Downhole sealing equipment for improving performance of rubber sleeve, packer and bridge plug

Abstract

The invention provides underground sealing equipment for improving the performance of a rubber sleeve, a packer and a bridge plug, the underground sealing equipment for improving the performance of the rubber sleeve comprises a casing pipe and the rubber sleeve arranged in the casing pipe, the rubber sleeve can be in abutting contact with the casing pipe through deformation so as to achieve sealing, and in the axial direction, the rubber sleeve can abut against the casing pipe; and the hardness of the rubber sleeve at the middle position is smaller than that far away from the middle position. The problem that the shoulders, close to the two axial end faces, of the rubber sleeve protrude excessively can be effectively solved, and the service life of the rubber sleeve is prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of oil drilling, and in particular to a downhole sealing device, a packer and a bridge plug for improving the performance of a rubber cartridge. Background Art

[0002] At present, the commonly used downhole sealing device is the packer, which forms a seal by axially compressing the rubber tube and making it expand radially to the inner diameter of the casing. During the rubber tube extrusion process, the upper and lower ends of the rubber tube bear the greatest pressure, causing the shoulder (the protruding part caused by the retaining ring squeezing the upper and lower ends of the rubber tube) to protrude. When the stress generated by the shoulder protrusion is greater than the allowable stress of the rubber tube material, it will cause the rubber tube seal to fail.

[0003] The Chinese invention patent with announcement number CN111911109A provides a sealing rubber sleeve, including an upper joint, a rubber sleeve body and a lower joint. Among them, the rubber sleeve body includes at least two layers of overlapping metal skeletons and an outer rubber sleeve and an inner rubber sleeve respectively arranged outside and inside the metal skeleton. The two ends of the rubber sleeve body are respectively connected to the upper joint and the lower joint. The sealing rubber sleeve provided by the invention can reduce the risk of damage during well entry, has high reliability, and reduces the probability of failure of the packer, but it cannot provide axial support for the rubber sleeve, and cannot alleviate the damage to the rubber sleeve caused by shear stress, resulting in reduced sealing performance of the rubber sleeve.

[0004] The Chinese invention patent with the announcement number CN116624123A provides a downhole sealing rubber cylinder for oil and gas fields. The key points of the technical solution are: comprising a positioning ring, the top surface of the positioning ring is provided with a first adjustment ring, and the bottom surface of the positioning ring is provided with a second adjustment ring; two extrusion rings, the two extrusion rings are respectively fixedly connected to the outer circular wall surface of the first adjustment ring and the outer circular wall surface of the second adjustment ring, the bottom surface of the extrusion ring is fixedly connected with an inner rubber cylinder, and the outer circular wall surface of the inner rubber cylinder is fixedly connected with an outer rubber cylinder; a connecting component, the connecting component is arranged on the top surface of the positioning ring, and is used to connect the first adjusting ring with the positioning ring; a fixing component, the fixing component is arranged on the top surface of the first adjusting ring, and after the limiting block and the limiting groove are movably sleeved together, the connecting rod is prevented from moving out of the inside of the connecting groove, and by setting a conical surface, when one side of the conical surface is completely in contact with the outer surface of the inner rubber cylinder, the sealing and high pressure resistance of the entire sealing rubber cylinder are further ensured, but it is impossible to provide support to the rubber cylinder in the axial direction, and it is impossible to alleviate the damage of the shear stress to the rubber cylinder, resulting in reduced sealing performance of the rubber cylinder.

[0005] The Chinese invention patent with announcement number CN112554837A involves a compression-expansion composite rubber sleeve casing external packer, in which the outer side of the upper part of the main body is connected to a liquid cylinder by opening a pin, the lower part of the liquid cylinder is connected to a pressure ring, the lower part of the pressure ring is provided with a composite rubber sleeve, and the lower part of the composite rubber sleeve is provided with a lower top ring; there is a gap between the upper part of the liquid cylinder and the main body, and the main body is provided with a liquid inlet hole corresponding to the gap; a retaining spring is provided between the liquid cylinder and the pressure ring, and the outer wall of the main body is provided with a plurality of retaining grooves that match the retaining spring. However, the invented packer cannot provide axial support for the rubber sleeve, and cannot alleviate the damage to the rubber sleeve caused by shear stress, resulting in reduced sealing performance of the rubber sleeve.

