Power centralizer for downhole casing

Abstract

The application discloses a strong centralizer for downhole casing. The technical scheme constructs annular support body between casing string and inner wall of wellbore, and adds independent centralizing assembly at guide pipe port, and fully strengthens centralizing effect. In structure aspect, the application adopts tubular body with rear protruding part as main structure of sliding sleeve, sets guide cone surface in inner side of rear protruding part, and facilitates installation cooperation of casing string and the application; inside the sliding sleeve, the application adopts support ring and fixing disc as two-stage inner support body, ensures that the application keeps stable in wellbore, and plays good positioning effect on guide pipe. While the guide pipe plays centralizing effect on casing string, the application sets radial extending slide rail at port, and matches with positioning block, when casing string is seriously offset in radial direction, the positioning block can play double centralizing effect by clamping effect. The application can prevent radial offset with high strength, and has obvious progress.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of mine machinery, in particular to a strong centralizer for downhole casing. BACKGROUND

[0002] The centralizer refers to a rigid and elastic centralizing frame installed on the outer surface of the casing in oil and gas drilling to ensure that the casing string is in the center of the wellbore. The centralizer is one of the casing accessories, which is installed on the casing string to keep the casing string centered in the wellbore.

[0003] In the prior art, the centralizer is divided into rigid centralizer and spring centralizer. The use of the centralizer can not only ensure that the cement sheath of the casing string has a certain thickness, but also reduce the resistance when the casing is lowered, avoid sticking the casing, and is beneficial to improving the cementing quality. The centralizer has the characteristics of simple structure, convenient use, long service life and relatively low cost. At present, the stability of the conventional centralizer needs to be improved, especially when the casing string has a serious radial deviation in the wellbore, the conventional centralizer often fails to meet the requirements. SUMMARY

[0004] The present application aims at the technical defects of the prior art, and provides a strong centralizer for downhole casing to solve the technical problem that the conventional centralizer is difficult to ensure sufficient stability when coping with the casing string with serious radial deviation.

[0005] To achieve the above technical purpose, the present application adopts the following technical scheme:

[0006] The strong centralizer for downhole casing comprises a sliding sleeve, a tubular body, a rear protruding part, a guide cone surface, a first screw, a support ring, a closed ring, a support seat, a positioning ring, a fixed disc, a guide pipe, a second screw, a sliding rail, a third screw and a positioning block. The tubular body is arranged at the front end of the sliding sleeve, the rear protruding part is arranged at the rear end of the sliding sleeve, the guide cone surface is arranged in the rear protruding part, the front end of the guide cone surface extends to the casing string hole, the rear protruding part is in communication with the tubular body through the casing string hole, the tubular body, the support ring and the closed ring are fixedly connected in sequence by the first screws, the positioning ring is kept on the front side of the closed ring, the guide pipe is arranged on the front side of the fixed disc and is in butt joint with the through hole in the middle of the positioning ring, the fixed disc is kept in the protruding part, the positioning ring and the closed ring are fixed by the second screw, the support seat is located on the front side of the closed ring, the sliding rail is fixed on the support seat by the third screw, and the positioning block is arranged on the inner side of the sliding rail and is located at the port of the through hole.

[0007] Preferably, the support seat has a plurality of support seats which are uniformly arranged in the circumferential direction on the front side of the closed ring.

[0008] Preferably, the inner end surface of the positioning block is a cylindrical surface, and the diameter of the cylindrical surface is equal to the diameter of the through hole.

[0009] Preferably, a disc-shaped mounting groove is arranged in the sliding sleeve, and the fixing disc is located in the mounting groove.

[0010] Preferably, the fixing disc has multiple layers, and edges of the multiple layers are folded and stacked with each other.

[0011] Preferably, a notch is arranged on a front end of the guide pipe, and an inwardly extending flange is arranged in a middle part of the support ring, and the flange and the notch are embedded with each other.

[0012] Preferably, a plurality of inwardly extending convex ribs are arranged on an inner wall of the guide pipe, and the convex ribs are in direct contact with the casing string.

[0013] Preferably, an outer edge of the tubular body and an outer edge of the rear protruding part are both rounded.

[0014] Preferably, the sliding rail is a fixing block with a strip-shaped hole, and the third screw is arranged to pass through the fixing block through the strip-shaped hole, and the strip-shaped hole extends in a radial direction of the guide pipe.

[0015] Preferably, a diameter of the rear protruding part is smaller than a diameter of the tubular body, and connecting points between the first screw and the tubular body are uniformly distributed on a periphery of the rear protruding part.

