A high-pressure packer and its unsealing method

Abstract

The application provides a high-pressure packer, comprising a central pipe, a rubber sleeve unit sleeved on the central pipe, which comprises an upper rubber sleeve seat, a rubber sleeve assembly and a lower rubber sleeve seat distributed from top to bottom, an upper anchoring unit and a lower anchoring unit at two ends of the rubber sleeve unit, the upper anchoring unit comprising a matched upper cone and upper slips, and the lower anchoring unit comprising a matched lower cone and lower slips, a unsealing mechanism arranged between the rubber sleeve unit and the upper anchoring unit and the lower anchoring unit, wherein the upper anchoring unit and the lower anchoring unit can be anchored to a wellbore casing under the action of a lower driving mechanism and make the rubber sleeve unit set, the unsealing mechanism is configured to move the upper rubber sleeve seat relative to the upper cone by lifting the central pipe to release the axial compression on the rubber sleeve unit, and make the central pipe drive the lower cone to go up to release the lower anchoring unit, and the central pipe can drive the upper cone to go down to release the upper anchoring unit by pressing down the central pipe. The application also provides a unsealing method of the high-pressure packer.

Description

Technical Field

[0001] This invention belongs to the field of oil and gas drilling and completion technology, specifically relating to a high-pressure packer and its unpacking method. Background Technology

[0002] Downhole packers for oil and gas wells are generally divided into retrievable packers and permanent packers. Retrievable packers have slips installed on one side of the rubber sleeve. Typically, the slips and cone are separated by lifting or lowering tools, allowing the slips to be retrieved and thus releasing the packer. However, under bidirectional alternating pressure, the slips experience poor stress conditions, which can lead to loosening. Alternatively, hydraulic pressure may be transmitted to the packer's self-locking mechanism, causing premature release and affecting the packer's pressure-bearing reliability.

[0003] Permanent packers typically employ a set of one-way slips on each side of the rubber sleeve. Axial compression causes the rubber sleeve to expand, simultaneously anchoring the slips on both sides to the casing. Therefore, when subjected to alternating pressure differentials, the load on the permanent packer always acts on the casing, preventing loosening. Simultaneously, other components of the permanent packer remain unaffected, significantly improving sealing reliability. However, because the cone of the permanent packer is positioned between the two slips, it cannot be released. Directly lifting the tubing string is extremely difficult due to the rubber sleeve's rebound force and the inability to release the cone. Only integral milling can achieve release, leading to difficulties in subsequent wellbore treatment, reduced operational efficiency, and limiting the application of this type of permanent packer. Summary of the Invention

[0004] To address the technical problems described above, this invention aims to provide a high-pressure packer that combines high pressure resistance and high availability. It has high pressure resistance, reliable sealing, and simple operation, enabling high-success-rate unsealing operations.

[0005] Therefore, according to the present invention, a high-pressure packer is provided, comprising: a central tube; a rubber sleeve unit sleeved on the central tube, comprising a rubber sleeve assembly and an upper rubber sleeve seat and a lower rubber sleeve seat disposed at both axial ends of the rubber sleeve assembly; an upper anchoring unit and a lower anchoring unit sleeved on the central tube and respectively located at both ends of the rubber sleeve unit, the upper anchoring unit comprising an upper cone and an upper slip adapted to the upper cone, the lower anchoring unit comprising a lower cone and a lower slip adapted to the lower cone; and a packer disposed between the rubber sleeve unit and the upper anchoring unit. The unsealing mechanism between the upper and lower anchoring units; wherein the upper and lower anchoring units are anchored to the well casing under the action of the lower drive mechanism, and the rubber sleeve unit is seated. The unsealing mechanism is configured to move the upper rubber sleeve seat relative to the upper cone by lifting the central tube to release the axial compression on the rubber sleeve unit, and to allow the central tube to drive the lower cone upward to unseal the lower anchoring unit. By pressing down the central tube, the upper cone can be driven downward to unseal the upper anchoring unit.

