A two-way universal slip assembly

Abstract

The present invention discloses a bidirectional universal slip assembly, including a driving oil cylinder, a guide slide, a conical slide and a slip tooth plate. The guide slide is composed of symmetrical slide splits, and the sliding hole in the center of the guide slide is in the shape of an hourglass formed by two cones with the smaller diameter end vertically opposed to each other; the conical slide is a conical boss composed of several identical sub-slides evenly arranged and assembled in the circumferential direction, and a slip tooth plate is installed in the vertical through hole in the center of the conical slide; two conical slides are installed oppositely in the sliding hole in the center of the guide slide, and the guide slide is driven by the driving oil cylinder to move horizontally, and the conical slide moves horizontally with the guide slide and can slide along the conical hole wall of the sliding hole. The present invention is suitable for bidirectional clamping of pipe columns, which can prevent the pipe column from pushing up and sliding down. The embracing slip tooth plate realizes synchronization and has a limit self-locking function to ensure safety.

Description

Technical Field

[0001] The invention relates to the technical field of well repairing operations under pressure in oil fields, in particular to a bidirectional universal slip assembly. Background Art

[0002] During the well repair operation under pressure in the oil field, slips are needed to clamp the oil pipe (hereinafter referred to as the pipe string) to achieve the pulling out and pressing down of the pipe string. Therefore, the performance of slips is directly related to the safety and stability of the well repair process. During the well repair operation under pressure, on the one hand, the slips must support the pipe string and bear the downward gravity of the pipe string; on the other hand, when there is pressure in the well or blowout, the well fluid pushes up the pipe string, and the slips must bear the upward force of the pipe string to prevent the pipe string from being pushed out. At this stage, the downward pressure and upward force of the pipe string during the well repair operation under pressure are usually controlled by several groups of slips. These slips mainly include anti-top load-bearing combined conical slips and gate-type universal slips. Among them, the anti-top load-bearing combined conical slips have a multi-petal split structure, and the conical slips need to be opened synchronously by swinging a connecting rod. Sometimes, due to the heavy load, the swinging method to open the conical slips cannot guarantee that they can be fully opened every time, and there is a safety risk of pulling out or pressing down the pipe string; the universal slips are mainly gate-type slips, and the clamping of the oil pipe relies on the clamping friction force, which determines that the universal slips have a small load-bearing capacity. If the load-bearing capacity is increased, one is to increase the clamping force, which may cause extrusion damage to the oil pipe; the other is to lengthen the contact area between the slip and the pipe string, which will greatly increase the height of the entire slip, affecting the working height of the entire device, which is not conducive to safe construction. During the construction process, the opening and closing of the slips are required to be fast to reduce the risk of flying pipes and falling pipes when the slips work alternately.

[0003] It can be seen that the above-mentioned existing slips are obviously still inconvenient and defective in structure and use, and are in urgent need of further improvement. How to create a new two-way universal slip assembly is one of the current important research and development topics. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a bidirectional universal slip assembly, which can be used for bidirectional clamping of a pipe column, can prevent the pipe column from pushing up, and can prevent the pipe column from sliding down, and can be opened and closed flexibly and quickly, thereby overcoming the shortcomings of existing slips.

[0005] In order to solve the above technical problems, the present invention provides a bidirectional universal slip assembly, comprising a driving cylinder, a guide slide, a conical slide and a slip tooth plate, wherein:

[0006] The guide slide is composed of two symmetrical slide parts horizontally assembled, and the center of the guide slide has a vertically penetrating sliding hole, and the shape of the sliding hole is an hourglass shape formed by two cones with the ends with smaller diameters vertically facing each other;

[0007] The conical slide seat is in the shape of a conical boss as a whole, and is composed of a number of identical sub-slide blocks evenly arranged in the circumferential direction, and a through hole is vertically penetrated in the center of the conical slide seat, and a slip plate is installed in the through hole;

[0008] The two conical slides are oppositely installed in the sliding hole in the center of the guide slide. The guide slide is driven by the driving cylinder to move horizontally. The conical slide moves horizontally with the guide slide and can slide along the conical hole wall of the sliding hole.

[0009] As an improvement of the present invention, a limit groove is provided on the guide slide, a limit pin assembly is arranged outside the limit groove, the limit pin assembly includes a limit pin and a limit cylinder, and the limit cylinder drives the limit pin to extend into or out of the limit groove.

