High-temperature-resistant and high-pressure-resistant underground packer

Abstract

The utility model discloses a high-temperature-resistant and high-pressure-resistant underground packer. An inner pipe of an upper connector in the packer is sequentially connected with an inner central pipe, a piston working barrel with a liquid inlet hole and a lower connector from top to bottom. An outer tube of the upper joint is sequentially connected with an upper outer cylinder, an outer core sleeve and an outer core tube from top to bottom; a lower outer cylinder installed outside the inner center pipe is sequentially connected with an upper pushing piston, a lower pushing piston and a lower connector from top to bottom, a communicating sleeve and a lock sleeve provided with a lock claw are arranged in an annular space formed by the lower outer cylinder and the inner center pipe in a sleeved mode, and the lower outer cylinder is connected with the communicating sleeve through a limiting shear pin. A lock claw in the lock sleeve can be meshed with lock teeth in the lower outer cylinder, and the oppositely-inserted rubber cylinder is made of a carbon nano composite material. The rubber sleeve is not only made of an excellent high-temperature-resistant material, but also subjected to an optimized structural design. The packer is simple in structure, low in manufacturing cost and capable of adapting to the working environment in a high-temperature and high-pressure well, an oil layer is effectively isolated, and efficient and safe development of heavy oil resources is promoted.

Description

Technical Field

[0001] The utility model relates to a downhole packer in the petroleum industry, in particular to a downhole packer resistant to high temperature and high pressure. Background Art

[0002] With the continuous growth of global energy demand and the deepening of oil reservoir development, the extraction of heavy oil resources has become a vital energy supply. However, due to its high viscosity and poor fluidity, traditional extraction methods are inefficient. Thermal recovery technology, which injects heat into the oil reservoir to reduce crude oil viscosity, has become an effective means of improving heavy oil recovery. However, during thermal recovery, wellbore and oil reservoir temperatures rise sharply, posing a severe challenge to downhole tools, especially the packers connected to the downhole tubing. These tools must withstand high temperatures and high pressures while maintaining a tight seal to prevent heat loss, ensure thermal recovery effectiveness, and reduce production costs.

[0003] The state-of-the-art in high-temperature packers has made significant progress in recent years, reaching a high level. Specifically, some oil production companies and research institutions have successfully developed high-temperature packers suitable for heavy oil thermal recovery environments. These packers feature improved structures and incorporate advanced high-temperature materials, such as graphite-based polymer composite sealing materials, to maintain stable sealing performance under high-temperature conditions. This allows the packers to adapt to a wide range of downhole temperatures, ensuring they maintain optimal operating conditions throughout the production process.

[0004] Through searching, the following types of downhole packers are currently resistant to high temperature and high pressure: China Patent Authorization Announcement No. CN207260988U discloses a high temperature and high pressure resistant ultra-deep small hole completion packer, the rubber sleeve in the middle of the packer is made of hydrogenated nitrile rubber and fluororubber materials; the length of the rubber sleeve is 106mm-110mm; the slips at the bottom of the packer are inlaid teeth.

[0005] The above-mentioned utility model is suitable for wells where completion operations are carried out in high-temperature, high-pressure, 5-1 / 2" casing. It meets the high-temperature, high-pressure downhole environment and the high-strength and small-wall thickness 5-1 / 2" casing setting requirements. It can be safely set in casing with a maximum steel grade of 140V, providing technical support for completion operations in high-temperature, high-pressure and ultra-deep blocks.

[0006] Although the above utility model can meet the setting requirements of small casing wells, it uses a ratchet lock ring device to provide force support for the annulus seal on the slips and the rubber cylinder. When the downhole pressure fluctuates, its working reliability is uncertain.

[0007] Chinese patent application No. 202011453193.8 discloses a high-temperature and high-pressure resistant seal, which is firmly installed and has good sealing performance, is resistant to high temperature and high pressure, and has improved reliability in use; it includes an upper joint, a sealing mechanism, a seating mechanism, a locking mechanism, a center tube, a lower piston, a thrust piston and a lower joint, and two groups of pressure transmission holes are connected on the lower joint, the center tube is threadedly screwed to the lower part of the upper joint, the lower piston is threadedly screwed to the thrust piston, and the lower joint is threadedly screwed to the center tube, and the upper half of the sealing mechanism and the seating mechanism are both sleeved on the middle part of the upper joint, the upper seating mechanism includes a positioning key, an upper cava and a first shear nail, the lower seating mechanism includes a lower cava, and the lower cava is provided with a second shear nail, and the sealing mechanism includes two groups of rubber cylinder fixing rings, two groups of fixed rubber cylinders, two groups of rubber baffles and two groups of protective covers.

