Slip type underground plugging tool capable of preventing setting deviation

Abstract

The utility model relates to a slip type underground plugging tool capable of preventing setting deviation, which comprises a base, a central pipe and a conical seat, a slip is arranged between the base and the conical seat, the slip is arranged outside the central pipe, one end of the central pipe is connected with the base, and the other end of the central pipe is connected with the conical seat. Weakening grooves facilitating opening of the slip are formed in the circumference of the slip at intervals, the weakening grooves are alternately formed in two opening directions facing the conical seat and the base respectively, and lateral fasteners are arranged in the weakening grooves with the openings facing the base. It can be ensured that the slips are stressed to move in the specific direction, and the percent of pass of well entering setting is greatly increased.

Description

Technical Field

[0001] This application relates to a downhole plugging tool, and more particularly to a slip-type downhole plugging tool that can prevent setting deviation. Background Technology

[0002] Downhole plugging tools are widely used in oilfield exploration and development to seal the lower sections of oil and water wells during stratified fracturing, acidizing, and testing. Common downhole plugging tools include bridge plugs and packers. During installation, they are delivered to the designated location in the wellbore using a cable or tubing string. Pressure generated by explosive detonation, hydraulic setting, or mechanical setting applies to the slips, while tension acts on the tension rod. The upper and lower cones apply both upward and downward pressure to the sealing sleeve. When the tension reaches a certain value, the tension rod breaks, and the setting tool disengages from the downhole plugging tool. At this point, the locking device on the center tube of the downhole plugging tool activates, the slips break and embed into the inner wall of the casing, and the sleeve expands and seals, completing the setting process.

[0003] Currently, most downhole plugging tools used in major oil and gas fields suffer from uneven slip opening during operation, leading to leaks during pressure testing. These tools must be removed from the well or dissolved before operations can continue, wasting significant time and money. The main reason for uneven slip opening during setting is that existing technologies often use segmented setting joints, with the gaps between each segment opening in the same direction. As the slip moves towards the cone seat, the segments often experience uneven stress, causing changes in their original movement trajectory and resulting in setting misalignment.

[0004] For example, Chinese patent application No. 202210072257.2 discloses a bridge plug setting mechanism. The disclosed segmented claw type fixing sleeve includes a second locking block, a fixing sleeve ring, and segmented claws. The upper end of the segmented claws is connected to the fixing sleeve ring, and the lower end is connected to the second locking block. The segmented claws are designed to open to one side. This structural design leads to uneven force distribution during movement, causing the movement trajectories of each segment to deviate, resulting in setting misalignment. After setting misalignment, the slips do not open sufficiently and fail to engage securely within the sleeve wall, causing the bridge plug to detach directly from the sleeve, resulting in setting failure. Utility Model Content

[0005] The purpose of this application is to design a slip-type downhole plugging tool that can prevent slip misalignment. By setting lateral fasteners in the weakened groove with the opening facing the base, the slip can move along a specific path during the expansion process, thus solving the problem of slip not being able to set evenly.

[0006] This application relates to a slip-type downhole plugging tool that can prevent settling misalignment, comprising a base, a central tube, and a conical seat. Slips are provided between the base and the conical seat. The slips are disposed outside the central tube. One end of the central tube is connected to the base. Weakening grooves are provided at intervals on the circumference of the slips to facilitate slip opening. The weakening grooves are alternately provided with two opening directions respectively facing the conical seat and the base. Lateral fasteners are provided in the weakening groove with the opening facing the base.

[0007] The central tube has a first end connected to the base via a thread, and a second end connected to the cone seat via a locking ring, which is mounted on the cone seat. The second end of the central tube is connected to the locking ring via a one-way thread. The lateral fastener includes a threaded portion and a smooth rod portion; the threaded portion is screwed into the cone seat and abuts against it. A first expansion ring and a second expansion ring are provided on the outer side of the cone seat near the base. The first and second expansion rings are used to tighten the slips. An upper pre-tightening ring and a lower pre-tightening ring are provided on the outer side of the slips. The downhole plugging tool is an all-metal downhole plugging tool, and the lateral fastener is installed in the cone seat.

