Slip for oil and gas drilling

Abstract

The utility model relates to the technical field of oil well drilling and production, and discloses a slip for petroleum and natural gas drilling, the slip is composed of a plurality of slip units, each slip unit comprises a slip body and an arc-shaped slip insert plate, the slip body is provided with an arc-shaped insert plate groove matched with the arc-shaped slip insert plate along the vertical direction, and the slip body is provided with an arc-shaped insert plate groove matched with the arc-shaped slip insert plate. The slip insert plate is fixedly mounted on the slip body through the insert plate groove; and after the slip is closed, the circular arc circle center of the circular arc-shaped slip insert plate is concentric with the circle center of the clamped object. The back face of the slip insert plate is matched with the straight cylindrical side face of the insert plate groove, when the slip works in a closed mode, the circular arc circle center of the slip insert plate and the circular arc circle center of the insert plate groove are concentric with the circle center of a clamped object, and no matter the slip insert plate deviates leftwards or rightwards, the front face of the slip insert plate is always concentric with a clamped drill rod. According to the slip insert plate, the attaching area of a contact surface can be increased when a clamped object is clamped by the slip, and the situation that the clamping stress is increased due to the fact that the slip insert plate and the clamped object are not concentric is avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of oil well drilling and production, especially to oil drilling equipment, and more specifically to a slip for oil and gas drilling. Background Art

[0002] A slip is a tool used to clamp and suspend drill pipes, clamped objects, etc. during tripping in the drilling process. It is applicable to oil and gas drilling operations to prevent components such as drill pipes and clamped objects from falling under the action of gravity. The slip mainly consists of a slip body and slip jaw plates, with a conical shape. It can be wedged into the inner hole of the slip seat. The inner walls of multiple slip bodies enclose a circular hole adapted to the outer dimension of the pipe string, on which slip jaw plates are installed, and slip teeth are provided on the slip jaw plates. During drilling, the slip is arranged in the slip seat, and the clamped object passes through the circular hole enclosed by the inner walls of the slip pieces. The slip teeth on the inner wall contact the outer wall of the clamped object. Under the combined action of the gravity of the clamped object and the conical surfaces of the inner wall of the slip seat and the outer wall of the slip, the slip teeth tightly hold the clamped object to prevent it from falling.

[0003] Since the slip jaw plates and the slip body are not integrated, there is usually a gap between them after assembly. Therefore, when the slip closes and works, after clamping the clamped object, the slip jaw plates on the slip body may shift. Generally, the back of the slip jaw plate is in plane contact with the jaw plate groove on the slip body. Once the slip jaw plate shifts left or right, the clamping surface of the slip jaw plate will be non-concentric with the clamped object, resulting in a reduction in the contact area between the slip jaw plate and the clamped object, and further leading to an increase in the clamping stress. The slip jaw plate and the clamped object may be damaged due to excessive stress. Summary of the Invention

[0004] In order to solve the problems and deficiencies existing in the above prior art, the utility model provides a slip for oil and gas drilling. The slip jaw plate is integrally arc-shaped, and the slip jaw plate is installed on the slip body through an arc-shaped jaw plate groove adapted to its shape. When the slip closes and works, the center of the arc of the arc-shaped slip jaw plate is concentric with the center of the clamped object. The utility model can improve the fitting area of the contact surface when the slip clamps the clamped object, avoid the increase in clamping stress caused by the non-concentricity between the slip jaw plate and the clamped object after the slip jaw plate shifts, and further prevent the slip jaw plate and the clamped object from being damaged due to excessive stress.

[0005] In order to achieve the above invention purpose, the technical solution of the utility model is as follows:

[0006] The present utility model provides a slip for oil and gas drilling. The slip is composed of a plurality of slip units. Each slip unit includes a slip body and an arc-shaped slip tooth plate. The arc-shaped slip tooth plate is provided with slip teeth. The slip body is vertically provided with an arc-shaped tooth plate groove adapted to the arc-shaped slip tooth plate, and the arc-shaped slip tooth plate is fixedly installed on the slip body through the tooth plate groove. After the slip is closed, the centers of the arcs of the arc-shaped slip tooth plate and the tooth plate groove are concentric with the center of the object to be clamped.

[0007] Preferably, adjacent slip units are rotatably connected by a hinge. The hinge includes a hinge bushing and a hinge shaft. The hinge bushing is provided with a bushing hole, and the hinge shaft is rotatably installed in the bushing hole. A positioning pin is arranged between the hinge bushing and the hinge shaft.

