Short rubber sleeve liquid-encountering self-expanding packer

Abstract

The utility model relates to the field of oil industry production engineering, disclose a short rubber tube liquid self -expanding packer. Including the central pipe, the upper joint is connected to the central pipe upper end, the outer wall of central pipe is sleeved with packer seal self -expanding rubber tube, the packer seal self -expanding rubber tube includes the skin bowl, the water -swelling rubber tube and the cone that are sequentially sleeved on the outer wall of central pipe, the upper joint is connected with the skin bowl, be provided with the unsealing peg on the cone. The utility model forms the initial sealing barrier when the skin bowl is tightly attached to the well wall under the pressure, the volume expansion after the water -swelling rubber tube meets the liquid, fills the possible fine gap between the skin bowl and the well wall, forms double seal with the skin bowl, the maximum radial expansion of rubber is obtained in the combination of both, thereby guarantees the effective expansion sealing effect under the minimum rubber tube length, the sealing performance of packer is improved significantly, reduces the abnormal situation of setting because of the unreasonable structure, simplifies the operation process.

Description

Technical Field

[0001] This utility model relates to the field of oil production engineering in the petroleum industry, specifically to a short rubber tube self-expanding packer when it comes into contact with liquid. Background Technology

[0002] In oilfield exploration and development, oil and gas wells often contain multiple layers with significant differences in properties. Layered testing is essential for better understanding the characteristics of each layer. Furthermore, layered fracturing and acidizing are frequently performed in production enhancement and injection measures. Packers are indispensable in all these measures. In recent years, low-permeability unconventional oil and gas resources have accounted for 70% of newly discovered oil and gas reserves in my country, becoming the main battleground for oil and gas field development. Multi-layered well production and horizontal well production technologies have become the primary oil production techniques for these reservoirs. During development, production profile testing and segmented production capacity evaluation play an increasingly important role in dynamic reservoir monitoring, providing a basis for rational reservoir development and measures. This has received widespread attention from geological and development departments. Packer sealing is a widely used technique and a key aspect of the development of these technologies.

[0003] Currently, in the process of segmented production of oil wells, conventional expander and compression packers are used for packing operations. However, due to the inherent structure of the packers, the on-site implementation process is complex, prone to premature setting or even failure to set, and most packers cannot be used in multiple stages. Existing self-sealing packers are simple to operate, highly reliable, and have no mechanical moving parts like traditional packers, making them easy to run in and safe to operate. However, in field use, long rubber sleeves are mostly used to ensure sealing pressure resistance, limiting the number of stages that can be combined. Furthermore, if irregular wellbore or scale buildup on the inner wall of the casing is encountered during the tubing string pulling process, the unsealing load is high, which can easily lead to stuck well accidents. Utility Model Content

[0004] The purpose of this invention is to provide a short rubber sleeve self-expanding packer that overcomes the shortcomings of existing technologies, which mostly use long rubber sleeves to ensure sealing and pressure resistance, resulting in limited number of combination stages, and the large unsealing load that can easily cause stuck well accidents if irregular wellbore or scale buildup on the inner wall of the casing is encountered during the stringing process.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A short rubber tube self-expanding packer includes a central tube with an upper connector at the upper end. A packer sealing self-expanding rubber tube is sleeved on the outer wall of the central tube. The packer sealing self-expanding rubber tube includes a cup, a water-expanding rubber tube, and a cone sequentially sleeved on the outer wall of the central tube. The upper connector is connected to the cup, and an unsealing pin is provided on the cone.

[0007] Furthermore, the upper connector is threaded to the upper end of the central tube, and eight fastening screws are radially evenly distributed on the upper connector.

[0008] Furthermore, the fastening screw is a hexagonal tapered set screw, and the hexagonal tapered end of the fastening screw is in close contact with the mating surfaces of the upper connector and the central tube.

[0009] Furthermore, the cup, the water-swellable rubber sleeve, the cone, and the central tube are fitted with a clearance fit.

[0010] Furthermore, the outer wall of the central tube is provided with an annular limiting groove, and the inner walls of the cup, the water-swellable rubber tube, and the cone are provided with annular protrusions that cooperate with the annular limiting groove.

[0011] Furthermore, the cone has a frustum-shaped structure, and the cone surface of the cone is attached to the end of the water-swellable rubber tube.