[0008] The downhole plugging tool of this application optimizes the structure of the slips and its adapter components based on the movement process of the slips, ensuring that the slips move under force and displace in a specific direction. This better solves the problem of slips not being able to set evenly, greatly improves the success rate of well setting, and thus saves time and construction costs. Attached Figure Description

[0009] Figure 1 This is a cross-sectional view of the slip-type downhole plugging tool of this application that can prevent setting deviation.

[0010] Figure 2 This is a schematic diagram showing the connection relationship between the slips and the cone seat of the downhole plugging tool in this application.

[0011] Figure 3 This is a schematic diagram of one embodiment of the lateral fastener of the downhole plugging tool of this application.

[0012] Figure 4 This is a schematic diagram of the slips of the downhole plugging tool in this application.

[0013] Figure 5 This is a schematic diagram of the unidirectional thread of this application.

[0014] Figure 6 This is a schematic diagram of a single-card, single-cylinder bridge plug using the structure of this application. Detailed Implementation

[0015] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in detail below with reference to the accompanying drawings. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be arbitrarily combined with each other. In the description of this application, references to terms such as "embodiment" or "example" indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. Furthermore, unless contradictory, those skilled in the art can combine and integrate the different embodiments or examples and features described in this specification.

[0016] It should be noted that all directional indications in this application, such as up, down, left, right, front, back, etc., are only used to explain the relative positional relationships and movement of the components in a specific posture as shown in the accompanying drawings. If the specific posture changes, the directional indications will also change accordingly. Furthermore, the descriptions involving "first," "second," etc., in this application are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of those features. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0017] According to this application, a slip-type downhole plugging tool for preventing setting misalignment includes a base 1, a central tube 3, and a conical seat 10. Slips 4 are provided between the base 1 and the conical seat 10, and the slips 4 are positioned outside the central tube 3. The first end of the central tube 3 is threaded to the base 1, and the second end of the central tube 3 is connected to the conical seat 10 via a locking ring 9, which is mounted on the conical seat 10. Specifically, the second end of the central tube 3 is connected to the locking ring 9 via a 90° one-way thread, allowing for unidirectional sliding without disrupting the threaded locking structure. A first expansion ring 7 and a second expansion ring 8 are provided on the outer side of the conical seat 10 near the base 1, which are used to tighten the slips 4. An upper pre-tightening ring 6 and a lower pre-tightening ring 2 are provided on the outer side of the slips 4 for pre-tightening to prevent premature setting. The slip 4 has a lateral fastener 12 on its side, such as a guide pin, to achieve uniform opening of the slip by sliding it in a fixed position, ensuring uniform stress on the set seal and providing a better working foundation for subsequent downhole fracturing operations. The downhole plugging tool of this application can be a bridge plug or a packer; the slips of this application can be in the form of single slips or double slips, and the material of the slips can be all-metal slips or rubber-sleeve slips. The slip-type downhole plugging tool of this application is preferably an all-metal soluble downhole plugging tool.

[0018] The advantage of a unidirectional thread is its unidirectional anti-loosening property. In this application, under the premise of ensuring the material strength of the central tube 4 and the base 1, the thread structure used can also achieve the anti-loosening effect. Figure 5 As shown, the threaded teeth are arranged in a right-angled trapezoidal shape, with the angle between the hypotenuse of the threaded teeth and the longitudinal direction of the thread being 30 degrees. To ensure the tightness of the threaded connection between the central tube 4 and the base 1, the thread shapes on both are matched. This application uses this 90° unidirectional thread, where the right-angled sides of the two threaded components interlock, thereby forming a mating surface perpendicular to the longitudinal direction, maximizing the mating surface and ensuring the connection strength and tightness of the threads.

