A packer

Abstract

The application provides a packer, which comprises a packer body, an expansion cone sleeved on the packer body and internally connected with the packer body through a first sealing element, an expansion sleeve connected on a tapered part of the expansion cone, the expansion sleeve being provided with a second sealing structure for sealingly connecting an outer sleeve in operation, a support sleeve having one end connected with and supporting one end of the expansion sleeve and the other end connected with the packer body in a direction away from the expansion cone, and a locking ring fixedly connected with the support sleeve and locking the support sleeve on the packer body. The packer is resistant to high temperature and high pressure, has good adaptability to the sleeve, and has good anti-suction and energy storage and tightening effects.

Description

Technical Field

[0001] This invention relates to the field of cementing technology, specifically to a composite sealing structure for connecting tailpipe hangers and a packer including the same. This packer is particularly suitable for cementing processes in high-temperature, high-pressure oil and gas wells. Background Technology

[0002] As exploration and development continue to deepen, the focus of global oil and gas exploration and development has shifted from conventional oil and gas reservoirs to unconventional ones, with target layers rapidly extending from shallow to deep and ultra-deep. This extension of target layers is accompanied by a series of harsh conditions, including high formation temperatures and significant operational pressures.

[0003] Chinese patent CN103348094B discloses an expansion packer with an axially movable support component induced by expansion. This packer uses a pure metal seal, and its sealing function relies on an external force provided by a tube trimmer. This packer is generally difficult to apply in situations with poor temperature resistance and high external setting force. Chinese patent CN107829705A discloses an expansion packer assembly and packer. The packer assembly includes an expansion tube comprising a skeleton, an inner layer, and an outer layer. The inner layer is located inside the skeleton, and the outer layer is located outside the skeleton. The skeleton is made of metal, and a protective tube made of rubber is also provided outside the expansion tube. Because this packer uses only rubber for sealing, its sealing performance and temperature resistance are generally poor, and the setting state is difficult to maintain.

[0004] In summary, the main materials used in conventional cementing packers are elastomers such as hydrogenated nitrile butadiene rubber and fluororubber. Their structures are primarily expansion-type and compression-type, but they suffer from low sealing capacity, low temperature resistance, and high setting force. Therefore, it is necessary to design a novel packer structure by innovating the packer's expansion sealing method and packer sleeve materials to optimize its temperature resistance and reduce setting force. Summary of the Invention

[0005] In view of some or all of the above-mentioned technical problems existing in the prior art, the present invention proposes a packer that is resistant to high temperature and high pressure and can improve the setting effect.

[0006] To achieve the above-mentioned objectives, the present invention provides a packer comprising:

[0007] Packer body;

[0008] An expansion cone is fitted onto the packer body and is internally sealed to the packer body via a first sealing element.

[0009] An expansion sleeve is connected to the conical part of an expansion cone, and the expansion sleeve is provided with a second sealing structure that seals the connection to the outer sleeve during operation.

[0010] A support sleeve, one end of which is connected to and supports one end of the expansion sleeve, and the other end is connected to the packer body in a direction away from the expansion cone;

[0011] The locking ring is fixedly connected to the support sleeve, locking the support sleeve to the packer body.

[0012] In one embodiment, the expansion cone is a tube with a certain taper on its outer surface and a cylindrical surface with a sealing ring groove on its inner surface, and the first sealing element is installed in the sealing ring groove of the expansion cone.

[0013] In one embodiment, the outer surface of the expansion cone is provided with a guide welding rib along the generatrix of the cone surface, and the guide welding rib engages with a guide groove on the inner surface of the expansion sleeve.

[0014] In one embodiment, the expansion sleeve is a tube made of easily expandable metal material, and the outer surface of the expansion sleeve is provided with two sealing ring grooves. The bottom and sides of the sealing ring grooves are provided with circumferential metal protrusions, and the second sealing structure is provided in the sealing ring grooves by integral vulcanization.

[0015] In one embodiment, the second sealing structure is a non-circular sealing ring. The interior of the second sealing structure is provided with a groove that matches the bottom protrusion of the sealing ring groove on the outer surface of the expansion sleeve. The groove is vulcanized in the outer surface of the expansion sleeve by direct vulcanization of rubber. The outer surface of the second sealing structure is provided with protrusions at both ends and / or a protrusion in the middle, depending on the working conditions.

[0016] In one embodiment, the two end protrusions and / or the middle protrusion of the second sealing structure are internally embedded with compressible springs, which improve the resilience of the rubber material and prevent the rubber from being over-compressed and flowing axially when the rubber of the second sealing structure is compressed and sealed.