[0016] The application discloses a strong centralizer for a downhole casing. The technical scheme constructs a ring-shaped support body between a casing string and an inner wall of a wellbore, and additionally arranges an independent guiding assembly at a port of a guide pipe, so that the centralizing effect is fully strengthened. In terms of structure, the tubular body with a rear protruding part is adopted as a main structure of a sliding sleeve, a guide cone is arranged on an inner side of the rear protruding part, and the casing string is conveniently mounted and matched with the application; the support ring and the fixing disc are adopted as two-stage inner support bodies in the sliding sleeve, so that the application can be kept stable in the wellbore, and the guide pipe is well positioned. While the guide pipe is used to centralize the casing string, the sliding rail extending in a radial direction is arranged at the port of the guide pipe, and the positioning block is matched, so that the double centralizing effect can be achieved by the clamping effect of the positioning block when the casing string is seriously offset in the radial direction. The application can prevent the radial offset with high strength, and has obvious progress. BRIEF DESCRIPTION OF DRAWINGS

[0017] Fig. 1 is an assembly drawing of the application;

[0018] Fig. 2 is another assembly drawing of the application;

[0019] Fig. 3 is an explosion drawing of the application;

[0020] Fig. 4 is another explosion drawing of the application;

[0021] Fig. 5 is the third explosion map of the present application;

[0022] wherein:

[0023] 1, sliding sleeve 2, tubular body 3, rear protruding part 4, guide cone

[0024] 5, first screw 6, support ring 7, closed ring 8, support seat

[0025] 9, positioning ring 10, fixed disc 11, guide tube 12, second screw

[0026] 13, slide rail 14, third screw 15, positioning block. DETAILED DESCRIPTION

[0027] The specific embodiments of the present application will be described in detail below. In order to avoid too many unnecessary details, the structures or functions belonging to the known will not be described in detail in the following examples. The approximate language used in the following examples can be used for quantitative description, indicating that the amount can be allowed to have certain variation without changing the basic function. Unless defined, the technical and scientific terms used in the following examples have the same meaning as generally understood by those skilled in the art to which the present application belongs.

[0028] Example 1

[0029] The strong centralizer for downhole casing, see Figs. 1-5 , including sliding sleeve 1, tubular body 2, rear protruding part 3, guide cone 4, first screw 5, support ring 6, closed ring 7, support seat 8, positioning ring 9, fixed disc 10, guide tube 11, second screw 12, slide rail 13, third screw 14, positioning block 15; The front end of the sliding sleeve 1 has a tubular body 2, the rear end of the sliding sleeve 1 has a rear protruding part 3, the rear protruding part 3 is provided with a guide cone 4, the front end of the guide cone 4 extends to the casing string hole, the rear protruding part 3 and the tubular body 2 are communicated through the casing string hole, a plurality of first screws 5 sequentially fix and connect the tubular body 2, the support ring 6 and the closed ring 7, the positioning ring 9 is kept in front of the closed ring 7, the guide tube 11 is arranged on the front side of the fixed disc 10, the guide tube 11 is butted with the through hole in the middle of the positioning ring 9, the fixed disc 10 is kept in the protruding part 3, the second screw 12 fixes the positioning ring 9 and the closed ring 7, the support seat 8 is located in front of the closed ring 7, the third screw 14 fixes the slide rail 13 on the support seat 8, the positioning block 15 is arranged on the inner side of the slide rail 13, and the positioning block 15 is located at the port of the through hole.