[0006] Therefore, there is an urgent need for a downhole sealing device for improving the performance of the rubber cartridge, which can solve the technical drawback that the upper and lower end surfaces of the rubber cartridge in the axial direction are subjected to greater pressure, causing shoulder protrusion, thereby causing the rubber cartridge seal to fail. Summary of the invention

[0007] One object of the present invention is to propose a downhole sealing device, a packer and a bridge plug for improving the performance of the rubber cartridge, so that the hardness of the middle position of the rubber cartridge in the axial direction is smaller than the hardness of the position away from the middle position, so that the middle section of the rubber cartridge with a smaller hardness can expand first, and the sections away from the middle position and with a larger hardness can expand after the middle section, so as to effectively reduce the problem of excessive protrusion of the shoulders of the rubber cartridge near the two end faces along the axial direction, thereby increasing the service life of the rubber cartridge.

[0008] According to the present invention, a downhole sealing device for improving the performance of a rubber cartridge is provided, comprising a casing and a rubber cartridge arranged in the casing, wherein the rubber cartridge can be pressed into contact with the casing by deformation to achieve sealing, and in the axial direction, the hardness of the rubber cartridge at a middle position is less than the hardness at a position away from the middle position.

[0009] In a preferred embodiment, the sleeve includes a sealing tube section, the rubber sleeve can cooperate with the inner surface of the sealing tube section so that the sealing tube section can apply a supporting force in the axial direction of the rubber sleeve, and the hardness of the rubber sleeve decreases radially outward.

[0010] In a preferred embodiment, the inner surface of the sealing tube section is provided with a plurality of grooves, and after the rubber sleeve is squeezed in the axial direction, part of the rubber sleeve can enter the groove and part of the outer surface of the rubber sleeve can be squeezed into contact with both the inner wall and the bottom surface of the groove.

[0011] In a preferred embodiment, the rubber cartridge includes a first rubber cartridge segment, a second rubber cartridge segment and a third rubber cartridge segment in the axial direction, and the second rubber cartridge segment is located between the first rubber cartridge segment and the third rubber cartridge segment.

[0012] In a preferred embodiment, the inner surface of the sealing tube section is provided with a plurality of grooves, and after the rubber sleeve is squeezed in the axial direction, part of the rubber sleeve can enter the groove and part of the outer surface of the rubber sleeve can be squeezed into contact with both the inner wall and the bottom surface of the groove.

[0013] In a preferred embodiment, the inner surface of the sealing tube section is provided with a plurality of protrusions, and after the rubber sleeve is squeezed in the axial direction, part of the rubber sleeve can enter the recessed area between each of the protrusions, and part of the outer surface of the rubber sleeve can be squeezed into contact with the recessed area and the side surface of each of the protrusions.

[0014] In a preferred embodiment, the inner surface of the sealing tube section is provided with a plurality of protrusions and a plurality of grooves. After the rubber sleeve is squeezed in the axial direction, part of the rubber sleeve can enter between each of the protrusions and inside the grooves, and part of the outer surface of the rubber sleeve can be squeezed into contact with the surface between the protrusions, the inner wall and the bottom surface of the groove.

[0015] In a preferred embodiment, the groove and / or the protrusion extend along the circumferential direction on the inner surface of the sealing tube section.

[0016] In a preferred embodiment, the rubber cartridge adopts a radial layered structure.

[0017] The present invention also provides a downhole sealer, which is arranged near the second end of the center pipe, including the aforementioned downhole sealing device for improving the performance of the rubber sleeve, a first retaining ring sleeved on the outer surface of the center pipe, and a second retaining ring sleeved on the outer surface of the center pipe. The rubber sleeve is sleeved on the outer surface of the center pipe and arranged between the first retaining ring and the second retaining ring.

[0018] In a preferred embodiment, the first retaining ring is located above the second retaining ring, the upper surface of the rubber cylinder abuts against the lower surface of the first retaining ring, and the lower surface of the rubber cylinder abuts against the upper surface of the second retaining ring.

[0019] The present invention also provides a downhole bridge plug, comprising the downhole sealing device for improving the performance of the rubber sleeve.

[0020] The present invention includes a sleeve and a rubber sleeve arranged in the sleeve, and the rubber sleeve can be pressed and contacted with the sleeve by deformation to achieve sealing. The hardness of the rubber sleeve at the middle position in the axial direction is less than the hardness at the position far away from the middle position. The middle section of the rubber sleeve with smaller hardness can expand first, and the sections far away from the middle position and with larger hardness can expand after the middle section, thereby effectively alleviating the problem of excessive protrusion of shoulders of the rubber sleeve near the two end surfaces along the axial direction, thereby improving the service life of the rubber sleeve.

