Reducing expansion cone assembly

Abstract

The utility model discloses a reducing expansion cone assembly which comprises a conical center pipe, an upper cone block, a lower cone block and a rubber sleeve. A plurality of dovetail groove conical guide rails are arranged on the conical surface of the conical center pipe, dovetail bosses matched with the dovetail groove conical guide rails are arranged on the inner surfaces of the upper conical blocks and the inner surfaces of the lower conical blocks respectively, and the adjacent upper conical blocks and the adjacent lower conical blocks are arranged at intervals and can slide up and down along the dovetail bosses. When the upper conical block and the lower conical block slide to the large end of the conical center pipe, the rubber barrel is compressed in the direction of the small end of the conical center pipe, the outer side walls of the upper conical block and the lower conical block abut against the rubber barrel, and the upper conical block and the lower conical block are matched to form a closed annular space structure. The dovetail groove conical guide rail is arranged on the conical surface of the conical central tube, and the dovetail bosses matched with the dovetail groove conical guide rail are arranged on the inner surfaces of the upper conical block and the lower conical block, so that the upper conical block and the lower conical block can smoothly slide along a specific direction, and when the conical blocks slide to the end part of the large end of the conical central tube, a rubber sleeve can be effectively compressed; and meanwhile, the upper conical block and the lower conical block are matched to form a closed annular space structure, so that the assembly has the dual functions of reducing and sealing and can be applied to pipeline expansion connection and other scenes needing sealing and pipe diameter changing.

Description

Technical Field

[0001] This utility model relates to the field of downhole tools technology in petroleum engineering, and specifically to a variable diameter expansion cone assembly. Background Technology

[0002] Expandable tubing patching technology emerged in the late 1980s, primarily used for repairing damaged or lost casing, plugging perforated sections of casing, completing sidetracked wells with expanded tubing, and sealing complex formations in wells. However, during expanded tubing installation, problems frequently arise, such as small well diameters where the expanded tubing cannot be lowered due to excessively large outer diameters of the firing chamber. Other issues include difficulty in the expansion cone's travel or jamming at certain points. These problems are mostly caused by casing inner wall deformation, corrosion, sediment buildup, or complex wellbore passages due to external forces, especially prevalent in horizontal wells. When the expansion cone cannot be retrieved due to travel difficulties, the common practice is to use a safety connector to detach the cone, leaving it inside the wellbore for subsequent drilling teams to clean or retrieve the trapped material. This not only increases the workload for the drilling teams but also makes cleaning and retrieving the trapped material difficult, potentially leading to well abandonment. This has negatively impacted the widespread adoption of expanded tubing patching. Therefore, in the face of this problem, we urgently need a variable diameter expansion cone that can reduce the diameter of the expansion cone when difficulties or jamming occur during the expansion of the expansion tube, thereby reducing the problem of the expansion cone jamming and enabling subsequent expansion tube patching to continue smoothly. Utility Model Content

[0003] Therefore, this utility model provides a variable diameter expansion cone assembly to solve the above-mentioned problems in the prior art.

[0004] To achieve the above objectives, this utility model provides the following technical solution:

[0005] According to a first aspect of the present invention, a variable diameter expansion cone assembly includes a conical central tube, an upper cone block, a lower cone block, and a rubber sleeve.

[0006] The conical surface of the conical central tube is provided with multiple dovetail conical guide rails, and the guiding direction of the dovetail conical guide rails is the same as that of the generatrix of the conical central tube.

[0007] The inner surfaces of the upper and lower conical blocks are respectively provided with dovetail bosses that mate with the dovetail groove conical guide rail. Adjacent upper and lower conical blocks are spaced apart and can slide up and down along the dovetail bosses.

[0008] The rubber sleeve is installed at the large end of the conical central tube. When the upper and lower conical blocks slide to the large end of the conical central tube, the rubber sleeve is compressed along the small end of the conical central tube. The outer walls of the upper and lower conical blocks abut against the rubber sleeve, and the upper and lower conical blocks fit together to form a closed annular space structure.

[0009] Furthermore, three upper and three lower cone blocks are provided, evenly distributed circumferentially on the surface of the conical central tube.

[0010] Furthermore, the included angle between any two adjacent upper cone blocks is 120°, and the included angle between any two adjacent lower cone blocks is 120°.

[0011] Furthermore, the cross-sections of the upper and lower cones are both isosceles trapezoids, the large end sidewall of the upper cone abuts against the small end sidewall of the lower cone, and the small end sidewall of the upper cone abuts against the large end sidewall of the lower cone.