[0008] However, the above invention has a relatively complex structure and is prone to failure in the complex working environment underground.

[0009] Chinese patent application No. 202310325578.3 discloses a high-temperature resistant seal for oil mining, including an automatic vertical sleeve of the seal, an automatic vertical suspension frame for installing the automatic vertical sleeve of the seal, a high-temperature resistant hollow seal bag for isolating oil wells, a seal bag plug-in tightening mechanism for reinforcing the high-temperature resistant hollow seal bag, an extension pipe, a reinforcing connecting rod for reinforcing the extension pipe connection, an oil well sidewall grinding assembly for grinding the oil well sidewall and an oil well sidewall drilling assembly for drilling the oil well sidewall; its descending process is smooth, there will be no blockage, and the installation is quick. The high-temperature resistant hollow seal bag realizes the basic sealing function, and the sealing effect and firmness are good and will not be easily damaged. The oil well sidewall drilling assembly drills holes at various positions on the inner wall of the oil well, and the oil well sidewall grinding assembly grinds the inner wall of the oil well installation groove, making the inner wall of the oil well installation groove smoother, thereby improving the sealing effect of the high-temperature resistant hollow seal bag.

[0010] The above inventions include multiple components with complex structures and high manufacturing costs. The maintenance and overhaul of the equipment also require relatively large investments. In high-temperature environments, the service life of the materials therein is subjected to more stringent tests. The above reasons limit their application in some cost-sensitive mining projects.

[0011] Despite significant progress in the development of high-temperature resistant packers, several challenges remain in their development and application in heavy oil thermal recovery wells. With the deepening of reservoir development, higher requirements are being placed on the high-temperature resistance of packers, necessitating the continuous development of new materials and processes to meet these demands. Furthermore, during heavy oil thermal recovery, the downhole environment is complex and ever-changing, placing higher demands on the adaptability and reliability of packers. Furthermore, the manufacturing cost and service life of packers are also significant factors limiting their widespread application. To meet the demands for efficient and safe development of heavy oil resources, it is particularly important to develop a high-temperature, high-pressure resistant packer suitable for use in heavy oil thermal recovery wells. Summary of the Invention

[0012] The purpose of the utility model is to provide a downhole packer resistant to high temperature and high pressure, so that it can be used in heavy oil thermal recovery wells and ultra-deep wells, improve the sealing performance and high temperature and high pressure resistance of the packer, reduce its manufacturing cost, and increase its service life, thereby reducing construction cost and production cost.

[0013] The technical solution of the utility model is: a high-temperature and high-pressure resistant downhole sealer, provided with an upper joint, a rubber cylinder and a lower joint, wherein: the inner tube of the upper joint is connected to the inner center tube, the piston working cylinder with a liquid inlet hole and the lower joint in sequence from top to bottom; the outer tube of the upper joint is connected to the upper outer tube, the outer core sleeve and the outer core tube in sequence from top to bottom, and the upper outer tube and the upper joint are connected by connecting shear nails; the lower outer tube installed outside the inner center tube is connected to the upper push piston, the lower push piston and the lower joint in sequence from top to bottom, the connecting sleeve and the locking sleeve with locking claws are sleeved in the annulus formed by the lower outer tube and the inner center tube, the lower outer tube with a limiting shear nail, an unsealing pressure hole and a locking tooth and the connecting sleeve are connected by the limiting shear nails; the plug-in rubber cylinder separated by a spacer ring is installed between the spacer of the outer core tube and the connecting sleeve; the locking claw in the locking sleeve can mesh with the locking tooth in the lower outer tube, and the plug-in rubber cylinder is made of carbon nanocomposite material.

[0014] Preferably, the plug-in type rubber cylinder includes, but is not limited to, two plug-in split bodies, and the plug-in end surfaces of the two plug-in split bodies are L-shaped.

[0015] Preferably, the plug-in type rubber cylinder includes, but is not limited to, two plug-in split bodies, and the plug-in end surfaces of the two plug-in split bodies have a Z-shaped structure.

