High-temperature and high-pressure self-balancing multistage packing casing packer

Abstract

The invention belongs to the technical field of petroleum drilling equipment, and provides a high-temperature and high-pressure self-balancing multi-stage packing casing packer which is used for working in a casing to pack the casing and comprises a pipe body, a plurality of high-temperature and high-pressure self-balancing multi-stage packing sleeves and a plurality of high-temperature and high-pressure sealing sleeves, the sleeve body is arranged outside the pipe body in a sliding manner; the multiple slips can be arranged on the sleeve body in a sliding mode in the radial direction, the multiple slips are arranged circumferentially and used for abutting against the inner wall of the casing pipe for seat sealing after sliding, and the lower ends of the slips are provided with third slopes; the pressing ring is arranged between the third inclined face and the pipe body and provided with a fourth inclined face, the fourth inclined face abuts against the third inclined face, and the pressing ring is configured in the mode that after the third inclined face pushes the fourth inclined face, the inner diameter of the pressing ring is increased, and after the third inclined face does not push the fourth inclined face, the inner diameter of the pressing ring is decreased. And the pressing ring is restored. By means of the technical scheme, the technical problem that in the prior art, slip seat sealing of a casing packer is prone to being affected in the high-temperature and high-pressure environment is solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of oil drilling equipment, and particularly relates to a high-temperature and high-pressure self-balancing multi-stage pack-off casing packer. Background Art

[0002] A casing packer is an important tool for separating different underground layers during oil and gas well completion and workover operations. Driven mechanically or hydraulically, the sealing rubber cylinder expands to squeeze the inner wall of the casing, forming an annular sealing space to achieve interlayer fluid isolation, effectively preventing interlayer crossflow, and ensuring the smooth progress of operations such as stratified production, stratified water injection, and fracturing. Its performance directly affects the oil and gas production efficiency, downhole safety, and recovery rate improvement. With the expansion of oil and gas field development to complex working conditions, higher requirements are put forward for the sealing reliability, temperature and pressure resistance performance, and long-term stability of the casing packer. Especially for high-temperature and high-pressure environments, some casing packers will have the friction between the slips for setting and the inner wall of the casing due to the high-temperature and high-pressure environment, resulting in a poor setting effect. In severe cases, the packer may even fall off, thus affecting the continuity and safety of oil and gas field development operations. Summary of the Invention

[0003] To overcome the above defects, an embodiment of the present invention provides a high-temperature and high-pressure self-balancing multi-stage pack-off casing packer, which solves the technical problem that the slip setting of the casing packer in the prior art is easily affected in high-temperature and high-pressure environments.

[0004] According to one aspect, at least one embodiment of the present invention provides a high-temperature and high-pressure self-balancing multi-stage pack-off casing packer for working inside a casing to pack off the casing, including: A pipe body; A sleeve body, which is slidably arranged outside the pipe body; Slips, there are several slips, which can be slidably arranged on the sleeve body in the radial direction and are arranged in a circular arrangement. After sliding, they are used to abut against the inner wall of the casing for setting, and the lower end has a third inclined surface; A pressure ring, which is arranged between the third inclined surface and the pipe body and has a fourth inclined surface. The fourth inclined surface abuts against the third inclined surface. The pressure ring is configured such that after the third inclined surface pushes the fourth inclined surface, the inner diameter of the pressure ring becomes larger, and after the third inclined surface cancels pushing the fourth inclined surface, the pressure ring returns to its original state; Wherein, the slips and the pressure ring can be switched between the in-and-out well state and the setting state. When in the setting state, the slips abut against the inner wall of the casing, and the third inclined surface pushes the fourth inclined surface so that the inner diameter of the pressure ring becomes larger and moves away from the outer wall of the pipe body; when in the in-and-out well state, the slips are away from the inner wall of the casing, the third inclined surface cancels pushing the fourth inclined surface, and the inner diameter of the pressure ring becomes smaller and presses tightly against the outer wall of the pipe body.

[0005] For example, the high-temperature and high-pressure self-balancing multi-stage packer sleeve packer provided by at least one embodiment of the present disclosure further includes: A slip seat, which is slidably arranged outside the pipe body, and has a plurality of first inclined surfaces arranged circumferentially at the lower end. The upper end of the slip has a second inclined surface, and the second inclined surface is in sliding contact with the first inclined surface. After the slip seat slides, it is used to push the slip to move through the first inclined surface and the second inclined surface; A rubber cylinder. The pipe body has an upper edge, and the upper end of the slip seat has a lower edge. The rubber cylinders are provided between the upper edge and the lower edge, and are configured to expand after the upper edge and the lower edge approach each other, so as to seal the casing.

[0006] For example, the high-temperature and high-pressure self-balancing multi-stage packer sleeve packer provided by at least one embodiment of the present disclosure further includes: An elastic member, one end of which acts on the slip and the other end acts on the sleeve body, providing a force for the slip to approach the pipe body so as to move away from the casing when the setting is released.

[0007] For example, in the high-temperature and high-pressure self-balancing multi-stage packer sleeve packer provided by at least one embodiment of the present disclosure, the inner wall of the compression ring is cylindrical, and the inner wall of the sleeve body has an annular accommodation space, and the compression ring is located in the annular accommodation space; The inner wall of the sleeve body also has an annular convex edge, which is located in the annular accommodation space. The outer wall of the compression ring has an annular groove, and the annular convex edge is arranged in the annular groove.

[0008] For example, in the high-temperature and high-pressure self-balancing multi-stage packer sleeve packer provided by at least one embodiment of the present disclosure, the compression ring has a plurality of first strip-shaped opening grooves arranged circumferentially. The upper ends of the first strip-shaped opening grooves penetrate through the upper end of the compression ring, so as to divide the compression ring into a plurality of upper pressing pieces.

[0009] For example, in the high-temperature and high-pressure self-balancing multi-stage packer sleeve packer provided by at least one embodiment of the present disclosure, the compression ring further has a plurality of second strip-shaped opening grooves arranged circumferentially. The lower ends of the second strip-shaped opening grooves penetrate through the lower end of the compression ring, so as to separate lower pressing pieces from adjacent two of the upper pressing pieces.

[0010] For example, in the high-temperature and high-pressure self-balancing multi-stage packer sleeve packer provided by at least one embodiment of the present disclosure, the lower end of the first strip-shaped opening groove has a first stress hole, and the upper end of the second strip-shaped opening groove has a second stress hole.