[0012] Furthermore, the rubber sleeve and the conical central tube are coaxially arranged.

[0013] Furthermore, the dovetail groove conical guide rail has a cone angle of 15° to 60°, and the upper and lower cone blocks are machined from a single cone with equal division angles of 5° to 75°.

[0014] Furthermore, it also includes expansion tubes, aluminum alloy bottom plugs, variable thread short sections, and pull-out pins;

[0015] The expansion tube has an internal thread at its bottom, and the aluminum alloy bottom plug has an external thread on its outer wall. The aluminum alloy bottom plug and the expansion tube are connected by the external thread and the internal thread. The bottom of the aluminum alloy bottom plug has a pull-out pin countersunk hole.

[0016] The small end of the tapered central tube is connected to the oil pipe via the variable threaded section and then inserted into the expansion tube. One end of the pull-out pin is fixed in the countersunk hole of the pull-out pin, and the other end of the pull-out pin is connected to the large end of the tapered central tube.

[0017] This utility model has the following advantages: By setting a dovetail groove conical guide rail on the conical surface of the conical central tube, and dovetail bosses that cooperate with the inner surfaces of the upper and lower conical blocks, the upper and lower conical blocks can be smoothly slid along a specific direction. When the conical blocks slide to the large end of the conical central tube, the rubber cylinder can be effectively compressed. At the same time, the upper and lower conical blocks fit together to form a closed annular space structure, so that the component has the dual functions of diameter change and sealing. It can be applied to scenarios that require sealing and pipe diameter change, such as pipe expansion connection. Attached Figure Description

[0018] To more clearly illustrate the embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0019] The structures, proportions, sizes, etc. illustrated in this specification are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed herein, and are not intended to limit the implementation conditions of this utility model. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size, without affecting the effects and objectives that this utility model can produce, should still fall within the scope of the technical content disclosed in this utility model.

[0020] Figure 1 This is a schematic diagram of the contracted state of a variable diameter expansion cone assembly provided for some embodiments of the present invention.

[0021] Figure 2 This is a schematic diagram of the expansion state of a variable diameter expansion cone assembly provided for some embodiments of the present invention.

[0022] Figure 3 This is a schematic diagram of the right side of a variable diameter expansion cone assembly provided for some embodiments of the present invention.

[0023] Figure 4 A variable diameter expansion cone assembly is provided for some embodiments of this utility model. Figure 3 The sectional view of AA in the diagram.

[0024] Figure 5 This is a schematic diagram of the upper cone block of a variable diameter expansion cone assembly provided in some embodiments of the present invention.

[0025] Figure 6 This is a schematic diagram of the unexpanded state of the variable diameter expansion cone assembly and its diameter contraction, provided for some embodiments of this utility model.

[0026] Figure 7 This is a schematic diagram showing the starting expansion state of a variable diameter expansion cone assembly, as provided in some embodiments of the present invention, where the expansion cone is expanding in a variable diameter manner.

[0027] Figure 8 This is a schematic diagram showing the completed expansion state of a variable diameter expansion cone assembly provided for some embodiments of the present invention.

[0028] In the picture:

[0029] 1. Tapered center tube; 11. Dovetail groove conical guide rail; 2. Upper cone block; 21. Dovetail boss; 3. Lower cone block; 4. Rubber sleeve; 5. Expansion tube; 6. Aluminum alloy bottom plug; 61. Pull-out pin countersunk hole; 7. Variable thread short section; 8. Pull-out pin. Detailed Implementation

[0030] The following specific embodiments illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0031] like Figures 1 to 8 As shown, a variable-diameter expansion cone assembly in the first aspect embodiment of this utility model comprises a conical central tube 1, an upper conical block 2, a lower conical block 3, and a rubber sleeve 4. The upper conical block 2 and the lower conical block 3 are machined from a single cone in equal sections, with the equal section cutting angle typically ranging from 5° to 75°. Multiple dovetail groove conical guide rails 11 are provided on the conical surface of the conical central tube 1. The cone angle of the dovetail groove conical guide rails 11 is typically from 15° to 60°. The guiding direction of the dovetail groove conical guide rails 11 is the same as the generatrix direction of the conical central tube 1, ensuring that the upper conical block 2 and the lower conical block 3 can slide stably and smoothly along the predetermined direction, avoiding deviation or jamming. The conical central tube 1, the upper conical block 2, and the lower conical block 3 are typically made of hard alloy material.

