Casing centralizer

Abstract

The utility model relates to the technical field of oil extraction and well cementation, in particular to a casing centralizer which comprises a double-bow spring piece and a clamping device, and the clamping device comprises a pressing ring and a cover plate. The pressing rings are semicircular rings, lug plates are arranged on the two sides of each pressing ring, threaded holes are formed in the lug plates, and locking bolts penetrate through the threaded holes to connect the two pressing rings. The pressing ring is connected with the cover plate, mounting grooves are formed in the inner sides of the pressing ring and the cover plate, and spring clamping blocks are mounted in the mounting grooves; a circular groove is formed in the arched part of the double-bow spring piece, and a roller is arranged in the circular groove. According to the utility model, the rollers are arranged on the double-bow spring piece, so that direct friction with the well wall is avoided, and the service life of the device is prolonged; and sliding friction between the original casing centralizer and the well wall is changed into rolling friction, so that the casing can be put down conveniently. The semi-circular ring pressing rings are arranged at the two ends of the novel casing centralizer, the novel casing centralizer is clamped on a casing through the locking bolts and the spring clamping blocks, and due to the compressibility of the spring clamping blocks, the novel casing centralizer can be applied to casings of different specifications and sizes.

Description

Technical Field

[0001] The utility model relates to the technical field of oil production and cementing, in particular to a casing centralizer. Background Art

[0002] The casing centralizer is a device loaded on the casing string to center the casing string in the wellbore. During drilling and cementing operations, the casing centralizer limits the casing string, thereby reducing the casing eccentricity, improving the cementing displacement efficiency, and reducing the casing curvature. It is one of the indispensable accessories for casing downhole.

[0003] Centralizers can be divided into two categories according to their styles: elastic centralizers and rigid centralizers. Elastic centralizers include single-bow, double-bow and multi-bow. Compared with single-bow centralizers, double-bow centralizers have smaller starting force and greater centralizing force.

[0004] The centralizer is fixed on the casing and then enters the well. The existing centralizer has the problem that when the casing enters the well, the friction between the centralizer and the well wall causes the casing to fall. When the wellhead is slightly smaller, the centralizer becomes stuck due to the unchanged size, resulting in a narrow application range of the centralizer. In actual application, the centralizer may move up and down on the casing due to the unstable fixation, affecting the progress of the construction. In addition, during the casing lowering process, some parts of the casing centralizer rub against the well wall severely, thus affecting the life of the entire casing centralizer. Utility Model Content

[0005] In order to overcome the problems existing in the prior art, the utility model aims to provide a casing centralizer to solve the shortcomings of the current centralizer, such as large downhole resistance, narrow application range, easy surface wear and short service life.

[0006] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: a casing centralizer, comprising a plurality of double-bow spring sheets and a clamping device, wherein the two ends of the double-bow spring sheets are respectively connected to a clamping device; the clamping device comprises a clamping ring and a cover plate; the clamping ring is a semicircular ring, and ear plates are provided on both sides of the clamping ring, and threaded holes are provided on the ear plates, and locking bolts are used to pass through the threaded holes to connect the two clamping rings;

[0007] The clamping ring and the cover plate are connected by connecting bolts. The inner sides of the clamping ring and the cover plate are provided with mounting grooves, and spring clamps are installed in the mounting grooves.

[0008] The utility model is further configured as follows: the installation groove includes a first fan-shaped groove and a second fan-shaped groove, the top of the clamping ring is provided with a first fan-shaped groove, and the bottom of the cover plate is provided with a second fan-shaped groove; the positions of the first fan-shaped groove and the second fan-shaped groove correspond to each other.

[0009] The utility model is further configured as follows: one end of the spring clamp block is a mounting block, and the other end is a clamping block; a spring groove is provided on the mounting block, and a spring is installed in the spring groove; and an anti-slip clamping pad is provided on the clamping block.

[0010] The utility model is further configured as follows: the spring clamp is arc-shaped, and the shape of the mounting block is matched with the shape of the mounting groove.