[0008] Preferably, adjacent slip units are rotatably connected by a hinge. The hinge includes a hinge bushing and a hinge shaft. The hinge shaft is in a conical shape with a larger upper part and a smaller lower part, and the hinge bushing is provided with a conical bushing hole adapted to the shape of the hinge shaft. The hinge shaft is rotatably installed in the conical bushing hole.

[0009] Preferably, adjacent slip units are rotatably connected by a hinge. The hinge includes a hinge bushing and a hinge shaft. The hinge shaft is provided with a step, and the hinge bushing is provided with a step hole adapted to the shape of the hinge shaft. The hinge shaft is rotatably installed in the step hole.

[0010] Preferably, the slip body is provided with a hook for cooperating with a slip lifting device.

[0011] Preferably, the hook is horizontally arranged on the slip body and is fixedly connected to the slip body through a locking nut.

[0012] Preferably, anti-detachment pins are respectively arranged on the hook body at the front end and the tail of the hook.

[0013] Preferably, the slip body is provided with multiple columns of arc-shaped slip tooth plates and a tooth plate pressing block that abuts against the tops of the multiple columns of arc-shaped slip tooth plates and is used to press the arc-shaped slip tooth plates. The tooth plate pressing block is fixedly connected to the slip body.

[0014] Preferably, there is a gap between adjacent slip units, and a baffle is arranged at the gap. After the slip is closed, the baffle cooperates with the side wall of the adjacent slip unit or the baffle arranged on the adjacent slip unit to block the gap.

[0015] Preferably, a baffle is arranged on one side of the slip body of the slip unit. After the slip is closed, the other end of the baffle abuts against the side wall of the adjacent slip body to block the gap.

[0016] Preferably, baffles are provided on both sides of the slip body of the slip unit. After the slips are closed, the projections of the baffles on adjacent slip bodies overlap in the horizontal plane to block the gap.

[0017] Advantages of the present utility model:

[0018] 1. The back surface of the slip tooth plate of the present utility model is in a straight cylindrical side surface fit with the tooth plate groove of the slip body. When the slips are closed, the center of the arc of the arc-shaped slip tooth plate is concentric with the center of the object to be clamped. First, the use of a straight cylindrical side surface contact can reduce the processing difficulty of the slip tooth plate. And the back surface of the slip tooth plate and the tooth plate groove of the slip body are in a straight cylindrical side surface fit contact. When the slips are closed, no matter whether the slip tooth plate is biased to the left or right, the front surface of the slip tooth plate is always concentric with the drill pipe to be clamped. Compared with the traditional plane contact method, it can increase the fitting area of the contact surface when the slips clamp the object to be clamped, avoid the increase of clamping stress caused by the non-concentricity between the slip tooth plate and the object to be clamped, and prevent the slip tooth plate and the object to be clamped from being damaged due to excessive stress.

[0019] 2. A hook is provided on the slip body of the present utility model for hanging a tension spring. When the slips are lifted, the tension spring can pull open the left and right flaps of the slips, so that the slips are completely separated from the middle hole of the slip seat, facilitating the passage of the object to be clamped and preventing the slips from colliding with the object to be clamped.

[0020] 3. A positioning pin is provided on the slip hinge shaft of the present utility model. The positioning pin can prevent the hinge shaft from falling into the well after breaking, avoiding the accidents and increased fishing work caused by the broken hinge shaft falling into the well.

[0021] 4. A tooth plate pressing block is provided at the top of the slip tooth plate of the present utility model. The tooth plate pressing block is used to fix the slip tooth plate, prevent the slip tooth plate from slipping out from the upper end, and at the same time prevent impurities from mixing into the fitting gap between the slip tooth plate and the tooth plate groove, thus avoiding the phenomenon of stress concentration of the slip tooth plate and further preventing the tooth plate and the object to be clamped in the high-stress part from being damaged due to stress concentration.