[0032] Three upper conical blocks 2 and three lower conical blocks 3 are evenly distributed circumferentially on the surface of the conical central tube 1. The included angle between any two adjacent upper conical blocks 2 is 120°, and the included angle between any two adjacent lower conical blocks 3 is 120°. This quantity and distribution ensures uniform force on the component in the circumferential direction, guaranteeing compression of the rubber sleeve 4 and the stability of the overall structure during the diameter change process. Dovetail bosses 21, which mate with the dovetail groove conical guide rail 11, are respectively provided on the inner surfaces of the upper conical blocks 2 and lower conical blocks 3. Adjacent upper conical blocks 2 and adjacent lower conical blocks 3 are spaced apart and can slide up and down along the dovetail bosses 21 to achieve the purpose of diameter change.

[0033] The rubber sleeve 4 is installed at the large end of the conical central tube 1, and the rubber sleeve 4 and the conical central tube 1 are coaxially arranged. When the upper conical block 2 and the lower conical block 3 slide to the large end of the conical central tube 1, the rubber sleeve 4 is compressed along the small end of the conical central tube 1. The outer walls of the upper conical block 2 and the lower conical block 3 abut against the rubber sleeve 4, and the upper conical block 2 and the lower conical block 3 fit together to form a closed annular space structure.

[0034] Before operation begins, the upper cone 2 and lower cone 3 are positioned near the small end of the conical central tube 1. At this point, the overall outer diameter formed by the upper cone 2 and lower cone 3 is relatively small, allowing the expansion cone assembly to easily pass through areas in the wellbore with small inner diameters or where deformation or sedimentation occurs, thus solving the problem of difficulty in lowering the expansion tube. Once the expansion cone assembly reaches the target position where the patching operation is required, external force is applied (usually through a device connected to the tubing to apply tension or thrust), causing the upper cone 2 and lower cone 3 to slide along the dovetail conical guide rail 11 towards the large end of the conical central tube 1. As the upper cone 2 and lower cone 3 gradually slide towards the large end of the conical central tube 1, since the conical central tube 1 is conical in shape and its outer diameter gradually decreases from the large end to the small end, the overall outer diameter formed by the upper cone 2 and lower cone 3 will also gradually increase, thus achieving a variable diameter effect. When the upper cone 2 and lower cone 3 slide to the large end of the conical central tube 1, they compress the rubber sleeve 4 installed at the large end along the direction of the small end of the conical central tube 1. Simultaneously, the outer walls of the upper cone 2 and lower cone 3 abut against the rubber sleeve 4, and the upper cone 2 and lower cone 3 fit together to form a sealed annular space structure. The rubber sleeve 4 deforms after compression, filling the gap between the upper cone 2, lower cone 3, and the surrounding sleeve, providing a good seal and preventing leakage during subsequent patching operations. The sealed annular space structure formed by the fit of the upper cone 2 and lower cone 3 enhances the stability of the entire expansion cone assembly, enabling it to better withstand various forces generated during operation and ensuring the smooth progress of diameter reduction and patching operations.

[0035] In summary, through the sliding of the upper cone block 2 and the lower cone block 3 on the conical central tube 1, and the sealing cooperation of the rubber sleeve 4, this variable diameter expansion cone assembly can effectively realize the variable diameter function, adapt to wellbore environments with different inner diameters, and solve many problems in the workover of subsidy wells.

[0036] Optionally, the cross-sections of the upper cone 2 and the lower cone 3 are both isosceles trapezoids. The large end sidewall of the upper cone 2 abuts against the small end sidewall of the lower cone 3, and the small end sidewall of the upper cone 2 abuts against the large end sidewall of the lower cone 3, so that the upper and lower cones can fit tightly when they are engaged, thereby enhancing the sealing of the formed closed annular space.