[0016] Preferably, the plug-in type rubber cylinder includes, but is not limited to, two plug-in split bodies, and the plug-in end surfaces of the two plug-in split bodies have a U-shaped structure.

[0017] Preferably, the carbon nanocomposite material used to manufacture the rubber sleeve is carbon fiber reinforced styrene butadiene rubber.

[0018] Preferably, a sealing gasket tube is installed between the bottommost rubber tube and the connecting sleeve, and the sealing gasket tube is installed outside the outer core tube.

[0019] Preferably, there are two groups of liquid inlet holes in the piston working cylinder, namely liquid inlet hole 1 and liquid inlet hole 2. The liquid inlet hole 1 is arranged above the sealing boss in the outer wall of the piston working cylinder and corresponds to the upper inner cavity of the upper push piston in the initial state of the downhole packer; the liquid inlet hole 2 is arranged below the sealing boss in the outer wall of the piston working cylinder and corresponds to the middle inner cavity of the lower push piston in the initial state of the downhole packer.

[0020] Preferably, the limiting shear pins and the unsealing pressure hole are respectively arranged at the upper and lower ends of the lower outer tube; the limiting shear pins arranged at the upper end of the lower outer tube correspond to the middle outer wall of the connecting sleeve in the initial state of the downhole packer and enable the connecting sleeve to be suspended above the limiting shear pins; the unsealing pressure hole arranged at the lower end of the lower outer tube corresponds to the upper end face of the upper push piston in the initial state of the downhole packer; the limiting shear pins and the unsealing pressure hole are both arranged in more than two.

[0021] Preferably, the outer circle of the locking sleeve is a non-uniform outer circle and the upper outer circle is larger than the lower outer circle, and a conical transition section is provided between the upper outer circle and the lower outer circle; the locking claws are arranged in the upper body of the locking sleeve and the conical transition section and are divided by an axial locking groove that passes through the upper end of the locking sleeve, and the locking claws are provided in more than three.

[0022] Preferably, the upper outer wall of the locking claw is provided with a tooth structure that meshes with the locking teeth in the inner wall of the lower outer tube; the lower tube body of the upper pushing piston is provided with two unsealing and pressure-pressing holes, and the two unsealing and pressure-pressing holes are in the initial state of the downhole packer, corresponding to the upper end face of the lower pushing piston and are arranged in more than two.

[0023] Compared with the prior art, the remarkable effects of the present invention are:

[0024] The sealing mechanism of the utility model is composed of a spacer ring, an inner center tube, a rubber tube and a sealing gasket tube. The rubber tube is a split structure and can be continuously inserted into each other and installed on the outer center tube and symmetrically separated by the spacer ring. The sealing gasket tube is provided at the lower end to isolate it from the unsealing mechanism, which effectively improves the sealing performance of the rubber tube and is particularly suitable for heavy oil wells.

[0025] The piston working cylinder in this utility model is circumferentially defined with two rows of fluid inlet holes at each end, each with at least two holes. A locking sleeve is formed with an axial locking groove extending through the top end, forming a locking pawl. The upper outer wall of the locking pawl features a toothed structure that meshes with locking teeth in the inner wall of the lower outer cylinder, ensuring engagement with the lower cylinder and enhancing the sealing performance and load-bearing capacity of the rubber sleeve. Under the action of hydraulic pressure, the upper and lower thrust pistons, as well as the lower outer cylinder, can move unidirectionally, completing the setting and release of downhole packers in high-temperature, high-pressure wells.

[0026] Compared with the high-temperature resistant seals currently used in oil fields, the rubber cylinder in the utility model is not only made of excellent high-temperature resistant materials, but also has an optimized structural design. It not only has a simple structure and low manufacturing cost, but also can adapt to the operating environment in high-temperature and high-pressure wells, ensuring that it can still work stably under high-temperature and high-pressure conditions, effectively isolating oil layers, improving crude oil recovery efficiency, and promoting the efficient and safe development of heavy oil resources.

[0027] In the present invention, the material used to manufacture the rubber cylinder is a carbon nanocomposite material, and carbon fiber reinforced styrene-butadiene rubber is selected. The rubber cylinder has excellent comprehensive performance, good corrosion resistance and a long service life, and can effectively improve the high temperature resistance, high pressure resistance and corrosion resistance of the seal. While this tool further meets the sealing performance and load-bearing capacity of the rubber cylinder, it can ultimately achieve the purpose of extending the service life of the downhole seal and reducing production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0029] Figure 1 It is a schematic diagram of the overall structure of the device.