[0006] In one embodiment, the unsealing mechanism includes a connecting sleeve disposed between the upper cone and the upper glue tube seat, the connecting sleeve being fixedly connected to the upper cone, the connecting sleeve being configured to axially fix the upper cone and the upper glue tube seat in an initial state to transmit axial force, and to allow the upper cone and the upper glue tube seat to move relative to each other during unsealing.

[0007] In one embodiment, the connecting sleeve is provided with at least one through groove, and an unlocking block that can slide along the through groove is installed in the through groove. The outer surface of the central tube is provided with a first pre-made groove, and the inner wall surface of the upper glue tube seat is provided with a slot. The unlocking block is axially offset from the first pre-made groove and adapted to the slot in the initial state, and can be adapted to the first pre-made groove and disengaged from the slot when the central tube is lifted.

[0008] In one embodiment, the outer ends of the unblocking block are chamfered to allow the unblocking block to enter the first prefabricated groove under the action of axial force.

[0009] In one embodiment, a locking ring is provided between the glue-filling sleeve and the connecting sleeve, the locking ring being configured such that the glue-filling sleeve can only move upward relative to the connecting sleeve.

[0010] In one embodiment, the inner surface of the locking ring is provided with a first one-way tooth, and the outer surface of the connecting sleeve is provided with a second one-way tooth, wherein the first one-way tooth and the second one-way tooth are adapted to each other.

[0011] In one embodiment, a locking ring sleeve for installing the locking ring is fixedly connected to the upper end of the upper glue tube seat.

[0012] In one embodiment, the lower cone is fixedly connected to the lower rubber sleeve seat.

[0013] In one embodiment, the unsealing mechanism further includes an unsealing ring disposed at the connection between the lower cone and the lower rubber sleeve seat. The outer surface of the central tube is provided with a second pre-made groove. The unsealing ring can be adapted to the second pre-made groove when the central tube is lifted, so as to drive the lower cone upward.

[0014] In one embodiment, an installation groove is provided on the inner wall of the lower rubber sleeve seat for installing the unsealing ring.

[0015] In one embodiment, both the locking ring and the unlocking ring are elastic open rings.

[0016] In one embodiment, the unsealing mechanism further includes an unsealing auxiliary mechanism, which includes a first elastic element and a second elastic element. The first elastic element is disposed between the upper cone and the axial end face of the upper column connected to the central tube, and the second elastic element is disposed between the lower cone and the axial end face of the lower drive mechanism.

[0017] According to a second aspect of the present invention, a method for unsealing a high-voltage packer as described above is provided, comprising the steps of: Lifting the central tube allows the upper glue tube seat to move axially relative to the upper cone under the action of the unsealing mechanism, thereby releasing the axial compression on the glue tube unit. Continue to lift the central tube, so that the central tube can drive the lower cone upward under the action of the unsealing mechanism, so as to release the radial support of the lower cone on the lower slip, thereby releasing the lower anchoring unit; After the predetermined tonnage is raised, the central tube is pressed down and the upper cone is driven downward through the unsealing mechanism to release the radial support of the upper cone on the upper slip, thereby releasing the upper anchoring unit; Raise the working string and retrieve the high-pressure packer.

[0018] Compared with the prior art, the advantages of this application are: The high-pressure packer of the present invention can reliably unseal a high-pressure packer with a centered rubber sleeve and a double-positioned bidirectional slip structure through its unsealing mechanism. This effectively solves the problem of unsealing failure or high unsealing failure of this type of packer. Furthermore, the high-pressure packer has high pressure resistance and reliable sealing. During the unsealing process, no other special tools are required; a high success rate of unsealing can be achieved simply by lifting and lowering the tubing string. Its structure is simple, safe, and reliable. Even in special working conditions where lifting fails to unseal, unsealing can still be achieved through a "lift-press-lift" unsealing method, greatly improving the success rate of unsealing the high-pressure packer and significantly enhancing its reliability and unsealing performance. Attached Figure Description

[0019] The present invention will now be described with reference to the accompanying drawings.

[0020] Figure 1 The structure of the high-pressure packer according to the present invention is schematically shown.

[0021] Figure 2 yes Figure 1 Enlarged view of section A.