[0030] Example 2

[0031] The strong centralizer for downhole casing, see Figs. 1-5, including sliding sleeve 1, tubular body 2, rear protruding part 3, guide cone 4, first screw 5, support ring 6, closed ring 7, support seat 8, positioning ring 9, fixed disc 10, guide tube 11, second screw 12, sliding rail 13, third screw 14, positioning block 15; the front end of sliding sleeve 1 has tubular body 2, the rear end of sliding sleeve 1 has rear protruding part 3, guide cone 4 is arranged in rear protruding part 3, the front end of guide cone 4 extends to casing hole, rear protruding part 3 communicates with tubular body 2 through the casing hole, a plurality of first screws 5 sequentially fix and connect tubular body 2, support ring 6 and closed ring 7, positioning ring 9 is kept in front of closed ring 7, guide tube 11 is arranged on the front side of fixed disc 10, guide tube 11 is butted with the through hole in the middle of positioning ring 9, fixed disc 10 is kept in protruding part 3, second screw 12 fixes positioning ring 9 and closed ring 7, support seat 8 is located in front of closed ring 7, third screw 14 fixes sliding rail 13 on support seat 8, positioning block 15 is arranged on the inner side of sliding rail 13, and the inner end surface of positioning block 15 is a cylindrical surface, the diameter of the cylindrical surface is equal to the diameter of the through hole.A disc-shaped mounting groove is arranged in sliding sleeve 1, and fixed disc 10 is located in the mounting groove.Fixed disc 10 has multiple layers, and the edges of the multiple layers of fixed disc 10 are overlapped and stacked with each other.A gap is formed in the front port of guide tube 11, and a flange extending inward is arranged in the middle of support ring 6, and the flange and the gap are embedded with each other.A plurality of inner convex edges extending in the axial direction are arranged on the inner wall of guide tube 11, and the inner convex edges are in direct contact with the casing.The outer edges of tubular body 2 and the outer edges of rear protruding part 3 are all rounded.The sliding rail 13 is a fixed block with a strip-shaped hole, the third screw 14 penetrates the fixed block through the strip-shaped hole, and the strip-shaped hole extends in the radial direction of guide tube 11.The diameter of rear protruding part 3 is smaller than the diameter of tubular body 2, and the connecting points between first screw 5 and tubular body 2 are uniformly distributed on the periphery of rear protruding part 3.

[0032] The above detailed description of the embodiments of the present application, but the content is only the preferred embodiments of the present application, and is not used to limit the present application. Any modification, equivalent replacement and improvement made within the scope of the application should be included in the protection scope of the present application.

Claims

1. A powerful centralizer for downhole casing, characterized in that, Includes a sliding sleeve (1), a tubular body (2), a rear protrusion (3), a guide cone surface (4), a first screw (5), a support ring (6), a closing ring (7), a support base (8), a positioning ring (9), a fixing plate (10), a guide tube (11), a second screw (12), a slide rail (13), a third screw (14), and a positioning block (15); the sliding sleeve (1) has a tubular body (2) at its front end and a rear protrusion (3) at its rear end. A guide cone surface (4) is provided inside the rear protrusion (3), with its front end extending to the sleeve post hole. The rear protrusion (3) and the tubular body (2) are connected through the sleeve post hole. Multiple first screws... The wire (5) sequentially fixes the tubular body (2), the support ring (6) and the closing ring (7). The positioning ring (9) is held in front of the closing ring (7). A guide tube (11) is provided in front of the fixing plate (10). The guide tube (11) is connected to the through hole in the middle of the positioning ring (9). The fixing plate (10) is held in the protrusion (3). The second screw (12) fixes the positioning ring (9) and the closing ring (7). The support base (8) is located in front of the closing ring (7). The third screw (14) fixes the slide rail (13) on the support base (8). A positioning block (15) is provided inside the slide rail (13). The positioning block (15) is located at the port of the through hole.

2. The powerful centralizer for downhole casing according to claim 1, characterized in that, There are multiple support seats (8), and the multiple support seats (8) are evenly arranged along the circumferential direction on the front side of the closed ring (7).

3. The powerful centralizer for downhole casing according to claim 1, characterized in that, The inner end face of the positioning block (15) is a cylindrical surface, and the diameter of the cylindrical surface is equal to the diameter of the through hole.

4. The powerful centralizer for downhole casing according to claim 1, characterized in that, A disc-shaped mounting groove is provided in the sliding sleeve (1), and the fixing plate (10) is located in the mounting groove.

5. The powerful centralizer for downhole casing according to claim 1, characterized in that, The fixing plate (10) has multiple layers, and the edges of the multiple fixing plates (10) are aligned and stacked together.

6. The powerful centralizer for downhole casing according to claim 1, characterized in that, The guide tube (11) has a notch at the front end and an inwardly extending flange in the middle of the support ring (6), the flange and the notch fitting together.

7. The powerful centralizer for downhole casing according to claim 1, characterized in that, The inner wall of the guide tube (11) has several axially extending inner protrusions, which are in direct contact with the sleeve column.

8. The powerful centralizer for downhole casing according to claim 1, characterized in that, The outer edge of the tubular body (2) and the outer edge of the posterior protrusion (3) are both rounded.

9. The powerful centralizer for downhole casing according to claim 1, characterized in that, The slide rail (13) is a fixing block with a strip hole, and the third screw (14) passes through the fixing block through the strip hole, which extends radially along the guide tube (11).

10. The powerful centralizer for downhole casing according to claim 1, characterized in that, The diameter of the rear protrusion (3) is smaller than the diameter of the tubular body (2), and the connection point between the first screw (5) and the tubular body (2) is evenly distributed around the rear protrusion (3).

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