[0030] Figure 2 yes Figure 1 Schematic diagram of the local structure of the connecting mechanism.

[0031] Figure 3 yes Figure 1 Schematic diagram of the structure of the sealing mechanism.

[0032] Figure 4 yes Figure 1 Schematic diagram of the structure of the Chinese unblocking mechanism.

[0033] Figure 5 yes Figure 1 Schematic diagram of the structure of the middle setting mechanism.

[0034] Figure 6 yes Figure 1Schematic diagram of the enlarged structure of the middle locking sleeve.

[0035] Figure 7 yes Figure 1 and Figure 3 An enlarged structural diagram of the first embodiment of the middle rubber cylinder.

[0036] Figure 8 It is an enlarged structural diagram of the second embodiment of the rubber cartridge.

[0037] Figure 9 It is an enlarged structural diagram of the third embodiment of the rubber cartridge.

[0038] In the picture:

[0039] Upper joint 1, connecting shear nail 1-1;

[0040] Upper outer tube 2, lower joint 3, outer core sleeve 4, outer core tube 5, rubber tube 6, spacer ring 7, inner center tube 8, sealing gasket tube 9, connecting sleeve 10, locking sleeve 11;

[0041] Lower outer cylinder 12, limiting shear nail 12-1, unsealing pressure hole 12-2;

[0042] Push the piston 13 upwards and unseal the second pressure hole 13-1;

[0043] Piston working cylinder 14, liquid inlet hole 1 14-1, liquid inlet hole 2 14-2;

[0044] Push piston 15 downward. DETAILED DESCRIPTION

[0045] The accompanying drawings are for reference and illustration purposes only and are not intended to limit the scope of protection of the present invention. The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0046] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0047] In the description of the present invention, it should be understood that the terms "length," "width," "up," "down," "front," "back," "left," "right," "vertical," "horizontal," "top," "bottom," "inside," "outside," and the like, indicating positions or location relationships, are based on the positions or location relationships shown in the accompanying drawings and are intended solely to facilitate the description of the present invention and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, in the description of the present invention, "plurality" means two or more, unless otherwise expressly and specifically defined.

[0048] See also Figures 1-9 A downhole packer resistant to high temperature and high pressure is provided with an upper joint 1, a rubber sleeve 6 and a lower joint 3, wherein: the inner tube of the upper joint 1 is connected to the inner center pipe 8, the piston working cylinder 14 with a liquid inlet hole and the lower joint 3 in sequence from top to bottom; the outer tube of the upper joint 1 is connected to the upper outer tube 2, the outer core sleeve 4 and the outer core pipe 5 in sequence from top to bottom, and the upper outer tube 2 is connected to the upper joint 1 by connecting shear nails 1-1; the lower outer tube 12 installed outside the inner center pipe 8 is connected to the upper push piston 13, the lower push piston 15 and The lower joint 3 is connected, and the connecting sleeve 10 and the locking sleeve 11 with locking claws are mounted in the annulus formed by the lower outer tube 12 and the inner central tube 8. The lower outer tube 12, which is equipped with a limiting shear pin 12-1, a deblocking pressure hole 12-2, and locking teeth, is connected to the connecting sleeve 10 via the limiting shear pin 12-1. A plug-in rubber sleeve 6, separated by a spacer ring 7, is installed between the spacer of the outer central tube 5 and the connecting sleeve 10. The locking claws in the locking sleeve 11 can engage with the locking teeth in the lower outer tube 12. The plug-in rubber sleeve 6 is made of carbon nanocomposite materials. Carbon nanocomposite materials include nitrile rubber (NBR), ethylene propylene rubber (EPDM), hydrogenated nitrile rubber (HNBR), fluororubber (FKM), tetrafluoroethylene rubber (AFLAS), perfluoroelastomer (FFKM), etc.

[0049] The utility model is equipped with a connection mechanism consisting of an upper joint 1, an upper outer tube 2, and an outer core sleeve 4; a sealing mechanism consisting of an outer core tube 5, a rubber sleeve 6, a spacer ring 7, and an inner center tube 8; an unsealing mechanism consisting of a connecting sleeve 10, a locking sleeve 11, and a lower outer tube 12; and a setting mechanism consisting of an upper push piston 13, a piston working cylinder 14, a lower push piston 15, and a lower joint 3. This enables the tool to smoothly complete setting in high-temperature and high-pressure wells and unsealing after use in the well.