[0022] 5. Baffles are provided on one or both sides of the slip body of the present utility model. After the slips are closed, the other end of the baffle abuts against the side wall of the adjacent slip body or cooperates with the baffle provided on the adjacent slip body to cover the gap between adjacent slip units, preventing foreign objects from falling through the gap. Description of the Drawings

[0023] The foregoing and following specific descriptions of the present utility model become clearer when read in conjunction with the following drawings, in which:

[0024] Figure 1 is a schematic structural diagram when the slips of the present utility model are closed;

[0025] Figure 2 isFigure 1 Top view;

[0026] Figure 3 is Figure 1 front view of;

[0027] Figure 4 is Figure 3 sectional view taken along line B-B in;

[0028] Figure 5 is sectional view of installation of slip locating pin in Example 4;

[0029] Figure 6 is sectional view of another installation method of slip locating pin in Example 4;

[0030] Figure 7 is sectional view of yet another installation method of slip locating pin in Example 4;

[0031] Figure 8 is sectional view of slip in Example 5;

[0032] Figure 9 is sectional view of slip in Example 6;

[0033] Figure 10 is sectional view of slip in another implementation method of Example 6.

[0034] In the figure:

[0035] 1. Slip unit; 2. Slip body; 3. Arc-shaped slip tooth plate; 4. Locating pin; 5. Hook; 6. Anti-disengagement pin; 7. Tooth plate pressing block; 8. Baffle; 9. Hinge bushing; 10. Hinge shaft. Specific implementation manners

[0036] In order to enable those skilled in the art to better understand the technical solutions in the present utility model, the following will further illustrate the technical solutions for achieving the invention purpose of the present utility model through several specific embodiments. It should be noted that the technical solutions claimed by the present utility model include but are not limited to the following embodiments. Based on the embodiments in the present utility model, all other embodiments obtained by those skilled in the art without creative efforts shall fall within the protection scope of the present utility model.

[0037] The slips are usually composed of multiple slip units, and each slip unit consists of a slip body and slip inserts mounted on the slip body. For traditional slips, the bottom of the insert groove on the slip body for mounting the slip inserts is flat, the back of the slip insert is flat, and the front is an arc surface. When the slip insert is installed on the slip body, the flat surface on the back of the slip insert mates with the flat bottom surface of the insert groove on the slip body. During the production process of traditional slip inserts, the front arc surface is machined by a lathe, and the back flat surface is machined by a milling machine. Multiple processes will result in relatively large geometric tolerances and dimensional tolerances for these two surfaces. After the slip inserts are assembled, there is usually a gap between them and the slip body. If the geometric tolerances and dimensional tolerances of the slip inserts are relatively large, after the slips are closed to grip the object to be clamped, the slip inserts on the slip body will shift. Also, since the back of the slip insert is usually a flat structure and is in flat contact with the insert groove on the slip body, once the slip insert shifts left or right, the clamping surface of the slip insert will be non-concentric with the object to be clamped. As a result, the contact area between the slip insert and the object to be clamped will decrease, and the stresses on the object to be clamped and the slip insert will be very uneven, prone to stress concentration, which will cause damage to the slip insert and the object to be clamped.

[0038] Based on this, the embodiments of the present utility model propose a slip that can ensure the concentricity between the clamping surface of the slip insert and the object to be clamped when the slips are closed, prevent relatively large geometric tolerances and dimensional tolerances of the slip insert, reduce the contact area between the slip insert and the object to be clamped after the slips are clamped, and avoid very uneven stresses on the object to be clamped and the slip insert, thus preventing stress concentration and damage to the slip insert and the object to be clamped.

[0039] Embodiment 1

[0040] As a basic implementation manner of the present utility model, this embodiment discloses a slip for oil and gas drilling. Referring to the attached Figure 1-4 description, the slip is composed of several slip units 1. Adjacent slip units 1 are rotationally connected by hinges. One side of the two outermost slip units 1 is connected to the adjacent slip unit by a hinge, and the other side is a free end and is not connected to other slip units 1. Further, each slip unit 1 includes a slip body 2 and a slip insert provided on the slip body 2. The slip insert is integrally arc-shaped. The inner and outer curved surfaces of the arc-shaped slip insert 3 are concentric, and the radius of each point on the inner curved surface is equal, and the radius of each point on the outer curved surface is also equal. The radius of the inner curved surface is smaller than that of the outer curved surface. The inner curved surface of the arc-shaped slip insert 3 is provided with slip teeth. A circular arc-shaped insert groove that matches the shape and size of the arc-shaped slip insert 3 is vertically provided on the slip body 2. The arc-shaped slip insert 3 is fixedly installed on the slip body 2 through the circular arc-shaped insert groove. After the slips are closed, the centers of the arcs of the arc-shaped slip insert 3 and the circular arc-shaped insert groove are concentric with the center of the object to be clamped.