[0022] In this application, all drawings are schematic and are used only to illustrate the principles of the invention, and are not drawn to scale. Detailed Implementation

[0023] The invention will now be described with reference to the accompanying drawings.

[0024] For ease of understanding, in this application, the end closest to the wellhead is defined as the upper end, upstream end, or similar terms, for example... Figure 1 The left end is defined as the end furthest from the wellhead, while the end furthest from the wellhead is defined as the lower end, downstream end, or similar terms, for example... Figure 1 The right end of the packer. Meanwhile, the direction along the length of the high-pressure packer is referred to as the longitudinal direction, axial direction, or similar terminology, while the direction perpendicular to it is referred to as the transverse direction, radial direction, or similar terminology.

[0025] Figure 1 The structure of the high-pressure packer 100 according to the present invention is schematically shown. For example... Figure 1As shown, the high-pressure packer 100 includes a central tube 1, a rubber sleeve unit 2, an upper anchoring unit 3, a lower anchoring unit 4, and a release mechanism 5. The upper part of the central tube 1 is used to connect to the upper tubing string 8, and the lower part of the central tube 1 is used to connect to the lower drilling tool. The lower drilling tool includes a lower drive mechanism 6, which may be, for example, a piston drive mechanism. The rubber sleeve unit 2 is sleeved on the central tube 1 and includes a rubber sleeve assembly 21 and an upper rubber sleeve seat 22 and a lower rubber sleeve seat 23 disposed at both axial ends of the rubber sleeve assembly 21. The upper anchoring unit 3 and the lower anchoring unit 4 are both sleeved on the central tube 1 and are respectively located at both axial ends of the rubber sleeve unit 2. The upper anchoring unit 3 includes an upper cone 31 and an upper slip 32 adapted to the upper cone 31, and the lower anchoring unit 4 includes a lower cone 41 and a lower slip 42 adapted to the lower cone 41. The unsealing mechanism 5 is located between the rubber sleeve unit 2 and the upper anchoring unit 3 and lower anchoring unit 4. The upper anchoring unit 3 and lower anchoring unit 4 can axially approach each other under the action of the lower drive mechanism 6, and sequentially axially push the lower cone 41 and upper cone 31, thereby causing the lower anchoring unit 4 and upper anchoring unit 3 to bite into the casing wall through the lower slip 42 and upper slip 32 respectively, thus anchoring the high-pressure packer 100. Furthermore, it can axially compress the rubber sleeve unit 2, causing it to set. The unsealing mechanism 5 is configured to move the upper rubber sleeve seat 22 relative to the upper cone 31 by lifting the central tube 1, releasing the axial compression on the rubber sleeve unit 2, and causing the central tube 1 to drive the lower cone 41 upward, thus unlocking the lower anchoring unit 4. Furthermore, by pressing down the central tube 1, it can drive the upper cone 31 downward, thus unlocking the upper anchoring unit 3. Thus, the high-pressure packer 100 is unsealed.

[0026] According to the present invention, such as Figure 1 As shown, the unsealing mechanism 5 includes a connecting sleeve 51 disposed between the upper cone 31 and the upper glue cartridge seat 22, with the upper end of the connecting sleeve 51 fixedly connected to the upper cone 31. In one embodiment, the connecting sleeve 51 and the upper cone 31 are fixedly connected by threads. In the initial state, the connecting sleeve 51 axially fixes the upper cone 31 and the upper glue cartridge seat 22 to transmit axial force, while during unsealing, it allows the upper cone 31 and the upper glue cartridge seat 22 to move relative to each other.

[0027] like Figure 1 As shown, the connecting sleeve 51 is cylindrical. The upper end of the connecting sleeve 51 is provided with an external thread, while the lower end of the upper cone 31 is constructed as an inner step, and the inner wall of the inner step is provided with an internal thread. The connecting sleeve 51 is fixedly connected by the external thread and the internal thread of the upper cone 31.