[0050] Since the rubber cylinder 6 in the tool is a plug-in type rubber cylinder, it is easier to expand and is separated by the spacer ring 7, which can effectively improve the sealing performance of the tool in the well.

[0051] The locking claws of the locking sleeve 11 in the tool are engaged with the locking teeth in the lower outer cylinder 12, which greatly improves the setting force of the tool on the rubber cylinder 6 and the load-bearing capacity after setting.

[0052] The setting mechanism in this tool consists of an upper push piston 13, a piston working cylinder 14, a lower push piston 15 and a lower joint 3. During the setting process downhole, high-pressure liquid from the inner center pipe 8 enters through the liquid inlet hole in the piston working cylinder 14, so that the lower outer cylinder 12, the upper push piston 13 and the lower push piston 15 can all move upward along the outer circle of the lower joint 3 under the impetus of the hydraulic pressure and compress the rubber sleeve 6, thereby sealing the oil-casing annulus between the tool and the casing.

[0053] Compared to existing high-temperature and high-pressure packers, this tool boasts a simpler structure, reducing manufacturing costs. Setting and releasing the tool underground can be accomplished through surface pressure injection. This tool is adaptable to the high-temperature and high-pressure operating environments found in heavy oil thermal recovery wells and ultra-deep wells, extending the tool's service life and reducing both construction and production costs.

[0054] The utility model is connected to the oil pipe string through the upper joint 1 and the lower joint 3, and works in a high-temperature and high-pressure environment underground. The setting and unsealing processes that must be completed during work are as follows.

[0055] Setting process: First, the inner center tube 8 is pressurized, and the high-pressure liquid enters from the liquid inlet hole in the piston working cylinder 14, pushing the upper push piston 13 and the lower push piston 15 upward and driving the lower outer cylinder 12 upward. During the upward process of the lower outer cylinder 12, the limit shear pins 12-1 in the lower outer cylinder 12 are broken, and the locking teeth therein are stuck with the locking claws in the locking sleeve 11, thereby compressing, tightening and locking the rubber cylinder 6, completing the setting of the rubber cylinder 6.

[0056] Unsealing process: Through the oil casing annulus pressure, high-pressure liquid enters from the unsealing pressure hole 12-2 in the lower outer tube 12, pushing the lower outer tube 12, the upper push piston 13 and the lower push piston 15 downward together, separating the lower outer tube 12 from the locking sleeve 11.

[0057] Based on the above embodiment 1, the present invention also has the following embodiments:

[0058] A preferred embodiment: the plug-in type rubber cylinder 6 includes, but is not limited to, two plug-in split bodies, and the plug-in end surfaces of the two plug-in split bodies are L-shaped. Figure 7One of the two plug-in parts of the rubber cartridge 6 has an L-shaped slot on its mating end surface, and the other has a matching mating protrusion on its mating end surface, forming a combined mating rubber cartridge 6. Of course, two or more combined mating parts with matching mating end surface structures can also be used to form the rubber cartridge 6. Making the rubber cartridge 6 a split structure not only facilitates setting of the tool but also provides a better sealing effect on the casing annulus.

[0059] A preferred embodiment: the plug-in type rubber cylinder 6 includes, but is not limited to, two plug-in split bodies, and the plug-in end surfaces of the two plug-in split bodies are in a Z-shape. Figure 8 A Z-shaped slot is provided in the plugging end face of one of the plug-in split bodies in the rubber cylinder 6 and a matching plug-in protrusion is provided in the plug-in end face of the other plug-in split body, thereby forming a combined plug-in type rubber cylinder 6.

[0060] A preferred embodiment: the plug-in type rubber cylinder 6 includes, but is not limited to, two plug-in split bodies, and the plug-in end surfaces of the two plug-in split bodies are U-shaped. Figure 9 A U-shaped slot is provided in the plugging end face of one of the plug-in split bodies in the rubber cylinder 6 and a matching plug-in protrusion is provided in the plug-in end face of the other plug-in split body, thereby forming a combined plug-in type rubber cylinder 6.

[0061] In a preferred embodiment, the carbon nanocomposite material used to manufacture the rubber sleeve 6 is carbon fiber-reinforced styrene-butadiene rubber (SBR). Using SBR to manufacture the rubber sleeve 6 effectively improves its strength and modulus. Because pure rubber has a low ability to withstand external forces, when reinforced with carbon fiber, its ability to withstand external forces increases with increasing carbon fiber content.

