Underground sealing device, packer and bridge plug

Abstract

The invention provides an underground sealing device, a packer and a bridge plug, the underground sealing device comprises a partial casing pipe and a rubber sleeve arranged in the partial casing pipe, the partial casing pipe is provided with a containing part, and the outer surface of the rubber sleeve can be contained in the containing part and matched with the containing part, so that the partial casing pipe can apply supporting force in the axial direction of the rubber sleeve. The sleeve is used for supporting the rubber sleeve in the axial direction so as to relieve damage of axial shear stress to the rubber sleeve, and the sealing performance of the rubber sleeve is improved while the reliability of the rubber sleeve is improved.

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. Background Art

[0002] As the main sealing component of the packer and bridge plug, the rubber sleeve plays a decisive role in the sealing performance of the packer and bridge plug. After the rubber sleeve is compressed and sealed, its upper and lower ends need to withstand a certain axial pressure difference, which will exert a certain shear stress on the rubber sleeve. At the same time, the rubber sleeve after sealing is also squeezed in the radial direction, so that a certain friction force is generated on the contact surface between the rubber sleeve and the casing. The direction of the friction force is opposite to the direction of the shear stress, which can offset part of the shear stress. In order to avoid shear failure of the rubber sleeve, the shear strength of the rubber material of the rubber sleeve must be greater than the difference between the maximum shear stress and the friction force it withstands. However, the friction force on the rubber sleeve is small, and the relief of the shear stress is limited. Providing support to the rubber sleeve in the axial direction can further alleviate the damage to the rubber sleeve caused by the shear stress and improve the sealing performance and sealing reliability of the rubber sleeve.

[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 that can overcome the technical drawbacks of being unable to provide axial support to the rubber cylinder and unable to alleviate the damage to the rubber cylinder caused by shear stress, resulting in reduced sealing performance of the rubber cylinder. Summary of the invention

[0007] One object of the present invention is to propose a downhole sealing device, a packer and a bridge plug to provide support to the rubber sleeve in the axial direction through the casing to alleviate the damage to the rubber sleeve caused by the axial shear stress, thereby improving the reliability of the rubber sleeve and enhancing the sealing performance of the rubber sleeve.

[0008] According to the present invention, a downhole sealing device is provided, comprising a portion of casing and a rubber tube arranged in the portion of the casing, wherein the portion of the casing has a receiving portion, and the outer surface of the rubber tube can be received in the receiving portion and cooperate with the receiving portion, so that the portion of the casing can apply a supporting force in the axial direction of the rubber tube.

[0009] In a preferred embodiment, the inner surface of the accommodating portion is provided with a plurality of grooves, and after the rubber cartridge is squeezed in the axial direction, part of the rubber cartridge can enter the groove and part of the outer surface of the rubber cartridge can be squeezed into contact with both the inner wall and the bottom surface of the groove.

[0010] In a preferred embodiment, the inner surface of the accommodating portion is provided with a plurality of protrusions, and after the rubber cartridge is squeezed in the axial direction, part of the rubber cartridge can enter the recessed area between each of the protrusions, and part of the outer surface of the rubber cartridge can be squeezed into contact with the recessed area and the side surface of each of the protrusions.

[0011] In a preferred embodiment, the inner surface of the accommodating portion is provided with a plurality of protrusions and a plurality of grooves. After the rubber cartridge is squeezed in the axial direction, part of the rubber cartridge can enter between each of the protrusions and inside the grooves, and part of the outer surface of the rubber cartridge can be squeezed into contact with the surface between the protrusions, the inner wall and the bottom surface of the groove.

[0012] In a preferred embodiment, the groove and / or the protrusion extend along the circumferential direction on the inner surface of the accommodating portion.

[0013] In a preferred embodiment, the rubber cartridge adopts a radial layered structure.

[0014] In a preferred embodiment, the rubber sleeve comprises a rubber sleeve inner layer and a rubber sleeve outer layer which is sleeved on the outer circumference of the rubber sleeve inner layer and in contact with the outer circumference.

[0015] In a preferred embodiment, the hardness of the inner layer of the rubber sleeve is greater than the hardness of the outer layer of the rubber sleeve.

[0016] In a preferred embodiment, the thickness of the outer layer of the rubber sleeve accounts for 5% to 30% of the thickness of the entire rubber sleeve.

[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, 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, and the rubber tube 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 mentioned above.