[0010] Furthermore, the limit cylinder is a double-acting cylinder.

[0011] Furthermore, a shell is installed outside the guide slide, the conical slide and the slip plate, the driving cylinder is installed on the shell, and the shell is provided with a flange for connecting to wellhead equipment.

[0012] Furthermore, the driving cylinder is a double-acting cylinder, a T-shaped block is provided at the end of the piston rod of the driving cylinder, a T-shaped slot is provided on the guide slide, and the T-shaped block is embedded in the T-shaped slot, so that the driving cylinder can drive the guide slide to move horizontally.

[0013] Furthermore, the outer wall of the conical slide is fitted with the wall of the sliding hole of the guide slide, the inner wall of the sliding hole is provided with a guide key, the outer surface of the conical slide is provided with a guide groove, the guide key extends into the guide groove, and the guide conical slide slides along the conical inner wall of the sliding hole.

[0014] Furthermore, a dovetail groove slide is provided on the conical slide, a fixing pin hole is provided on the top of the slide, a compression spring and a fixing pin are provided in the fixing pin hole, and the fixing pin extends out of the conical slide under the action of the compression spring to lock the cava tooth plate.

[0015] Furthermore, the slip tooth plate is evenly divided into a plurality of tooth dividing plates in the circumferential direction, the number of the tooth dividing plates is the same as the number of the sub-sliding blocks of the conical sliding seat, and a tooth dividing plate is correspondingly installed on each sub-sliding block.

[0016] Furthermore, a plurality of grooves are provided on the inner surface of the slip tooth plate.

[0017] After adopting such a design, the present invention has at least the following advantages:

[0018] 1. The tapered slide can slide along the inner wall of the tapered sliding hole of the guide slide, so that the pipe column will slide in the corresponding direction regardless of the upward force or its own gravity. Since the shape of the sliding hole is an hourglass shape formed by two cones with the smaller diameter end facing each other, whether sliding up or down, it will slide in the direction of the smaller aperture of the sliding hole. The smaller aperture forces the tapered slide and the tooth plate to apply a greater clamping force to the pipe column to ensure that the pipe column does not fall off.

[0019] 2. The conical slide is composed of several sub-slides evenly arranged in the circumferential direction. Correspondingly, the slip plate is also divided into the same number of sub-slides and installed on each sub-slide accordingly, so that the slip plate can be contracted or opened in an embracing manner, ensuring the synchronization of the opening and closing of the slip.

[0020] 3. A limit groove is provided on the guide slide, and a limit pin assembly is provided outside the limit groove, so that after the guide slide pushes the conical slide and the slip plate to clamp the pipe column, the limit pin assembly can limit and lock the guide slide to prevent the pipe column from accidentally falling off due to power source interruption, thereby increasing the safety of use. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The above is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0022] Figure 1 It is a front cross-sectional view of a bidirectional universal slip assembly provided by the present invention;

[0023] Figure 2 It is a top cross-sectional view of a bidirectional universal slip assembly provided by the present invention;

[0024] Figure 3 It is a three-dimensional axonometric diagram of a bidirectional universal slip assembly provided by the present invention;

[0025] Figure 4 It is a three-dimensional axonometric drawing of the limit pin assembly.

[0026] Explanation of the reference numerals: 01-housing; 02-driving cylinder; 021-piston rod; 03-guide slide; 031-guide groove; 032-guide key; 033-limiting groove; 04-tapered slide; 05-cavo tooth plate; 06-limiting pin assembly; 061-limiting pin; 062-limiting cylinder; 07-pipe column. DETAILED DESCRIPTION

[0027] Please refer to Figures 1 to 3The present invention provides a bidirectional universal slip assembly, including a shell 01, a driving cylinder 02, a guide slide 03, a conical slide 04, a slip tooth plate 05 and a limit pin assembly 06. The guide slide 03, the conical slide 04 and the slip tooth plate 05 are installed inside the shell 01, and the driving cylinder 02 and the limit pin assembly 06 are installed on the shell 01. The shell 01 serves to provide support for other components, and the lower part of the shell 01 is connected to the wellhead equipment through a flange.

[0028] The guide slide 03 is of a split type as a whole, consisting of two completely symmetrical slide parts horizontally spliced ​​together. A sliding hole is provided in the center of the guide slide 03, and the sliding hole runs through the top surface to the bottom surface of the guide slide. The shape of the sliding hole is an hourglass shape formed by two cones with the smaller diameter end facing each other. A guide key 032 is provided on the inner wall of the sliding hole, and a T-shaped slot is provided on the outer side of the guide slide (the end away from the sliding hole) for connecting with the driving cylinder.