[0062] In a preferred embodiment, a sealing gasket 9 is installed between the bottom rubber tube 6 and the connecting sleeve 10. The sealing gasket 9 is installed outside the outer core tube 5. The sealing gasket 9 can further improve the sealing performance and effect of the sealing mechanism composed of the rubber tube 6 and the spacer ring 7.

[0063] In a preferred embodiment, the piston working cylinder 14 is provided with two groups of liquid inlet holes, namely liquid inlet hole 14-1 and liquid inlet hole 2 14-2. Liquid inlet hole 14-1 is provided above the sealing boss in the outer wall of the piston working cylinder 14 and corresponds to the upper inner cavity of the upper push piston 13 in the initial state of the downhole packer; liquid inlet hole 2 14-2 is provided below the sealing boss in the outer wall of the piston working cylinder 14 and corresponds to the middle inner cavity of the lower push piston 15 in the initial state of the downhole packer. In the present utility model, two groups of liquid inlet holes are provided in the piston working cylinder 14, and the two groups of liquid inlet holes in the piston working cylinder 14 simultaneously push the two groups of push pistons, making the setting and release of the present utility model smoother.

[0064] A preferred embodiment: the limiting shear pins 12-1 and the unsealing and pressure-pressuring holes 12-2 are respectively arranged at the upper and lower ends of the lower outer tube 12; the limiting shear pins 12-1 arranged at the upper end of the lower outer tube 12 correspond to the middle outer wall of the connecting sleeve 10 in the initial state of the downhole packer and enable the connecting sleeve 10 to be suspended on the limiting shear pins 12-1; the unsealing and pressure-pressuring holes 12-2 arranged at the lower end of the lower outer tube 12 correspond to the upper end face of the upper push piston 13 in the initial state of the downhole packer; the limiting shear pins 12-1 and the unsealing and pressure-pressuring holes 12-2 are both arranged in more than two.

[0065] A preferred embodiment: see Figure 6 The outer circle of the locking sleeve 11 is a non-uniform outer circle and the upper outer circle is larger than the lower outer circle. A tapered transition section is provided between the upper outer circle and the lower outer circle; the locking claws are arranged in the upper body of the locking sleeve 11 and the tapered transition section and are divided by an axial locking groove that passes through the upper end of the locking sleeve 11. The locking claws are provided in more than three.

[0066] A preferred embodiment: see Figure 1 and Figure 4 The upper outer wall of the locking claw is provided with a toothed structure that meshes with the locking teeth in the inner wall of the lower outer tube 12. The lower tubular body of the upper thrust piston 13 is provided with two or more unsealing and pressure-relief holes 13-1. In the initial state of the downhole packer, these two unsealing and pressure-relief holes 13-1 correspond to the upper end surface of the lower thrust piston 15, and two or more of these holes 13-1 are provided. Using this tool, high-pressure liquid, through both the unsealing and pressure-relief holes 12-2 in the lower outer tube 12 and the unsealing and pressure-relief holes 13-1 in the upper thrust piston 13, rapidly separates the lower outer tube 12 from the locking sleeve 11.

[0067] The utility model works under high temperature and high pressure environment, and the setting and unsealing processes during operation are as follows.

[0068] The setting process is as follows: first, the inner center tube 8 is pressurized to push the upper push piston 13 and the lower push piston 15 upward, and drive the lower outer tube 12 upward. At the same time, the locking teeth in the lower outer tube 12 clamp the locking claws of the locking sleeve 11, thereby compressing the rubber cylinder 6 and completing the setting.

[0069] The unsealing process is as follows: first, the oil casing annulus is pressurized, and high-pressure liquid enters the lower outer tube 12 and the upper push piston 13, pushing the lower outer tube 12, the upper push piston 13 and the lower push piston 15 downward, so that the locking sleeve 11 and the lower outer tube 12 are quickly unlocked, thereby achieving rapid and complete unsealing.

[0070] The embodiments described above are merely typical embodiments, but the present invention is not limited to these embodiments, and those skilled in the art can make modifications without departing from the spirit and enlightenment of the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. Any modifications, equivalent replacements, improvements, etc. made within the creative spirit and creative concept of the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection is not limited to the above description.