[0011] For example, the high-temperature and high-pressure self-balancing multi-stage packer sleeve packer provided by at least one embodiment of the present disclosure has guiding columns on the outer wall of the pipe body. The sleeve body has a first chute, a second chute, and a connecting groove. The length of the first chute is longer than that of the second chute. The upper ends of the first chute and the second chute are connected by the connecting groove. The guiding columns are slidably arranged in the first chute, the second chute, and the connecting groove. When entering and leaving the well, the guiding columns are located in the second chute, and when in the set state, the guiding columns are located in the first chute.

[0012] For example, the high-temperature and high-pressure self-balancing multi-stage packer sleeve packer provided by at least one embodiment of the present disclosure further includes: Slip limit bolts, which are arranged on the sleeve body; A separator, which is sleeved outside the pipe body and is located between the rubber cylinder and the slip limit bolts. The separator has a limiting portion, which is located above the slip limit bolts and is used to abut against the slip limit bolts to limit the upward movement position of the sleeve body.

[0013] For example, in the high-temperature and high-pressure self-balancing multi-stage packer sleeve packer provided by at least one embodiment of the present disclosure, the separator has a guiding space, and the upper end of the slip limit bolt is slidably arranged in the guiding space, and the limiting portion is located in the upper part of the guiding space.

[0014] The beneficial effects of the embodiments of the present invention are as follows: In the present invention, by using the sliding abutment between the slip seat and the slip inclined surface, and the cooperation between the pressure ring and the slip inclined surface, the slips and the pressure ring can be switched between the two states of entering and leaving the well and setting. In a high-temperature and high-pressure environment, it is ensured that there is sufficient friction between the slips and the inner wall of the casing, the setting effect is improved, the packer is prevented from falling off, and the continuity and safety of oil and gas field development operations are guaranteed. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for description in the embodiments of the present invention. Obviously, the following drawings are only some exemplary embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained according to the content of the exemplary embodiments of the present invention and these drawings.

[0016] Figure 1 It is a schematic three-dimensional structure diagram of a casing packer in an embodiment of the present invention; Figure 2 For Figure 1 The enlarged partial structure diagram at A in Figure 3 For Figure 1Schematic top view structure of the casing packer in the embodiment of Figure 4 is Figure 3 Schematic B-B sectional view structure in Figure 5 is Figure 4 Schematic enlarged partial D structure view in Figure 6 is Figure 4 Schematic enlarged partial E structure view in Figure 7 is Figure 1 Top view structure of the casing packer in the embodiment of Figure 8 is Figure 3 Schematic C-C sectional view structure in Figure 9 is Figure 8 Schematic enlarged partial F structure view in Figure 10 is Figure 1 Schematic side view structure of the casing packer in the embodiment of Figure 11 is Figure 10 Schematic G-G sectional view structure in In the figure: pipe body - 100, upper edge - 101, guide post - 102, slip seat - 200, upper edge - 201, first inclined surface - 202, rubber cylinder - 300, sleeve body - 400, annular accommodation space - 401, annular convex edge - 402, chute one - 403, chute two - 404, connection groove - 405, slip - 500, second inclined surface - 501, third inclined surface - 502, pressing ring - 600, fourth inclined surface - 601, annular groove - 602, first strip-shaped opening groove - 603, first stress hole - 6031, second strip-shaped opening groove - 604, second stress hole - 6041, elastic member - 700, slip limit bolt - 800, separator - 900, limit part - 901, guide space - 902. Detailed implementation manners

[0017] The present invention will be further described in detail below with reference to the drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present invention, rather than limiting the present invention.

[0018] For the sake of simplicity of the drawings, only the parts related to the invention are schematically shown in each figure, and they do not represent the actual structure of the product. Additionally, for the sake of simplicity and ease of understanding of the drawings, for components with the same structure or function in some figures, only one of them is schematically shown, or only one of them is labeled. In this article, "one" not only means "only this one", but can also mean "more than one" situation, and "several" includes "two" and "more than two".

[0019] In this article, it should be noted that unless otherwise clearly stipulated and defined, the terms "install", "connect", and "join" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0020] In the present invention, unless otherwise clearly stipulated and defined, the first feature being "above" or "below" the second feature can include the direct contact between the first and second features, or can also include the situation where the first and second features are not in direct contact but in contact through other features between them. Moreover, the first feature being "above", "over", and "on top of" the second feature includes the first feature being directly above and obliquely above the second feature, or simply indicating that the horizontal height of the first feature is higher than that of the second feature. The first feature being "below", "under", and "beneath" the second feature includes the first feature being directly below and obliquely below the second feature, or simply indicating that the horizontal height of the first feature is lower than that of the second feature.

[0021] In the description of this embodiment, the orientation or positional relationships such as "above", "below", "left", and "right" are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of description and simplifying the operation, rather than indicating or implying that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as a limitation to the present invention.

[0022] Additionally, in the description of this application, the terms "first", "second", etc. are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance.

[0023] Such as Figures 1 to 11As shown, it shows a high-temperature and high-pressure self-balancing multi-stage packer for casing in an embodiment of the present invention, which is used to seal the casing in the casing. The casing is the wellbore, and stable and efficient sealing is achieved through the coordinated operation of various components. Specifically, by utilizing the sliding abutment between the slip seat 200 and the inclined surface of the slips 500, and the cooperation between the pressure ring 600 and the inclined surface of the slips 500, the slips 500 and the pressure ring 600 can be switched between the states of entering and leaving the well and setting. In a high-temperature and high-pressure environment, it is ensured that there is sufficient friction between the slips 500 and the inner wall of the casing, improving the setting effect, preventing the packer from falling, and ensuring the continuity and safety of oil and gas field development operations. At the same time, the multi-stage sealing structure composed of multiple rubber cylinders 300 enhances the sealing performance to adapt to complex downhole environments.

[0024] The pipe body 100 is a hollow cylinder, and the upper retaining edge 101 is provided near the upper end of the pipe body 100, which is annular and integrally formed with or separately installed on the pipe body 100, and is used to limit the upward movement of the rubber cylinder 300. The outer surface of the pipe body 100 is treated with wear resistance to enhance the wear resistance when contacting other components, reduce friction loss, and extend the service life of the pipe body 100.

[0025] The slip seat 200 is sleeved outside the pipe body 100 in a cylindrical shape and can slide axially along the pipe body 100. The lower retaining edge 201 at the upper end is annular and jointly presses the rubber cylinder 300 with the upper retaining edge 101 of the pipe body 100. A number of first inclined surfaces 202 are evenly arranged in a circumferential direction at the lower end and are in sliding abutment with the second inclined surface 501 of the slips 500 to transmit the setting force.