[0021] The present invention includes a sealing tube section through a sleeve, and the rubber sleeve can cooperate with the inner surface of the sealing tube section, so that the sealing tube section can apply a supporting force in the axial direction of the rubber sleeve, and the hardness of the rubber sleeve decreases radially outward. On the one hand, it can alleviate the damage caused by the shear stress on the rubber sleeve in the axial direction, thereby effectively avoiding the rubber sleeve from failing due to the axial shear stress and effectively ensuring its sealing. On the other hand, the hardness of the rubber sleeve decreases radially outward, which can provide strong support for the rubber sleeve and enable it to better fit the sealing tube section, thereby facilitating the provision of axial support for the rubber sleeve when it is subjected to a pressure difference, and effectively reducing the shear stress on the rubber sleeve when it is under pressure.

[0022] The present invention provides a plurality of grooves on the inner surface of the sealing pipe section. After the rubber tube is squeezed in the axial direction, part of the rubber tube can enter the groove and part of the outer surface of the rubber tube can be squeezed and contacted with the inner wall and bottom surface of the groove, so that the sleeve can bear part of the shear stress on the rubber tube through the groove, thereby alleviating the damage to the rubber tube caused by the shear stress. The sleeve provides support for the rubber tube in the axial direction to alleviate the damage to the rubber tube caused by the axial shear stress, thereby improving the reliability of the rubber tube and the sealing performance of the rubber tube.

[0023] The present invention provides a plurality of protrusions on the inner surface of the sealing tube section. After the rubber tube is squeezed in the axial direction, part of the rubber tube can enter the recessed area between the protrusions, and part of the outer surface of the rubber tube can be squeezed and contacted with the recessed area and the side surfaces of each protrusion. The sleeve can bear part of the shear stress on the rubber tube through the protrusions, thereby alleviating the damage to the rubber tube caused by the shear stress. The sleeve provides support for the rubber tube in the axial direction to alleviate the damage to the rubber tube caused by the axial shear stress, thereby improving the reliability of the rubber tube and the sealing performance of the rubber tube.

[0024] The present invention provides a plurality of protrusions and a plurality of grooves on the inner surface of the sealing pipe section. After the rubber tube is squeezed in the axial direction, part of the rubber tube can enter between the protrusions and inside the grooves, and part of the outer surface of the rubber tube can be squeezed and contacted with the surface between the protrusions, the inner wall and the bottom surface of the groove. The sleeve can bear part of the shear stress on the rubber tube through the protrusions and the grooves, thereby alleviating the damage to the rubber tube caused by the shear stress. The sleeve provides support for the rubber tube in the axial direction to alleviate the damage to the rubber tube caused by the axial shear stress, thereby improving the reliability of the rubber tube and the sealing performance of the rubber tube.

[0025] The present invention enables the rubber sleeve to adopt a radial layered structure, so that the rubber sleeve can be easily filled with the sealing pipe section through deformation. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The overall structure of the downhole sealing device for improving the performance of the rubber cartridge according to the present invention is schematically shown;

[0027] Figure 2 The hardness distribution diagram of the rubber cartridge of the downhole sealing device for improving the performance of the rubber cartridge according to the present invention is schematically shown.

[0028] In the present application, all drawings are schematic drawings, which are only used to illustrate the principles of the present invention and are not drawn according to the actual scale. DETAILED DESCRIPTION

[0029] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention. It should be noted that, in the absence of conflict, the embodiments in this application and the features in the embodiments can be combined with each other arbitrarily.

[0030] In the description of the present invention, it is necessary to understand that the terms "inside", "outside", "axial", "radial", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0031] It should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features.

[0032] In the description of the present invention, “plurality” means two or more than two, unless otherwise clearly and specifically defined.

[0033] In the present invention, unless otherwise clearly specified and limited, the terms "connection", "fixation" and the like 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 a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0034] Figure 1 and Figure 2All schematically show an overall structural diagram of a downhole sealing device for improving the performance of a rubber cartridge according to the present invention. As shown in the figure, the downhole sealing device 100 for improving the performance of a rubber cartridge according to the present invention comprises: a casing 1002 and a rubber cartridge 1006 disposed in the casing 1002, the rubber cartridge 1006 can be pressed against the casing 1002 by deformation to achieve sealing, and in the axial direction, the hardness of the rubber cartridge 1006 in the middle position is less than the hardness away from the middle position. The "middle position" of the rubber cartridge 1006 mentioned in the present invention refers to the rubber cartridge segment that includes the center line of the rubber cartridge 1006 in the axial direction. The rubber cartridge 1006 is constructed as a cylindrical body.

