Bow spring centralizer for sleeve

Abstract

The bow spring centralizer for the casing pipe comprises two supporting cylinders which are arranged at intervals and arranged on the outer edge face of the casing pipe in a sleeving mode, the ends, close to each other, of the two supporting cylinders are oppositely hinged to a plurality of connecting arms, and the connecting arms are arranged in the circumferential direction of the supporting cylinders; the two opposite connecting arms on the different supporting cylinders are hinged, the outer end faces of the connecting arms are provided with bow-shaped spring pieces, and the bow-shaped spring pieces are bent in the direction away from the connecting arms; one end of each bow-shaped spring piece is detachably and fixedly connected with the corresponding connecting arm, the other end of each bow-shaped spring piece is slidably connected with the corresponding connecting arm, and the fixedly-connected ends of the two opposite bow-shaped spring pieces are both close to the same supporting cylinder. When abutting against the side wall of the hoistway, the bow-shaped spring pieces can move relatively along the sliding grooves, excessive extrusion between the bow-shaped spring pieces and the side wall of the hoistway is avoided, on one hand, the casing pipe can enter the hoistway more smoothly, and on the other hand, damage to the side wall of the hoistway caused by strong extrusion can be reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of core shooting machines, in particular to a bow spring centralizer for casing. Background Art

[0002] During oil extraction, drilling operations are required. After drilling is completed, casing needs to be inserted for fixing. This is an important component of well stability. Poor fixing quality can cause major problems throughout the life cycle of the well. To achieve optimal results, the casing should be prepared with a centralizer in advance. Its function is to straighten the casing during insertion into the well. During installation, the centralizer is usually installed at intervals on the outer edge of the casing. Traditional centralizers include elastic centralizers, which usually consist of casing and fixed elastic plates. However, during use, the inventors discovered that there are many defects. Because the side walls of the well are sharp, hard, relatively fragile, and have a certain curvature, when the centralizer enters the well along with the casing, the elastic plates clash with the protrusions or bends of the side walls, generating significant friction between the elastic plates and the well wall, affecting the movement of the casing and even damaging the well. Moreover, multiple elastic plates are often fixed by welding, making it difficult to replace individual elastic plates if one or more elastic plates are insufficiently elastic or damaged. Utility Model Content

[0003] In order to solve the technical problems existing in the above background technology, the utility model provides a bow spring centralizer for casing.

[0004] The technical solution of this utility model is as follows:

[0005] A bow spring centralizer for casing comprises two spaced support tubes sleeved on the outer edge of the casing, wherein the two support tubes are hingedly connected to the ends thereof adjacent to each other with a plurality of connecting arms, and the plurality of connecting arms are arranged along the circumference of the support tubes;

[0006] Two connecting arms on different supporting cylinders are hinged to each other, and the outer end surfaces of the connecting arms are provided with bow-shaped spring pieces, and the bow-shaped spring pieces are bent in a direction away from the connecting arms;

[0007] One end of the bow-shaped spring piece is detachably fixed to the connecting arm, and the other end is slidably connected to the connecting arm, and the fixed ends of the two opposite bow-shaped spring pieces are both close to one end of the same support tube.

[0008] In order to limit the support tube, a limiting sleeve is provided at one end of the support tube away from the connecting arm, and one end of the limiting sleeve extends into the support tube and is threadedly connected to the sleeve, and the other end is connected to a limiting ring.

[0009] In order to ensure the supporting effect on the sleeve, the length of the bow-shaped spring piece is 1 / 2-2 / 3 of the length of the connecting arm.

[0010] In order to ensure that the sliding end of the bow-shaped spring piece has sufficient sliding travel during extrusion, the length between the lowest end of the bow-shaped spring piece and the end of the connecting arm in the natural state is 1 / 5-2 / 5 of the length of the connecting arm.