[0037] The bottom of the expansion tube 5 is machined with internal threads, and the outer wall of the aluminum alloy bottom plug 6 is machined with external threads. The aluminum alloy bottom plug 6 is connected to the bottom of the expansion tube 5 by threads. The bottom of the aluminum alloy bottom plug 6 is provided with a pull-out pin countersunk hole 61. The small end of the tapered center tube 1 is connected to the tubing through the variable thread short section 7 and then inserted into the expansion tube 5. One end of the pull-out pin 8 is fixed in the pull-out pin countersunk hole 61, and the other end of the pull-out pin 8 is connected to the large end of the tapered center tube 1. At this time, the expansion tube 5 and the variable diameter expansion cone assembly are in an integral fixed state. After the expansion tube 5 is lowered into the well and fixed in the working position through the tubing, the tubing is pressurized, and the pull-out pin 8 is pulled off under the action of hydraulic pressure. At this time, the expansion tube 5 and the aluminum alloy bottom plug 6 are separated from the variable diameter expansion cone assembly. Under the action of hydraulic pressure and lifting force, the upper and lower cone blocks of the variable diameter expansion cone assembly merge on the dovetail groove conical guide rail 11 to expand the expansion tube. Continuous pressurization makes the entire expansion tube fully expand. To ensure expansion quality, the pump displacement should be adjusted in real time, and the pressurization pressure should be stabilized within the range of 30±5 MPa. After expansion is complete, the oil pipe and the variable diameter expansion cone assembly should be removed. Then, a milling cone or grinding shoe should be lowered to mill the unexpanded tail section of the expansion tube and the aluminum alloy bottom plug, completing all expansion tube operations. If the variable diameter expansion cone assembly gets stuck in expansion tube 5 and cannot expand, the pipe string should be frequently lowered and raised to vibrate the variable diameter expansion cone and slowly remove it. Then, the expansion tube should be retrieved or other remedial operations should be carried out.

[0038] Although the present invention has been described in detail above with general descriptions and specific embodiments, some modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

[0039] The terms such as "upper," "lower," "left," "right," and "middle" used in this specification are merely for clarity of description and are not intended to limit the scope of implementation of this utility model. Any changes or adjustments to their relative relationships, without substantially altering the technical content, shall also be considered within the scope of implementation of this utility model.

Claims

1. A variable diameter expansion cone assembly, characterized in that, It includes a conical central tube (1), an upper conical block (2), a lower conical block (3), and a rubber sleeve (4); The conical surface of the conical central tube (1) is provided with a plurality of dovetail conical guide rails (11), and the guiding direction of the dovetail conical guide rails (11) is the same as that of the generatrix of the conical central tube (1). The inner surfaces of the upper cone block (2) and the lower cone block (3) are respectively provided with dovetail bosses (21) that cooperate with the dovetail groove conical guide rail (11). Adjacent upper cone blocks (2) and adjacent lower cone blocks (3) are spaced apart and can slide up and down along the dovetail bosses (21). The rubber sleeve (4) is installed at the large end of the conical central tube (1). When the upper conical block (2) and the lower conical block (3) slide to the large end of the conical central tube (1), the rubber sleeve (4) is compressed along the small end of the conical central tube (1). The outer walls of the upper conical block (2) and the lower conical block (3) abut against the rubber sleeve (4), and the upper conical block (2) and the lower conical block (3) fit together to form a closed annular space structure.

2. The variable diameter expansion cone assembly according to claim 1, characterized in that, Three upper cone blocks (2) and three lower cone blocks (3) are provided, and they are evenly distributed along the circumference on the surface of the conical central tube (1).

3. The variable diameter expansion cone assembly according to claim 2, characterized in that, The included angle between any two adjacent upper cone blocks (2) is 120°, and the included angle between any two adjacent lower cone blocks (3) is 120°.

4. The variable diameter expansion cone assembly according to claim 1, characterized in that, The cross-sections of the upper cone (2) and the lower cone (3) are both isosceles trapezoids. The large end sidewall of the upper cone (2) and the small end sidewall of the lower cone (3) abut against each other. The small end sidewall of the upper cone (2) and the large end sidewall of the lower cone (3) abut against each other.

5. A variable diameter expansion cone assembly according to claim 1, characterized in that, The rubber sleeve (4) and the conical central tube (1) are coaxially arranged.

6. A variable diameter expansion cone assembly according to claim 1, characterized in that, The dovetail groove conical guide rail (11) has a cone angle of 15° to 60°. The upper cone block (2) and the lower cone block (3) are made by equally dividing the whole cone, with an equally divided cutting angle of 5° to 75°.

7. A variable diameter expansion cone assembly according to claim 1, characterized in that, It also includes an expansion tube (5), an aluminum alloy bottom plug (6), a variable threaded short section (7), and a pull-out pin (8); The bottom of the expansion tube (5) is provided with an internal thread, and the outer wall of the aluminum alloy bottom plug (6) is provided with an external thread. The aluminum alloy bottom plug (6) and the expansion tube (5) are connected by the external thread and the internal thread. The bottom of the aluminum alloy bottom plug (6) is provided with a pull-out pin countersunk hole (61). The small end of the tapered central tube (1) is connected to the oil pipe via the variable threaded short section (7) and then inserted into the expansion tube (5). One end of the pull-out pin (8) is fixed in the pull-out pin countersunk hole (61), and the other end of the pull-out pin (8) is connected to the large end of the tapered central tube (1).

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