locking ring 92 and the second locking ring 94 are unidirectionally (in this case, towards the upper connector) slidably fitted onto the central tube 20, with the first locking ring 92 positioned above the second locking ring 94, and the two are engaged with an inclined surface. An annular opening is provided between the lower outer wall of the first locking ring 92 and the central tube 20, the size of which gradually increases from top to bottom. A tapered portion is provided at the upper end of the second locking ring 94, which inserts into the annular opening to form an inclined surface engagement with the first locking ring 92. The first locking ring 92 is connected to the outer sleeve assembly 60 via the locking pin 96, and the bottom of the second locking ring 94 is supported by the outer sleeve assembly 60. For example, the inner wall of the outer sleeve assembly 60 has a radially protruding flange, and the bottom of the second locking ring 94 is supported by the flange of the outer sleeve assembly 60. In other embodiments, the outer sleeve assembly 60 includes an upper sleeve 62 and a lower sleeve 64 fixedly connected. The bottom end of the upper sleeve 62 has a radially inwardly extending bottom wall, and the bottom of the second locking ring 94 is supported by the bottom wall. This setting and locking assembly 90 locks the setting force after the packer is set, preventing it from automatically disengaging during construction and ensuring that the packer has the ability to withstand a pressure differential of at least 90 MPa.

[0066] In some embodiments, the packer assembly 40 includes an upper gauge ring 42 and a lower packer sleeve 44. The gauge ring 42 is fitted over the center tube 20. Taking a 5-1 / 2” casing as an example, the maximum outer diameter of the gauge ring 42 is only 98 mm, which is the largest outer diameter of the packer. Its size is better suited for the installation of the packer in a variable well. The packer sleeve of the present invention also has a special design to meet high-temperature requirements. Currently, most high-temperature rubbers on the market are AFLAS fluororubber, which is a polymer with an alternating structure of tetrafluoroethylene and propylene as the main chain, and almost all propylene segments are located between adjacent tetrafluoroethylene segments. It can be used continuously at temperatures of around 230°C and produces almost no oxidation in high-temperature, strong acid, and strong alkali environments. It exhibits excellent aging resistance and chemical resistance. Hydrogenated nitrile butadiene rubber (NBR) is a product obtained by hydrogenating and saturating the carbon-carbon double bonds in the molecular chain of NBR, hence it is also called highly saturated NBR. It possesses excellent characteristics such as high strength, high tear resistance, and abrasion resistance. Addressing the requirement for significant deformation of the packer in casing wells, this invention does not use a single base material in its rubber selection. Instead, it primarily uses AFLAS fluororubber, mixed with a certain amount of hydrogenated NBR. This allows the packer to possess not only the high-temperature resistance and corrosion resistance of fluororubber but also the high strength and high tear resistance of NBR, ensuring a tight seal and enabling the packer to withstand temperatures up to 200 degrees Celsius.

[0067] In some embodiments, the lower connector 12 is fitted around the center tube 20 and fixedly connected to the center tube. When the center tube 20 includes an upper center tube 22 and a lower center tube 24, the lower connector 12 is fixedly connected to the lower center tube 24. The lower part of the lower connector 12 is provided with external threads for connection to the downhole tubing string, and the lower connector thread is, for example, a 2-7 / 8” TBG tubing thread.

[0068] Sealing operation

[0069] The high-temperature and high-pressure packer for variable wells of the present invention is used in conjunction with a setting ball seat at the bottom, and a hydraulic anchor can be added at the top to ensure the stability of the reservoir stimulation process.