[0041] In the embodiment depicted by the present utility model, the inner curved surface of the arc-shaped slip jaw plate 3 is the clamping surface of the slip jaw plate.

[0042] During use, the slip is placed in the conical hole provided on the slip seat. The inner walls of multiple slip units enclose a circular hole that is adapted to the outer dimension of the object to be clamped. The outer wall of the slip unit located within the conical hole is in contact and wedged with the inner wall of the conical hole. The object to be clamped is disposed within the circular hole enclosed by the inner walls of the slip units. The slip teeth located on the slip jaw plate are in contact with the outer wall of the object to be clamped. Under the combined action of the gravity of the object to be clamped and the cooperation between the conical surface of the inner wall of the slip seat and the conical surface of the outer wall of the heavy-duty slip, the slip teeth tightly hold the object to be clamped, preventing the object to be clamped from falling. For the traditional slip, the bottom of the tooth plate groove on the slip body for installing the slip jaw plate is a plane, the back of the slip jaw plate is a plane, and the front is an arc surface. When the slip jaw plate is installed on the slip body, the plane on the back of the slip jaw plate cooperates with the bottom plane of the tooth plate groove of the slip body. During the production process of the traditional slip jaw plate, the front arc surface is machined by a lathe, and the back plane is machined by a milling machine. Multiple processes will result in relatively large shape and position tolerances and dimensional tolerances for these two surfaces. After the slip jaw plate is assembled, there is usually a gap between it and the slip body. If the shape and position tolerances and dimensional tolerances of the slip jaw plate are relatively large, after the slip closes and works to clamp the object to be clamped, the slip jaw plate on the slip body will shift. Also, since the back of the slip jaw plate is usually a plane structure and is in plane contact with the tooth plate groove on the slip body, once the slip jaw plate shifts left or right, the clamping surface of the slip jaw plate will be non-concentric with the object to be clamped, resulting in a reduction in the contact area between the slip jaw plate and the object to be clamped. The stress received by the object to be clamped and the slip jaw plate is very uneven, and stress concentration is extremely likely to occur, which will cause damage to the slip jaw plate and the object to be clamped.

[0043] Therefore, after the present utility model sets the back surface of the slip jaw plate as an arc surface concentric with the front arc surface, when machining the slip jaw plate, only one process is required to machine the back arc surface and the front arc surface of the slip jaw plate, and there will hardly be obvious shape and position tolerances and dimensional tolerances. Due to the reduction of one process, the processing cost is also saved. The inner and outer curved surfaces of the slip jaw plate are concentric, and the radius of each part of the inner curved surface is equal, and the radius of each part of the outer curved surface is also equal. The radius of the inner curved surface is smaller than the radius of the outer curved surface. Based on the arc-shaped slip jaw plate 3, the tooth plate groove on the slip body 2 is also designed as an arc-shaped tooth plate groove that is adapted to its shape and size. Finally, through the straight cylindrical side surface contact relationship between the arc-shaped slip jaw plate 3 and the tooth plate groove, when the slip closes and works, no matter whether the arc-shaped slip jaw plate 3 shifts left or right, the front surface (i.e., the clamping surface) of the arc-shaped slip jaw plate 3 is always concentric with the drill pipe to be clamped. Therefore, compared with the traditional slip structure, it can increase the fitting area of the contact surface when the slip clamps the object to be clamped, avoid the increase of clamping stress caused by the non-concentricity between the slip jaw plate and the object to be clamped, and prevent the slip jaw plate and the object to be clamped from being damaged due to excessive stress.

[0044] Embodiment 2

[0045] This embodiment discloses a slip for oil and gas drilling. On the basis of Embodiment 1, referring to the attached drawings of the specification Figure 1 , attached Figure 2 and attached Figure 4 As shown, multiple rows of jaw plate grooves are provided on the slip body 2, and a row of arc-shaped slip jaw plates 3 are correspondingly installed in each row of jaw plate grooves; moreover, a jaw plate pressing block 7 is provided at the top of the slip body 2, and the one jaw plate pressing block 7 abuts against the tops of the multiple rows of arc-shaped slip jaw plates 3 to press the arc-shaped slip jaw plates 3, and the jaw plate pressing block 7 and the slip body 2 are fixedly connected by bolts arranged longitudinally.