[0035] The practical application of the downhole sealing device 100 for improving the performance of the rubber cartridge described in the present invention is described below. The first end of the central tube 1001 is close to the ground, and the central tube 1001 is provided with a packer near its second end. The second end of the central tube 1001 is located in the well, and the rubber cartridge 1006 is sleeved on the outer periphery of the central tube 1001. Before the packer is used for setting, the casing 1002 is lowered into the well, and then the central tube 1001 and the rubber cartridge 1006 are lowered into the area to be sealed in the casing 1002. During the setting process, by squeezing the rubber cartridge 1006 in the axial direction, the rubber cartridge 1006 can be pressed and contacted with the inner surface of the casing 1002 through deformation and completely fit, so as to achieve sealing.

[0036] During the sealing process, the two end faces of the rubber cylinder 1006 in the axial direction are squeezed. Since the hardness of the rubber cylinder 1006 in the middle position in the axial direction is less than the hardness away from the middle position, the middle section of the rubber cylinder 1006 with smaller hardness can expand first, and the sections away from the middle position and with larger hardness can expand after the middle section.

[0037] The present invention includes a sleeve 1002 and a rubber sleeve 1006 arranged in the sleeve 1002, and the rubber sleeve 1006 can be pressed and contacted with the sleeve 1002 by deformation to achieve sealing. The hardness of the rubber sleeve 1006 at the middle position in the axial direction is less than the hardness at the position far away from the middle position. The middle section of the rubber sleeve 1006 with a smaller hardness can expand first, and the sections far away from the middle position and with a larger hardness can expand after the middle section, thereby effectively alleviating the problem of excessive protrusion of the shoulders of the rubber sleeve 1006 near the two end faces along the axial direction, thereby improving the service life of the rubber sleeve 1006.

[0038] In one or more embodiments, the sleeve 1002 includes a sealing tube section 1008, and the rubber sleeve 1006 can cooperate with the inner surface of the sealing tube section 1008 so that the sealing tube section 1008 can apply a supporting force in the axial direction of the rubber sleeve 1006, and the hardness of the rubber sleeve 1006 decreases radially outward.

[0039] The outer surface of the rubber cylinder 1006 can be accommodated in the sealing tube section 1008 and cooperate with it during the sealing process, so that the sealing tube section 1008 can apply a supporting force in the axial direction of the rubber cylinder 1006, thereby alleviating the damage caused to the rubber cylinder 1006 by the shear stress in the axial direction, thereby effectively preventing the rubber cylinder 1006 from failing due to the axial shear stress and effectively ensuring its sealing.

[0040] The hardness of the rubber sleeve 1006 decreases radially outward. Figure 2 As shown, the hardness mark H4>H3>H2>H1, and the hardness of the rubber cylinder 1006 decreases in the radial outward direction along the rubber cylinder 6, that is, the hardness of the rubber cylinder 1006 is greater near the center tube 1001, which can provide stronger support for the rubber cylinder 1006, and the hardness of the rubber cylinder 1006 is smaller near the sealing pipe section 1008, which can make it better fit the sealing pipe section 1008, thereby facilitating the provision of axial support for the rubber cylinder 1006 when it is subjected to pressure difference, and effectively reducing the shear stress on the rubber cylinder 1006 when it is under pressure.

[0041] The present invention includes a sealing tube section 1008 through a sleeve 1002, and the rubber sleeve 1006 can cooperate with the inner surface of the sealing tube section 1008, so that the sealing tube section 1008 can apply a supporting force in the axial direction of the rubber sleeve 1006, and the hardness of the rubber sleeve 1006 decreases radially outward. On the one hand, it can alleviate the damage caused by the shear stress on the rubber sleeve 1006 in the axial direction, thereby effectively preventing the rubber sleeve 1006 from failing due to the axial shear stress and effectively ensuring its sealing. On the other hand, the hardness of the rubber sleeve 1006 decreases radially outward, which can provide strong support for the rubber sleeve 1006 and make it better fit the sealing tube section 1008, thereby facilitating the provision of axial support for the rubber sleeve 1006 when it is subjected to a pressure difference, and effectively reducing the shear stress on the rubber sleeve 1006 when it is under pressure.