[0020] The present invention comprises a partial sleeve and a rubber cylinder arranged in the partial sleeve, wherein the partial sleeve has a receiving portion, and the rubber cylinder can be received in and cooperate with the receiving portion, so that the partial sleeve can apply a supporting force in the axial direction of the rubber cylinder to alleviate the damage to the rubber cylinder caused by shear stress. The sleeve provides support to the rubber cylinder in the axial direction to alleviate the damage to the rubber cylinder caused by the axial shear stress, thereby improving the reliability of the rubber cylinder and the sealing performance of the rubber cylinder.

[0021] The present invention provides a plurality of grooves on the inner surface of the accommodating portion. After the rubber tube is squeezed in the axial direction, part of the rubber tube can enter the grooves and part of the outer surface of the rubber tube can be squeezed and contacted with the inner wall and bottom surface of the grooves. The sleeve can bear part of the shear stress on the rubber tube through 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.

[0022] The present invention provides a plurality of protrusions on the inner surface of the accommodating portion. 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.

[0023] The present invention provides a plurality of protrusions and a plurality of grooves on the inner surface of the accommodating portion. 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.

[0024] The present invention enables the rubber sleeve to adopt a radial layered structure, so that the rubber sleeve can fill the accommodating portion through deformation.

[0025] The rubber sleeve of the present invention includes a rubber sleeve inner layer and a rubber sleeve outer layer which is sleeved on and in contact with the outer peripheral surface of the rubber sleeve inner layer. Different materials can be selected for the rubber sleeve inner layer and the rubber sleeve outer layer to adapt to the deformation property of the rubber sleeve.

[0026] The present invention makes the hardness of the outer layer of the rubber sleeve smaller than the hardness of the inner layer of the rubber sleeve. On the one hand, this is beneficial to the cooperation between the outer layer of the rubber sleeve and the multiple protrusions and / or multiple grooves set on the inner surface of the sleeve. On the other hand, it can ensure the ductility of the rubber sleeve itself while maintaining a certain strength. After being subjected to axial shear force, it can shrink in the axial direction and expand in the radial direction.

[0027] In the present invention, the ratio of the thickness of the outer layer of the rubber sleeve to the thickness of the entire rubber sleeve is 5% to 30%, thereby ensuring that the rubber sleeve can completely fill the accommodating portion. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 The figure schematically shows an overall structural diagram of a downhole sealing device of the present invention;

[0029] Figure 2 Another overall structural diagram of the downhole sealing device of the present invention is schematically shown;

[0030] Figure 3 The structural diagram of the rubber cylinder of the downhole sealing device according to the present invention is schematically shown.

[0031] Illustration: 100-downhole sealing device; 1001-central pipe; 1002-casing; 1003-prefabricated sealing pipe section; 1004-packer; 1005-reservoir; 1006-rubber tube; 1007-first retaining ring; 1008-accommodating portion; 1009-second retaining ring; 1010-rubber tube inner layer; 1011-rubber tube outer layer;

[0032] 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

[0033] 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.

[0034] 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.

[0035] 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 technical features indicated. Therefore, features defined as "first" and "second" may explicitly or implicitly include one or more of the features.

[0036] In the description of the present invention, “plurality” means two or more than two, unless otherwise clearly and specifically defined.

[0037] 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.

[0038] Figure 1 and Figure 2 Schematically shows an overall structural diagram of a downhole sealing device of the present invention. As shown in the figure, the downhole sealing device 100 of the present invention comprises: a partial casing 1002 and a rubber tube 1006 disposed in the partial casing 1002, the partial casing 1002 has a receiving portion 1008, and the outer surface of the rubber tube 1006 can be received in the receiving portion 1008 and cooperate with it, so that the partial casing 1002 can apply a supporting force in the axial direction of the rubber tube 1006 to alleviate the damage caused by the shear stress on the rubber tube 1006 in the axial direction, thereby effectively solving the failure problem caused by the axial shear stress on the rubber tube 1006 and effectively ensuring the sealing performance.

[0039] In one or more embodiments, the cartridge 1006 is configured as a cylindrical body.

[0040] In one or more embodiments, the receiving portion 1008 is ring-shaped.

[0041] The practical application of the downhole sealing device 100 of the present invention is described below. The first end of the central pipe 1001 is close to the ground, the central pipe 1001 is provided with a packer 1004 near its second end, the second end of the central pipe 1001 is located in the well, and a prefabricated sealing pipe section 1003 is provided inside the casing 1002. Before the packer is used for sealing, the casing 1002 is lowered into the well, and the prefabricated sealing pipe section 1003 is located at the position in the well where sealing is required.

