High strength low friction composite semi-rigid casing centralizer

Abstract

The present application relates to the field of well cementing completion consolidation, and more particularly to a high-strength low-friction composite semi-rigid casing centralizer, aiming at solving the problem of the existing centralizer encountering greater resistance, which is not conducive to the pipe string running or is easily damaged due to insufficient strength. The present application comprises a rigid support and an elastic covering body. The rigid support comprises a main body and a rib plate protrudingly arranged on the outer surface of the main body, and the rib plate is uniformly distributed around the axis of the main body. The elastic covering body wraps the rib plate, and during the running of the centralizer, the elastic covering body is in contact with the well wall and is deformed by the extrusion of the well wall. The rigid support of the present application enables the centralizer to maintain sufficient strength and avoid structural damage. Meanwhile, the elastic covering body is deformed by the extrusion of the well wall during the running of the pipe string, avoiding direct pressure on the rib plate, reducing resistance, and further deforming the elastic covering body when encountering a reduced diameter, thereby improving the passability.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of well cementing and completion consolidation, and particularly relates to a high-strength and low-friction composite semi-rigid casing centralizer. BACKGROUND

[0002] The centralizer is a supporting tool frequently used in well cementing and completion operations. In the casing running operation, in order to keep the casing centered and improve the cementing quality, various centralizers are generally added to the pipe string, mainly including rigid centralizers, semi-rigid centralizers, elastic centralizers and various non-metal centralizers (resin or nylon centralizers). The rigid centralizer has high strength, but its outer diameter is fixed, which leads to large friction between the rigid centralizer and the upper casing or the well wall, and is not conducive to the running of the pipe string. Although the non-metal centralizer and the elastic centralizer effectively reduce the friction, they have low strength and are easily damaged during running, which affects the centralization of the casing and the cementing quality. SUMMARY

[0003] The present application aims to provide a high-strength and low-friction composite semi-rigid casing centralizer to solve the problems of large resistance encountered by the existing centralizer and poor strength of the existing centralizer.

[0004] To solve the above technical problems, the technical scheme provided by the present application is as follows:

[0005] A high-strength and low-friction composite semi-rigid casing centralizer includes a rigid support and an elastic covering body. The rigid support includes a main body and a rib plate protruding from the outer surface of the main body. The rib plate is uniformly distributed around the axis of the main body.

[0006] The elastic covering body covers the rib plate. During the running of the centralizer, the elastic covering body is in contact with the well wall and is deformed by the extrusion of the well wall.

[0007] Further, the rib plate includes a vertical plate and a horizontal plate perpendicular to the vertical plate. A T-shaped slot is formed in the main body, and the rib plate is connected to the T-shaped slot.

[0008] Further, the horizontal plate is arranged in the T-shaped slot, and the horizontal plate is perpendicular to the radial direction of the main body. The vertical plate protrudes from the outer surface of the main body.

[0009] Further, an elastic pad is arranged between the side of the horizontal plate away from the vertical plate and the T-shaped slot.

[0010] Further, the plane in which the vertical plate is located is not perpendicular to the axis of the main body.

[0011] Further, the inner side of the main body is covered by the elastic covering body.

[0012] Further, the main body includes a middle ring and end rings connected to both ends of the middle ring. The T-shaped slot is arranged on the middle ring, and the end rings block the side surfaces of the T-shaped slot.

[0013] Further, the main body is provided with a first auxiliary connecting through hole.

[0014] Further, the vertical plate is provided with a second auxiliary connecting through hole.

[0015] Further, the rigid support is made of metal material.

[0016] Further, the elastic covering body is made of plastic.

[0017] The technical effects that can be achieved by the above technical solutions are as follows:

[0018] The high-strength low-friction composite semi-rigid casing centralizer provided by the application comprises a rigid support and an elastic covering body, the rigid support comprises a main body and a rib plate protruding from the outer surface of the main body, and the rib plate is uniformly distributed around the axis of the main body.

[0019] The elastic covering body wraps the rib plate, and in the process of lowering the centralizer, the elastic covering body is pressed by the well wall and deformed.