[0070] During the setting process, the setting ball is inserted, the ground is pressurized and water is added, and water is injected from the lower second water inlet O2, shearing the anti-setting pin 82. The water pressure pushes the anti-setting piston 84 downward. When the anti-setting piston 84 reaches the bottom, the anti-setting locking block 88 enters the recess of the lower section 84b of the anti-setting piston and no longer jams the lower sleeve 64, leaving the lower sleeve 64 in a free state. At this point, since the anti-setting piston 84 has reached the bottom and cannot move further, the water entering the second water inlet O2 pushes the slip piston upward. As the slip piston engages with the lower sleeve 64, the slip piston drives the lower sleeve 64 to move upward. The lower sleeve 64 pushes against the upper sleeve 62 and moves upward. The top of the upper sleeve 62 applies force to the outer flange of the slip seat 56, pushing the slip seat 56 to shear the slip pin 58. Then, the slip 54 and the slip seat 56 move relative to each other along the inclined surface of the slip cone 52 under the pushing action of the slip piston. As the slip moves upward, it extends radially outward until it locks into the inner wall of the sleeve, completing the slip setting. Pressurization continues, and water is injected from the first inlet O1, pushing the piston 72 of the rubber sleeve drive assembly 70 upward. The piston 72 pushes against the slip cone 52 and compresses the rubber sleeve 44. As the rubber sleeve 44 is compressed, it pushes the gauge ring 42 upward. The gauge ring 42 applies force to the slider 34, causing it to move upward and causing the shoulder pin 14 to be sheared. After the shoulder pin 14 is sheared, the slider 34 moves relative to the inclined surface of the gauge ring 42 and the inclined surface of the upper connector 10 or the shoulder body 32. The slider 34 moves to the expansion position of the outer wall of the upper connector 10 or the shoulder body 32 until it is tightly attached to the inner wall of the casing and then stops moving. Since the slider 34 fills the annular space, it protects the rubber sleeve 44 from tearing. In addition, at the same time as the packer sets, the upper hydraulic anchor claws open and bite into the inner wall of the casing to ensure a firm and reliable setting, thus completing the setting.

[0071] The first locking ring 92 and the second locking ring 94 move upward along the central tube 20 together with the upper sleeve 62. The first locking ring 92 and the second locking ring 94 are two circular rings with inclined planes. After the packer completes setting, the two circular rings will mesh with each other and tightly lock the various moving parts inside the packer.

[0072] Unsealing process

[0073] Upon release, the pressure inside the tubing is released, balancing the pressure inside and outside the packer. The hydraulic anchor claws retract under the force of the internal springs. Lifting the tubing causes the central tube 20 to move upward, shearing the locking pin 96. The sleeve assembly 60, losing its support, moves downward. The slip 54 retracts to its original position under the rebound force of the rubber sleeve 44, and the slider 34 also returns to its original position under the rebound force of the rubber sleeve 44 and the interlocking action, completing the release. The packer can then be removed by lifting the tubing.

[0074] The high-temperature and high-pressure packer for casing deformation wells provided by this invention is a downhole operation tool that can be used in wells where casing deformation occurs during geological and reservoir modification. Taking 5-1 / 2” casing as an example, the packer has a minimum outer diameter of 98mm and can be used in an environment with a working pressure of 90MPa and a working temperature of 200℃, thus meeting most of the requirements of oil and gas wells for reservoir modification.

[0075] The preferred embodiments of this disclosure have been described in detail above with reference to the accompanying drawings. However, this disclosure is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this disclosure, various simple modifications can be made to the technical solutions of this disclosure, and these simple modifications all fall within the protection scope of this disclosure.

[0076] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately.

[0077] Furthermore, various different embodiments of this disclosure can be combined in any way, as long as they do not violate the spirit of this disclosure, they should also be regarded as the content disclosed in this disclosure.

Claims

1. A high-temperature and high-pressure packer for use in variable wells, characterized in that, include: Cylindrical upper connector; Cylindrical lower connector; A central tube, the upper end of which is connected to the upper connector and the lower connector is sleeved near the lower end of the central tube; A rubber sleeve assembly, a slip assembly, and an outer sleeve assembly are arranged sequentially from top to bottom and abutting each other around the central tube. The slip assembly has a radially protruding flange near its lower end. The top of the outer sleeve assembly abuts against the flange. A gap is defined between the outer sleeve assembly and the central tube. A rubber sleeve drive assembly and a slip drive assembly are sequentially arranged from top to bottom within the gap. The rubber sleeve drive assembly abuts against the lower end of the slip assembly. The slip drive assembly drives the outer sleeve assembly to move upward and moves the lower end of the slip assembly upward. The central tube has a first water inlet at a position corresponding to the rubber sleeve drive assembly and a second water inlet at a position corresponding to the slip drive assembly.