[0042] like Figure 2 As shown, in one or more embodiments, the rubber cylinder 1006 includes a first rubber cylinder segment, a second rubber cylinder segment and a third rubber cylinder segment in the axial direction, wherein the second rubber cylinder is between the first rubber cylinder segment and the third rubber cylinder segment. The second rubber cylinder segment is in the middle position of the rubber cylinder 1006, and the first rubber cylinder segment and the third rubber cylinder segment are at two end surface positions away from the middle position of the rubber cylinder 1006. The hardness of the first rubber cylinder segment and the third rubber cylinder segment is greater than the hardness of the second rubber cylinder segment, so that the middle segment with a smaller hardness of the rubber cylinder 1006 can expand first, and the segment far away from the middle position and with a larger hardness expands after the middle segment, so that the shoulder protrusion problem of the rubber cylinder 1006 can be effectively alleviated. Optionally, the hardness of the first rubber cylinder segment is the same as the hardness of the third rubber cylinder segment. In some other embodiments, the hardness of the first rubber cylinder segment and the hardness of the third rubber cylinder segment may also be different.

[0043] In one or more embodiments, the sealing tube segment 1008 is annular.

[0044] In one or more embodiments, the inner surface of the sealing tube section 1008 is provided with a plurality of grooves, each groove being spaced a certain distance apart, and during the setting process, after the rubber sleeve 1006 is squeezed in the axial direction, part of the rubber sleeve 1006 can enter the interior of each groove and part of the outer surface of the rubber sleeve 1006 can be squeezed and contacted with the inner wall and bottom surface of each groove. Optionally, the groove extends in the circumferential direction.

[0045] Specifically, after the center tube 1001, the rubber tube 1006 and other components are lowered into the sealing pipe section 1008 inside the casing 1002, the rubber tube 1006 is squeezed in the axial direction so that the rubber tube 1006 is deformed and fills the sealing pipe section 1008. The outer circumferential surface of the rubber tube 1006 squeezes the groove and forms small convex portions on part of the rubber tube 1006, which enter into each groove. Each small convex portion formed by the rubber tube 1006 can be squeezed and contacted with the inner wall and bottom surface of each groove respectively.

[0046] According to the present invention, a plurality of grooves are arranged on the inner surface of the sealing tube section 1008. After the rubber sleeve 1006 is squeezed in the axial direction, part of the rubber sleeve 1006 can enter the grooves and part of the outer surface of the rubber sleeve 1006 can be squeezed and contacted with the inner wall and the bottom surface of the grooves. The sleeve 1002 can bear part of the shear stress on the rubber sleeve 1006 through the grooves, thereby alleviating the damage to the rubber sleeve 1006 caused by the shear stress. The sleeve 1002 provides support for the rubber sleeve 1006 in the axial direction to alleviate the damage to the rubber sleeve 1006 caused by the axial shear stress, thereby improving the reliability of the rubber sleeve 1006 and improving the sealing performance of the rubber sleeve 1006.

[0047] In one or more embodiments, the inner surface of the sealing tube section is provided with a plurality of protrusions, and after the rubber sleeve 1006 is squeezed in the axial direction, part of the rubber sleeve 1006 can enter the concave area between each protrusion, and part of the outer surface of the rubber sleeve 1006 can be squeezed and contacted with the concave area between each protrusion and the side surface of each protrusion. Optionally, the protrusions extend in the circumferential direction.

[0048] Specifically, after the center tube 1001, the rubber tube 1006 and other components are lowered into the sealing pipe section 1008 inside the casing 1002, the rubber tube 1006 is squeezed in the axial direction so that the rubber tube 1006 is deformed and fills the sealing pipe section 1008. After the outer circumferential surface of the rubber tube 1006 is squeezed with each protrusion, a part of the rubber tube 1006 forms a small protrusion and enters the recessed area between each protrusion. The small protrusion formed by the rubber tube 1006 can be squeezed and contacted with the recessed area and the side surface of each protrusion.

