A drilling power slips centering device

Abstract

The present application discloses a centering device for a drilling power slip. The drilling power slip includes a slip seat and slips located within the slip seat, and a drill pipe string for drilling is located within the slips. The centering device includes an annular support plate that is fixed to the bottom of the slip seat and is concentric with the slips, and a pushing device that is fixed to the support plate. The pushing device includes at least two hydraulic cylinders and push plates pushed by each hydraulic cylinder. When the at least two push plates are pushed by the hydraulic cylinders to a set position, they form a complete circle located at the center of the slips. By designing a support plate at the bottom of the slip seat and designing push plates on the support plate that are pushed to rotate by the hydraulic cylinders, when all the push plates are pushed by the hydraulic cylinders to the set position, they form a complete circle located at the center of the slips. Therefore, during the process of pushing the push plates, the drill pipe string that is roughly located in the middle of the slips but not aligned is pushed to the center of the slips, thereby achieving the centering of the drill pipe string and ensuring the normal use of the drilling power slip.

Description

Technical Field

[0001] The present invention generally relates to oil and gas drilling tools, and particularly to a centering device and method for a drilling power slip. Background Art

[0002] During the existing oil and gas drilling process, the traditional double elevators operation or the single elevator plus hand-held slip operation mode is gradually being replaced by hydraulic power slips or pneumatic power slips. The hydraulic power slips and pneumatic power slips are collectively referred to as drilling power slips, which have the functions of automatic mud scraping, remote operation, and hydraulic or pneumatic up and down control to clamp or release the drill pipe string. However, during the drilling construction of most oil wells, the drill pipe string is not necessarily located at the center of the wellhead. Especially in recent years, during the drilling construction of special wells such as horizontal wells, multilateral wells, and highly deviated wells, the drill pipe string generally deviates from the center position of the wellhead. During the process of the multi-piece slip clamping the drill pipe string, since the drill pipe string is not at the center position of the wellhead, the slip body is extremely likely to be skewed and thus cannot effectively center and clamp the drill pipe, resulting in the situation that the drilling power slips cannot be used normally. It is urgent to solve the centering problem of the drill pipe string during the use of the drilling power slips. Summary of the Invention

[0003] In view of the above-mentioned defects or deficiencies in the prior art, it is desirable to provide a centering device and method for a drilling power slip.

[0004] In a first aspect, the present application provides a centering device for a drilling power slip. The drilling power slip includes a slip seat and a slip located inside the slip seat, and a drill pipe string for drilling is located inside the slip. The centering device includes an annular support plate fixed at the bottom of the slip seat and concentric with the slip, and a pushing device fixed on the support plate. The pushing device includes at least two hydraulic cylinders and a push plate pushed by each hydraulic cylinder. When at least two of the push plates are pushed by the hydraulic cylinders to a set position, they form a complete circle located at the center of the slip.

[0005] According to the technical solution provided by the embodiment of the present application, the number of the hydraulic cylinders is 2, and each hydraulic cylinder and the push plate it pushes form a set of pushing mechanisms. The two sets of pushing mechanisms are symmetrically arranged along the radial line of the slip;

[0006] In each of the pushing mechanisms: one end of the push plate is hinged to the support plate, and the other end is hinged to the end of the piston rod of the hydraulic cylinder. A semi-circular groove is provided on the side of the push plate;

[0007] When the piston rods of the hydraulic cylinders of the two pushing mechanisms extend to the set position, the two semi-circular grooves form a complete circle located at the center of the slip. The diameter of the complete circle is larger than the diameter of the drill pipe string.

[0008] According to the technical solution provided by the embodiment of the present application, the number of the hydraulic cylinders is at least 3, and a push plate is fixed to the end of the piston rod of each hydraulic cylinder; the push plate is arc-shaped; the piston rod of the hydraulic cylinder is parallel to the radial line of the slip.

[0009] When the piston rods of the three hydraulic cylinders extend to a set position, a complete circle located at the center of the slip is formed between the three push plates; the diameter of the complete circle is slightly larger than the diameter of the drill pipe string.

[0010] According to the technical solution provided by the embodiment of the present application, fins extend from the edge of the push plate in a direction away from its center of the circle.

[0011] According to the technical solution provided by the embodiment of the present application, a slewing base is provided on the support plate, and the hydraulic cylinder is fixed to the support plate through the slewing base.

[0012] According to the technical solution provided by the embodiment of the present application, a double-earring is provided on the support plate, and the end of the piston rod of the hydraulic cylinder is connected to the end of the push plate through the double-earring.