Claims

1. A downhole packer resistant to high temperature and high pressure, comprising an upper joint, a rubber sleeve and a lower joint, characterized in that: The inner tube of the upper joint is connected to the inner center tube, the piston working cylinder with a liquid inlet hole and the lower joint in sequence from top to bottom; the outer tube of the upper joint is connected to the upper outer tube, the outer core sleeve and the outer core tube in sequence from top to bottom, and the upper outer tube and the upper joint are connected by connecting shear pins; the lower outer tube installed outside the inner center tube is connected to the upper push piston, the lower push piston and the lower joint in sequence from top to bottom, the connecting sleeve and the locking sleeve with locking claws are sleeved in the annulus formed by the lower outer tube and the inner center tube, and the lower outer tube with limiting shear pins, an unsealing pressure hole and locking teeth is connected to the connecting sleeve through limiting shear pins; the plug-in rubber cylinder separated by a spacer ring is installed between the spacer of the outer core tube and the connecting sleeve; the locking claws in the locking sleeve can engage with the locking teeth in the lower outer tube, and the plug-in rubber cylinder is made of carbon nanocomposite material.

2. A downhole packer resistant to high temperature and high pressure according to claim 1, characterized in that: The plug-in type rubber cylinder includes, but is not limited to, two plug-in split bodies, and the plug-in end surfaces of the two plug-in split bodies are L-shaped.

3. The high-temperature and high-pressure downhole packer according to claim 1, characterized in that: The plug-in type rubber cylinder includes, but is not limited to, two plug-in split bodies, and the plug-in end surfaces of the two plug-in split bodies are in a Z-shape.

4. The high-temperature and high-pressure downhole packer according to claim 1, characterized in that: The plug-in type rubber cylinder includes, but is not limited to, two plug-in split bodies, and the plug-in end surfaces of the two plug-in split bodies are U-shaped.

5. A high-temperature and high-pressure downhole packer according to any one of claims 1 to 4, characterized in that: The carbon nanocomposite material used in manufacturing the rubber sleeve is carbon fiber reinforced styrene-butadiene rubber.

6. A downhole packer resistant to high temperature and high pressure as claimed in claim 5, characterized in that A sealing gasket cylinder is also arranged between the rubber cylinder of the lowermost layer and the communicating sleeve, and the sealing gasket cylinder is arranged outside the outer core tube.

7. The high-temperature and high-pressure downhole packer according to claim 5, characterized in that: There are two groups of liquid inlet holes in the piston working cylinder, namely liquid inlet hole 1 and liquid inlet hole 2. The liquid inlet hole 1 is arranged above the sealing boss in the outer wall of the piston working cylinder and corresponds to the upper inner cavity of the upper push piston in the initial state of the downhole packer; the liquid inlet hole 2 is arranged below the sealing boss in the outer wall of the piston working cylinder and corresponds to the middle inner cavity of the lower push piston in the initial state of the downhole packer.

8. The high-temperature and high-pressure downhole packer according to claim 5, characterized in that: The limiting shear pins and the unsealing and pressure-pressuring holes are respectively arranged at the upper and lower ends of the lower outer tube; the limiting shear pins arranged at the upper end of the lower outer tube correspond to the middle outer wall of the connecting sleeve in the initial state of the downhole packer and enable the connecting sleeve to be suspended on the limiting shear pins; the unsealing and pressure-pressuring holes arranged at the lower end of the lower outer tube correspond to the upper end face of the upper push piston in the initial state of the downhole packer; the limiting shear pins and the unsealing and pressure-pressuring holes are both arranged in more than two.

9. The high-temperature and high-pressure downhole packer according to claim 5, characterized in that: The outer circle of the locking sleeve is a non-uniform outer circle and the upper outer circle is larger than the lower outer circle. A conical transition section is provided between the upper outer circle and the lower outer circle; the locking claws are arranged in the upper body of the locking sleeve and the conical transition section and are divided by an axial locking groove that passes through the upper end of the locking sleeve. The locking claws are provided in more than three.

10. The high-temperature and high-pressure downhole packer according to claim 9, characterized in that: The upper outer wall of the locking claw is provided with a tooth structure that meshes with the locking teeth in the inner wall of the lower outer tube; the lower tube body of the upper pushing piston is provided with two unsealing and pressure-pressing holes, and the two unsealing and pressure-pressing holes correspond to the upper end surface of the lower pushing piston in the initial state of the downhole packer and are arranged in more than two.

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