[0026] A friction reduction coating is provided on the inner surface of the slip seat 200 to reduce the friction coefficient with the outer surface of the pipe body 100. At the same time, a guiding key is provided between the slip seat 200 and the pipe body 100 to limit the radial movement and ensure smooth axial sliding.

[0027] There are multiple rubber cylinders 300, which are arranged at intervals along the axial direction of the pipe body 100 to form a multi-stage sealing structure. The rubber cylinder 300 is in a hollow cylindrical shape and is made of a rubber material with high temperature and high pressure resistance, such as fluororubber. The inner diameter is adapted to the outer diameter of the pipe body 100, and the outer diameter is slightly smaller than the inner diameter of the casing. After being squeezed by the upper retaining edge 101 and the lower retaining edge 201, it can expand and fit the inner wall of the casing. A metal skeleton is provided inside the rubber cylinder 300 to enhance the overall strength and prevent it from being squeezed or overly deformed under high pressure, affecting the sealing effect.

[0028] The sleeve body 400 is sleeved outside the pipe body 100 in a cylindrical shape and can be slidably arranged radially on the sleeve body 400, and is located below the first inclined surface 202 at the lower end of the slip seat 200. The dimension design ensures that it can freely slide outside the pipe body 100 and provides an installation space for the slips 500. A number of radially arranged chutes are provided on the sleeve body 400, and the number is the same as that of the slips 500, and the dimensions are adapted, and the inner wall is smooth to reduce the sliding resistance of the slips 500.

[0029] Multiple slips 500 are arranged circumferentially and evenly on the sleeve body 400. The second inclined surface 501 at the upper end is in sliding contact with the first inclined surface 202 at the lower end of the slip seat 200, and the third inclined surface 502 at the lower end cooperates with the fourth inclined surface 601 of the pressure ring 600. Both the third inclined surface 502 and the fourth inclined surface 601 can be flat surfaces or conical surfaces, as long as relative sliding and pushing for movement can be achieved. The outer surface of the slip 500 is provided with a serrated structure to increase the friction force with the inner wall of the casing. The slip 500 realizes the transition between the in-and-out well state and the setting state through the cooperation of the inclined surfaces with the slip seat 200 and the pressure ring 600. In the in-and-out well state, the slip 500 is close to the pipe body 100 and away from the inner wall of the casing; during setting, it slides radially outward to contact the inner wall of the casing for setting.

[0030] The pressure ring 600 is arranged in a ring between the third inclined surface 502 and the pipe body 100, and the fourth inclined surface 601 is in close contact with the third inclined surface 502 of the slip 500. The pressure ring 600 can be designed to have a certain elastic deformation ability, and its inner diameter increases after the external force provided by the third inclined surface 502 acts on the fourth inclined surface 601, and it returns to its original state after the provided external force is cancelled, so that the inner diameter can change under force, realizing the change of the inner diameter, and further ensuring that it can be in contact with and press the pipe body 100 tightly without relative movement to maintain synchronous movement. During the in-and-out well stage, first prepare for lowering the well. Lower the packer to the predetermined downhole position through tools such as tubing. At this time, the slip 500 is close to the pipe body 100 in the chute of the sleeve body 400 and away from the inner wall of the casing, being in the in-and-out well state. The inner diameter of the pressure ring 600 is small, tightly pressing the outer wall of the pipe body 100 to ensure the stability of each component. The rubber cylinder 300 is not expanded, and the relative positions of each component are initial and firmly connected.

[0031] During the setting stage, apply an axial force to the pipe body 100 to make the slip seat 200 slide downward along the axis of the pipe body 100. The first inclined surface 202 at its lower end pushes the second inclined surface 501 of the slip 500, causing the slip 500 to slide radially outward.

[0032] The slip 500 slides outward, and its third inclined surface 502 at the lower end pushes the fourth inclined surface 601 of the pressure ring 600, and the inner diameter of the pressure ring 600 becomes larger and moves away from the outer wall of the pipe body 100. At the same time, the serrations on the outer surface of the slip 500 are in close contact with the inner wall of the casing to realize setting. During the downward sliding of the slip seat 200, the upper and lower retaining edges squeeze the rubber cylinder 300, and the rubber cylinder 300 expands to fit the inner wall of the casing, forming a multi-stage sealing space to seal the casing.

[0033] During the working stage, in operations such as oil and gas production, the packer is in the working state. The rubber cylinder 300 withstands the casing pressure to maintain sealing by virtue of its own material and the internal metal skeleton. The slip 500 is fixed in position by relying on the friction force with the inner wall of the casing and the interaction between the pressure ring 600 and the pipe body 100. The inner diameter of the pressure ring 600 remains enlarged to provide support for the slip 500, further ensuring the stability of setting.

[0034] For the unsealing operation, an axial force in the reverse direction is applied to the pipe body 100, causing the slip bushing seat 200 to slide upward. Its first inclined surface 202 disengages from the second inclined surface 501 of the slip 500. The slip 500 slides radially inward away from the inner wall of the casing, and the inner diameter of the compression ring 600 decreases to tightly press against the outer wall of the pipe body 100.

[0035] Remove the packer. The rubber barrel 300 returns to its initial state and disengages from the inner wall of the casing, achieving unsealing, and the packer can be removed from the wellbore.

[0036] Through the inclined surface cooperation and state conversion mechanism between components, under high temperature and high pressure, the slip 500 maintains sufficient stable friction force with the inner wall of the casing. In particular, the compression ring 600 provides an elastic support for the slip 500. Compared with traditional packers, the setting stability is significantly improved, effectively preventing the packer from falling, and ensuring the continuity and safety of the operation. The multi-stage rubber barrel 300 enables efficient sealing under high temperature and high pressure, improves the sealing reliability, effectively prevents cross-flow between layers, and enhances the oil and gas production efficiency and recovery rate. The structural design of each component can adapt to different casing and pipe body sizes, as well as downhole pressure and temperature conditions, and can be widely applied to oil and gas field development operations in various complex working conditions.

[0037] In some examples, as Figure 11 shown, an elastic member 700 is added to optimize the position of the slip 500 when the packer is unset. One end of the elastic member 700 is connected to the slip 500, and the other end acts on the sleeve body 400, providing a force for the slip 500 to approach the pipe body 100. The elastic member 700 can be a tension spring. When it is necessary to unset the packer, the elastic force provided by the elastic member 700 assists the slip 500 to quickly and reliably move away from the inner wall of the casing, making the unsealing process of the packer smoother, and avoiding the difficulty of resetting the slip 500 due to various complex downhole conditions, such as minor deformation and scaling, further ensuring the efficiency and safety of oil and gas field development operations.