[0028] According to the present invention, such as Figure 2As shown, the connecting sleeve 51 is provided with at least one through groove 511. The through groove 511 is preferably located on the lower end sidewall of the connecting sleeve 51 and extends radially through the sidewall of the connecting sleeve 51. Unlocking blocks 52, capable of sliding along the through groove 511, are installed in each through groove 511. The outer surface of the central tube 1 is provided with a first pre-formed groove 11, which extends axially and can be an annular groove. Meanwhile, the inner wall surface of the upper glue tube seat 22 is provided with a retaining groove 221. In the initial state, the unlocking block 52 is axially offset from the first pre-formed groove 11 and fits into the retaining groove 221, causing the unlocking block 52 in the through groove 511 to extend outward and engage in the retaining groove 221, thereby fixing the connecting sleeve 51 and the upper glue tube seat 22 axially. When the central tube 1 is lifted, the unblocking block 52 can enter the first pre-made groove 11 to match the first pre-made groove 11 when the central tube 1 moves to the point where the first pre-made groove 11 corresponds to the through groove 511, thereby disengaging from the slot 221. As a result, the upper glue cylinder seat 22 can move relative to the upper cone 31.

[0029] To ensure that the unblocking block 52 does not affect the relative movement between the upper glue tube seat 22 and the upper cone 31 when it is adapted to the first prefabricated groove 11, the thickness of the unblocking block 52 is set to be no greater than the sum of the depth of the first prefabricated groove 11 and the wall thickness of the connecting sleeve 51.

[0030] According to one embodiment of the present invention, the outer ends of the unlocking block 52 are chamfered to allow the unlocking block 52 to enter the first pre-formed groove 11 under the action of axial force. Since the connecting sleeve 51 is subjected to axial forces from the upper cone 31 and the upper glue tube seat 22 respectively in the seated state, when the central tube 1 moves to align the first pre-formed groove 11 with the through groove 511, the chamfers of the unlocking block 52 will cause the unlocking block 52 to retract inward under the action of axial force, thereby releasing the connection sleeve 51 from the upper glue tube seat 22. Furthermore, the chamfers can further prevent the retraction of the unlocking block 52 from affecting the relative movement between the connection sleeve 51 and the upper glue tube seat 22.

[0031] Preferably, multiple unblocking blocks 52 can be arranged in the circumferential direction, and the multiple unblocking blocks 52 are evenly spaced apart in the circumferential direction.

[0032] like Figure 1 and Figure 2As shown, a locking ring 53 is provided at the upper end of the upper glue sleeve seat 22. The locking ring 53 is configured so that the upper glue sleeve seat 22 can only move upward relative to the connecting sleeve 51. Preferably, the locking ring 53 is an open elastic locking ring. A first one-way tooth, such as a one-way sawtooth internal thread, is provided on the inner surface of the locking ring 53. At the same time, a second one-way tooth, such as a one-way sawtooth external thread, is provided on the outer surface of the connecting sleeve 51. The first one-way tooth of the locking ring 53 cooperates with the second one-way tooth of the connecting sleeve 51, thereby realizing one-way movement and reverse locking between the locking ring 53 and the connecting sleeve 51, so that the upper glue sleeve seat 22 can only move upward relative to the connecting sleeve 51.

[0033] like Figure 1 and Figure 2 As shown, a locking ring sleeve 54 for mounting a locking ring 53 is fixedly connected to the upper end of the upper glue sleeve seat 22. The inner surface of the locking ring sleeve 54 has a certain angled bevel for engaging with the locking ring 53, thereby allowing the locking ring 53 to move only upwards relative to the connecting sleeve 51. In one embodiment, the locking ring sleeve 54 is fixedly connected to the upper glue sleeve seat 22 via threads, facilitating the installation and removal of the locking ring 53.