[0017] In one embodiment, the outer surface of the expansion sleeve is provided with a plurality of circumferential metal protrusions. When the expansion sleeve expands, the metal protrusions first come into contact with the interior of the outer sleeve and are then compressed and deformed, so that the expansion sleeve and the outer sleeve form a metal seal.

[0018] In one embodiment, in the initial state, the height of the metal protrusion on the outer surface of the expansion sleeve is not higher than the height of the protrusions at both ends and / or the middle protrusion of the second sealing structure.

[0019] In one embodiment, the support sleeve is made of high-performance spring steel, and a groove is provided at one end of the support sleeve near the expansion sleeve. The groove is embedded in the expansion sleeve to support the expansion sleeve, and the other end of the support sleeve is fixedly connected to the packer body.

[0020] In one embodiment, when the expansion cone pushes the expansion sleeve to set, the expansion sleeve transmits axial force to the support sleeve, which can deform to store energy; after the expansion is completed, the energy stored in the support sleeve is transmitted back to the expansion sleeve to ensure that the expansion sleeve is continuously compressed.

[0021] In one embodiment, the second sealing structure is made of a special high-temperature resistant fluororubber and a metal spring, which can withstand high-temperature and high-pressure gas of up to 204°C and 70MPa.

[0022] In one embodiment, the first seal is an O-ring rubber seal that is resistant to high temperature and high pressure gases.

[0023] Compared with the prior art, the advantages of the present invention are as follows:

[0024] 1) Excellent high temperature and high pressure resistance. Currently, existing cementing packers can withstand temperatures of up to 120℃-150℃ and pressures of 35MPa-40MPa. The second sealing structure of the packer in this invention uses a composite of special high-temperature resistant fluororubber and a metal spring, overcoming the shortcomings of existing pure rubber elastomer materials. Therefore, it can be used in high-temperature and high-pressure oil and gas setting environments with a maximum temperature of 204℃ and a pressure of 70MPa.

[0025] 2) Good casing adaptability. The expansion sleeve is designed with metal and rubber protrusions on the outside, which can adapt well to irregular casings;

[0026] 3) Anti-sucking function of the rubber sealing ring. The second sealing structure and the expansion sleeve are vulcanized as a whole, and a metal protrusion is designed between the expansion sleeve and the second sealing structure to ensure that the rubber sealing ring is firmly vulcanized on the expansion sleeve;

[0027] 4) Energy storage and sealing function. During the packer expansion and sealing process, the support sleeve undergoes slight deformation to accumulate some energy. After the expansion and sealing is completed, the support sleeve continues to provide the expansion sleeve with expansion and sealing force to ensure the setting and sealing effect.

[0028] 5) This packer is particularly useful in cementing processes for high-temperature and high-pressure oil and gas wells, enabling cementing and setting in environments with temperatures up to 204°C and pressures up to 70MPa without any air bubble leakage. Attached Figure Description

[0029] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, in which:

[0030] Figure 1 The diagram shown is a schematic representation of the packer assembly of the present invention.

[0031] Figure 2 What is shown is Figure 1 A schematic diagram of the key sealing component;

[0032] Figure 3 What is shown is Figure 1 A schematic diagram of the combined sealing ring in the diagram;

[0033] Figure 4 What is shown is Figure 1 A schematic diagram of the expansion sleeve in the diagram;

[0034] Figure 5 What is shown is Figure 1 A schematic diagram of the expansion cone structure in the diagram;

[0035] Figure 6 What is shown is Figure 1 A schematic diagram of the support sleeve in the middle.

[0036] In the accompanying drawings, the same parts use the same reference numerals. The drawings are not drawn to scale. Detailed Implementation

[0037] To make the technical solutions and advantages of the present invention clearer, exemplary embodiments of the present invention will be described in further detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not an exhaustive list of all embodiments. Furthermore, without conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0038] During the invention process, the inventors noticed that the existing packer's rubber sleeve sealing material has problems such as low sealing ability, low temperature resistance and high setting force, making it unsuitable for a series of harsh conditions such as high formation temperature and high construction pressure.

[0039] To address the above shortcomings, embodiments of the present invention provide a composite sealing structure for a packer and a packer including the same, which will be described in detail below.