[0038] During the stage of entering and exiting the well, the elastic member 700 is in a natural compression state, providing a certain pre-tightening force for the slip 500, making the slip 500 more stably maintain a position close to the pipe body 100 and away from the inner wall of the casing, ensuring that during the lowering process of the packer, the slip 500 will not accidentally extend due to accidental factors such as vibration and collision, further ensuring the safety and stability of the downhole process.

[0039] In the sealing stage, when an axial force is applied to the pipe body 100 by hydraulic or mechanical means, so that the slip seat 200 slides axially downward along the pipe body 100, the first inclined surface 202 at the lower end of the slip seat 200 pushes the second inclined surface 501 of the slip 500, so that the slip 500 overcomes the elastic force of the elastic member 700 and slides radially outward. As the slip 500 slides outward, the third inclined surface 502 at its lower end pushes the fourth inclined surface 601 of the pressure ring 600, and the inner diameter of the pressure ring 600 increases and moves away from the outer wall of the pipe body 100. At the same time, the serrations on the outer surface of the slip 500 are in close contact with the inner wall of the casing to achieve sealing. In this process, the elastic member 700 is further compressed to store elastic potential energy.

[0040] During the working stage, during the oil and gas production, water injection or fracturing operations, the packer is in working condition. The elastic member 700 is continuously in a compressed state, and its elastic force exerts an inward force on the slip 500. However, due to the friction between the slip 500 and the inner wall of the casing and the interaction between the pressure ring 600 and the pipe body 100, the elastic member 700 can provide a force to tighten and avoid shaking, and the slip 500 can be stably maintained in the sealing position, ensuring that the packer can work reliably in a high temperature and high pressure environment.

[0041] In the unsealing stage, when it is necessary to unseal the packer, a reverse axial force is applied to the pipe body 100 to make the slip seat 200 slide upward along the axial direction of the pipe body 100. The first inclined surface 202 of the slip seat 200 is out of contact with the second inclined surface 501 of the slip 500. At this time, the elastic member 700 releases the stored elastic potential energy, providing the slip 500 with a fast and stable force to approach the pipe body 100, assisting the slip 500 to slide radially inward and quickly away from the inner wall of the casing. At the same time, the fourth inclined surface 601 of the pressure ring 600 is no longer pushed by the third inclined surface 502, and the inner diameter of the pressure ring 600 becomes smaller and is re-pressed on the outer wall of the pipe body 100. The rubber cylinder 300 returns to its initial state under the action of its own elasticity and the pressure in the casing, and is out of contact with the inner wall of the casing to achieve unsealing. The action of the elastic member 700 makes the unsealing process smoother, reduces the possibility of the slip 500 being difficult to reset due to complex conditions downhole, and improves the reliability and service life of the packer.

[0042] The setting of the elastic member 700 provides a reliable auxiliary force for the resetting of the slip 500. Compared with the packer without the elastic member, the success rate of unsealing is improved under various complex downhole working conditions, which effectively avoids the problem of the packer being unable to be unsealed normally due to the poor resetting of the slip, and ensures the smooth progress of oil and gas field development operations.

[0043] Since the elastic member 700 can quickly and stably reset the slip 500, the unsealing time is shortened compared with the traditional method, which reduces the downhole operation time, improves the overall operation efficiency, and reduces the operation cost.

[0044] Optimize sealing stability: Under normal sealing conditions, the preload and compression of the elastic member 700 provide additional stability for the slip 500, making the contact between the slip 500 and the inner wall of the casing tighter and more stable, further improving the sealing effect and effectively preventing the risk of the packer loosening or falling due to slight vibrations or pressure fluctuations.

[0045] In some examples, such as Figure 6 As shown, the inner wall of the pressure ring 600 is set to be cylindrical, and an annular accommodation space 401 is constructed on the inner wall of the casing 400 and the pressure ring 600 is installed therein. The cylindrical inner wall of the pressure ring 600 can be more closely and smoothly matched with the outer wall of the pipe body 100, which is conducive to uniformly transmitting pressure under various working conditions, thereby improving the stability of the sealing. The annular accommodation space 401 provides positioning for the pressure ring 600, ensuring that the pressure ring 600 is firmly positioned during operation, thereby comprehensively enhancing the overall reliability and adaptability of the packer, so that it can better cope with complex downhole environments such as high temperature and high pressure.

[0046] The pressure ring 600 is annular as a whole, and its outer wall is adapted to the annular accommodating space 401 of the sleeve 400. The thickness of the pressure ring 600 is determined according to the actual stress conditions and structural strength requirements to ensure that it will not be excessively deformed when subjected to the pressure transmitted by the cava 500, thereby ensuring the stability and reliability of the inner diameter change.

[0047] The annular accommodation space 401 on the inner wall of the sleeve body 400 is a complete annular groove, so as to better accommodate the pressing ring 600 and provide the pressing ring 600 with a certain movable space.

[0048] During the well entry and exit stage, when the packer is lowered to the predetermined downhole position, the pressure ring 600 is located in the annular accommodation space 401 of the casing 400, and its cylindrical inner wall maintains a stable relative position with the outer wall of the pipe body 100. Since the pressure ring 600 is restricted by the annular accommodation space 401, and the inner wall of the pressure ring 600 is in close contact with the outer wall of the pipe body 100, the displacement or shaking of the pipe body 100 due to vibration, collision and other factors during transportation and lowering is effectively avoided, ensuring the stability of each component of the packer in the initial state, and laying a reliable foundation for the subsequent sealing operation.

[0049] The cylindrical structure of the inner wall of the pressure ring 600 is tightly and evenly matched with the outer wall of the pipe body 100, and the annular accommodating space 401 of the sleeve body 400 limits the pressure ring 600, making the force transmission during the sealing process more stable and uniform, greatly improving the sealing stability, and effectively reducing the risk of failure of the packer due to unstable sealing, providing a more reliable guarantee for the continuity and safety of oil and gas field development operations.

[0050] The matching structure of the pressure ring 600 and the sleeve body 400 reduces the wear and damage caused by factors such as shaking and uneven friction between components, significantly enhances the reliability of the structure, extends the service life of the packer, and reduces maintenance costs and operational risks.