[0011] The bow-shaped spring sheet is specifically designed as follows: the bow-shaped spring sheet comprises a middle bow-shaped portion and two connecting portions connected to the connecting arm, wherein one connecting portion is fixed to the connecting arm by a bolt;

[0012] The other connecting portion is connected to a sliding block at one end close to the connecting arm, and a sliding groove for the sliding block to slide is provided at a corresponding position of the connecting arm.

[0013] In order to facilitate the resetting of the bow-shaped spring piece and support the sliding block, a support spring is installed on the end surface of the sliding groove away from the fixed end of the bow-shaped spring piece.

[0014] In order to improve the stability of the bow-shaped spring piece when sliding, limiting blocks are connected on both sides of the connection part away from the fixed end of the bow-shaped spring piece, and a sliding bar is provided at one end of the limiting block close to the connecting arm, and a strip groove for sliding the sliding bar is opened on the side of the connecting arm corresponding to the position of the sliding bar.

[0015] In order to ensure that the sliding block and the sliding bar can slide synchronously, the length of the sliding groove is consistent with the length of the strip groove.

[0016] The beneficial effects of the utility model are as follows: the utility model is a bow spring centralizer for casing, firstly, the connecting arm hingedly connected to the support tube cooperates with the bow spring sheet installed on the outer end surface thereof, so that it can be mounted on the outside of the casing along with the support tube, and the casing can be supported after entering the wellbore, effectively preventing the eccentricity of the casing; secondly, the two support arms are hingedly arranged, and then the two bow spring sheets are connected relatively, thereby improving the supporting force of the casing; finally, one end of the bow spring sheet is fixed to the connecting arm, and the other end is slidably connected to the connecting arm, so that when the bow spring sheet enters the wellbore along with the casing, it can move relative to the slide groove when it collides with the side wall of the wellbore, thereby avoiding excessive squeezing of the bow spring sheet and the side wall of the wellbore, on the one hand, making the casing enter the wellbore smoother, and on the other hand, reducing the damage to the side wall of the wellbore caused by strong squeezing, and the bolt connection adopted at the fixed end facilitates the disassembly of the bow spring sheet, and then facilitates the replacement of a single or multiple spring sheets after damage. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] By reading the detailed description of the preferred embodiment below, the solutions and advantages of the present application will become clear to those skilled in the art. The accompanying drawings are only used to illustrate the preferred embodiment and are not to be considered as limiting the present invention.

[0018] In the attached figure:

[0019] Figure 1 This is a schematic diagram of the structure of the utility model;

[0020] Figure 2 This is the enlarged view of point A;

[0021] Figure 3 It is a cross-sectional view of the utility model;

[0022] The components represented by the reference numerals in the figure are:

[0023] 1. Sleeve; 2. Support tube; 3. Connecting arm; 4. Bow-shaped spring sheet; 41. Bow-shaped portion; 42. Connecting portion; 5. Limit sleeve; 6. Limit ring; 7. Sliding block; 8. Slide groove; 9. Support spring; 10. Limit block; 11. Slide bar; 12. Strip groove. DETAILED DESCRIPTION

[0024] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings.

[0025] Example

[0026] As mentioned in the background technology, a centralizer is required when the casing 1 is lowered into the well to ensure that it is in the center of the well and to ensure the service life of the entire well. The inventor found that the existing centralizer has many defects when in use. For example, it is difficult to replace the spring sheet after it is damaged. Secondly, when the spring sheet is lowered into the well along with the casing 1, it is easy to cause friction with the side wall of the well, affecting the lowering speed of the casing 1 and the structure of the well. Therefore, the inventor made improvements on the basis of the existing centralizer and designed a new bow-shaped spring centralizer, which is described in detail below with reference to the drawings.