[0013] According to the technical solution provided by the embodiment of the present application, a hinge pin seat is provided on the support plate, and the end of the push plate is fixed to the support plate through the hinge pin seat.

[0014] According to the technical solution provided by the embodiment of the present application, a limit block for defining the moving position of the push plate is provided at a set position on the support plate.

[0015] According to the technical solution provided by the embodiment of the present application, at least 5 legs are uniformly fixed to the bottom of the slip seat; the top end of the support plate is fixed to the bottom of the slip seat through the legs.

[0016] According to the technical solution provided by the embodiment of the present application, an installation channel bent at 90 degrees is provided circumferentially at the bottom of the slip seat; one end of the installation channel leads to the bottom surface of the slip seat, and the other end leads to the inner side surface of the slip seat; the horizontal part of the installation channel is a threaded surface.

[0017] An installation through hole corresponding to the installation channel is provided on the support plate; a T-shaped nail that sequentially extends into the installation through hole and the installation channel penetrates through the bottom surface of the support plate; a threaded hole is provided at the end of the T-shaped nail.

[0018] A screw is threadedly inserted into the side surface of the slip seat, and the screw sequentially extends into the installation channel and the T-shaped nail to fix the support plate to the bottom surface of the slip seat.

[0019] In the above technical solution of the present application, by designing a support plate at the bottom of the slip seat, and designing a push plate on the support plate that is driven to rotate by a hydraulic cylinder. When all the push plates are pushed by the hydraulic cylinder to the set position, they form a complete circle located at the center of the slip. Therefore, during the process of pushing the push plates, the drill pipe string that is roughly in the middle of the slip but not aligned is pushed to the center of the slip, thus achieving the centering of the drill pipe string, that is, located at the center of the slip, thereby ensuring the normal use of the drilling power slip. Description of the Drawings

[0020] By reading the detailed description of the non-restrictive embodiments with reference to the following drawings, other features, objects, and advantages of the present application will become more apparent:

[0021] Figures 1 to 4 It is a schematic structural diagram of Embodiment 1 of the present application;

[0022] Figures 5 to 6 It is a schematic structural diagram of Embodiment 2 of the present application;

[0023] Figure 7 It is a schematic structural diagram of Embodiment 3 of the present application;

[0024] Figure 8 It is a schematic structural diagram of Embodiment 4 of the present application.

[0025] Reference numerals in the drawings:

[0026] 1. Slip seat; 2. Slip; 3. Drill pipe string; 4. Annular support plate; 5. Hydraulic cylinder; 6. Push plate; 7. Piston rod; 8. Semi-circular groove; 10. Rotary seat; 11. Hinge pin seat; 12. Leg; 18. Complete circle; 9. Fin; 13. Installation channel; 14. Installation through hole; 15. T-shaped nail; 16. Threaded hole; 17. Screw; Detailed Embodiments

[0027] The present application will be further described in detail below with reference to the drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the related invention and are not intended to limit the invention. Additionally, it should be noted that for the sake of description, only the parts related to the invention are shown in the drawings.

[0028] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present application will be described in detail below with reference to the drawings and embodiments. Embodiment 1

[0029] Please refer to Figure 1 and Figure 2This is a schematic structural diagram of a centering device for a drilling power slip in this embodiment. The drilling power slip includes a slip seat 1 and slips 2 located within the slip seat 1. A drill string 3 for drilling is located within the slips 2. The centering device includes an annular support plate 4 fixed to the bottom of the slip seat 1 and concentric with the slips 2, and a pushing device fixed to the support plate 4. The pushing device includes at least two hydraulic cylinders 5 and push plates 6 pushed by each hydraulic cylinder 5. When at least two of the push plates 6 are pushed by the hydraulic cylinders 5 to a set position, they form a complete circle located at the center of the slips 2.

[0030] In this embodiment, the number of hydraulic cylinders 5 is 2, and each hydraulic cylinder 5 and the push plate 6 it pushes form a set of pushing mechanisms. The two sets of pushing mechanisms are symmetrically arranged along the radial line of the slips 2.

[0031] Within each pushing mechanism: One end of the push plate 6 is hinged to the support plate 4, and the other end is hinged to the end of the piston rod 7 of the hydraulic cylinder 5. A semi-circular groove 8 is provided on the side of the push plate 6. Specifically, a swivel seat 10 is provided on the support plate 4, and the hydraulic cylinder 5 is fixed to the support plate 4 through the swivel seat 10. A double earring is provided on the support plate 4, and the end of the piston rod 7 of the hydraulic cylinder 5 is connected to the end of the push plate 6 through the double earring. A hinge pin seat 11 is provided on the support plate 4, and the end of the push plate 6 is fixed to the support plate 4 through the hinge pin seat 11.