[0034] like Figure 2 As shown, the glue sleeve seat 22 has a through hole, and the unblocking block 52 has an auxiliary mounting hole for assisting in the installation of the unblocking block 52, ensuring that the unblocking block 52 can be aligned with the slot 221 of the glue sleeve seat 22. Specifically, when installing the unblocking block 52, first install the unblocking block 52 into the through groove 511 of the connecting sleeve 51, and align the unblocking block 52 with the first pre-made groove 11, so that the unblocking block 52 is in a radially retracted state. Then, install the glue sleeve seat 22, fitting the glue sleeve seat 22 and the connecting sleeve 51 together, aligning the through hole on the glue sleeve seat 22 with the auxiliary mounting hole of the unblocking block 52, and then install auxiliary mounting screws in the auxiliary mounting hole and the through hole, thereby fixing the relative position of the unblocking block 52 and the glue sleeve seat 22. Afterwards, push the connecting sleeve 51 upward until the unblocking block 52 is pushed out of the first pre-made groove 11 and extends radially, locking in the corresponding slot 221 of the glue sleeve seat. After the high-pressure packer 100 is assembled, the auxiliary mounting screws are removed, thereby completing the installation of the release block 52. In order to ensure that the release block 52 can be pushed out of the first prefabricated groove 11, the upper and lower end sidewalls of the first prefabricated groove 11 are both constructed as conical surfaces.

[0035] Preferably, the rubber sleeve assembly 21 is a multi-sleeve combination. For example, in Figure 1In the illustrated embodiment, the glue tube assembly 21 is a three-glue tube combination. The upper glue tube seat 22 and the lower glue tube seat 23 are respectively arranged at the upper and lower ends of the glue tube assembly 21. On one hand, the upper glue tube seat 22 can provide axial compression and support force for the setting and sealing of the glue tube assembly 21; on the other hand, the upper glue tube seat 22 can serve as an important part of the unsealing mechanism 5, cooperating with the locking ring 53, the unsealing block 52, and the central tube 1 to realize the main function of the unsealing mechanism 5.

[0036] like Figure 1 As shown, the upper end face of the upper glue tube seat 22 is constructed as an outward-facing conical surface, and the lower end face of the lower glue tube seat 23 is constructed as an outward-facing conical surface. This structure allows the glue tube assembly 21 to expand radially when the upper glue tube seat 22 and the lower glue tube seat 23 are axially compressed, which is beneficial for achieving setting and sealing.

[0037] According to the present invention, the lower cone 41 is fixedly connected to the lower rubber sleeve seat 23. For example... Figure 1 As shown, the lower cone 41 and the lower rubber sleeve seat 23 are fixedly connected by a stepped threaded connection. This makes the lower cone 41 and the lower rubber sleeve seat 23 a single unit.

[0038] According to the present invention, the unsealing mechanism 5 further includes an unsealing ring 55. A second pre-formed groove 12 is provided on the outer surface of the central tube 1, and the second pre-formed groove 12 is located downstream of the first pre-formed groove 11. The unsealing ring 55 is initially sleeved on the central tube 1 and located at the upper end of the second pre-formed groove 12. The unsealing ring 55 can be adapted to the second pre-formed groove 12 when the central tube 1 is lifted, so as to drive the lower cone 41 upward.

[0039] like Figure 1 As shown, an installation groove 7 is provided on the inner wall of the lower cone 41 for installing the unsealing ring 55. The installation groove 7 is an annular groove. Preferably, the unsealing ring 55 is an open elastic locking ring made of spring steel, and the unsealing ring 55 is installed in the installation groove 7. When the central tube 1 moves relative to the unsealing ring 55 to make the second prefabricated groove 12 correspond to the installation groove 7, the unsealing ring 55 can be locked into the corresponding second prefabricated groove 12 under the action of elastic force. The unsealing ring 55 and the second prefabricated groove 12 adopt a unidirectional design. Therefore, after the unsealing ring 55 is locked into the second prefabricated groove 12, the radial inner end of the unsealing ring 55 is adapted to the second prefabricated groove 12, and the radial outer end of the unsealing ring 55 still corresponds to the installation groove 7. This allows the central tube 1 to drive the lower cone 41 to move upward, thereby causing the lower clamp 42 to retract after losing radial support, and thus realizing the unlocking of the lower anchoring unit 4.

[0040] In one embodiment, the mounting groove 7 is formed at the connection between the lower rubber sleeve seat 23 and the lower cone 41. The inner wall of the lower rubber sleeve seat 23 is provided with an inner step with the end face facing downward. The mounting groove 7 is formed between the end face of the inner step and the upper end face of the lower cone 41.