[0049] According to the present invention, a plurality of protrusions are arranged on the inner surface of the sealing tube section 1008. After the rubber sleeve 1006 is squeezed in the axial direction, part of the rubber sleeve 1006 can enter the recessed area between the protrusions, and part of the outer surface of the rubber sleeve 1006 can be squeezed and contacted with the recessed area and the side surfaces of each protrusion, so that the sleeve 1002 can bear part of the shear stress on the rubber sleeve 1006 through the protrusions, thereby alleviating the damage to the rubber sleeve 1006 caused by the shear stress. The sleeve 1002 provides support for the rubber sleeve 1006 in the axial direction to alleviate the damage to the rubber sleeve 1006 caused by the axial shear stress, thereby improving the reliability of the rubber sleeve 1006 and improving the sealing performance of the rubber sleeve 1006.

[0050] In one or more embodiments, the inner surface of the sealing tube section 1008 is provided with a plurality of protrusions and a plurality of grooves. After the rubber sleeve 1006 is squeezed in the axial direction, part of the rubber sleeve 1006 can enter between each protrusion and inside the groove, and part of the outer surface of the rubber sleeve 1006 can be squeezed and contacted with the surface between the protrusions, the inner wall and the bottom surface of the groove. Optionally, the groove and the protrusion extend in the circumferential direction. Optionally, the protrusion and the groove are arranged at intervals.

[0051] Specifically, after the center tube 1001, the rubber tube 1006 and other components are lowered into the sealing pipe section 1008 inside the casing 1002, the rubber tube 1006 is squeezed in the axial direction so that the rubber tube 1006 is deformed and fills the sealing pipe section 1008. After the outer circumferential surface of the rubber tube 1006 is squeezed with the various protrusions and grooves, part of the rubber tube 1006 forms small protrusions, which respectively enter the recessed areas between the protrusions and the interior of the grooves. The small protrusions formed by the rubber tube 1006 can be squeezed and contacted with the surfaces between the protrusions, the inner walls of the grooves and the bottom surface.

[0052] According to the present invention, a plurality of protrusions and a plurality of grooves are arranged on the inner surface of the sealing pipe section. After the rubber sleeve 1006 is squeezed in the axial direction, part of the rubber sleeve 1006 can enter between the protrusions and inside the grooves, and part of the outer surface of the rubber sleeve 1006 can be squeezed and contacted with the surface between the protrusions, the inner wall and the bottom surface of the groove. The sleeve 1002 can bear part of the shear stress on the rubber sleeve 1006 through the protrusions and the grooves, thereby alleviating the damage to the rubber sleeve 1006 caused by the shear stress. The sleeve 1002 provides support for the rubber sleeve 1006 in the axial direction to alleviate the damage to the rubber sleeve 1006 caused by the axial shear stress, thereby improving the reliability of the rubber sleeve 1006 and improving the sealing performance of the rubber sleeve 1006.

[0053] like Figure 2 As shown, in one or more embodiments, the cartridge 1006 adopts a radially layered structure.

[0054] The present invention enables the rubber sleeve 1006 to adopt a radial layered structure, so that the rubber sleeve 1006 can be easily filled with the sealing tube section 1008 through deformation.

[0055] Based on the above-mentioned downhole sealing device 100 for improving the performance of the rubber cartridge, the present invention also provides a downhole isolation device, which is arranged near the second end of the central pipe 1001, comprising the above-mentioned downhole sealing device 100 for improving the performance of the rubber cartridge, a first retaining ring 1007 sleeved on the outer surface of the central pipe 1001, a second retaining ring 1009 sleeved on the outer surface of the central pipe 1001, and a rubber cartridge 1006 sleeved on the outer surface of the central pipe 1001 and arranged between the first retaining ring 1007 and the second retaining ring 1009.

[0056] In one or more embodiments, the first stop ring 1007 is located above the second stop ring 1009 , the upper surface of the rubber sleeve 1006 abuts against the lower surface of the first stop ring 1007 , and the lower surface of the rubber sleeve 1006 abuts against the upper surface of the second stop ring 1009 .

[0057] The application of the packer of the present invention is described below. During construction, the central pipe 1001 is lowered into the casing 1002 in the well together with the packer, and is moved to the sealing pipe section 1008, and the packer is set. A downward pressure in the axial direction is applied to the first baffle ring 1007, so that the first baffle ring 1007 squeezes the rubber tube 1006. Since the rubber tube 1006 is located between the first baffle ring 1007 and the second baffle ring 1009, and the upper surface of the rubber tube 1006 abuts against the lower surface of the first baffle ring 1007, and the lower surface of the rubber tube 1006 abuts against the upper surface of the second baffle ring 1009, the first baffle ring 1007 and the second baffle ring 1009 can squeeze the rubber tube 1006, so that the rubber tube 1006 is gradually shortened in its axial direction and expanded in its radial direction until it can completely fill the sealing pipe section 1008.