[0040] Figure 1 The diagram shown is a schematic of the packer assembly of the present invention. Figure 2 What is shown is Figure 1 A schematic diagram of the central sealing structure. Figure 3 What is shown is Figure 1 A schematic diagram of the second sealing structure. Figure 3 (a) is a half-section diagram of the second sealing structure. Figure 3 (b) and Figure 3 (c) represents two specific embodiments of the second sealing structure. Figure 4 What is shown is Figure 1 A schematic diagram of the expansion sleeve in the diagram. Figure 4 (a) is a half-sectional schematic diagram of the expansion sleeve. Figure 4 (b) is a cross-sectional view of the expansion sleeve when it is in operation. Figure 5 What is shown is Figure 1 A schematic diagram of the expansion cone structure. Figure 6 What is shown is Figure 1 A schematic diagram of the support sleeve in the middle.

[0041] Figure 1 and Figure 2 One embodiment of the packer of the present invention is shown. In this embodiment, the packer structure mainly includes a packer body 1, an expansion cone 3, an expansion sleeve 4, a first sealing element 2, a second sealing structure 5, a support sleeve 6, and a locking ring 7. The expansion cone 3 is sleeved on the packer body 1, and the inner surface of the expansion cone 3 is sealed to the packer body 1 through the first sealing element 2. The expansion sleeve 4 is connected to the conical portion of the expansion cone 3. In one embodiment, as... Figures 1 to 6 As shown, the packer body 1 is a tube with a certain wall thickness suitable for tube string structures. The outer surface of the packer body 1 is smooth and can form a seal with the expansion cone 3 and the first sealing element 2. The packer body 1 has connecting buckles at the top and bottom to connect with the tube string.

[0042] In one embodiment, such as Figure 1 and Figure 2 As shown, the packer of the present invention includes: a packer body 1, an expansion cone 3, an expansion sleeve 4, a support sleeve 6, and a locking ring 7. The expansion cone 3 is sleeved on the packer body 1 and is internally sealed to the packer body 1 via a first sealing element 2. The expansion sleeve 4 is connected to the conical portion of the expansion cone 3, and the expansion sleeve 4 is provided with a second sealing structure 5 for sealing the outer sleeve during operation. One end of the support sleeve 6 ( Figure 1 The left end of the support sleeve 6 connects to and supports one end of the expansion sleeve 4. Figure 1 The middle end is the right end of the expansion sleeve 4, and the other end is in a direction away from the expansion cone. Figure 1 The right end of the support sleeve 6 (located in the middle) is connected to the packer body 1. The locking ring 7 is fixedly connected to the support sleeve 6, locking the support sleeve 6 to the packer body 1. In the axial direction, the locking ring 7 presses the support sleeve 6 against the expansion sleeve 4, maintaining the preload.

[0043] In one embodiment, such as Figure 1 , Figure 2 and Figure 5 As shown, the expansion cone 3 is a tube with a certain taper on its outer surface. The inner surface of the expansion cone 3 is a cylindrical surface with a sealing ring groove. The first sealing element 2 is installed in the sealing ring groove of the expansion cone. In a preferred embodiment, the first sealing element 2 is an O-ring rubber sealing ring resistant to high temperature and high pressure gas.

[0044] In one embodiment, such as Figure 1 , Figure 2 and Figure 5As shown, the outer surface of the expansion cone is provided with a guide welding rib along the generatrix of the cone surface. This guide welding rib engages with the guide groove on the inner surface of the expansion sleeve 4.

[0045] In a preferred embodiment, such as Figures 1 to 6 As shown, the expansion cone 3 is made of a weldable metal material. The expansion cone 3 is a tube with a tapered outer surface and a smooth cylindrical inner surface. A sealing ring groove is designed on the inner surface of the expansion cone 3, and the first sealing element 2 is installed in the sealing ring groove. During operation, the first sealing element 2, the expansion cone 3, and the packer body 1 form a seal. The outer surface of the expansion cone 3 has guide welding ribs along the generatrix of the cone surface, which engage with guide grooves on the inner surface of the expansion sleeve 4.

[0046] In one embodiment, such as Figure 1 , Figure 2 and Figure 5 As shown, the expansion sleeve 4 is a tube made of easily expandable metal material. The outer surface of the expansion sleeve 4 is provided with two sealing ring grooves 41 and 42. The bottom and sides of the sealing ring grooves are provided with circumferential metal protrusions. The second sealing structure 5 is provided in the sealing ring grooves 41 and 42 by integral vulcanization.

[0047] In one embodiment, such as Figures 1 to 4 As shown, the expansion sleeve 4 is a metal tube made of easily expandable metal material, featuring a groove structure and a guide groove structure. The outer surface of the expansion sleeve 4 is designed with two sealing ring grooves 41 and 42, as shown... Figure 4 As shown in (b), the bottom and sides of the sealing ring groove have circumferential metal protrusions, and the second sealing structure 5 is integrally vulcanized within the sealing ring groove. The metal protrusions effectively bond the second sealing structure 5 to the expansion sleeve 4. The inner surface of the expansion sleeve 4 has a guide groove that engages with the guide welding rib of the expansion cone 3.