[0051] The annular accommodation space 401 provides a stable accommodation space for the pressure ring 600 during the unsealing process, avoiding the unsealing difficulty caused by displacement or deformation of the pressure ring 600, optimizing the smoothness of unsealing, and further improving the overall performance and operating efficiency of the packer.

[0052] In some examples, such as Figure 6 As shown, an annular convex edge 402 is provided on the inner wall of the casing 400 and is located in the annular accommodation space 401, an annular groove 602 is provided on the outer wall of the pressure ring 600, and the annular convex edge 402 is embedded in the annular groove 602. Thus, the connection stability and synergy effect between the pressure ring 600 and the casing 400 are enhanced. The movement of the pressure ring 600 in the annular accommodation space 401 is restricted to prevent circumferential rotation and axial movement, ensure that the inner diameter changes according to a predetermined trajectory, and improve the structural integrity, sealing performance and sealing reliability of the packer under complex downhole conditions.

[0053] The annular convex edge 402 of the sleeve body 400 surrounds the inner wall of the sleeve body 400 and is integrally formed with the sleeve body 400 in the annular accommodation space 401 to ensure structural strength and stability.

[0054] The annular groove 602 of the pressure ring 600 surrounds the outer wall of the pressure ring 600, and its size and shape correspond to the annular ridge 402. The depth is sufficient to accommodate the annular ridge 402, ensuring that the inner diameter of the pressure ring 600 changes in a predetermined direction to prevent circumferential and axial displacement.

[0055] During the well entry and exit phase, the annular convex edge 402 is embedded in the annular groove 602, further fixing the position of the pressure ring 600 in the annular accommodation space 401. Even if it encounters vibration or collision, it can prevent the pressure ring 600 from circumferential rotation and axial movement, ensuring the relative position of each component is stable, laying a more reliable foundation for the sealing operation.

[0056] In the sealing stage, when the slip 500 pushes the pressure ring 600, the annular convex edge 402 cooperates with the annular groove 602 to limit the movement trajectory of the pressure ring 600, so that it stably changes the inner diameter and evenly transmits pressure. This makes the transmission of force in the sealing process more stable and reliable, and further improves the accuracy and stability of the sealing.

[0057] During the working stage, in the complex underground environment of high temperature and high pressure, the annular convex edge 402 and the annular groove 602 are closely matched to enhance the connection stability between the pressure ring 600 and the casing 400. The pressure ring 600 can better maintain the stability of position and shape, maintain close contact with the outer wall of the pipe body 100, ensure the sealing effect, and prevent interlayer crossflow.

[0058] During the unsealing stage, when unsealing, the annular convex edge 402 and the annular groove 602 ensure that the compression ring 600 has an accurate movement trajectory within the annular accommodation space 401, preventing abnormal displacement or jamming, making the unsealing operation smoother, and improving the maintainability and reusability of the packer.

[0059] The annular convex edge 402 and the annular groove 602 define the movement trajectory of the compression ring 600. Compared with the packer without this structure, the setting accuracy and stability are further improved, reducing the risk of the packer failing due to setting problems.

[0060] The matching structure significantly improves the connection stability between the compression ring 600 and the sleeve body 400, enhances the structural integrity under complex working conditions, reduces the risk of damage caused by component displacement or loosening, and improves the reliability and service life of the packer.

[0061] The annular convex edge 402 and the annular groove 602 ensure that the compression ring 600 has an accurate movement trajectory when unsealing, preventing abnormal situations, making the unsealing smoother, improving the maintainability and reusability of the packer, and reducing the maintenance cost and operation risk.

[0062] In some examples, as Figure 7 shown, by providing a plurality of first strip-shaped opening grooves 603 arranged in a circumferential manner on the compression ring 600 and allowing the upper ends of the first strip-shaped opening grooves 603 to penetrate through the upper end of the compression ring 600, the compression ring 600 is divided into several upper pressing pieces. Thereby, the flexibility and adaptability of the inner diameter change of the compression ring 600 are improved. When the slips 500 push the compression ring 600, each upper pressing piece can deform relatively independently, more precisely respond to the force from the slips 500, and thus more effectively change the inner diameter of the compression ring 600, enhancing the setting effect. At the same time, this structure helps to disperse the pressure borne by the compression ring 600, improves the structural stability and reliability of the compression ring 600 in high-temperature and high-pressure environments, and further ensures the sealing performance and working efficiency of the packer in complex downhole working conditions.

[0063] The first strip-shaped opening grooves 603 are evenly arranged along the circumference of the compression ring 600, and their quantity is determined according to the size of the compression ring 600 and the actual working requirements. The distribution design can ensure that when the compression ring 600 is stressed, the forces received by each upper pressing piece are relatively balanced, so that the inner diameter change of the compression ring 600 is more uniform and stable.

[0064] When the compression ring 600 is subjected to the thrust of the slips 500, each upper pressing piece can undergo radial deformation relatively independently under the action of the first strip-shaped opening groove 603. Due to the existence of the first strip-shaped opening groove 603, there is a certain movement space between the upper pressing pieces, enabling them to make fine adjustments according to the actual force conditions, so as to more accurately adapt to the shape and pressure distribution of the outer wall of the pipe body 100, achieve a closer fit, and enhance the setting effect. At the same time, in a high-temperature and high-pressure environment, this cooperative deformation mechanism between the upper pressing pieces can effectively disperse the pressure, avoid stress concentration at a certain part, and improve the structural stability and reliability of the compression ring 600.

[0065] During the stage of entering and leaving the well, when the packer is lowered to the predetermined downhole position, each upper pressing piece of the compression ring 600 maintains a relatively stable position under the constraint of the first strip-shaped opening groove 603. Although there is a certain movement space between the upper pressing pieces, due to the constraint of the overall structure and the cooperation with the sleeve body 400, the compression ring 600 will not undergo excessive deformation or displacement, ensuring the stability of each component of the packer during transportation and lowering, and preparing for the subsequent setting operation.

[0066] During the setting stage, when the slip seat 200 slides downward along the axial direction of the pipe body 100, the slips 500 slide radially outward under the push of the slip seat 200 and push the compression ring 600. At this time, each upper pressing piece on the compression ring 600 can respond to the thrust of the slips 500 relatively independently under the action of the first strip-shaped opening groove 603 and undergo radial deformation according to the actual force conditions. This deformation mode enables the inner diameter of the compression ring 600 to change more accurately, achieve a closer fit with the outer wall of the pipe body 100, thereby enhancing the setting effect. At the same time, each upper pressing piece works together to disperse the pressure borne by the compression ring 600, improves the structural stability of the compression ring 600 during the setting process, and ensures the reliability of the setting.