[0020] The rigid support of the high-strength low-friction composite semi-rigid casing centralizer provided by the application can maintain sufficient strength of the centralizer and avoid structural damage, and at the same time, the elastic covering body is deformed by the well wall during the process of lowering the pipe string, avoiding direct pressure on the rib plate, reducing resistance, and further deforming the elastic covering body when encountering a reduced diameter, improving passability, restoring the original diameter under the action of its own elasticity after passing through the reduced diameter, maintaining abutment with the well wall, ensuring casing centralization, and improving the passability of the centralizer on the premise of ensuring the rigidity of the centralizer. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the specific embodiments of the application or the technical solutions in the prior art, the following will briefly introduce the drawings needed to be used in the description of the specific embodiments or the prior art. Obviously, the drawings described below are some embodiments of the application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0022] Figure 1 The figure is a perspective view of the high-strength low-friction composite semi-rigid casing centralizer provided by the embodiment of the application.

[0023] Figure 2 The figure is an axial sectional view of the high-strength low-friction composite semi-rigid casing centralizer provided by the embodiment of the application.

[0024] Figure 3 The figure is a radial sectional view of the high-strength low-friction composite semi-rigid casing centralizer provided by the embodiment of the application.

[0025] Figure 4 For Figure 3 A partial enlarged view of the middle A;

[0026] Figure 5 For Figure 2 A structural schematic view of the rigid support 100;

[0027] Figure 6 For Figure 5 A perspective view of the middle ring 112;

[0028] Figure 7 For Figure 5 A perspective view of the end ring 113;

[0029] Figure 8 For Figure 5 A perspective view of the rib 120;

[0030] Figure 9 A structural schematic view of the rib 120.

[0031] Figure: 100-rigid support; 200-elastic covering body; 300-elastic pad; 110-main body; 120-rib; 111-T-shaped groove; 112-middle ring; 113-end ring; 114-first auxiliary connecting through hole; 121-vertical plate; 122-horizontal plate; 123-second auxiliary connecting through hole. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations.

[0033] Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without making creative efforts fall within the scope of protection of the present application.

[0034] It should be noted that: similar reference numbers and letters represent similar items in the following drawings, therefore, once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings.

[0035] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings or the orientation or positional relationship commonly used when the product of the present application is used, and are merely for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third" and the like are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0036] In addition, the terms "horizontal", "vertical", "overhanging" and the like do not mean that the components must be absolutely horizontal or overhanging, but can be slightly inclined. For example, "horizontal" only means that it is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0037] In the description of the present application, it should be noted that unless otherwise specified and limited, the terms "arrangement", "installation", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0038] Some embodiments of the present application will be described in detail below with reference to the accompanying drawings. The following examples and features in the examples can be combined with each other without conflict.

[0039] The centralizer is a supporting tool often used in well cementing and completion operations, which keeps the casing centered during casing running operation to improve well cementing quality. The existing rigid centralizer has high strength, but because its outer diameter is fixed, it causes large friction between the upper casing or the well wall, which is not conducive to the running of the pipe string. Although the non-metallic centralizer and the elastic centralizer effectively reduce the friction, they have low strength and are often damaged during running, which affects the centralization of the casing and the well cementing quality. That is, the existing centralizer has the problem of large resistance encountered, which is not conducive to the running of the pipe string, or the problem of insufficient strength and easy damage.

[0040] Therefore, the present application provides a high-strength low-friction composite semi-rigid casing centralizer, which comprises a rigid support 100 and an elastic covering body 200, the rigid support 100 comprises a main body 110 and a rib 120 protrudingly arranged on the outer surface of the main body 110, the ribs 120 are uniformly distributed around the axis of the main body 110;

[0041] The elastic cover 200 wraps around the rib 120. During the process of the centralizer being lowered, the elastic cover 200 abuts against the well wall and is deformed by the compression of the well wall.

[0042] The rigid support 100 of the high-strength, low-friction composite semi-rigid casing centralizer provided by this invention enables the centralizer to maintain sufficient strength and avoid structural damage. At the same time, the elastic cover 200 deforms under the pressure of the well wall during the tubing string insertion process, preventing the ribs 120 from being directly compressed and reducing resistance. Furthermore, when encountering a diameter reduction, the elastic cover 200 deforms further, improving the throughput. After passing through the diameter reduction, it can restore its original diameter under its own elasticity, maintaining contact with the well wall and ensuring the casing is centered. This improves the throughput of the centralizer while ensuring its rigidity.