[0027] This embodiment provides a bow spring centralizer for casing. Figure 1 The arrow indicates the direction in which the casing 1 is placed into the wellbore, comprising two spaced support tubes 2 which are sleeved on the outer edge of the casing 1, and a limiting sleeve 5 is provided at the opposite ends of the two support tubes 2. The limiting sleeve 5 is used to limit the support tube 2 and can be fixed to the casing 1, and a hole for the limiting sleeve 5 to enter is provided at the end of the support tube 2 close to the limiting sleeve 5. The limiting sleeve 5 is threadedly connected to the casing 1, and a limiting ring 6 is connected to the end of the limiting sleeve 5 away from the support tube 2, the diameter of which is larger than the outer diameter of the support tube 2, which can block the support tube 2.

[0028] In this embodiment, the reason for arranging the two support tubes 2 at intervals is to facilitate the installation of the bow-shaped spring sheet 4. Specifically, the ends of the two support tubes 2 that are close to each other are relatively hinged with multiple connecting arms 3, and the multiple connecting arms 3 are arranged circumferentially along the support tube 2. Each support tube 2 has at least three connecting arms 3 evenly distributed circumferentially, and the two connecting arms 3 on different support tubes 2 are hinged, that is, the connecting arms 3 connecting the two support tubes 2 are hinged to each other, and the hinged position abuts against the casing 1. Through the hinged setting, the stabilizer can be suitable for use with a large number of casings 1 of different sizes, and can all play a supporting role with the side wall of the well. Moreover, the outer end face of the connecting arm 3 is installed with a bow-shaped spring sheet 4, and the bow-shaped spring sheet 4 is bent in the direction away from the connecting arm 3. The outward-bent bow-shaped spring sheet 4 can form a support with the side wall of the well, so that the casing 1 is in the center position of the well.

[0029] In this scheme, combined with Figure 2 and Figure 3 , the installation of the bow-shaped spring piece 4 is designed. One end of the bow-shaped spring piece 4 is detachably fixed to the connecting arm 3, and the other end is slidably connected to the connecting arm 3. The fixed ends of the two opposite bow-shaped spring pieces 4 are both close to one end of the same support tube 2, that is, the front end position of the direction in which the casing 1 is lowered into the well is fixed. Specifically, the bow-shaped spring piece 4 includes a middle bow-shaped portion 41 and two connecting portions 42 connected to the connecting arm 3. The bow-shaped portion 41 is made of elastic material and can be made using existing technology. The connecting portions 42 are located at both ends of the bow-shaped portion 41 and are used to connect with the connecting arm 3 connection, one of the connecting parts 42 is fixed to the connecting arm 3 by a bolt, the connecting part 42 is the front connecting part 42 in the direction of the casing 1 being lowered into the well, and the other connecting part 42 is connected to a sliding block 7 at one end close to the connecting arm 3, and a sliding groove 8 for the sliding block 7 to slide is opened at the corresponding position of the connecting arm 3. When the arched part 41 is lowered into the well along with the casing 1, the side wall of the well can squeeze the arched part 41 to push the arched part 41 to slide in the sliding groove 8 along with the sliding block 7, and when the sliding block 7 slides to conflict with the sliding groove 8, the arched part 41 still maintains the arched state to ensure that it plays a supporting role.

[0030] Moreover, a support spring 9 is installed on the end surface of the slide groove 8 away from the fixed end of the bow-shaped spring sheet 4, which can support the sliding block 7, so that after the casing 1 is lowered into the well, it can support the sliding block 7 and then support the bow portion 41, so as to ensure its bow-shaped state and support the casing 1.

[0031] On the basis of the above structure, the length of the bow-shaped spring piece 4 is 1 / 2-2 / 3 of the length of the connecting arm 3, ensuring the overall length of the bow-shaped spring piece 4, increasing the contact area with the side wall of the well, and then improving the support effect. In addition, the length of the lowest end of the bow-shaped spring piece 4 from the end of the connecting arm 3 in the natural state is 1 / 5-2 / 5 of the length of the connecting arm 3. It should be noted that when the bow portion 41 is in the natural state, that is, the extrusion state, no extrusion occurs between the sliding block 7 and the support spring 9. The above design makes the bottom end of the bow-shaped spring piece 4 have a certain distance from the end of the connecting arm 3, so that the bow-shaped spring piece 4 can slide at this distance when squeezed, providing it with sufficient movement stroke.