[0042] The downhole sealing device 100 of the present invention is a part of the packer 1004, and is used to achieve downhole sealing. On the ground, the rubber tube 1006 and other components are installed at the position of the central pipe 1001 near the second end, and the central pipe 1001 together with the rubber tube 1006 and other components are lowered into the casing 1002 in the well.

[0043] After the center pipe 1001, the rubber sleeve 1006 and other components are lowered into the casing 1002, the rubber sleeve 1006 and other components of the center pipe 1001 near the second end can reach the prefabricated sealing pipe section 1003, and the rubber sleeve 1006 can form a seal with the prefabricated sealing pipe section 1003 after compression. Since the center pipe 1001 and the casing 1002 are both tubular bodies and the center pipe 1001 is located inside the casing 1002, an annular space is formed between the outer surface of the center pipe 1001 and the inner surface of the casing 1002. The casing 1002 is formed with a receiving portion 1008 in the annular space. During the sealing process, the rubber sleeve 1006 cooperates with the receiving portion 1008 to fill the receiving portion 1008, thereby realizing the isolation of the annular space between the reservoir 1005 and the upper part of the casing 1002.

[0044] The present invention includes a partial sleeve 1002 and a rubber cartridge 1006 disposed in the partial sleeve 1002. The partial sleeve 1002 has a receiving portion 1008. The rubber cartridge 1006 can be received in the receiving portion 1008 and cooperate with the receiving portion 1008, so that the partial sleeve 1002 can apply a supporting force in the axial direction of the rubber cartridge 1006 to alleviate the damage to the rubber cartridge 1006 caused by the shear stress. The sleeve 1002 provides support for the rubber cartridge 1006 in the axial direction to alleviate the damage to the rubber cartridge 1006 caused by the axial shear stress, thereby improving the reliability of the rubber cartridge 1006 and improving the sealing performance of the rubber cartridge 1006.

[0045] In one or more embodiments, the inner surface of the accommodating portion 1008 is provided with a plurality of grooves, each of which is spaced a certain distance apart, so that 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.

[0046] Specifically, after the center tube 1001 and the rubber tube 1006 and other components are lowered into the casing 1002, the center tube 1001 and the rubber tube 1006 and other components at the position near the second end can reach the prefabricated sealing pipe section 1003, and at the prefabricated sealing pipe section 1003, the rubber tube 1006 is squeezed in the axial direction so that the rubber tube 1006 is deformed and fills the accommodating portion 1008. The outer circumferential surface of the rubber tube 1006 squeezes the groove and forms small protrusions on part of the rubber tube 1006, which enter each groove. Each small protrusion formed by the rubber tube 1006 can be respectively squeezed and contacted with the inner wall and bottom surface of each groove.

[0047] According to the present invention, a plurality of grooves are arranged on the inner surface of the accommodating portion 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.

[0048] In one or more embodiments, the inner surface of the receiving portion 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.

[0049] Specifically, after the center tube 1001 and the rubber tube 1006 and other components are lowered into the casing 1002, the center tube 1001 and the rubber tube 1006 and other components near the second end can reach the prefabricated sealing pipe section 1003, and squeeze the rubber tube 1006 in the axial direction at the prefabricated sealing pipe section 1003 so that the rubber tube 1006 is deformed and fills the accommodating portion 1008. After the outer circumferential surface of the rubber tube 1006 is squeezed with each protrusion, a small protrusion is formed on part of the rubber tube 1006, which 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.

[0050] According to the present invention, a plurality of protrusions are arranged on the inner surface of the accommodating portion 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. 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.

[0051] In one or more embodiments, the inner surface of the accommodating portion 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.

[0052] Specifically, after the center tube 1001 and the rubber tube 1006 and other components are lowered into the casing 1002, the center tube 1001 and the rubber tube 1006 and other components at the position near the second end can reach the prefabricated sealing pipe section 1003, and the rubber tube 1006 is squeezed in the axial direction at the prefabricated sealing pipe section 1003 so that the rubber tube 1006 is deformed and fills the accommodating portion 1008. After the outer circumferential surface of the rubber tube 1006 is squeezed with each protrusion and groove, part of the rubber tube 1006 forms small protrusions, which respectively enter the recessed area between each protrusion and the interior of the groove. The small protrusions formed by the rubber tube 1006 can be squeezed and contacted with the surface between the protrusions, the inner wall of the groove and the bottom surface.