[0032] As Figure 3 shown, when the piston rods 7 of the hydraulic cylinders 5 of the two pushing mechanisms extend to the set position, the two semi-circular grooves 8 form a complete circle located at the center of the slips 2. The diameter of the complete circle is greater than the diameter of the drill string 3.

[0033] Among them, the symmetric arrangement method of the two pushing mechanisms can also adopt a centrosymmetric method with the center of the circle of the slips as the center; as Figure 4 shown; that is, as long as the two support plates 4 can form a complete circle 18 when pushed to the set position.

[0034] In this solution, after the drill string 3 is installed, oil is supplied to the hydraulic cylinder 5, causing the hydraulic cylinder 5 to push the push plate to rotate and push the push plate 6 to the set position. The set position is the position where the push plate 6 is pushed to be parallel to the radial line of the drill string 3, and the complete circle formed by the two semi-circular grooves 8 is larger than the outer diameter of the drill string 3, so that no matter which direction the drill string 3 deviates from the center after actual installation, it can be pushed to the center position.

[0035] When the drill string 3 is pushed to the center position, the hydraulic cylinder 5 returns oil, the piston rod 7 is retracted, pulling the push plate 6 back to its original position, so that the slips can start to work.

[0036] Preferably, a limit block for defining the moving position of the push plate 6 is provided at a set position on the support plate 4. The limit block can prevent the push plate 6 from being pushed out beyond the set position, ensuring that the perfect circle formed by the push plate 6 each time is at the central position of the slip

[0037] In this embodiment, the support plate 4 is fixed to the bottom of the slip seat 1 by screws. Embodiment 2

[0038] In this embodiment, as Figure 5 shown, on the basis of Embodiment 1, the pushing device is changed to: the number of the hydraulic cylinders 5 is at least 3, and the end of the piston rod of each hydraulic cylinder 5 is fixed with a push plate 6; the push plate 6 is arc-shaped; the piston rod 7 of the hydraulic cylinder 5 is parallel to the radial line of the slip 2;

[0039] As Figure 6 shown, when the piston rods 7 of the three hydraulic cylinders 5 extend to the set position, a perfect circle located at the center of the slip 2 is formed among the three push plates 6; the diameter of the perfect circle is slightly larger than the diameter of the drill string 3.

[0040] In this embodiment, the 3 hydraulic cylinders 5 are evenly and equidistantly distributed around the center of the slip. After the piston rods 7 of the 3 hydraulic cylinders 5 extend by the same amount, the three push plates 6 are located on the same circumference. At this time, the set position is the position reached by the push plate 6 when the piston rods 7 of the three hydraulic cylinders 5 extend by the set amount. Since the push plates 6 are evenly distributed, no matter which eccentric position the drill string 3 is located at, it can be pushed to the central position.

[0041] In other embodiments, the number of the hydraulic cylinders 5 and the push plates 6 can also be 4 or even more.

[0042] Preferably, fins 9 extend from the edge of the push plate 6 in a direction away from its center. The fins 9 can exert a thrust on the drill string between two push plates, playing an auxiliary role. Embodiment 3

[0043] As Figure 7 shown, on the basis of Embodiment 1, the supporting method of the support plate 4 is changed to the following method: at least 5 legs 12 are evenly fixed to the bottom of the slip seat 1; the top end of the support plate 4 is fixed to the bottom of the slip seat 1 through the legs 12. In this embodiment, the legs 12 and the slip seat 1 are connected by screws. Embodiment 4

[0044] As Figure 8As shown in the figure, based on Embodiment 1, the support method of the support plate 4 is changed to the following method: The bottom of the slip seat 1 is circumferentially provided with an installation channel 13 bent at 90 degrees; One end of the installation channel 13 leads to the bottom surface of the slip seat 1, and the other end leads to the inner side surface of the slip seat 1; The horizontal part of the installation channel 13 is a threaded surface;

[0045] The support plate 4 is provided with an installation through hole 14 corresponding to the installation channel 13; A T-shaped nail 15 that sequentially extends into the installation through hole 14 and the installation channel 13 penetrates through the bottom surface of the support plate 4; A threaded hole 16 is opened at the end of the T-shaped nail 15;

[0046] A screw 17 is screwed into the side surface of the slip seat 1, and the screw 17 sequentially extends into the installation channel 13 and the T-shaped nail 15 to fix the support plate 4 to the bottom surface of the slip seat 1.