[0058] When the rubber sleeve 1006 is compressed and sealed, its two ends will be subjected to a certain axial pressure difference during operation, thereby generating shear stress. Regardless of whether the direction of the shear stress is upward or downward, it will have an impact on the rubber sleeve 1006, accelerating its deformation and failure. When the packer described in the present invention is used, since the rubber sleeve 1006 is fully engaged with the grooves and / or protrusions of the sealing pipe section 1008, the sealing pipe section 1008 of the casing 1002 has a support surface perpendicular to the axial direction, which can effectively offset the shear stress on the rubber sleeve 1006 in the axial direction, thereby alleviating the damage of the shear stress to the rubber sleeve 1006, and further improving the sealing performance and sealing reliability of the packer.

[0059] The present invention also provides a downhole bridge plug, comprising the downhole sealing device 100 for improving the performance of the rubber sleeve.

[0060] The present invention mainly has the following technical effects:

[0061] The present invention includes a sleeve 1002 and a rubber sleeve 1006 arranged in the sleeve 1002, and the rubber sleeve 1006 can be pressed and contacted with the sleeve 1002 by deformation to achieve sealing. The hardness of the rubber sleeve 1006 at the middle position in the axial direction is less than the hardness at the position far away from the middle position. The middle section of the rubber sleeve 1006 with smaller hardness can expand first, and the sections far away from the middle position and with larger hardness can expand after the middle section, thereby effectively alleviating the problem of excessive protrusion of the shoulders of the rubber sleeve 1006 close to the two end faces along the axial direction, thereby improving the service life of the rubber sleeve 1006.

[0062] The present invention includes a sealing tube section 1008 through a sleeve 1002, and the rubber sleeve 1006 can cooperate with the inner surface of the sealing tube section 1008, so that the sealing tube section 1008 can apply a supporting force in the axial direction of the rubber sleeve 1006, and the hardness of the rubber sleeve 1006 decreases radially outward. On the one hand, it can alleviate the damage caused by the shear stress on the rubber sleeve 1006 in the axial direction, thereby effectively preventing the rubber sleeve 1006 from failing due to the axial shear stress and effectively ensuring its sealing. On the other hand, the hardness of the rubber sleeve 1006 decreases radially outward, which can provide strong support for the rubber sleeve 1006 and make it better fit the sealing tube section 1008, thereby facilitating the provision of axial support for the rubber sleeve 1006 when it is subjected to a pressure difference, and effectively reducing the shear stress on the rubber sleeve 1006 when it is under pressure.

[0063] According to the present invention, a plurality of grooves are arranged on the inner surface of the sealing tube section 1008. After the rubber sleeve 1006 is squeezed in the axial direction, part of the rubber sleeve 1006 can enter the grooves and part of the outer surface of the rubber sleeve 1006 can be squeezed and contacted with the inner wall and the bottom surface of the grooves. The sleeve 1002 can bear part of the shear stress on the rubber sleeve 1006 through the grooves, thereby alleviating the damage to the rubber sleeve 1006 caused by the shear stress. The sleeve 1002 provides support for the rubber sleeve 1006 in the axial direction to alleviate the damage to the rubber sleeve 1006 caused by the axial shear stress, thereby improving the reliability of the rubber sleeve 1006 and improving the sealing performance of the rubber sleeve 1006.

[0064] According to the present invention, a plurality of protrusions are arranged on the inner surface of the sealing tube section 1008. After the rubber sleeve 1006 is squeezed in the axial direction, part of the rubber sleeve 1006 can enter the recessed area between the protrusions, and part of the outer surface of the rubber sleeve 1006 can be squeezed and contacted with the recessed area and the side surfaces of each protrusion, so that the sleeve 1002 can bear part of the shear stress on the rubber sleeve 1006 through the protrusions, thereby alleviating the damage to the rubber sleeve 1006 caused by the shear stress. The sleeve 1002 provides support for the rubber sleeve 1006 in the axial direction to alleviate the damage to the rubber sleeve 1006 caused by the axial shear stress, thereby improving the reliability of the rubber sleeve 1006 and improving the sealing performance of the rubber sleeve 1006.