[0046] In the embodiment depicted by the present utility model, the arc-shaped slip jaw plates 3 vertically installed in the jaw plate grooves can be an integral structure or a segmented type. Considering the processing difficulty, the segmented type structure is preferably selected, that is to say, multiple segments of arc-shaped slip jaw plates 3 are vertically installed in a row of jaw plate grooves.

[0047] In the embodiment depicted by the present utility model, the multiple rows of arc-shaped slip jaw plates 3 on the slip body 2 in this embodiment are limited and fixed by one jaw plate pressing block 7 to prevent them from moving up and down. Compared with using a separate pressing block to limit and fix each row of arc-shaped slip jaw plates 3, not only can the production cost be reduced, but also the limiting and fixing effect is better and it is less likely to fall off. Moreover, compared with the horizontal pressing block, the vertical pressing block takes up less slip height and has a lower production cost.

[0048] Embodiment 3

[0049] This embodiment discloses a slip for oil and gas drilling. On the basis of Embodiment 1 or Embodiment 2, referring to the attached drawings of the specification Figure 1-3 As shown, a hook 5 for cooperating with a slip lifting device is provided on the slip body 2; the hook 5 is horizontally arranged on the slip body 2 and is fixedly connected to the slip body 2 through a locking nut at the tail; further, anti-drop pins 6 are respectively installed on the front hook body of the hook 5 and the tail of the hook 5, and the anti-drop pin 6 located at the tail abuts against the locking nut.

[0050] Embodiment 4

[0051] This embodiment discloses a slip for oil and gas drilling. On the basis of any of the above embodiments, referring to the attached drawings of the specification Figure 5As shown in the figure, the hinge provided between adjacent slip units 1 includes a hinge bushing 9 and a hinge shaft 10. The hinge bushing 9 has a three-section structure and is composed of three hinge bushing bodies. For two adjacent slip units 1, two hinge bushing bodies are arranged vertically from top to bottom on the slip body 2 of one slip unit 1, and one hinge bushing body is arranged on the slip body 2 of the other slip unit 1. A bushing hole is provided on each hinge bushing body, and the hinge shaft 10 is rotatably installed in the bushing holes of the three hinge bushing bodies. When installing and connecting the slip units 1, the three hinge bushing bodies are arranged in sequence from top to bottom, and the hinge shaft 10 is respectively inserted into the hinge bushing bodies on two adjacent slip bodies 2, finally realizing the rotational connection between two adjacent slip units 1.

[0052] During the use of the slips, when the slip unit 1 is subjected to a lateral force, the slip unit 1 acts the lateral force on the hinge shaft 10 through the hinge bushing 9. When the lateral force exceeds the limit that the hinge shaft 10 can bear, the hinge shaft 10 will break at the junction of two adjacent hinge bushing bodies. After the hinge shaft 10 breaks, two adjacent slip units 1 will separate under the lateral force, and the broken hinge shaft 10 will fall downward; further, if the slip unit 1 is subjected to an upward force, the broken hinge shaft 10 may also be thrown out from above the hinge bushing 9 by the slip unit.

[0053] Therefore, in order to prevent the safety accident and the increased fishing work caused by the broken hinge shaft 10 falling into the well, a pin hole is radially formed on the hinge shaft 10, a positioning pin 4 is horizontally inserted into the pin hole, and the other end of the positioning pin 4 is located in the slot hole formed on the hinge bushing body. And in order to avoid affecting the rotation of the slip unit 1, the positioning pin can move in the slot hole formed on the hinge bushing body.

[0054] In the embodiment depicted in the present utility model, the pin hole formed on the hinge shaft can be a through hole or a blind hole. When the pin hole is a through hole, refer to the attached drawings of the specification Figure 5 As shown, the positioning pin 4 penetrates the entire hinge shaft radially, and both ends are located in the slot holes formed on the hinge bushing body. When it is a blind hole, refer to the attached drawings of the specification Figure 6 As shown, the pin hole on the hinge shaft 10 is a threaded blind hole, one end of the positioning pin 4 is provided with an external thread matching the threaded blind hole, the external thread section is threadedly connected in the threaded blind hole, and the other end of the positioning pin 4 is located in the slot hole formed on the hinge bushing body.