[0019] According to this application, the assembly connection relationship of a slip-type downhole plugging tool for preventing setting deviation is as follows: First, the locking ring 9 is installed on the cone seat 10, then the center tube 3 is installed on the locking ring 9, and then the first expansion ring 7 and the second expansion ring 8 are installed on the cone seat 10; second, the lower pre-tightening ring 2 and the upper pre-tightening ring 6 are installed on the slip 4, and then the installed slip 4 is installed on the cone seat 10; third, the base 1 is installed on the center tube 3, and finally the lateral fastener 12 for preventing setting deviation is installed on the cone seat 10. During the slip advancement process, it moves according to the designed sliding trajectory to prevent uneven cracking during the slip opening process, which could lead to pressure failure.

[0020] To prevent seat misalignment, this application not only modifies the shape of each lobe of the slip in the prior art, but also adds a calibration component when the slip lobe experiences uneven force during movement, ensuring that the movement trajectory of each slip lobe does not deviate. Specifically, as shown... Figure 2 As shown, weakening grooves 11 are spaced apart on the circumference of the slip 4 to facilitate its opening. These weakening grooves 11 have two alternating opening directions: one facing upwards (towards the cone seat 10) and the other facing downwards (towards the base 1). This application only provides lateral fasteners 12 in the downward-opening weakening grooves 11, meaning the lateral fasteners 12 are spaced apart within the weakening grooves 11. This prevents the slip from failing to open properly and resulting in poor sealing. The reason is that as the slip 4 moves towards the cone seat 10, the space in the upward-opening weakening grooves 11 gradually decreases. After the slip 4 has moved a certain distance, the upward-opening space may become insufficient, thus blocking the lateral fasteners 12. However, the downward-opening weakening grooves are the opposite; as the slip 4 moves towards the cone seat 10, the downward-opening space in the weakening grooves 11 gradually increases, preventing obstruction of the lateral fasteners 12.

[0021] like Figure 3 As shown, the lateral fastener 12 includes a threaded portion and a smooth rod portion. The threaded portion screws into the cone seat 10 and abuts against the cone seat 10 to ensure a stable connection. The smooth rod portion protrudes and contacts the slip, which can effectively reduce the resistance during the movement of the slip 4. At the same time, the smooth rod has higher strength than the threaded portion, which can ensure sufficient support when the slip segments deviate. Multiple lateral fasteners 12 are arranged in the circumferentially downward weakening groove 11. When the slip 4 deviates during movement, the multiple lateral fasteners 12 will prevent the deviation, thereby ensuring that the movement trajectory does not deviate and the setting does not shift. It can also make the slip segments open evenly and the spacing between the segments is relatively equal. When the slip is fully opened, it will be tightly locked on the inner wall of the sleeve, achieving a good setting effect.

[0022] This application sets the weakening grooves on the circumferential side of the slips to have upward and downward openings, and sets lateral fasteners in the downward-opening weakening grooves. This allows the space in the downward-opening weakening grooves to gradually increase as the slips move towards the cone seat, preventing obstruction of the lateral fasteners. Simultaneously, the lateral fasteners prevent the slip segments from shifting, ensuring the movement trajectory remains unchanged and the setting is not misaligned. The novel design of this downhole plugging tool solves the problem of slips opening prematurely before setting. Furthermore, when slip opening is required, the difference in size between the upper and lower pre-tightening rings addresses the issue of controllable slip opening sequence. The reserved locking points on the cone seat 10, combined with the weakening grooves 11 on the slips 4 and the lateral fasteners 12, ensure uniform slip opening, avoiding secondary downhole runs due to uneven slip opening, improving downhole pass rate, and reducing construction costs.