[0043] The following is in conjunction with the appendix Figures 1-9 The structure and shape of the high-strength, low-friction composite semi-rigid sleeve centralizer provided in this embodiment are described in detail below:

[0044] In the optional solutions of this embodiment, such as Figure 2 , 5 As shown, the rigid support 100 includes a main body 110 and ribs 120 connected to the main body 110. The main body 110 is composed of end rings 113 and intermediate rings 112. The end rings 113 and intermediate rings 112 are coaxially arranged, and each end of the intermediate ring 112 is connected to an end ring 113. The inner diameters of the end rings 113 and intermediate rings 112 are the same.

[0045] Furthermore, such as Figure 3 , 4 As shown in Figure 6, a T-shaped groove 111 is provided on the intermediate ring 112. The T-shaped groove 111 is arranged along the axial direction of the intermediate ring 112 and penetrates the intermediate ring 112 along the axial direction of the intermediate ring 112.

[0046] Optionally, the T-groove 111 is at a certain angle to the axis of the intermediate ring 112, and the starting point and ending point of the T-groove 111 are located at the two end faces of the intermediate ring 112, respectively.

[0047] Optionally, the T-groove 111 does not penetrate the intermediate ring 112, but only opens on one end face of the intermediate ring 112.

[0048] Furthermore, the rib 120 includes a vertical plate 121 and a horizontal plate 122, such as Figure 8 As shown, the vertical plate 121 is perpendicular to the horizontal plate 122, forming a T-shape, and is inserted into the T-shaped groove 111, so that the rib 120 is engaged in the T-shaped groove 111, while the vertical plate 121 protrudes from the outer surface of the middle ring 112.

[0049] Further, the side of the horizontal plate 122 away from the vertical plate 121 is provided with an elastic pad 300 between the T-shaped groove 111, when the rib 120 is pressed vertically to the horizontal plate 122, the rib 120 is pressed to the elastic pad 300, and the rib 120 moves to the inside of the middle ring 112 in the direction perpendicular to the horizontal plate 122, the thickness of the elastic pad 300 is compressed, so that the diameter of the centralizer is reduced, and the passability of the centralizer is improved.

[0050] Further, the length of the elastic pad 300 is less than the length of the horizontal plate 122, which ensures that the elastic pad 300 has enough deformation space after being deformed under pressure.

[0051] Further, the plane in which the vertical plate 121 is located is not perpendicular to the axis of the middle ring 112.

[0052] Optionally, the plane in which the vertical plate 121 is located is not parallel to the axis of the middle ring 112, so that the fluid flowing through generates a vortex, improving the displacement efficiency.

[0053] Further, as shown in Figure 8 The side of the vertical plate 121 away from the horizontal plate 122 is provided with a chamfer, which plays a guiding role, improves the passability of the centralizer during running in, and prevents the centralizer from being stuck.

[0054] Further, the rib 120 is uniformly distributed around the axis direction of the middle ring 112.

[0055] Further, the number of ribs 120 is 6.

[0056] Further, as shown in Figure 7 The side of the end ring 113 connected with the middle ring 112 is provided with a flange, which seals the opening of the T-shaped groove 111, and further fixes the position of the rib 120, so that the rib 120 does not slide in the T-shaped groove 111 along the length direction of the T-shaped groove 111.

[0057] Further, the flange of the end ring 113 and the end surface of the middle ring 112 can be connected by bolts, which improves the maintainability of the centralizer, and facilitates the replacement of the failed rib 120 or elastic pad 300.

[0058] Optionally, the end ring 113 and the middle ring 112 are connected by welding, which reduces the machining amount of parts.

[0059] In an optional scheme of the embodiment, the inside of the main body 110 is covered by the elastic covering body 200, so that the centralizer is easily sleeved into the casing, and after being sleeved into the casing, the elastic covering body 200 between the casing and the centralizer is deformed, eliminating the gap between the casing and the centralizer, and improving the coaxiality of the centralizer and the casing.

[0060] Further, as shown in Figure 1As shown, the elastic cover 200 completely wraps the rigid support 100, so that the elastic cover 200 is firmly connected with the rigid support 100 and the elastic cover 200 is not easily damaged.

[0061] Further, the first auxiliary connecting through hole 114 is arranged on the side wall of the main body 110, so as to improve the connecting strength between the elastic cover 200 and the main body 110 and prevent the elastic cover 200 from being separated from the centralizer during the centralizer running-in process.

[0062] Further, the second auxiliary connecting through hole 123 is arranged on the vertical plate 121, as shown in Figure 8 so as to improve the connecting strength between the rib 120 and the elastic cover 200 and prevent the elastic cover 200 from being stripped during the centralizer running-in process.