[0067] During the working stage, during operations such as oil and gas production, water injection, or fracturing, the packer is in the working state. The high-temperature and high-pressure downhole environment will exert complex forces on the compression ring 600. Since the compression ring 600 is divided into several upper pressing pieces and a relatively flexible deformation mechanism is achieved through the first strip-shaped opening groove 603, each upper pressing piece can better adapt to this complex pressure environment. Under the action of pressure, the upper pressing pieces can cooperate to adjust the degree of deformation, effectively disperse the pressure, and avoid structural damage caused by stress concentration. This structure enables the compression ring 600 to maintain a stable inner diameter change and good sealing performance during the working process, continuously provide reliable support for the slips 500, and ensure the smooth progress of oil and gas field development operations.

[0068] In the unsealing stage, when the packer needs to be unsealed, a reverse axial force is applied to the pipe body 100, the slip seat 200 slides upward, and the slip 500 slides radially inward, driving the inner diameter of the pressure ring 600 to decrease. At this time, the elastically compressed upper pressure plate of the pressure ring 600 can be relatively flexibly restored to the initial position under the influence of the first strip opening groove 603, and the unsealing process is smoother, avoiding the unsealing difficulty caused by excessive deformation or stress concentration of the pressure ring 600, and improving the maintainability and reusability of the packer.

[0069] The pressure ring 600 is divided into an upper pressure plate by the first strip opening groove 603, so that the pressure ring 600 can change the inner diameter more accurately when subjected to force, and achieve a tighter fit with the outer wall of the pipe body 100, thereby improving the safety and efficiency of oil and gas field development operations.

[0070] The pressure between the upper pressure plates is effectively dispersed to avoid stress concentration on a certain part of the pressure ring 600, which significantly improves the structural stability and reliability of the pressure ring 600 under complex downhole conditions such as high temperature and high pressure. This enables the packer to work stably for a long time in harsh environments, prolongs the service life of the packer, and reduces maintenance costs and operational risks.

[0071] The first strip opening groove 603 enables the upper pressure plate of the pressure ring 600 to have relatively flexible deformation and recovery capabilities. During the unsealing process, the upper pressure plate can return to its initial position more smoothly, avoiding the problem of unsealing difficulties, improving the maintainability and reusability of the packer, and further improving the overall performance and economic benefits of the packer.

[0072] In some examples, such as Figure 7 As shown, on the basis of setting the first strip opening groove 603 to divide the pressure ring 600 into a number of upper pressure plates, a number of circumferentially arranged second strip opening grooves 604 are further set on the pressure ring 600, so that two adjacent upper pressure plates can be further divided into lower pressure plates. The structure of the pressure ring 600 is further refined, thereby improving the performance of the pressure ring 600. On the one hand, the addition of the lower pressure plate further enhances the flexibility and accuracy of the change of the inner diameter of the pressure ring 600, so that it can better adapt to the complex pressure distribution downhole and the outer wall conditions of the pipe body 100, and strengthen the clamping effect of the pressure ring 600 on the pipe body 100. On the other hand, the double strip opening groove structure optimizes the stress distribution of the pressure ring 600, and the upper pressure plate and the lower pressure plate work together to further improve the structural stability and reliability of the pressure ring 600 under high temperature and high pressure environment, and ensure the long-term stable operation of the packer.

[0073] The second strip-shaped opening groove 604 is also evenly arranged along the circumference of the pressure ring 600, and its quantity is the same as that of the first strip-shaped opening groove 603, ensuring that adjacent upper pressing pieces can separate the lower pressing pieces. Such a layout design ensures that the pressure ring 600 is evenly stressed in the circumferential direction, and when each lower pressing piece and upper pressing piece work together, they can maintain consistency, so that the inner diameter change of the pressure ring 600 is more stable and accurate.

[0074] The width of the second strip-shaped opening groove 604 is the same as that of the first strip-shaped opening groove 603, which not only ensures the structural strength of the pressure ring 600 after being divided, but also enables the lower pressing piece to have appropriate moving space to deform flexibly. It cooperates with the first strip-shaped opening groove 603 but does not penetrate, ensuring that the upper pressing piece and the lower pressing piece can move relatively independently and work together.

[0075] During the setting process, when the slips 500 push the pressure ring 600, the upper pressing piece and the lower pressing piece radially deform relatively independently. The upper pressing piece and the lower pressing piece cooperate with each other through the gap formed by the strip-shaped opening groove, can fit the outer wall shape of the pipe body 100 more accurately, and evenly disperse the pressure. For example, in the area with relatively large local pressure, the upper and lower pressing pieces at the corresponding positions can increase the deformation degree to adapt to the pressure and avoid stress concentration. In the high-temperature and high-pressure environment, this cooperation mechanism ensures the structural stability of the pressure ring 600 and maintains a good pressing effect on the pipe body 100.

[0076] During the lowering process of the packer, due to the existence of the first strip-shaped opening groove 603 and the second strip-shaped opening groove 604, although the pressure ring 600 is divided into multiple upper and lower pressing pieces, the whole still remains relatively stable. The mutual restraint between the upper and lower pressing pieces and the cooperation with the sleeve body 400 prevent the pressure ring 600 from undergoing excessive deformation or displacement due to vibration, collision, etc. during transportation and lowering, ensuring the stability of each component and preparing for setting.

[0077] The setting of the second strip-shaped opening groove 604 and the appearance of the lower pressing piece make the inner diameter change of the pressure ring 600 more flexible and accurate, can better adapt to the complex downhole conditions. Compared with the structure with only the first strip-shaped opening groove, it has a good pressing effect on the pipe body 100, further reduces the risk of seal failure, and improves the safety and efficiency of oil and gas field development operations. The upper pressing piece and the lower pressing piece work together, optimizing the stress distribution of the pressure ring 600. Under harsh working conditions such as high temperature and high pressure, it significantly improves the structural stability and reliability of the pressure ring 600, extends the service life of the packer, and reduces the maintenance cost and operation risk. The double strip-shaped opening grooves enable the upper and lower pressing pieces to have better deformation and recovery capabilities, further improving the maintainability and reusability of the packer, and enhancing the overall performance and economic benefits of the packer.