[0032] Secondly, limit blocks 10 are connected on both sides of the connection portion 42 away from the fixed end of the bow spring piece 4, and the limit blocks 10 are connected to the connection portion 42 of the bow spring piece 4. Figure 1 and Figure 2 The cam 11 is provided with a plurality of grooves 12 on the side of the connecting arm 3 so that the sliding bar 11 can slide in the cam 12. The length of the groove 8 is consistent with the length of the groove 12. The sliding block 7 and the sliding bar have the same movement distance and will not limit the movement of the other party. In order to facilitate the disassembly and installation of the bow spring sheet 4, the limit block 10 is made of rubber or other elastic material. Under the action of external force, it can be pulled toward the outside away from the connecting part 42, and the distance between the two connecting blocks becomes larger, which makes it convenient for the two limit blocks 10 to be buckled onto both sides of the connecting arm 3, so that the sliding bar 11 enters the groove 12, and it is convenient for the disassembly and installation of the connecting arm 3.

Claims

1. A bow spring centralizer for casing, comprising two spaced support tubes (2) sleeved on the outer edge of the casing (1), characterized in that: A plurality of connecting arms (3) are hingedly connected to the adjacent ends of the two support cylinders (2), and the plurality of connecting arms (3) are arranged along the circumference of the support cylinders (2); Two connecting arms (3) on different supporting cylinders (2) are hinged to each other, and a bow-shaped spring piece (4) is installed on the outer end surface of the connecting arm (3), and the bow-shaped spring piece (4) is bent in a direction away from the connecting arm (3); One end of the bow-shaped spring piece (4) is detachably fixed to the connecting arm (3), and the other end is slidably connected to the connecting arm (3), and the fixed ends of the two opposite bow-shaped spring pieces (4) are both close to one end of the same support tube (2).

2. The bow spring centralizer for casing according to claim 1, characterized in that: A limiting sleeve (5) is provided at one end of the support tube (2) away from the connecting arm (3), and one end of the limiting sleeve (5) extends into the support tube (2) and is threadedly connected to the sleeve (1), while the other end is connected to the limiting ring (6).

3. The bow spring centralizer for casing according to claim 1, characterized in that: The length of the bow-shaped spring piece (4) is 1 / 2-2 / 3 of the length of the connecting arm (3).

4. The bow spring centralizer for casing according to claim 3, characterized in that: The length of the lowest end of the bow-shaped spring piece (4) from the end of the connecting arm (3) in the natural state is 1 / 5-2 / 5 of the length of the connecting arm (3).

5. The bow spring centralizer for casing according to claim 1, characterized in that: The bow-shaped spring sheet (4) comprises a middle bow-shaped portion (41) and two connecting portions (42) connected to the connecting arm (3), wherein one of the connecting portions (42) is fixed to the connecting arm (3) by a bolt; The other connecting portion (42) is connected to a sliding block (7) at one end close to the connecting arm (3), and a sliding groove (8) for the sliding block (7) to slide is provided at a corresponding position of the connecting arm (3).

6. The bow spring centralizer for casing according to claim 5, characterized in that: A support spring (9) is installed on the end surface of the sliding groove (8) away from the fixed end of the bow-shaped spring piece (4).

7. The bow spring centralizer for casing according to claim 5, characterized in that: The connection portion (42) away from the fixed end of the bow-shaped spring piece (4) is connected to the limiting blocks (10) on both sides, and the limiting blocks (10) are provided with a sliding bar (11) at one end close to the connecting arm (3), and the side of the connecting arm (3) is provided with a strip groove (12) for the sliding bar (11) to slide at a position corresponding to the sliding bar (11).

8. The bow spring centralizer for casing according to claim 7, characterized in that: The length of the sliding groove (8) is consistent with the length of the strip groove (12).

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