[0055] In the embodiment depicted in the present utility model, there is another installation and fixation method for the positioning pin 4. Refer to the attached drawings of the specification Figure 7As shown, a slot is formed on the hinge shaft 10, a threaded hole is provided on the hinge bushing body, one end of the positioning pin 4 is provided with an external thread adapted to the threaded hole, the external thread section of the positioning pin is threadedly connected in the threaded hole, and the other end is inserted into the slot formed on the hinge shaft 10 and can move freely in the slot.

[0056] Based on the above structure, when the hinge shaft 10 accidentally breaks, the slot formed on the hinge bushing body provides support, thereby holding the positioning pin 5 and the hinge shaft 10 connected thereto to prevent them from falling into the well.

[0057] In the embodiment depicted by the present utility model, a plurality of positioning pins 4 are arranged longitudinally along the hinge shaft 10, and generally a positioning pin 4 is provided at each section of the hinge bushing body.

[0058] In the embodiment depicted by the present utility model, the bottom of the lowermost hinge bushing body is usually sealed to support the hinge shaft 10. It can be understood that, in order to facilitate the cleaning of the hinge shaft 10 remaining in the bushing hole after breakage, a cleaning hole with a smaller aperture is formed at the sealed part of the bottom of the lowermost hinge bushing body. This hole is used to eject the hinge shaft during disassembly and can also facilitate the discharge of sundries such as soil and mud in the hole during use, so as to prevent the hinge shaft from being stuck.

[0059] Embodiment 5

[0060] This embodiment discloses a slip for oil and gas drilling. The difference between this embodiment and Embodiment 4 is that, referring to the attached Figure 8 As shown, the hinge shaft 10 is in a conical shape with a larger upper part and a smaller lower part, and the bushing hole on the hinge bushing body is a conical bushing hole adapted to the shape and size of the hinge shaft 10. The hinge shaft 10 is rotatably installed in the conical bushing hole.

[0061] In this embodiment, a limiting structure for the hinge shaft is formed by the conical bushing hole with a larger upper part and a smaller lower part. When the hinge shaft 10 accidentally breaks, the conical bushing hole will hold the broken hinge shaft to prevent it from falling.

[0062] In the embodiment depicted by this embodiment, a positioning pin 4 may not be provided between the hinge shaft 10 and the hinge bushing 9 of this embodiment, or a positioning pin 4 may be provided simultaneously as a second anti - detachment protection mechanism.

[0063] Embodiment 6

[0064] This embodiment discloses a slip for oil and gas drilling. The difference between this embodiment and Embodiment 4 is that, referring to the attached Figure 9 As shown, a step is provided along the circumferential direction on the outer wall of the hinge shaft 10, and the bushing hole of the hinge bushing 9 is a step hole adapted to the shape and size of the hinge shaft 10. The hinge shaft 10 is rotatably installed in the step hole.

[0065] In this embodiment, the stepped surface of the stepped hole cooperates with the stepped surface of the hinge shaft 10. When the hinge shaft 10 accidentally breaks, the stepped surface of the bushing hole will hold the broken hinge shaft to prevent it from falling.

[0066] In the embodiment depicted, a positioning pin 4 may not be provided between the hinge shaft 10 and the hinge bushing 9 of this embodiment, or a positioning pin 4 may be provided simultaneously as a second anti-disengagement protection mechanism.

[0067] In the embodiment depicted, the step may be a right-angled step or a tapered step (refer to the structure of the tapered step in the attached drawings of the specification). Figure 10 as shown.

[0068] Embodiment 7

[0069] This embodiment discloses a slip for oil and gas drilling. On the basis of any of the above embodiments, referring to the attached drawings of the specification Figure 2 and the attached Figure 4 as shown, baffles 8 are provided on both sides of the slip body 2. After the slip is closed, the projections of the baffles 8 on adjacent slip bodies 2 in the horizontal plane partially overlap. The overlapping baffles 8 exactly block and seal the gap between adjacent slip bodies 2 after the slip is closed. Therefore, foreign objects can be prevented from falling through the gap, thus avoiding safety accidents.

[0070] In the embodiment depicted by the present utility model, during the opening and closing process of the slip, adjacent slip units 1 will rotate relative to each other. Therefore, in order to avoid affecting the normal rotation of the slip units 1, the baffles 8 provided between adjacent slip bodies 2 have a height difference, usually staggered with one being higher and the other being lower, rather than at the same height.

[0071] Embodiment 8

[0072] This embodiment discloses a slip for oil and gas drilling. The difference between this embodiment and Embodiment 7 is that the slip body 2 has a baffle 8 provided only on one side. After the slip is closed, the other end of the baffle 8 abuts against the side wall of the adjacent slip body 2, thereby blocking the gap between adjacent slip units 1.