[0041] According to the present invention, the unsealing mechanism 5 also unseales the auxiliary mechanism. For example... Figure 1 As shown, the unsealing auxiliary mechanism includes a first elastic element 91 and a second elastic element 92. The first elastic element 91 is disposed between the upper cone 31 and the axial end face of the upper column 8 connected to the central tube 1. The second elastic element 92 is disposed between the lower cone 41 and the axial end face of the piston connecting seat of the lower drive mechanism 6. When the high-pressure packer 100 is set, the first elastic element 91 and the second elastic element 92 are in a compressed state. When the upper anchoring unit 3 and the lower anchoring unit 4 are released, the unsealing auxiliary mechanism can use the first elastic element 91 and the second elastic element 92 to provide a certain axial force to separate the corresponding upper cone 31 and upper slip 32, and lower cone 41 and lower slip 42, thereby assisting the upper anchoring unit 3 and lower anchoring unit 4 in releasing, thus realizing the auxiliary unsealing of the high-pressure packer 100.

[0042] According to the present invention, a method for unsealing the above-mentioned high-pressure packer is also provided. The unsealing method is described in detail below.

[0043] In practical applications, the high-pressure packer 100 according to the present invention is connected to the tubing string through the central tube 1 and lowered to a predetermined position in the wellbore.

[0044] When the high-pressure packer 100 is set, the lower drive mechanism 6 drives the piston connecting seat upward axially. This, in turn, drives the lower cone 41 and the upper cone 31 axially, bringing them closer together axially. The lower anchoring unit 4 and the upper anchoring unit 3 are then anchored to the well casing by the lower slip 42 and the upper slip 32, respectively, thus achieving anchoring of the high-pressure packer 100. Furthermore, the lower cone 41 transmits axial force through the lower rubber sleeve seat 23, and the upper cone 31 transmits axial force through the connecting sleeve 51 and the upper rubber sleeve seat 22, thereby axially compressing the rubber sleeve unit 2. This causes the rubber sleeve unit 2 to expand radially until it is in close contact with the casing wall, thus achieving setting.

[0045] When the high-pressure packer 100 needs to be released, firstly, the central tube 1 is lifted. As the central tube 1 moves upward, it moves axially relative to the connecting sleeve 51. When the central tube 1 moves to the point where the first pre-formed groove 11 corresponds to the through groove 511, the release block 52 automatically retracts under the action of axial force using its chamfered structure. This allows the radially inner end of the release block 52 to enter the first pre-formed groove 11 to fit into it, thereby disengaging from the locking groove 221. At this time, the upper rubber sleeve seat 22 can move axially upward relative to the upper cone 31. Under the cooperation of the first one-way tooth of the locking ring 53 and the second one-way tooth of the connecting sleeve 51, the upper rubber sleeve seat 22 can only move upward relative to the connecting sleeve 51. At the same time, the upper cone 31 is no longer supported by the upper rubber sleeve seat 22 and the lower rubber sleeve seat 23.

[0046] Subsequently, the tubing is further lifted. When the central tube 1 moves relative to the unsealing ring 55 to the point where the second prefabricated groove 12 aligns with the installation groove 7, the unsealing ring 55 is engaged in the corresponding second prefabricated groove 12 under the action of elastic force. This allows the central tube 1 to drive the lower cone 41 upward, causing the lower slip 42 to retract after losing radial support, thereby releasing the lower anchoring unit 4.

[0047] Next, the central pipe 1 is raised. At this point, the upper slip 32 will be under a relatively large lifting load due to the continued support of the upper cone 31. Therefore, after raising the predetermined tonnage, the tubing string needs to be lowered. The predetermined tonnage is determined based on the specific tubing string and well conditions. During the lowering of the tubing string, the unblocking block 52 can drive the upper cone 31 downward through the connecting sleeve 51 during the descent of the central pipe 1, thereby causing the upper slip 32 to lose its radial support and retract, thus releasing the lower anchoring unit 4.

[0048] After both the upper slip 32 and the lower slip 42 are released, the tubing is lifted to recover the entire high-pressure packer 100.