2. The high-temperature and high-pressure packer for casing wells according to claim 1, characterized in that, The slip assembly includes a slip cone, a slip, a slip seat, and a slip pin. The slip cone has a cylindrical body arranged along a central tube and a sliding part arranged in a conical shape at the upper end of the body. The radial dimension of the sliding part decreases from top to bottom. The slip seat is installed on the periphery of the cylindrical body via the slip pin and is located at the lower end of the cylindrical body. The slip is installed between the sliding part and the slip seat and abuts against the cylindrical body. The upper end of the slip has an inclined surface adapted to the conical surface of the sliding part.

3. The high-temperature and high-pressure packer for casing wells according to claim 2, characterized in that, The latch comprises multiple latch pieces, which are radially and evenly installed in the latch slots of the latch seat.

4. The high-temperature and high-pressure packer for casing wells according to claim 1, characterized in that, The rubber sleeve drive assembly includes a rubber sleeve piston, a sealing block, and a sealing seat arranged sequentially from top to bottom. The rubber sleeve piston and the sealing block are located on both sides of the first water inlet. The sealing block and the sealing seat are fixed to the central tube. The rubber sleeve piston can move upward under water pressure.

5. The high-temperature and high-pressure packer for casing wells according to claim 2, characterized in that, The central tube includes an upper central tube and a lower central tube that are detachably connected. A seated ball is provided at the bottom end of the upper central tube. The first water inlet and the second water inlet are both located on the upper central tube.

6. The high-temperature and high-pressure packer for casing wells according to claim 1, characterized in that, The slip drive assembly includes a slip piston, which is adjacent to and above the second inlet. The gap below the second inlet is closed. The inner wall of the outer sleeve assembly is provided with radially protruding protrusions that abut against the slip piston.

7. The high-temperature and high-pressure packer for casing wells according to claim 1, characterized in that, It also includes a rubber sleeve shoulder assembly located between the upper connector and the rubber sleeve assembly. The rubber sleeve shoulder assembly includes a plurality of sliders and shoulder pins. The lower part of the upper connector has a plurality of grooves evenly arranged circumferentially. Each groove slides in contact with a single slider. The grooves are defined by a ramp extending from the outer wall of the upper connector to the inner wall of the upper connector from top to bottom. Each shoulder pin extends through the slider, the upper connector, and the central tube. When the shoulder pin is sheared, the slider is movable between a contracted position aligned with the sidewall of the upper connector and an expanded position overlapping the radially outer sidewall of the upper connector. In the contracted position, the plurality of sliders are joined together to form a ring. In the expanded position, there is a gap between adjacent sliders.

8. The high-temperature and high-pressure packer for casing wells according to claim 1, characterized in that, It also includes a rubber sleeve shoulder assembly located between the upper connector and the rubber sleeve assembly. The rubber sleeve shoulder assembly includes a shoulder body, a plurality of sliders, and shoulder pins. The upper end of the shoulder body is connected to the upper connector, and the lower end of the shoulder body has a plurality of grooves evenly arranged circumferentially. Each groove slides with a single slider. Each shoulder pin extends through the slider, the shoulder body, and the central tube. When the shoulder pin is sheared, the slider is movable between a contracted position aligned with the sidewall of the shoulder body and an expanded position overlapping the radially outer side of the shoulder body. In the contracted position, the plurality of sliders are joined together to form a ring, and in the expanded position, there is a gap between adjacent sliders.