[0011] The utility model is further configured as follows: the clamping ring is provided with a plurality of first threaded connection holes along the circumferential direction, the cover plate is provided with a plurality of second threaded connection holes along the circumferential direction, and the positions of the first threaded connection holes correspond to those of the second threaded connection holes; the clamping ring is connected to the cover plate by connecting bolts.

[0012] When the clamping ring is installed with the cover plate, the positions of the first fan-shaped groove and the second fan-shaped groove correspond to each other, forming the installation groove. The shape of the installation block is adapted to the installation groove, and the spring clamping block is installed in the installation groove between the clamping ring and the cover plate through the installation block. The spring clamping block is arc-shaped, and the shape of the clamping block is adapted to the sleeve.

[0013] The utility model is further configured as follows: a limiting groove is arranged at the bottom of the clamping ring, and the double-bow spring sheet is movably connected in the limiting groove.

[0014] The utility model is further configured as follows: the double-bow spring sheets are evenly distributed in a circumferential direction with the axis of the clamping ring as the center.

[0015] The utility model is further configured as follows: a circular groove is provided at the center of the arched part of the double-bow spring sheet, and a roller is arranged in the circular groove.

[0016] The utility model is further configured as follows: a roller shaft is arranged in the circular groove, the roller is installed in the circular groove through the roller shaft, and the roller does not contact the circular groove; a wear-resistant layer is clad on the surface of the roller, and the wear-resistant layer is an iron-based alloy layer reinforced by nickel-coated tungsten carbide, with a thickness of 1-2mm and a microhardness of 170-240HRC.

[0017] In summary, the beneficial effects of the above technical solution of the utility model are as follows:

[0018] 1. The casing centralizer described in the utility model adopts a double-bow spring sheet. By arranging a roller on the double-bow spring sheet, on the one hand, direct friction between the double-bow spring sheet and the well wall is avoided, and the service life of the double-bow spring sheet is extended; on the other hand, the sliding friction between the original casing centralizer and the well wall is changed to rolling friction, which is conducive to the lowering of the casing.

[0019] 2. The casing centralizer is provided with semicircular clamping rings at both ends, which are clamped on the casing by locking bolts and spring clamps. Due to the compressibility of the spring clamps, the new casing centralizer can be applied to casings of different specifications and sizes, and the installation is also more convenient.

[0020] 3. The parts of the casing centralizer, such as the roller surface, are strengthened by laser cladding technology, which has high hardness and strong wear resistance, extending the working life of the new casing centralizer. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for describing the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0022] Figure 1 It is a schematic diagram of the overall structure of the utility model.

[0023] Figure 2 It is a top view of the utility model.

[0024] Figure 3 A schematic diagram of the clamping device structure.

[0025] Figure 4 Schematic diagram of the bottom limit groove of the clamping device.

[0026] Figure 5 A schematic diagram of the installation slot.

[0027] Figure 6 This is a schematic diagram of the spring clamp installation.

[0028] Figure 7 Schematic diagram of the roller structure.

[0029] Figure 8 This is a schematic diagram of installing casings of different specifications according to the utility model.

[0030] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0031] 1. Double-bow spring sheet; 2. Pressure ring; 3. Cover plate; 4. Connecting bolt; 5. Locking bolt; 6. Spring clamp block; 61. Mounting block; 62. Clamping block; 7. Spring; 8. Roller; 9. Anti-slip clamping pad; 101. Round groove; 201. Ear plate; 202. Threaded hole; 203. First fan-shaped groove; 204. Limiting groove; 205. First threaded connection hole; 301. Second fan-shaped groove; 302. Second threaded connection hole; 601. Spring groove; 801. Wear-resistant layer. DETAILED DESCRIPTION

[0032] In order to enable those skilled in the art to better understand the technical solution of the present invention, the following is a clear and complete description of the technical solution of the present invention in conjunction with the drawings of the present invention. Based on the embodiments of the present invention, other similar embodiments obtained by ordinary technicians in the field without creative work should all fall within the scope of protection of the present invention. In addition, the directional words mentioned in the following embodiments, such as "up", "down", "left", "right", etc., are only referenced to the directions of the drawings. Therefore, the directional words used are used to illustrate rather than limit the creation of the present invention.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0034] The utility model is further described below in conjunction with the accompanying drawings and preferred embodiments.