[0023] When designing the downhole plugging tool of this application, the expansion force of the slips is an important design parameter. It can be used to determine the magnitude of the external load to prevent premature setting of the downhole plugging tool, facilitating protection during use; it can also be used to calculate the release force required for complete slip opening. This is because the release force is ensured by the threads of the base, but the required release force must meet the expansion force requirements and is also an important reference parameter for the design of the cone face angle, as the release force is converted into expansion force through the cone face pressure. The expansion force F of the downhole plugging tool of this application... T The following empirical formula can be used for calculation:

[0024] F T =MAX[F H1 ,F H2 ,F P1 ,F P2 ]

[0025] F H1 =σ L1 B1δ1=σ L1 (D SHW -D SHN B1

[0026] F H2 =σ L2 B2δ2=σ L2 (D XHW -D XHN B2

[0027] F P1 =1 / 2σ L3 (L K -L C (D) XHW -D XHN )+(D XHN -D KN )B2]

[0028]

[0029] In the formula, F H1 For the destructive force of the upper pre-tightening ring, F H2 For the destructive force of the lower preload ring, F P1 For the radial breaking force of the slip connection, F P2 For the tangential fracture force of the slip joint, σ L1 B1 is the tensile strength of the upper preload ring, B2 is the effective width of the upper preload ring, B2 is the effective width of the lower preload ring, δ1 is the effective thickness of the upper preload ring, and D is the tensile strength of the upper preload ring. SHW D is the maximum outer diameter of the upper preload ring. SHN σ is the maximum inner diameter of the upper preload ring. L2 D represents the tensile strength of the lower preload ring.XHW D is the maximum outer diameter of the lower preload ring. XHN δ2 is the maximum inner diameter of the lower preload ring, σ is the effective thickness of the lower preload ring, and σ is the maximum inner diameter of the lower preload ring. L3 For the tensile strength of the card, L K L is the length of the card. C D is the length of the weakening groove. KN Where S is the maximum inner diameter of the vane, θ is the number of vane lobes, and D is the angle of each vane lobe. KW This is the maximum outer diameter of the Kava.

[0030] Conversely, given the design value F of the expansion force of the downhole plugging tool... T By analyzing the performance parameters of the chuck material, the designed chuck dimensions can be verified to ensure they meet design requirements. The table below shows example parameters for design guidance using the above formulas.

[0031] Table 1. Calculation Examples of Design Parameters for Downhole Plugging Tools

[0032]

[0033]

[0034] Although the embodiments disclosed in this application are as described above, the content is merely for the purpose of facilitating understanding of this application and is not intended to limit this application. Any person skilled in the art to which this application pertains may make any modifications and changes in the form and details of the implementation without departing from the spirit and scope disclosed in this application; however, the scope of patent protection of this application shall still be determined by the scope defined in the appended claims.

Claims

1. A slip-type downhole plugging tool to prevent setting misalignment, characterized in that, The device includes a base, a central tube, and a conical seat. A retainer is provided between the base and the conical seat. The retainer is disposed outside the central tube. One end of the central tube is connected to the base. Weakening grooves are provided at intervals on the retainer to facilitate the opening of the retainer. The weakening grooves are alternately provided with two opening directions facing the conical seat and the base, respectively. Lateral fasteners are provided in the weakening groove with the opening facing the base.

2. The slip-type downhole plugging tool according to claim 1, characterized in that, The first end of the central tube is connected to the base by a thread, and the second end of the central tube is connected to the cone seat by a locking ring, which is installed on the cone seat.

3. The slip-type downhole plugging tool according to claim 2, characterized in that, The second end of the central tube is connected to the locking ring via a one-way thread.

4. The slip-type downhole plugging tool according to any one of claims 1-3, characterized in that, The lateral fastener includes a threaded portion and a smooth portion, wherein the threaded portion is screwed into the cone seat and abuts against the cone seat.

5. The slip-type downhole plugging tool according to claim 1, characterized in that, The cone seat has a first expansion ring and a second expansion ring on the outer side of the end near the base, which are used to tighten the slip.

6. The slip-type downhole plugging tool according to claim 5, characterized in that, The outer side of the slip is provided with an upper pre-tightening ring and a lower pre-tightening ring.

7. The slip-type downhole plugging tool according to any one of claims 1-3 and 6, characterized in that, The downhole plugging tool is an all-metal downhole plugging tool.

8. The slip-type downhole plugging tool according to any one of claims 1-3 and 6, characterized in that, The lateral fastener is installed into the cone.

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