[0048] In one embodiment, such as Figures 1 to 4 As shown, the outer surface of the expansion sleeve 4 has an axially oriented metal protrusion 43. When the expansion sleeve 4 expands, the metal protrusion 43 first contacts the inner wall of the outer sleeve. After contact, the metal protrusion 43 is compressed and deformed, which can effectively fill the gap between the expansion sleeve 4 and the inner wall of the outer sleeve, forming a tight metal seal.

[0049] In one embodiment, such as Figures 1 to 4 As shown, in the initial state, the height of the metal protrusion 43 on the outer surface of the expansion sleeve 4 is not higher than the height of the two end protrusions and / or the middle protrusion of the second sealing structure 5. This ensures that the metal protrusion 43 can contact the inner wall of the outer sleeve first when the expansion sleeve 4 expands, and is not easily subjected to excessive wear.

[0050] In one embodiment, such as Figure 3As shown, the second sealing structure 5 is a non-circular sealing ring. The interior of the second sealing structure 5 has a groove that mates with the bottom protrusion of the sealing ring groove on the outer surface of the expansion sleeve 4, and it is vulcanized in the groove on the outer surface of the expansion sleeve 4 by direct vulcanization of rubber. The outer surface of the second sealing structure 5 has protrusions at both ends and / or a middle protrusion depending on the operating conditions. (Refer to...) Figure 3 (a) and Figure 3 (b)

[0051] In one embodiment, such as Figure 3 As shown, the protrusions at both ends and / or the middle protrusion of the second sealing structure 5 are internally embedded with compressible springs. When the rubber of the second sealing structure 5 is compressed and sealed, the embedded springs can improve the resilience of the rubber material and prevent axial flow due to over-compression, as is the case with a simple rubber seal.

[0052] In one embodiment, such as Figures 1 to 6 As shown, the expansion cone 3 can move axially along the packer body 1, causing the expansion sleeve 4 to expand radially. The inner wall of the expansion sleeve 4 is a tapered surface (the taper is the same as that of the expansion cone 3), and a guide groove is designed on the tapered surface along the generatrix of the taper. The groove acts as a guide, preventing the expansion sleeve 4 from rotating circumferentially when the expansion cone 3 moves axially. Furthermore, the groove depth gradually changes, causing the expansion cone 3 and the expansion sleeve 4 to become increasingly tightly pressed together. When the expansion sleeve 4 contacts the outer sleeve, continued pressure causes the guide ribs on the outer surface of the expansion cone 3 to undergo a cold-press welding effect with the grooves of the expansion sleeve 4, achieving metal-to-metal bonding between the expansion cone 3 and the expansion sleeve 4, forming a seal.

[0053] In one embodiment, such as Figures 1 to 6 As shown, the support sleeve 6 is made of high-performance spring steel. A curved groove is provided at one end of the support sleeve 6 near the expansion sleeve 4. This groove is inserted into the expansion sleeve 4 from bottom to top and supports the expansion sleeve 4. The other end of the support sleeve 6 is fixedly connected to the packer body 1 by means of threads or other methods.

[0054] In one embodiment, such as Figures 1 to 6 As shown, when the expansion cone 3 pushes the expansion sleeve 4 to set, the expansion sleeve 4 transmits axial force to the support sleeve 6, which can deform to store energy. After the expansion is completed, the stored energy of the support sleeve 6 is transmitted in reverse to the expansion sleeve 4, ensuring that the expansion sleeve 4 is continuously compressed.

[0055] In one embodiment, such as Figures 1 to 6 As shown, the second sealing structure 5 is made of a special high-temperature resistant fluororubber and a metal spring, which can withstand high-temperature and high-pressure gas of up to 204℃ and 70MPa.