[0035] Example:

[0036] like Figure 1-Figure 7 As shown, a preferred embodiment of the utility model is a casing centralizer, comprising a plurality of double-bow spring sheets 1 and a clamping device, wherein the two ends of the double-bow spring sheets 1 are respectively connected to a clamping device; the casing centralizer is a vertically symmetrical structure.

[0037] like Figure 3 , Figure 5 As shown, the clamping device includes a clamping ring 2 and a cover plate 3; the clamping ring 2 is a semicircular ring, and ear plates 201 are provided on both sides of the clamping ring 2, threaded holes are provided on the ear plates, and threaded holes 202 are provided on the ear plates 201, and locking bolts 5 pass through the threaded holes 202 to connect the two semicircular clamping rings 2.

[0038] The clamping ring 2 and the cover plate 3 are connected by connecting bolts 4. The inner sides of the clamping ring 2 and the cover plate 3 are provided with mounting grooves, and spring clamps 6 are installed in the mounting grooves.

[0039] The mounting groove includes a first fan-shaped groove 203 and a second fan-shaped groove 301. The first fan-shaped groove 203 is provided on the top of the clamping ring 2, and the second fan-shaped groove 301 is provided on the bottom of the cover plate 3. The positions of the first fan-shaped groove 203 and the second fan-shaped groove 301 correspond to each other. Figure 5 As shown, Figure 5 Figure (a) is a schematic diagram of the first fan-shaped groove 203. Figure 5 Figure (b) is a schematic diagram of the second fan-shaped groove 301.

[0040] Combination Figure 6 As shown, one end of the spring clamp block 6 is a mounting block 61, and the other end is a clamp block 62; a spring slot 601 is provided on the back of the mounting block 61, and a spring 7 is installed in the spring slot 601; an anti-slip clamp pad 9 is provided on the clamp block 62. The spring clamp block 6 is arc-shaped, and the shape of the mounting block 61 is adapted to the shape of the mounting slot 601.

[0041] The clamping ring 2 is provided with a plurality of first threaded connection holes 205 along the circumferential direction, and the cover plate 3 is provided with a plurality of second threaded connection holes 302 along the circumferential direction, and the positions of the first threaded connection holes 205 correspond to those of the second threaded connection holes 302; the clamping ring 2 is connected to the cover plate 3 by connecting bolts 4.

[0042] When the clamping ring 2 is installed with the cover plate 3, the positions of the first fan-shaped groove 203 and the second fan-shaped groove 301 correspond to each other, forming the installation groove. The shape of the installation block 61 is adapted to the installation groove, and the spring clamp block 6 is installed in the installation groove between the clamping ring 2 and the cover plate 3 through the installation block 61. The spring clamp block 6 is arc-shaped, and the shape of the clamp block 62 is adapted to the sleeve. The spring clamp block 6 is integrally formed by additive manufacturing.

[0043] like Figure 4 As shown, the bottom of the clamping ring 2 is provided with a limiting groove 204, and the double-bow spring piece 1 is movably connected in the limiting groove 204. The double-bow spring piece 1 is evenly distributed in the circumferential direction with the axis of the clamping ring 2 as the center. Figure 1-Figure 2 As shown, the double-bow spring piece 1 is in a double-bow shape, including two arches, and the number is six. The six double-bow spring pieces 1 are symmetrical about the axis of the clamping ring 2 and are evenly distributed.

[0044] A circular groove 101 is provided at the center of the arched portion of the double-bow spring sheet 1 , and a roller 8 is arranged in the circular groove 101 .

[0045] like Figure 7 As shown, Figure 7 Figure (a) is a partial enlarged view of the arched part of the double-bow spring sheet 1. Figure 7 Figure (b) is a schematic diagram of the roller structure. The roller 8 is a metal roller 8, and a wear-resistant layer 801 is clad on the surface of the roller 8 by laser cladding technology. The wear-resistant layer 801 is a nickel-clad tungsten carbide-reinforced iron-based alloy layer with a thickness of 1-2 mm and a microhardness of 170-240 HRC. The roller 8 does not contact the circular groove 101.