[0065] According to the present invention, a plurality of protrusions and a plurality of grooves are arranged on the inner surface of the sealing pipe section. After the rubber sleeve 1006 is squeezed in the axial direction, part of the rubber sleeve 1006 can enter between the protrusions and inside the grooves, and part of the outer surface of the rubber sleeve 1006 can be squeezed and contacted with the surface between the protrusions, the inner wall and the bottom surface of the groove. The sleeve 1002 can bear part of the shear stress on the rubber sleeve 1006 through the protrusions and the grooves, thereby alleviating the damage to the rubber sleeve 1006 caused by the shear stress. The sleeve 1002 provides support for the rubber sleeve 1006 in the axial direction to alleviate the damage to the rubber sleeve 1006 caused by the axial shear stress, thereby improving the reliability of the rubber sleeve 1006 and improving the sealing performance of the rubber sleeve 1006.

[0066] Although the present invention has been described with reference to preferred embodiments, various modifications may be made thereto and parts thereof may be replaced by equivalents without departing from the scope of the present invention. In particular, the various technical features mentioned in the various embodiments may be combined in any manner as long as there are no structural conflicts. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A downhole sealing device for improving the performance of a rubber cartridge, comprising a casing and a rubber cartridge disposed in the casing, wherein the rubber cartridge can be pressed against the casing by deformation to achieve sealing, and in the axial direction, the hardness of the rubber cartridge at a middle position is less than the hardness at a position away from the middle position.

2. The downhole sealing device for improving the performance of the rubber cartridge according to claim 1, characterized in that: The sleeve includes a sealing tube section, and the rubber sleeve can cooperate with the inner surface of the sealing tube section so that the sealing tube section can apply a supporting force in the axial direction of the rubber sleeve, and the hardness of the rubber sleeve decreases radially outward.

3. The downhole sealing device for improving the performance of the rubber cartridge according to claim 1, characterized in that: The rubber cartridge includes a first rubber cartridge segment, a second rubber cartridge segment and a third rubber cartridge segment in the axial direction, and the second rubber cartridge segment is located between the first rubber cartridge segment and the third rubber cartridge segment.

4. The downhole sealing device for improving the performance of the rubber cartridge according to claim 2, characterized in that: The inner surface of the sealing tube section is provided with a plurality of grooves. After the rubber sleeve is squeezed in the axial direction, part of the rubber sleeve can enter the groove and part of the outer surface of the rubber sleeve can be squeezed and contacted with both the inner wall and the bottom surface of the groove.

5. The downhole sealing device for improving the performance of the rubber cartridge according to claim 2, characterized in that: The inner surface of the sealing tube section is provided with a plurality of protrusions. After the rubber sleeve is squeezed in the axial direction, part of the rubber sleeve can enter the recessed area between each of the protrusions, and part of the outer surface of the rubber sleeve can be squeezed into contact with the recessed area and the side surface of each of the protrusions.

6. The downhole sealing device for improving the performance of the rubber cartridge according to claim 2, characterized in that: The inner surface of the sealing tube section is provided with a plurality of protrusions and a plurality of grooves. After the rubber tube is squeezed in the axial direction, part of the rubber tube can enter between each of the protrusions and inside the grooves, and part of the outer surface of the rubber tube can be squeezed and contacted with the surface between the protrusions, the inner wall and the bottom surface of the groove.

7. The downhole sealing device for improving the performance of the rubber cartridge according to any one of claims 4 to 6, characterized in that: The groove and / or the protrusion extend along the circumferential direction on the inner surface of the sealing tube section.

8. The downhole sealing device for improving the performance of the rubber cartridge according to any one of claim 2, characterized in that: The rubber cylinder adopts a radial layered structure.

9. A downhole sealer, arranged at the center pipe near the second end, comprising a downhole sealing device for improving the performance of a rubber sleeve according to any one of claims 1 to 8, a first retaining ring sleeved on the outer surface of the center pipe, and a second retaining ring sleeved on the outer surface of the center pipe, the rubber sleeve being sleeved on the outer surface of the center pipe and arranged between the first retaining ring and the second retaining ring.

10. The downhole packer according to claim 9, characterized in that: The first retaining ring is located above the second retaining ring, the upper surface of the rubber cylinder abuts against the lower surface of the first retaining ring, and the lower surface of the rubber cylinder abuts against the upper surface of the second retaining ring.

11. A downhole bridge plug, characterized in that: It comprises a downhole sealing device for improving the performance of the rubber cartridge according to any one of claims 1 to 8.

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