[0078] In some examples, such as Figure 7As shown, the lower end of the first strip-shaped opening groove 603 has a first stress hole 6031, and the upper end of the second strip-shaped opening groove 604 has a second stress hole 6041. Thereby, the stress distribution of the compression ring 600 during operation is optimized, and its structural performance is improved. The stress holes can effectively release the concentrated stress generated during the deformation of the compression ring 600, avoid structural damage caused by stress concentration, and enhance the durability of the compression ring 600. At the same time, the setting of the stress holes helps the upper pressing piece and the lower pressing piece to deform more flexibly when stressed, enabling the compression ring 600 to better adapt to the complex downhole pressure environment, further improving the setting effect and the overall reliability of the packer.

[0079] In some examples, the outer wall of the pipe body 100 has guide posts 102, and the sleeve body 400 has a first chute 403, a second chute 404, and a connecting groove 405. The directions of the first chute 403 and the second chute 404 are both parallel to the axial direction of the pipe body 100. The length of the first chute 403 is longer than that of the second chute 404. The upper ends of the first chute 403 and the second chute 404 are connected by the connecting groove 405. The guide posts 102 are used to be slidably arranged in the first chute 403, the second chute 404, and the connecting groove 405. And in the state of entering and leaving the well, the guide posts 102 are located in the second chute 404, and in the set state, the guide posts 102 are located in the first chute 403.

[0080] In some examples, as Figure 1 shown, by arranging guide posts 102 on the outer wall of the pipe body 100 and designing a first chute 403, a second chute 404, and a connecting groove 405 on the sleeve body 400, a set of guiding systems is constructed. Thereby, the relative movement between the sleeve body 400 and the pipe body 100 of the packer in different working states is guided, ensuring that all components can accurately move along the predetermined trajectory during the process of entering and leaving the well and the setting stage, further improving the stability and reliability of the packer operation. Through the movement of the guide posts 102 between different chutes, the states of entering and leaving the well and the set state are clearly distinguished, effectively avoiding problems such as seal failure or structural damage caused by movement deviation, and ensuring the smooth progress of oil and gas field development operations.

[0081] During the stage of entering and leaving the well, during the process of lowering the packer to the predetermined downhole position, the guide posts 102 are located in the second chute 404. Since the length of the second chute 404 is shorter, the movement range of the sleeve body 400 relative to the pipe body 100 is restricted, making the relative position relationship of all components of the packer remain relatively stable during transportation and lowering. Even in the case of vibrations, collisions, etc., the limiting effect of the guide posts 102 in the second chute 404 can prevent the sleeve body 400 from moving excessively, thereby ensuring that components such as the slips 500 and the compression ring 600 will not be damaged or affect the subsequent setting effect due to abnormal movement of the sleeve body 400, providing a stable initial state for the setting operation.

[0082] Sealing stage. When an axial force is applied to the pipe body 100 hydraulically or mechanically, causing the slip seat 200 to slide downward axially along the pipe body 100, the sleeve body 400 will also move accordingly. At this time, the guide post 102 passes through the second chute 404 and the connection groove 405 and enters the first chute 403. Since the length of the first chute 403 is relatively long, it can meet the moving distance required for the sleeve body 400 relative to the pipe body 100 during the sealing process. During the sliding process of the guide post 102 along the first chute 403, it accurately guides the movement track of the sleeve body 400 to ensure that the slip 500 can accurately contact the inner wall of the casing and achieve sealing. At the same time, the stable sliding of the guide post 102 in the first chute 403 ensures that components such as the compression ring 600 can work together in a predetermined manner, enhancing the stability and reliability of the sealing.

[0083] In some examples, as Figure 9 shown, a slip limiting bolt 800 and a separator 900 are added to optimize the structural stability and working reliability of the packer. The slip limiting bolt 800 is installed on the sleeve body 400, and the separator 900 is sleeved outside the pipe body 100 and is located between the rubber barrel 300 and the slip limiting bolt 800. Its limiting part 901 can abut against the slip limiting bolt 800. Thereby restricting the upward movement position of the sleeve body 400, ensuring that during the working process of the packer, the relative positions of each component are stable, and avoiding abnormal operation of components such as the slip 500 and the rubber barrel 300 due to excessive movement of the sleeve body 400, thereby improving the overall performance of the packer and ensuring the smooth progress of oil and gas field exploitation operations.

[0084] The slip limiting bolt 800 is arranged on the sleeve body 400 in a threaded connection manner, usually evenly distributed around the circumference of the sleeve body 400, and the quantity is determined according to the size of the sleeve body 400 and actual needs. This uniform distribution enables the sleeve body 400 to be evenly stressed at each position when subjected to an upward acting force, ensuring the consistency of the limiting effect.

[0085] The separator 900 The separator 900 is integrally cylindrical, with an inner diameter adapted to the outer diameter of the pipe body 100, and can be tightly sleeved outside the pipe body 100.

[0086] The limiting part 901 is arranged at one end of the separator 900 close to the slip limiting bolt 800 and is an annular surface. The limiting part 901 can abut against the head of the slip limiting bolt 800 to restrict the further movement of the sleeve body 400.

[0087] In the sealing stage, when an axial force is applied to the pipe body 100 to make the slip seat 200 slide downward, the sleeve body 400 moves downward accordingly, driving the slip 500 to achieve sealing. In this process, the partition 900 remains relatively still due to being sleeved outside the pipe body 100. After the sealing is completed, if the sleeve body 400 tends to move upward due to reasons such as downhole pressure fluctuations, the limiting portion 901 of the partition 900 will abut against the slip limiting bolt 800 to prevent the sleeve body 400 from moving upward, thereby ensuring the close contact between the slip 500 and the inner wall of the casing and maintaining the stability of the sealing state.

[0088] Through the cooperation of the cava limit bolt 800 and the partition 900, the upward movement of the sleeve 400 is effectively limited, thereby avoiding the failure of the cava 500 seal due to the displacement of the sleeve 400. Compared with the seal without this structure, the sealing stability is significantly improved, reducing the risk of oil and gas leakage caused by unstable sealing, thereby ensuring the safe implementation of oil and gas field exploitation operations.

[0089] The arrangement of the slip limit bolts 800 and the separator 900 makes the relative positions of the components of the packer more stable in a complex downhole environment, reduces the risk of structural damage caused by component displacement, improves the reliability of the overall structure of the packer, extends the service life of the packer, and reduces maintenance costs.

[0090] The slip limit bolts 800 and the separator 900 will not hinder the movement of the casing 400 during the unsealing process, thus ensuring a smooth unsealing operation, improving the maintainability and reusability of the packer, and further improving the overall economic benefits of the packer.