[0012] Furthermore, the lower end face of the upper connector is provided with a positioning boss, and the upper end face of the leather cup is provided with a positioning groove that mates with the positioning boss.

[0013] Furthermore, the central tube is provided with a pin hole, and the unsealing pin penetrates the cone and engages with the pin hole on the central tube.

[0014] Furthermore, the leather cup is made of rubber.

[0015] Furthermore, the upper connector, central tube, and cone are all made of alloy steel.

[0016] Compared with the prior art, the present invention has the following beneficial technical effects:

[0017] This utility model provides a short rubber tube self-expanding packer. The packer, which is sealed on the outer wall of the central tube, includes a cup, a water-expanding rubber tube, and a cone. The cup can tightly fit against the well wall under pressure, forming an initial sealing barrier and providing preliminary obstruction of the fluid. The water-expanding rubber tube expands in volume upon contact with the liquid, filling any tiny gaps that may exist between the cup and the well wall, forming a double seal. The combination of these two elements maximizes the radial expansion of the rubber while keeping the tube length as short as possible, thus ensuring an effective expansion and sealing effect with the minimum tube length. This significantly improves the sealing performance of the packer, reduces abnormal setting conditions caused by unreasonable structure, and simplifies the operation process.

[0018] Specifically, this invention employs a packer consisting of a cup, a water-swellable rubber sleeve, and a cone to seal the self-expanding rubber sleeve, effectively shortening the sleeve length, reducing limitations on the number of assembly stages, and improving the packer's applicability in multi-layer systems. In this invention, the release pin on the cone engages with the pin hole on the central tube. During release, external force is applied to break the release pin, thus separating the cone from the central tube. This simplifies operation, reduces the difficulty of release, and minimizes the risk of stuck well accidents due to high release loads. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of a short rubber tube self-expanding packer in an embodiment of this utility model.

[0020] In the diagram: 1. Upper connector; 2. Fastening screw; 3. Leather cup; 4. Water-swellable rubber sleeve; 5. Cone; 6. Unsealing pin; 7. Central tube. Detailed Implementation

[0021] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of this invention. Therefore, the drawings and description are considered exemplary in nature and not restrictive.

[0022] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", 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 this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0023] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0024] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0025] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0026] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0027] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the scope of the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0028] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0029] The accompanying drawings show various structural schematic diagrams according to embodiments of the present invention. These drawings are not to scale, and some details have been enlarged and may have been omitted for clarity. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.

[0030] See Figure 1 This utility model provides a short rubber tube self-expanding packer that comes into contact with liquid, including an upper connector 1, a fastening screw 2, a packer sealing self-expanding rubber tube, an unsealing pin 6, and a central tube 7.

[0031] The upper end of the central tube 7 is threaded to the upper connector 1. The upper connector 1 has eight fastening screws 2 evenly distributed radially. The fastening screws 2 are internal hexagonal cone end set screws. The internal hexagonal cone end of the fastening screw 2 is in close contact with the mating surface of the upper connector 1 and the central tube 7, and is used to anchor the upper connector 1.

[0032] A packer sealing self-expanding rubber sleeve is fitted on the outer wall of the central tube 7. The packer sealing self-expanding rubber sleeve includes a cup 3, a water-swellable rubber sleeve 4 and a cone 5, which are sequentially fitted on the outer wall of the central tube 7. The cup 3, the water-swellable rubber sleeve 4 and the cone 5 are fitted with the central tube 7 with a clearance fit, which facilitates installation and disassembly.

[0033] The water-swellable rubber sleeve 4 uses rubber as the base material, with 70% by weight of water-absorbing polymers, carbon black, and other reinforcing materials added. A compound is prepared using a physical-mechanical blending method, and then vulcanized to obtain the water-swellable rubber. The water-swellable rubber sleeve 4 expands upon contact with water. The cup 3 is made of ordinary rubber and expands outwards under the longitudinal deformation and compression caused by the self-expansion of the water-swellable rubber sleeve 4 to seal the annulus of the oil sleeve.

[0034] The upper connector 1 is connected to the cup 3. The cone 5 is provided with a release pin 6. The release pin 6 is set with a specific shear load. When the rubber sleeve gets stuck due to deformation or scaling of the well casing, and the tonnage of the lifting string increases to the set shear load, the release pin 6 is sheared, the cone 5 moves downward, and the water-swellable rubber sleeve 4 and the cup 3 are released and radially contracted under their own rebound force.