[0073] It can be understood that based on the above structure, the baffle 8 is usually of a telescopic structure. After the slip is closed, the baffle 8 expands circumferentially, and its end portion abuts against the side wall of the adjacent slip body 2, thereby blocking the gap between adjacent slip units 1; when the slip needs to be opened, the baffle 8 retracts circumferentially to avoid affecting the normal rotation of the slip units 1.

[0074] In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation on the protection scope of the present utility model.

[0075] In the description of the present utility model, it should also be noted that unless otherwise clearly specified and defined, the terms "set", "installed", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific situations.

[0076] The above are only the preferred embodiments of the present utility model, and do not impose any form of limitation on the present utility model. Any simple modification or equivalent change made to the above embodiments based on the technical essence of the present utility model falls within the protection scope of the present utility model.

Claims

1. A slip for oil and gas drilling, characterized in that: The slip is composed of a plurality of slip units (1), wherein the slip unit (1) comprises a slip body (2) and an arc-shaped slip tooth plate (3), wherein the arc-shaped slip tooth plate (3) is provided with slip teeth, and the slip body (2) is provided with an arc-shaped tooth plate groove adapted to the arc-shaped slip tooth plate (3) in the vertical direction, wherein the arc-shaped slip tooth plate (3) is fixedly mounted on the slip body (2) via the tooth plate groove; when the slip is closed, the arc centers of the arc-shaped slip tooth plate (3) and the tooth plate groove are concentric with the center of the clamped object.

2. The slip for oil and gas drilling according to claim 1, characterized in that: Adjacent slip units (1) are rotatably connected via a hinge, wherein the hinge comprises a hinge sleeve (9) and a hinge shaft (10), wherein the hinge shaft (10) is rotatably mounted in a sleeve hole of the hinge sleeve (9), and a positioning pin (4) is provided between the hinge sleeve (9) and the hinge shaft (10).

3. The slip for oil and gas drilling according to claim 1, characterized in that: Adjacent slip units (1) are rotatably connected via a hinge, wherein the hinge comprises a hinge sleeve (9) and a hinge shaft (10), wherein the hinge shaft (10) is in a conical shape with a larger top and a smaller bottom, and the hinge sleeve (9) is provided with a conical sleeve hole that matches the shape of the hinge shaft (10), and the hinge shaft (10) is rotatably mounted in the conical sleeve hole.

4. The slip for oil and gas drilling according to claim 1, characterized in that: Adjacent slip units (1) are rotatably connected via a hinge, wherein the hinge comprises a hinge sleeve (9) and a hinge shaft (10), wherein the hinge shaft (10) is provided with a step, and the hinge sleeve (9) is provided with a step hole that matches the shape of the hinge shaft (10), and the hinge shaft (10) is rotatably mounted in the step hole.

5. The slip for oil and gas drilling according to claim 1, characterized in that: The slip body (2) is provided with a hook (5) that cooperates with the slip lifting device.

6. The slip for oil and gas drilling according to claim 5, characterized in that: The hook body at the front end and the tail end of the hook (5) are respectively provided with anti-drop pins (6).

7. The slips for oil and gas drilling according to claim 1, characterized in that: The slip body (2) is provided with a plurality of rows of arc-shaped slip tooth plates (3) and a tooth plate pressing block (7) abutting against the top of the plurality of rows of arc-shaped slip tooth plates (3) and used for pressing the arc-shaped slip tooth plates (3); the tooth plate pressing block (7) is fixedly connected to the slip body (2).

8. The slips for oil and gas drilling according to claim 1, characterized in that: A baffle (8) is provided at the gap between adjacent slip units (1); after the slips are closed, the baffle (8) cooperates with the side walls of adjacent slip units (1) or baffles (8) provided on adjacent slip units (1) to cover the gap.

9. The slip for oil and gas drilling according to claim 8, characterized in that: A baffle (8) is provided on one side of the slip body (2); after the slip is closed, the other end of the baffle (8) abuts against the side wall of the adjacent slip body (2).

10. The slip for oil and gas drilling according to claim 8, characterized in that: Baffles (8) are provided on both sides of the slip body (2); after the slip is closed, the projections of the baffles (8) on adjacent slip bodies (2) in the horizontal plane overlap.

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