[0046] When working, first clamp the assembled casing centralizer to the casing, tighten the locking bolt 5, drive the spring 7 to compress, and then lock and fix the casing centralizer on the casing. It should be noted that the utility model clamps the casing on the casing through the locking bolt 5 and the spring clamp 6. Due to the compressibility of the spring clamp 6 and the adjustability of the locking bolt 5, the new casing centralizer can be used on casings of different specifications and sizes, and the installation is also more convenient. Figure 8 As shown, Figure 8 (a) is a schematic diagram of the casing centralizer installed on a pipe with a smaller diameter. Figure 8 (b) is a schematic diagram of the casing centralizer installed on a pipe with a larger diameter.

[0047] When the casing is lowered, the double-bow spring sheet 1 is squeezed by the well wall and deformed, thereby maintaining the casing in the center. The roller 8 is arranged on the double-bow spring sheet 1, which, on the one hand, avoids direct friction between the double-bow spring sheet 1 and the well wall, prolongs the life of the double-bow spring sheet 1; on the other hand, the sliding friction between the original casing centralizer and the well wall is changed to rolling friction, which is conducive to the lowering of the casing. As the well wall continues to shrink, when the double-bow spring sheet 1 is deformed to the point where the center part contacts the casing, it reaches the deformation limit.

[0048] Finally, it should be noted that the above content is only used to illustrate the technical solution of the utility model, rather than to limit the protection scope of the utility model. Simple modifications or equivalent substitutions of the technical solution of the utility model by ordinary technicians in this field do not deviate from the essence and scope of the technical solution of the utility model.

Claims

1. A casing centralizer, comprising a plurality of double-bow spring sheets and a clamping device, wherein the two ends of the double-bow spring sheets are respectively connected to a clamping device; characterized in that: The clamping device comprises a clamping ring and a cover plate; the clamping ring is a semicircular ring, and ear plates are provided on both sides of the clamping ring, and threaded holes are provided on the ear plates, and locking bolts are used to pass through the threaded holes to connect the two clamping rings; The clamping ring is connected to the cover plate, and mounting grooves are arranged on the inner sides of the clamping ring and the cover plate, and spring clamps are installed in the mounting grooves.

2. A casing centralizer according to claim 1, characterized in that: The mounting groove comprises a first fan-shaped groove and a second fan-shaped groove. The first fan-shaped groove is arranged on the top of the clamping ring, and the second fan-shaped groove is arranged on the bottom of the cover plate. The positions of the first fan-shaped groove and the second fan-shaped groove correspond to each other.

3. A casing centralizer according to claim 2, characterized in that: One end of the spring clamp block is a mounting block, and the other end is a clamping block; a spring slot is provided on the mounting block, and a spring is installed in the spring slot; and an anti-slip clamping pad is provided on the clamping block.

4. A casing centralizer according to claim 3, characterized in that: The spring clamp is arc-shaped, and the shape of the mounting block matches the shape of the mounting groove.

5. The casing centralizer according to claim 1, characterized in that: The clamping ring is provided with a plurality of first threaded connection holes along the circumferential direction, and the cover plate is provided with a plurality of second threaded connection holes along the circumferential direction, and the positions of the first threaded connection holes correspond to those of the second threaded connection holes; the clamping ring is connected to the cover plate by connecting bolts.

6. The casing centralizer according to claim 1, characterized in that: A limiting groove is arranged at the bottom of the clamping ring, and the double-bow spring sheet is movably connected in the limiting groove.

7. The casing centralizer according to claim 1, characterized in that: The double-bow spring sheets are evenly distributed in a circumferential direction with the axis of the clamping ring as the center.

8. The casing centralizer according to claim 1, characterized in that: A circular groove is provided at the center of the arched part of the double-bow spring sheet, and a roller is arranged in the circular groove.

9. A casing centralizer according to claim 8, characterized in that: A roller shaft is arranged in the circular groove, and the roller is installed in the circular groove through the roller shaft, and the roller does not contact the circular groove; The surface of the roller is clad with a wear-resistant layer, which is an iron-based alloy layer reinforced with nickel-coated tungsten carbide. The thickness is 1-2mm and the microhardness is 170-240HRC.

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