[0049] In practical applications, after releasing the internal forces between the rubber sleeve unit, upper slip 32, and lower slip 42 by lifting the tubing column, theoretically, further lifting for unsealing should be relatively easy. However, when special working conditions prevent unsealing by lifting, the unsealing mechanism 5, located between the rubber sleeve unit 2 and the upper and lower anchoring units 3 and 4, provides an alternative unsealing method by pressing down the tubing column. Specifically, by pressing down the tubing column to drive the unsealing block 52, connecting sleeve 51, and upper cone 31 downwards, the upper slip 32 is released, and the lifting operation resumes, making unsealing much easier. Thus, the high-pressure packer 100 according to the present invention has two unsealing methods: direct lifting for unsealing and "lift-press-lift," improving the unsealing success rate of the high-pressure packer 100 and significantly enhancing its reliability and unsealing performance.

[0050] The high-pressure packer 100 according to the present invention can achieve effective setting through the rubber sleeve unit 2, and can maintain structural stability and effectively transmit axial force through the upper anchoring unit 3 and the lower anchoring unit 4. During unsealing, the upper anchoring unit 3 and the lower anchoring unit 4 can be released by lifting and pressing the tubing, thereby releasing the internal force of the rubber sleeve assembly 21, allowing the rubber sleeve assembly 21 to spring back and unseal, and releasing the internal force between the upper cone 31 and the upper slip 32, and between the lower cone 41 and the lower slip 42, so as to allow the upper cone 31 and the lower cone 41 to move, thereby realizing the retraction of the upper slip 32 and the lower slip 42, so that the upper anchoring unit 3 and the lower anchoring unit 4 can be unlocked. Thus, by lifting and pressing the tubing, the lower cone 41 can be lifted and the upper cone 31 can be pressed down, thereby successfully unsealing the high-pressure packer 100. The high-pressure packer 100, through its unsealing mechanism 5, reliably unseales a high-pressure packer with a centered rubber sleeve and a double-positioned bidirectional slip structure. This effectively solves the problem of unsealing failure or high unsealing rate of this type of packer. Furthermore, the high-pressure packer 100 boasts high pressure resistance and reliable sealing. During the unsealing process, no other special tools are required; simply raising and lowering the tubing string is sufficient for a high-success-rate unsealing operation. Its simple structure and high reliability make it safe and reliable. The high-pressure packer 100 combines high pressure resistance and high retrievability, making the application of high-pressure packers with a centered rubber sleeve and a double-positioned bidirectional slip structure more flexible and diverse. It is suitable for downhole environments with high temperature and pressure where tubing retrievability is required.