[0063] Optionally, as shown in Figure 9 the second auxiliary connecting through hole 123 can be arranged as a square hole, and a groove is formed on the side of the vertical plate 121 away from the horizontal plate 122, so as to improve the connecting strength between the rib 120 and the elastic cover 200.

[0064] Further, the rigid support 100 is made of a metal material.

[0065] Optionally, the rigid support 100 is made of steel or aluminum.

[0066] Further, the elastic cover 200 is made of a non-metal material.

[0067] Optionally, the elastic cover 200 is made of plastic.

[0068] The working process of the high-strength and low-friction composite semi-rigid casing centralizer provided in the embodiment is as follows:

[0069] The centralizer is sleeved into the casing, and a stop ring is arranged at both ends of the centralizer. During the running-in process, the elastic cover 200 at the rib 120 is extruded by the pipe column or the wellbore, so as to maintain the centralization of the casing.

[0070] When a reduced-diameter section is encountered, the elastic cover 200 at the rib 120 is further extruded and deformed, so that the outer diameter of the centralizer is reduced, thereby ensuring that the centralizer passes through the reduced-diameter section without being damaged.

[0071] When a reduced-diameter section with a smaller cross section is encountered, the rib 120 is further extruded, and at this time, the rib 120 extrudes the elastic pad 300 under the action of an external force, so that the elastic pad 300 is deformed, and the outer shape of the centralizer is further reduced, thereby ensuring that the centralizer passes through.

[0072] After the centralizer passes through the reduced diameter section, the elastic pad plate 300 and the elastic covering body 200 return to the original state by virtue of the elasticity thereof, keep the state of abutting against the well wall or the pipe string, and realize the centralization of the casing. The elasticity deformation of the centralizer improves the passability of the centralizer and reduces the resistance encountered in the process of lowering the centralizer.

[0073] Meanwhile, the centralizer is guaranteed to have sufficient strength by the support of the rigid support 100, so that the centralizer is not easy to be damaged.

[0074] In an optional solution of the embodiment, the elastic pad plate 300 can not be arranged, the fin 120 and the main body 110 are fixedly connected, and only the elasticity of the elastic covering body 200 is relied on to guarantee the passability and the centralizing effect of the centralizer.

[0075] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A high-strength, low-friction composite semi-rigid sleeve centralizer, characterized in that, It includes a rigid support (100) and an elastic cover (200). The rigid support (100) includes a main body (110) and ribs (120) protruding from the outer surface of the main body (110). The ribs (120) are evenly distributed around the axis of the main body (110). The elastic covering (200) wraps around the rib (120). During the process of the centralizer being lowered, the elastic covering (200) abuts against the well wall and is deformed by the compression of the well wall. The rib (120) includes a vertical plate (121) and a horizontal plate (122) perpendicular to the vertical plate (121). The main body (110) has a T-shaped groove (111) and the rib (120) is engaged in the T-shaped groove (111). The horizontal plate (122) is disposed in the T-shaped groove (111), and the horizontal plate (122) is perpendicular to the radial direction of the main body (110); The vertical plate (121) protrudes from the outer surface of the main body (110); An elastic pad (300) is provided between the side of the horizontal plate (122) away from the vertical plate (121) and the T-shaped groove (111). The plane containing the vertical plate (121) is not perpendicular to the axis of the main body (110); The inner side of the main body (110) is covered by an elastic covering (200).

2. The high-strength, low-friction composite semi-rigid sleeve centralizer according to claim 1, characterized in that, The main body (110) includes an intermediate ring (112) and end rings (113) connected to both ends of the intermediate ring (112). The T-shaped groove (111) is disposed on the intermediate ring (112), and the end ring (113) blocks the side of the T-shaped groove (111).

3. The high-strength, low-friction composite semi-rigid sleeve centralizer according to claim 2, characterized in that, The main body (110) is provided with a first auxiliary connection through hole (114).

4. The high-strength, low-friction composite semi-rigid sleeve centralizer according to claim 3, characterized in that... The vertical plate (121) is provided with a second auxiliary connection through hole (123).

5. The high-strength, low-friction composite semi-rigid sleeve centralizer according to claim 1, characterized in that, The rigid support (100) is made of metal.

6. The high-strength, low-friction composite semi-rigid sleeve centralizer according to claim 1, characterized in that, The elastic covering (200) is made of plastic.

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