[0053] According to the present invention, a plurality of protrusions and a plurality of grooves are arranged on the inner surface of the accommodating portion. 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.

[0054] like Figure 3 As shown, in one or more embodiments, the cartridge 1006 adopts a radially layered structure.

[0055] The present invention enables the rubber sleeve 1006 to adopt a radial layered structure, so that the rubber sleeve 1006 can fill the accommodating portion 1008 through deformation.

[0056] In one or more embodiments, the rubber cartridge 1006 includes a rubber cartridge inner layer 1010 and a rubber cartridge outer layer 1011 which is sleeved on and in contact with the outer circumference of the rubber cartridge inner layer 1010 .

[0057] In the present invention, the rubber sleeve 1006 includes a rubber sleeve inner layer 1010 and a rubber sleeve outer layer 1011 which is sleeved on and in contact with the outer circumference of the rubber sleeve inner layer 1010 . Different materials can be selected for the rubber sleeve inner layer 1010 and the rubber sleeve outer layer 1011 to adapt to the deformation properties of the rubber sleeve 1006 .

[0058] In one or more embodiments, the hardness of the outer layer 1011 of the rubber sleeve is less than the hardness of the inner layer 1010 of the rubber sleeve.

[0059] The present invention makes the hardness of the outer layer 1011 of the rubber sleeve smaller than the hardness of the inner layer 1010 of the rubber sleeve. On the one hand, this is beneficial to the cooperation between the outer layer 1011 of the rubber sleeve and the multiple protrusions and / or multiple grooves set on the inner surface of the sleeve 1002. On the other hand, it can ensure the ductility of the rubber sleeve 1006 itself while maintaining a certain strength. After being subjected to axial shear force, it can shrink in the axial direction and expand in the radial direction.

[0060] In one or more embodiments, the thickness of the outer layer 1011 of the rubber sleeve accounts for 5% to 30% of the thickness of the entire rubber sleeve 1006 .

[0061] In the present invention, the ratio of the thickness of the outer layer 1011 of the rubber sleeve to the thickness of the entire rubber sleeve 1006 is 5% to 30%, thereby ensuring that the rubber sleeve 1006 can completely fill the accommodating portion 1008 .

[0062] Based on the above-mentioned downhole sealing device 100, the present invention also provides a downhole sealer 1004, which is arranged near the second end of the central pipe 1001, including the aforementioned downhole sealing device 100, 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 sleeve 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.

[0063] 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 .

[0064] The application of the packer 1004 of the present invention is described below. The upper and lower sections of the pre-set sealing pipe section 1003 are connected to the casing 1002 through threads. During construction, the pre-set sealing pipe section 1003 is lowered to the position where the sealing is required in advance, and then the central pipe 1001 together with the packer 1004 are lowered into the casing 1002 in the well. When the packer 1004 at the position close to the second end of the central pipe 1001 is lowered to the position where the pre-set sealing pipe section 1003 is located, the packer 1004 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 cylinder 1006. Since the rubber cylinder 1006 is located between the first baffle ring 1007 and the second baffle ring 1009 and the upper surface of the rubber cylinder 1006 abuts against the lower surface of the first baffle ring 1007 and the lower surface of the rubber cylinder 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 cylinder 1006, so that the rubber cylinder 1006 gradually shortens in its axial direction and expands in its radial direction until it can completely fill the accommodating portion 1008.

[0065] When the rubber cylinder 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 cylinder 1006, accelerating its deformation and failure. When the packer 1004 described in the present invention is used, since the rubber cylinder 1006 is fully engaged with the grooves and / or protrusions of the receiving portion 1008, the receiving portion 1008 of the casing 1002 has a support surface perpendicular to the axial direction, which can effectively offset the shear stress on the rubber cylinder 1006 in the axial direction, thereby alleviating the damage of the shear stress to the rubber cylinder 1006, and further improving the sealing performance and sealing reliability of the packer 1004.

[0066] The present invention further provides a downhole bridge plug, comprising the downhole sealing device 100 mentioned above.