[0056] In a preferred embodiment, such as Figure 1 and Figure 2As shown, the left end of the packer body 1 is connected to the upper end of the tube string, and the right end is connected to the lower end of the tube string. The expansion cone 3 descends under the action of the upper mechanical force. The expansion cone 3 is designed with a taper. During the descent, the outer surface of the expansion cone 3 contacts the inner surface of the expansion sleeve 4, causing the outer diameter of the expansion sleeve 4 to expand until it contacts the inner wall of the sleeve. As it continues to press down, the guide ribs of the expansion cone 3 engage with the guide grooves of the expansion sleeve 4, becoming increasingly tighter, causing the guide grooves of the expansion sleeve 4 to deform and the oxide film on the surface to rupture. The expansion cone 3 and the expansion sleeve 4 then come into pure metal contact with each other, forming a strong metal bond. The second sealing structure 5 has a metal spring embedded inside, which effectively prevents the rubber from being damaged by excessive compression. Figure 3 As shown. The expansion sleeve 4 has metal protrusions designed on its external sealing ring grooves 41 and 42. The second sealing structure 5 is directly and integrally vulcanized within the sealing ring grooves 41 and 42. The metal protrusions within the sealing ring grooves 41 and 42 increase the contact area between the metal and the rubber, effectively fixing the rubber sealing ring within the groove and preventing the sealing ring from being eroded away during the packer's insertion into the well. Figure 4 As shown. The expansion cone 3 is a tube with an external tapered surface. Six welded metal guide ribs are designed on the tapered surface along the generatrix direction, as shown... Figure 5 As shown, the support sleeve 6 is fixedly connected to the packer body 1 via the locking ring 7. When the expansion cone 3 descends to seal the packer, the support sleeve 6 deforms, thus storing energy. After the sealing process is complete, the support sleeve 6 provides a continuous reverse force to the expansion sleeve 4, ensuring the sealing effect.

[0057] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and / or modifications falling within the scope of the invention, and all changes and / or modifications made according to embodiments of the invention should be covered within the protection scope of the invention.

Claims

1. A packer, characterized in that, include: Packer body; An expansion cone is fitted onto the packer body and is internally sealed to the packer body via a first sealing element. An expansion sleeve is connected to the conical part of an expansion cone, and the expansion sleeve is provided with a second sealing structure that seals the connection to the outer sleeve during operation. A support sleeve, one end of which is connected to and supports one end of the expansion sleeve, and the other end is connected to the packer body in a direction away from the expansion cone; The locking ring is fixedly connected to the support sleeve, locking the support sleeve to the packer body. The expansion sleeve is a tube made of easily expandable metal material. The outer surface of the expansion sleeve has two sealing grooves. The bottom and sides of the sealing grooves have circumferential metal protrusions. The second sealing structure is integrally vulcanized within the sealing grooves. The outer surface of the expansion sleeve is provided with several axially arranged metal protrusions. When the expansion sleeve expands, these metal protrusions first come into contact with the inside of the outer sleeve and are then compressed and deformed, thereby forming a metal seal between the expansion sleeve and the outer sleeve. The outer surface of the second sealing structure is provided with protrusions at both ends and a middle protrusion according to the working conditions. In the initial state, the height of the metal protrusions on the outer surface of the expansion sleeve is not higher than the height of the protrusions at both ends and the middle protrusion of the second sealing structure. The protrusions at both ends and the middle protrusion embed compressible springs inside, thereby improving the elasticity of the rubber material and preventing the rubber from being over-compressed and causing axial flow when the rubber of the second sealing structure is compressed and sealed. The outer surface of the expansion cone is provided with guide welding ribs along the generatrix of the cone surface. The guide welding ribs engage with the guide grooves on the inner surface of the expansion sleeve. The depth of the guide grooves gradually changes, so that the expansion cone and the expansion sleeve are pressed tighter and tighter. When the expansion sleeve contacts the outer sleeve, pressure is continued to be applied, and the guide welding ribs on the outer surface of the expansion cone and the guide grooves on the expansion sleeve produce a cold pressure welding effect, realizing the metal bonding between the expansion cone and the expansion sleeve to form a seal.

2. The packer according to claim 1, characterized in that, The expansion cone is a tube with a certain taper on its outer surface and a cylindrical surface with a sealing ring groove on its inner surface. The first sealing element is installed in the sealing ring groove of the expansion cone.

3. The packer according to claim 1 or 2, characterized in that, The second sealing structure is a special-shaped sealing ring. The interior of the second sealing structure has a groove that matches the bottom protrusion of the sealing ring groove on the outer surface of the expansion sleeve, and it is vulcanized in the groove on the outer surface of the expansion sleeve by direct vulcanization of rubber.

4. The packer according to claim 1, characterized in that, The support sleeve is made of high-performance spring steel. One end of the support sleeve near the expansion sleeve has a curved groove, which is embedded in the expansion sleeve to support it. The other end of the support sleeve is fixedly connected to the packer body.

5. The packer according to claim 4, characterized in that, When the expansion cone pushes the expansion sleeve to set, the expansion sleeve transmits axial force to the support sleeve, which can deform to store energy; after the expansion is completed, the energy stored in the support sleeve is transmitted back to the expansion sleeve to ensure that the expansion sleeve is continuously compressed.

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