[0029] The conical slide 04 is in the shape of a conical boss as a whole. The outer wall of the conical slide 04 can fit with the inner wall of the sliding hole of the guide slide 043. The conical slide 04 can be divided into a load-bearing conical slide and an anti-top conical slide. The shapes and structures of the two are exactly the same. The only difference is the installation position of the two. The load-bearing conical slide is installed in the upper inverted conical hole of the sliding hole, while the anti-top conical slide is installed in the conical hole at the bottom of the sliding hole. The conical slide 04 is evenly divided into several identical sub-slides in the circumferential direction. It should be noted that the number of sub-slides is generally greater than 4, preferably 6-8. In this embodiment, the number of sub-slides is 6. A vertical through hole is opened at the center of the cone 04, and a slip plate is installed on the inner wall of the through hole.

[0030] Preferably, a guide groove 031 is provided on the side wall of the conical slide 04, which cooperates with a guide key 032 on the inner wall of the sliding hole of the guide slide 03. The guide key 032 is inserted into the guide groove 031, and together they play a guiding role, so that the conical slide 04 can slide along the conical inner wall of the sliding hole.

[0031] The slip plate 05 is installed in the through hole of the conical slide 04. The slip plate 05 is also evenly divided into several tooth plates in the circumferential direction. The number of the tooth plates is consistent with the number of the conical slide 04, which is 6 in this embodiment. Each tooth plate is in the shape of an arc surface, and the 6 tooth plates are assembled together to form a torus. The central circular hole of the slip plate 05 is used to fix the pipe column 07, and the outer wall of the slip plate 05 is completely in contact with the through hole wall of the conical slide 04.

[0032] Preferably, a dovetail groove slide is provided on the conical slide 04, a fixing pin hole is provided on the top of the slide, a compression spring and a fixing pin are provided in the fixing pin hole, and the fixing pin extends out of the conical slide 04 under the action of the compression spring to lock the cava tooth plate.

[0033] Preferably, a plurality of grooves are provided on the inner wall surface of the slip plate 05 , that is, on the hole wall of the central circular hole of the slip plate 05 , so as to increase the friction between the inner wall surface of the slip plate 05 and the outer wall of the pipe column 07 .

[0034] The driving oil cylinder 02 is mounted on the housing 01. The end of the piston rod 021 of the driving oil cylinder 02 is provided with a T-shaped block. The outer side of the guide slide 03 (the end away from the sliding hole) is provided with a T-shaped slot. The T-shaped block is embedded in the T-shaped slot to achieve the connection between the piston rod 021 and the guide slide 03. The driving oil cylinder 02 is a double-acting oil cylinder. The horizontal extension or retraction movement of the piston rod 021 can be achieved by inputting or discharging pressure medium into the driving oil cylinder 02. The piston rod 021 can drive the guide slide 03 to move horizontally.

[0035] Preferably, a limiting groove 033 is provided on the guide slide 03, and a limiting pin assembly 06 is installed on the housing 01. The limiting pin assembly 06 includes a limiting pin 061 and a limiting oil cylinder 062. The limiting oil cylinder 062 is a double-acting oil cylinder, which can push the limiting pin 061 to move horizontally. When the guide slide 03 moves to the locking position, the limiting oil cylinder 062 pushes the limiting pin 061 to extend into the limiting groove 033 to limit the guide slide 03. Such a design can avoid the accidental return of the guide slide 03 caused by the hydraulic oil cut-off of the driving oil cylinder 02, resulting in the slip losing the clamping force and the pipe column 07 coming out. In addition, the driving oil cylinder 02 and the limiting oil cylinder 062 can control the oil source supply through the program to realize the linkage control of the guide slide 03 and the limiting pin 06 to avoid human error.