[0051] In the description of this invention, it should be understood that the terms "upper" and "lower" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "upper" or "lower" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0052] Furthermore, in the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0053] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A high-pressure packer, comprising: Central tube (1); The rubber sleeve unit (2) sleeved on the central tube (1) includes a rubber sleeve assembly (21) and an upper rubber sleeve seat (22) and a lower rubber sleeve seat (23) disposed at both axial ends of the rubber sleeve assembly (21). An upper anchoring unit (3) and a lower anchoring unit (4) are respectively fitted onto the central tube (1) and located at both ends of the rubber sleeve unit (2). The upper anchoring unit (3) includes an upper cone (31) and an upper slip (32) adapted to the upper cone (31). The lower anchoring unit (4) includes a lower cone (41) and a lower slip (42) adapted to the lower cone (41). An unsealing mechanism (5) is provided between the rubber sleeve unit (2) and the upper anchoring unit (3) and the lower anchoring unit (4). The unsealing mechanism (5) includes a connecting sleeve (51) provided between the upper cone (31) and the upper rubber sleeve seat (22). The connecting sleeve (51) is fixedly connected to the upper cone (31). The connecting sleeve (51) is configured to axially fix the upper cone (31) and the upper rubber sleeve seat (22) in the initial state to transmit axial force, and to allow the upper cone (31) and the upper rubber sleeve seat (22) to move relative to each other when unsealed. The connecting sleeve (51) is provided with at least one through groove (511) that radially penetrates the connecting sleeve (51). An unsealing block (52) that can slide along the through groove (511) is installed in the through groove (511). The outer surface of the central tube (1) is provided with a first prefabricated groove (11). In the initial state, the unblocking block (52) is located above the first prefabricated groove (11) and is axially offset from the first prefabricated groove (11). The inner wall of the upper glue tube seat (22) is provided with a slot (221). In the initial state, the slot (221) is opposite to the through groove (511). The unblocking block (52) protrudes radially outward from the through groove (511) into the slot (221). When the central tube (1) is lifted up to the first prefabricated groove (11) and the through groove (511) are opposite, the radial inner end of the unblocking block (52) enters the first prefabricated groove (11) to adapt to the first prefabricated groove (11) and disengages from the slot (221). The upper anchoring unit (3) and the lower anchoring unit (4) can be anchored to the well casing under the action of the lower drive mechanism (6) and the rubber sleeve unit (2) is seated. The unsealing mechanism (5) is configured to move the upper rubber sleeve seat (22) relative to the upper cone (31) by lifting the central tube (1) to release the axial compression on the rubber sleeve unit (2), and to make the central tube (1) drive the lower cone (41) upward to unseal the lower anchoring unit (4). By pressing down the central tube (1), the upper cone (31) can be driven downward to unseal the upper anchoring unit (3). The outer ends of the unblocking block (52) are chamfered to allow the unblocking block (52) to enter the first prefabricated groove (11) under the action of axial force. A locking ring (53) is provided between the upper glue tube seat (22) and the connecting sleeve (51). The locking ring (53) is configured to allow the upper glue tube seat (22) to move only relative to the connecting sleeve (51). The inner surface of the locking ring (53) is provided with a first one-way tooth, and the outer surface of the connecting sleeve (51) is provided with a second one-way tooth. The first one-way tooth and the second one-way tooth are adapted to each other. A locking ring sleeve (54) for installing the locking ring (53) is fixedly connected to the upper end of the upper glue tube seat (22).

2. The high-voltage packer according to claim 1, characterized in that, The lower cone (41) is fixedly connected to the lower rubber sleeve seat (23).

3. The high-pressure packer according to claim 2, characterized in that, The unsealing mechanism (5) also includes an unsealing ring (55) disposed at the connection between the lower cone (41) and the lower rubber tube seat (23), and the outer surface of the central tube (1) is provided with a second pre-made groove (12). The unsealing ring (55) can be adapted to the second prefabricated groove (12) when the central tube is lifted, so as to drive the lower cone (41) upward.

4. The high-pressure packer according to claim 3, characterized in that, An installation groove (7) is provided on the inner wall of the lower rubber sleeve seat (23) for installing the unsealing ring (55).

5. The high-voltage packer according to claim 3, characterized in that, Both the locking ring (53) and the unsealing ring (55) are elastic open rings.

6. The high-pressure packer according to any one of claims 1 to 5, characterized in that, The unsealing mechanism (5) also includes an unsealing auxiliary mechanism, which includes a first elastic element (91) and a second elastic element (92). The first elastic element (91) is disposed between the upper cone (31) and the upper column (8) connected to the central tube (1) and the second elastic element (92) is disposed between the lower cone (41) and the lower drive mechanism (6).

7. The method for unsealing a high-voltage packer according to any one of claims 1 to 6, comprising the steps of: Lifting the central tube (1) allows the upper glue tube seat (22) to move axially relative to the upper cone (31) under the action of the unsealing mechanism (5), thereby releasing the axial compression on the glue tube unit (2). Continue to lift the central tube (1) so that the central tube (1) can drive the lower cone (41) upward under the action of the unsealing mechanism (5) to release the radial support of the lower cone (41) on the lower slip (42), thereby releasing the lower anchoring unit (4); After the predetermined tonnage is raised, the central tube (1) is pressed down and the upper cone (31) is driven down through the unsealing mechanism (5) to release the radial support of the upper cone (31) on the upper slip (32), thereby releasing the upper anchoring unit (3); Raise the working string and retrieve the high-pressure packer.

Images