[0091] In some examples, such as Figure 9 As shown, a guide space 902 is added so that the upper end of the slip limit bolt 800 can be slidably arranged therein, and the limit portion 901 is located at the upper part of the guide space 902. This can better realize the movement of the casing 400 and enhance the stability and reliability of the packer under different working conditions. The guide space 902 provides a guide for the slip limit bolt 800 to ensure that the slip limit bolt 800 and the partition 900 always maintain a good matching relationship during the axial movement of the casing 400. The setting of the limit portion 901 at the upper part of the guide space 902 makes the limiting effect more timely and reliable when the casing 400 moves upward, avoiding the excessive movement of the casing 400 to cause adverse effects on the slip 500, the rubber cylinder 300 and other components, further improving the overall performance of the packer and ensuring the stable operation of oil and gas field exploitation.

[0092] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered within the scope of the claims of the present invention.

Claims

1. A high-temperature and high-pressure self-balancing multi-stage packer for casing, which is used to seal the casing inside the casing, and is characterized in that Comprising: A pipe body (100); A sleeve body (400), which is slidably arranged outside the pipe body (100); Slips (500), there are several of the slips (500), which can be slidably arranged on the sleeve body (400) along the radial direction, and are arranged in a circular arrangement, and are used to abut against the inner wall of the casing for setting after sliding, and the lower end has a third inclined surface (502); A pressing ring (600), which is arranged between the third inclined surface (502) and the pipe body (100), has a fourth inclined surface (601), the fourth inclined surface (601) abuts against the third inclined surface (502), and the pressing ring (600) is configured such that after the third inclined surface (502) pushes the fourth inclined surface (601), the inner diameter of the pressing ring (600) becomes larger, and after the third inclined surface (502) cancels pushing the fourth inclined surface (601), the pressing ring (600) resumes its original state; Wherein, the slips (500) and the pressing ring (600) can be switched between the in-and-out well state and the setting state. When in the setting state, the slips (500) abut against the inner wall of the casing, and the third inclined surface (502) pushes the fourth inclined surface (601) to make the inner diameter of the pressing ring (600) become larger and move away from the outer wall of the pipe body (100); when in the in-and-out well state, the slips (500) are away from the inner wall of the casing, the third inclined surface (502) cancels pushing the fourth inclined surface (601), and the inner diameter of the pressing ring (600) becomes smaller and presses tightly against the outer wall of the pipe body (100).

2. The high-temperature and high-pressure self-balancing multi-stage packer for casing isolation according to claim 1, wherein Further comprising: A slip seat (200), which is slidably arranged outside the pipe body (100), and the lower end has several first inclined surfaces (202) arranged in a circular arrangement. The upper end of the slips (500) has a second inclined surface (501), and the second inclined surface (501) slidably abuts against the first inclined surface (202). After the slip seat (200) slides, it is used to push the slips (500) to move through the first inclined surface (202) and the second inclined surface (501); A rubber cylinder (300), the pipe body (100) has an upper retaining edge (101), the upper end of the slip seat (200) has a lower retaining edge (201), there are several rubber cylinders (300) and they are arranged between the upper retaining edge (101) and the lower retaining edge (201), and are configured such that after the upper retaining edge (101) and the lower retaining edge (201) approach each other, the rubber cylinder (300) can expand to seal off the casing.

3. The high-temperature and high-pressure self-balancing multi-stage packer for casing isolation according to claim 1, wherein Further comprising: An elastic member (700), one end of the elastic member (700) acts on the slips (500), and the other end acts on the sleeve body (400), providing a force for the slips (500) to approach the pipe body (100) so as to be away from the casing when the setting is cancelled.

4. The high-temperature and high-pressure self-balancing multi-stage packer for casing according to claim 3, wherein The inner wall of the pressing ring (600) is cylindrical, the inner wall of the sleeve body (400) has an annular accommodation space (401), and the pressing ring (600) is located in the annular accommodation space (401); The inner wall of the sleeve body (400) further has an annular convex edge (402), the annular convex edge (402) is located in the annular accommodation space (401), the outer wall of the pressure ring (600) has an annular groove (602), and the annular convex edge (402) is arranged in the annular groove (602).

5. The high-temperature and high-pressure self-balancing multi-stage packer for casing according to claim 3 or 4, characterized in that The pressure ring (600) has a number of first strip-shaped open slots (603) arranged circumferentially. The upper ends of the first strip-shaped open slots (603) penetrate through the upper end of the pressure ring (600) to divide the pressure ring (600) into a number of upper pressing pieces.

6. The high-temperature and high-pressure self-balancing multi-stage packer for casing isolation according to claim 5, characterized in that, The pressure ring (600) further has a number of second strip-shaped open slots (604) arranged circumferentially. The lower ends of the second strip-shaped open slots (604) penetrate through the lower end of the pressure ring (600) to divide a lower pressing piece from two adjacent upper pressing pieces.

7. The high-temperature and high-pressure self-balancing multi-stage packer for casing according to claim 6, characterized in that, The lower end of the first strip-shaped open slot (603) has a first stress hole (6031), and the upper end of the second strip-shaped open slot (604) has a second stress hole (6041).

8. The high-temperature and high-pressure self-balancing multi-stage packer for casing isolation according to claim 7, characterized in that, The outer wall of the pipe body (100) has a guide post (102). The sleeve body (400) has a first chute (403), a second chute (404) and a connecting groove (405). The length of the first chute (403) is longer than that of the second chute (404). The upper ends of the first chute (403) and the second chute (404) are connected by the connecting groove (405). The guide post (102) is used for slidingly arranging in the first chute (403), the second chute (404) and the connecting groove (405). When in the state of entering and leaving the well, the guide post (102) is located in the second chute (404), and when in the setting state, the guide post (102) is located in the first chute (403).

9. The high-temperature and high-pressure self-balancing multi-stage packer for casing according to claim 2, wherein Further included are: A slip limit bolt (800), which is arranged on the sleeve body (400); A separator (900), which is sleeved outside the pipe body (100) and is located between the rubber cylinder (300) and the slip limit bolt (800). The separator (900) has a limit portion (901), and the limit portion (901) is located above the slip limit bolt (800) and is used for abutting against the slip limit bolt (800) to limit the upward movement position of the sleeve body (400).

10. The high-temperature and high-pressure self-balancing multi-stage packer for casing isolation according to claim 9, characterized in that, Wherein, The separator (900) has a guide space (902), and the upper end of the slip limit bolt (800) is slidingly arranged in the guide space (902), and the limit portion (901) is located in the upper part of the guide space (902).

Images