[0036] During the working process of the present invention, taking the clamping of the pipe column as an example, the overall movement process is as follows:

[0037] When the driving cylinder 02 has power input, the driving piston rod 021 drives the guide slide 03 to move toward the pipe column 07, and the conical slide 04 moves with the guide slide 03. The left and right sides simultaneously squeeze the pipe column 07 inward, and the slip teeth 05 are in close contact with the pipe column 07, thereby forming sufficient friction between the slip teeth 05 and the pipe column 07. At this time, the limit pin 061 is inserted and pressed tightly into the limit groove 033 of the guide slide 03 under the pushing action of the limit cylinder 062, and the limit pin 061 and the limit groove 033 generate a certain compression friction force to achieve the self-locking of the pin. The friction force generated between the pipe string 07 and the slip teeth 05 enables the pipe string 07 to drive the conical slide 04 to slide up and down in the slip assembly. At this time, whether the pipe string 07 drives the conical slide 04 to slide downward due to its own gravity, or the pipe string 07 is driven by the well fluid pressure from the top to drive the conical slide 04 to slide upward, the sliding hole of the guide slide 03 has a smaller aperture, thereby further pressing the conical slide 04 and the slip teeth 05, and applying a greater clamping force to the pipe string 07. Therefore, the greater the gravity or top force on the pipe string 07, the greater the clamping force applied by the slip teeth 05 to the pipe string 07, thereby ensuring that the pipe string 07 does not fall off.

[0038] The movement process of the present invention when loosening the pipe string is opposite to the process of clamping the pipe string, which will not be described in detail here.

[0039] The invention is suitable for bidirectional clamping of a pipe column, which can prevent the pipe column from being pushed up and sliding down. The surrounding slip tooth plate can clamp or release the pipe column at the same time, realizing synchronization, and has a limit self-locking function, thereby ensuring safety.

[0040] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Those skilled in the art may make some simple modifications, equivalent changes or modifications using the technical contents disclosed above, which all fall within the protection scope of the present invention.

Claims

1. A bidirectional universal slip assembly, characterized in that: It includes a driving cylinder, a guide slide, a conical slide and a slip plate, wherein: The guide slide is composed of two symmetrical slide parts horizontally assembled, and the center of the guide slide has a vertically penetrating sliding hole, and the shape of the sliding hole is an hourglass shape formed by two cones with the ends with smaller diameters vertically facing each other; The conical slide seat is in the shape of a conical boss as a whole, and is composed of a number of identical sub-slide blocks evenly arranged in the circumferential direction, and a through hole is vertically penetrated in the center of the conical slide seat, and a slip plate is installed in the through hole; The two tapered slides are oppositely mounted in the sliding hole in the center of the guide slide. The guide slide is driven by a driving cylinder to move horizontally. The tapered slide moves horizontally with the guide slide and can slide along the tapered hole wall of the sliding hole. The outer wall of the tapered slide is fitted with the wall of the sliding hole of the guide slide, the inner wall of the sliding hole is provided with a guide key, the outer surface of the tapered slide is provided with a guide groove, the guide key extends into the guide groove, and the guide tapered slide slides along the tapered inner wall of the sliding hole; The conical slide is provided with a dovetail groove slide, a fixing pin hole is provided at the top of the slide, a compression spring and a fixing pin are provided in the fixing pin hole, and the fixing pin extends out of the conical slide under the action of the compression spring to lock the slip plate.

2. A two-way universal slip assembly according to claim 1, characterized in that: The guide slide is provided with a limit groove, a limit pin assembly is arranged outside the limit groove, the limit pin assembly comprises a limit pin and a limit oil cylinder, and the limit oil cylinder drives the limit pin to extend into or out of the limit groove.

3. A two-way universal slip assembly according to claim 2, characterized in that: The limit cylinder is a double-acting cylinder.

4. A bidirectional universal slip assembly according to claim 1, characterized in that: A shell is installed outside the guide slide, the conical slide and the slip plate, the driving cylinder is installed on the shell, and the shell is provided with a flange for connecting wellhead equipment.

5. The bidirectional universal slip assembly according to claim 1, characterized in that: The driving cylinder is a double-acting cylinder, the piston rod end of the driving cylinder is provided with a T-shaped block, the guide slide is provided with a T-shaped slot, the T-shaped block is embedded in the T-shaped slot, so that the driving cylinder can drive the guide slide to move horizontally.

6. A bidirectional universal slip assembly according to claim 1, characterized in that: The slip tooth plate is evenly divided into a plurality of tooth dividing plates in the circumferential direction. The number of the tooth dividing plates is the same as the number of the sub-sliding blocks of the conical sliding seat, and a tooth dividing plate is correspondingly installed on each sub-sliding block.

7. A two-way universal slip assembly according to claim 1 or 6, characterized in that: The inner surface of the slip plate is provided with a plurality of grooves.

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