[0035] In some preferred embodiments of this utility model, the outer wall of the central tube 7 is provided with an annular limiting groove, and the inner walls of the cup 3, the water-swellable rubber tube 4 and the cone 5 are provided with annular protrusions that cooperate with the annular limiting groove to limit the axial position of each component.

[0036] In some preferred embodiments of this utility model, the lower end face of the upper connector 1 is provided with a positioning boss, and the upper end face of the leather cup 3 is provided with a positioning groove that cooperates with the positioning boss, so as to realize the precise positioning connection between the upper connector 1 and the leather cup 3.

[0037] In some preferred embodiments of this utility model, a pin hole is provided on the central tube 7, and the unsealing pin 6 penetrates the cone 5 and engages with the pin hole on the central tube 7.

[0038] In some preferred embodiments of this utility model, the upper connector 1, the central tube 7, and the cone 5 are all made of alloy steel, which has good mechanical strength and corrosion resistance.

[0039] During operation, the short rubber sleeve self-expanding packer is assembled and inserted into the well according to the sealing requirements. When the short rubber sleeve self-expanding packer comes into contact with the well fluid, it absorbs water and expands upon contact with water. Under longitudinal deformation and compression, it expands to seal the annulus of the casing and simultaneously compresses the cup 3 for double sealing. When pulling out the well, the tubing string is lifted. If the rubber sleeve gets stuck due to deformation or scaling of the well casing, the lifting tonnage of the tubing string increases to a certain extent, the unsealing pin 6 is sheared, the cone 5 moves down, and the water-expanding rubber sleeve 4 and the cup 3 release under their own rebound force and contract radially to ensure safe retrieval.

[0040] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A short rubber tube self-expanding packer upon contact with liquid, characterized in that, It includes a central tube (7), the upper end of which is connected to an upper connector (1). A packer sealing self-expanding rubber sleeve is fitted on the outer wall of the central tube (7). The packer sealing self-expanding rubber sleeve includes a cup (3), a water-expanding rubber sleeve (4), and a cone (5) sequentially fitted on the outer wall of the central tube (7). The upper connector (1) is connected to the cup (3), and an unsealing pin (6) is provided on the cone (5).

2. The short rubber tube self-expanding packer according to claim 1, characterized in that, The upper connector (1) is threaded to the upper end of the central tube (7), and the upper connector (1) has eight fastening screws (2) evenly distributed radially.

3. The short rubber tube self-expanding packer according to claim 2, characterized in that, The fastening screw (2) is an internal hexagonal cone-shaped set screw, and the internal hexagonal cone end of the fastening screw (2) is in close contact with the mating surfaces of the upper connector (1) and the central tube (7).

4. A short rubber tube self-expanding packer according to claim 3, characterized in that, The cup (3), the water-swellable rubber tube (4), the cone (5), and the central tube (7) are fitted with a clearance.

5. A short rubber tube self-expanding packer according to claim 4, characterized in that, The outer wall of the central tube (7) is provided with an annular limiting groove, and the inner walls of the leather cup (3), the water-swellable rubber tube (4) and the cone (5) are provided with annular protrusions that cooperate with the annular limiting groove.

6. A short rubber tube self-expanding packer according to claim 5, characterized in that, The cone (5) is a frustum-shaped structure, and the cone surface of the cone (5) is attached to the end of the water-swellable rubber tube (4).

7. A short rubber tube self-expanding packer according to claim 6, characterized in that, The lower end face of the upper connector (1) is provided with a positioning boss, and the upper end face of the leather cup (3) is provided with a positioning groove that cooperates with the positioning boss.

8. A short rubber tube self-expanding packer according to claim 7, characterized in that, The central tube (7) is provided with a pin hole, and the unsealing pin (6) penetrates the cone (5) and engages with the pin hole on the central tube (7).

9. A short rubber tube self-expanding packer according to claim 8, characterized in that, The leather cup (3) is made of rubber.

10. A short rubber tube self-expanding packer according to claim 9, characterized in that, The upper connector (1), the central tube (7), and the cone (5) are all made of alloy steel.

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