[0067] The present invention mainly has the following technical effects:

[0068] The present invention includes a partial sleeve 1002 and a rubber cartridge 1006 disposed in the partial sleeve 1002. The partial sleeve 1002 has a receiving portion 1008. The rubber cartridge 1006 can be received in the receiving portion 1008 and cooperate with the receiving portion 1008, so that the partial sleeve 1002 can apply a supporting force in the axial direction of the rubber cartridge 1006 to alleviate the damage to the rubber cartridge 1006 caused by the shear stress. The sleeve 1002 provides support for the rubber cartridge 1006 in the axial direction to alleviate the damage to the rubber cartridge 1006 caused by the axial shear stress, thereby improving the reliability of the rubber cartridge 1006 and improving the sealing performance of the rubber cartridge 1006.

[0069] According to the present invention, a plurality of grooves are arranged on the inner surface of the accommodating portion 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.

[0070] According to the present invention, a plurality of protrusions are arranged on the inner surface of the accommodating portion 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. 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.

[0071] According to the present invention, a plurality of protrusions and a plurality of grooves are arranged on the inner surface of the accommodating portion. 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.

[0072] The present invention makes the hardness of the outer layer 1011 of the rubber sleeve smaller than the hardness of the inner layer 1010 of the rubber sleeve. On the one hand, this is beneficial to the cooperation between the outer layer 1011 of the rubber sleeve and the multiple protrusions and / or multiple grooves set on the inner surface of the sleeve 1002. On the other hand, it can ensure the ductility of the rubber sleeve 1006 itself while maintaining a certain strength. After being subjected to axial shear force, it can shrink in the axial direction and expand in the radial direction.

[0073] The present invention discloses a downhole sealing device 100, a packer 1004 and a bridge plug. A pre-set sealing section 1003 with a receiving portion 8 is lowered to a sealing position in advance, and a radially layered rubber sleeve 8 is used for sealing, so that the rubber sleeve 8 can completely fill the pre-set sealing section 1003. This can effectively alleviate the damage to the rubber sleeve 8 caused by shear stress, provide a high-performance and high-reliability technical means for the sealing of oil and gas wells, and is conducive to the efficient development and utilization of oil and gas fields.

[0074] 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, comprising a portion of casing and a rubber tube arranged in the portion of the casing, wherein the portion of the casing has a receiving portion, and the outer surface of the rubber tube can be received in the receiving portion and cooperate with the receiving portion, so that the portion of the casing can apply a supporting force in the axial direction of the rubber tube.

2. The downhole sealing device according to claim 1, characterized in that: The inner surface of the accommodating portion is provided with a plurality of grooves. 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 both the inner wall and the bottom surface of the groove.

3. The downhole sealing device according to claim 1, characterized in that: The inner surface of the accommodating portion is provided with a plurality of protrusions. After the rubber cartridge is squeezed in the axial direction, part of the rubber cartridge can enter the recessed area between each of the protrusions, and part of the outer surface of the rubber cartridge can be squeezed into contact with the recessed area and the side surface of each of the protrusions.

4. The downhole sealing device according to claim 1, characterized in that: The inner surface of the accommodating portion is provided with a plurality of protrusions and a plurality of grooves. After the rubber cartridge is squeezed in the axial direction, part of the rubber cartridge can enter between each of the protrusions and inside the grooves, and part of the outer surface of the rubber cartridge can be squeezed into contact with the surface between the protrusions, the inner wall and the bottom surface of the groove.

5. The downhole sealing device according to any one of claims 2 to 4, characterized in that: The groove and / or the protrusion extend along the circumferential direction on the inner surface of the accommodating portion.

6. The downhole sealing device according to any one of claims 2 to 4, characterized in that: The rubber cylinder adopts a radial layered structure.

7. The downhole sealing device according to claim 6, characterized in that: The rubber sleeve comprises a rubber sleeve inner layer and a rubber sleeve outer layer which is sleeved on the outer peripheral surface of the rubber sleeve inner layer and contacts with the outer peripheral surface.

8. The downhole sealing device according to claim 7, characterized in that: The hardness of the inner layer of the rubber sleeve is greater than the hardness of the outer layer of the rubber sleeve.

9. The downhole sealing device according to claim 7, characterized in that: The thickness of the outer layer of the rubber cylinder accounts for 5% to 30% of the thickness of the entire rubber cylinder.

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

11. The downhole packer according to claim 10, 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.

12. A downhole bridge plug, characterized in that: Comprising a downhole sealing device according to any one of claims 1 to 9.

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