[0047] When installing the support plate 4, first insert the T-shaped nail 15 from the bottom of the support plate 4, and then insert it into the vertical part of the installation channel 13. Therefore, the length of the T-shaped nail 15 is greater than or equal to the sum of the thickness of the support plate 4 and the length of the vertical part of the installation channel 13; When the end of the T-shaped nail 15 contacts the slip seat 1, then insert the screw 17 horizontally into the horizontal part of the installation channel 13 from the side; Since the end of the T-shaped nail 15 is provided with a threaded hole, the screw 17 can be threadedly connected to the horizontal part of the installation channel 13 and the threaded hole at the end of the T-shaped nail 15. Thus, the support plate 4 is fixed to the bottom surface of the slip seat 1.

[0048] Therefore, preferably, in order to facilitate the alignment of the threaded hole at the end of the T-shaped nail 15, an indication line parallel to the axial direction of the threaded hole is provided at the exposed end of the T-shaped nail;

[0049] The fixing method of the support plate in this embodiment enables the support plate 4 to be in close contact with the slip seat 1, thereby making the structure more compact.

[0050] The above description is only for the preferred embodiments of the present application and the description of the applied technical principles. Those skilled in the art should understand that the scope of the invention involved in the present application is not limited to the technical solutions formed by the specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the inventive concept. For example, the technical solutions formed by mutually replacing the above features with the (but not limited to) technical features with similar functions disclosed in the present application.

Claims

1. A drilling power slips centering device, the drilling power slips comprising a slips seat (1) and slips (2) located within the slips seat (1), and a drill pipe string (3) for drilling is located within the slips (2); characterized in that, The centering device includes an annular support plate (4) fixed to the bottom of the slip seat (1) and concentric with the slips (2), and a pushing device fixed to the support plate (4); the pushing device includes at least two hydraulic cylinders (5) and a push plate (6) pushed by each hydraulic cylinder (5); when at least two push plates (6) are pushed by the hydraulic cylinders (5) to a set position, they form a complete circle located at the center of the slips (2). When the number of the hydraulic cylinders (5) is 2, each hydraulic cylinder (5) and the push plate (6) it pushes form a set of pushing mechanisms; the two sets of pushing mechanisms are symmetrically arranged along the radial line of the slips (2). Inside each pushing mechanism: one end of the push plate (6) is hinged to the support plate (4), and the other end is hinged to the end of the piston rod (7) of the hydraulic cylinder (5); a semi-circular groove (8) is provided on the side of the push plate (6); a hinge pin seat (11) is provided on the support plate (4), and the end of the push plate (6) is fixed to the support plate (4) through the hinge pin seat (11). When the piston rods (7) of the hydraulic cylinders (5) of the two pushing mechanisms extend to a set position, the two semi-circular grooves (8) form a complete circle located at the center of the slips (2); the diameter of the complete circle is larger than the diameter of the drill string (3); or When the number of the hydraulic cylinders (5) is at least 3, the end of the piston rod of each hydraulic cylinder (5) is fixed with a push plate (6); the push plate (6) is arc-shaped; the piston rod (7) of the hydraulic cylinder (5) is parallel to the radial line of the slips (2). When the piston rods (7) of all the hydraulic cylinders (5) extend to a set position, a complete circle located at the center of the slips (2) is formed between all the push plates (6); the diameter of the complete circle is slightly larger than the diameter of the drill string (3). An installation channel (13) with a 90-degree bend is circumferentially provided at the bottom of the slip seat (1); one end of the installation channel (13) leads to the bottom surface of the slip seat (1), and the other end leads to the inner side surface of the slip seat (1); the horizontal part of the installation channel (13) is a threaded surface. An installation through hole (14) corresponding to the installation channel (13) is provided on the support plate (4); a T-shaped nail (15) that sequentially extends into the installation through hole (14) and the installation channel (13) penetrates into the bottom surface of the support plate (4); a threaded hole (16) is provided at the end of the T-shaped nail (15). A screw (17) is screwed into the side surface of the slip seat (1), and the screw (17) sequentially extends into the installation channel (13) and the T-shaped nail (15) to fix the support plate (4) to the bottom surface of the slip seat (1).

2. The centering device for a drilling power slip according to claim 1, wherein When the number of the hydraulic cylinders (5) is at least 3, fins (9) extend from the edge of the push plate (6) in a direction away from its center.

3. The drilling power slips centering device according to any one of claims 1 to 2, characterized in that A swivel seat (10) is provided on the support plate (4), and the hydraulic cylinder (5) is fixed to the support plate (4) through the swivel seat (10).

4. The drilling power slip centering device according to claim 1, wherein, Limit blocks for limiting the moving position of the push plate (6) are provided at set positions on the support plate (4).

Images