9. The high-temperature and high-pressure packer for casing wells according to claim 7 or 8, characterized in that, Each of the sliders includes a base and a mounting portion arranged axially. The mounting portion has a flange that protrudes circumferentially outward on its radially inner side. The flange of the mounting portion is engaged in the groove. The circumferential dimension of the base is larger than that of the mounting portion and is configured such that the bases of all the sliders form a complete ring when they are in the retracted position.

10. The high-temperature and high-pressure packer for casing wells according to claim 1, characterized in that, It also includes an anti-sit lock assembly, which is located within the gap and below the second water inlet. The anti-sit lock assembly includes an anti-sit pin, an anti-sit piston, an anti-sit lock block sleeve, and an anti-sit lock block.

11. The high-temperature and high-pressure packer for casing wells according to claim 10, characterized in that, The anti-sit locking block sleeve is fixedly installed on the lower connector or the central tube. The anti-sit locking block sleeve has an anti-sit locking block mounting hole. The inner wall of the outer sleeve assembly has a recess at a position corresponding to the anti-sit locking block mounting hole. The anti-sit piston includes an upper section and a lower section connected together and extending axially. The upper section is tightly fitted with the outer wall of the central tube and the inner wall of the outer sleeve assembly and is fixed to the central tube by the anti-sit pin near its top. The lower section is located radially inward compared to the upper section. The radial section is thicker at both ends and thinner in the middle to form a notch that is radially recessed from the outer wall in the middle. The bottom end of the lower section is radially stacked on the inner side of the upper end of the anti-sit lock block sleeve. The anti-sit lock block is received in the anti-sit lock block mounting hole and extends outward to the inner wall recess of the outer sleeve assembly. The inner side abuts against the lower end of the anti-sit piston. The size of the notch is set such that when the anti-sit piston moves down, after the anti-sit lock block enters the notch, the outer wall of the anti-sit lock block is located radially inward of the inner wall of the outer sleeve assembly.

12. The high-temperature and high-pressure packer for casing wells according to claim 1, characterized in that, It also includes a seat locking assembly disposed within the gap and located between the rubber sleeve drive assembly and the slip drive assembly, the seat locking assembly including a first locking ring, a second locking ring and a locking pin.

13. The high-temperature and high-pressure packer for casing wells according to claim 12, characterized in that, The first locking ring and the second locking ring are unidirectionally slidably sleeved on the central tube, with the first locking ring located above the second locking ring. The two are engaged with an inclined surface. The first locking ring is connected to the outer sleeve assembly via the locking pin, and the bottom of the second locking ring is supported by the outer sleeve assembly.

14. The high-temperature and high-pressure packer for casing wells according to claim 13, characterized in that, The inner wall of the outer sleeve assembly is provided with a radially protruding flange, and the bottom of the second locking ring is supported by the flange of the outer sleeve assembly.

15. The high-temperature and high-pressure packer for casing wells according to claim 13, characterized in that, The outer sleeve assembly includes an upper sleeve and a lower sleeve that are fixedly connected. The bottom end of the upper sleeve is provided with a bottom wall that extends radially inward, and the bottom of the second locking ring is supported by the bottom wall.

16. The high-temperature and high-pressure packer for casing wells according to claim 13, characterized in that, The lower outer wall of the first locking ring is provided with an annular opening between it and the central tube. The size of the annular opening gradually increases from top to bottom. The upper end of the second locking ring is provided with a tapered part, which is inserted into the annular opening to form an inclined surface fit with the first locking ring.

17. The high-temperature and high-pressure packer for casing wells according to claim 1, characterized in that, The rubber sleeve assembly includes a gauge ring at the top and a rubber sleeve at the bottom.

18. The high-temperature and high-pressure packer for casing wells according to claim 16, characterized in that, The rubber sleeve is made of materials including AFLAS fluororubber and hydrogenated nitrile rubber.

19. The high-temperature and high-pressure packer for casing wells according to claim 1, characterized in that, The lower connector is fixedly installed on the central tube.

20. The high-temperature and high-pressure packer for casing wells according to claim 1, characterized in that, Both the upper part of the upper connector and the lower part of the lower connector are provided with external threads.

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