WO2020215534A1

WO2020215534A1 - Centralizer

Info

Publication number: WO2020215534A1
Application number: PCT/CN2019/100517
Authority: WO
Inventors: 王北兴; 陈龙龙
Original assignee: 陕西纽兰德实业有限公司
Priority date: 2019-04-22
Filing date: 2019-08-14
Publication date: 2020-10-29
Also published as: CN110043199B; CN110043199A

Abstract

A centralizer, comprising an upper end ring (1) and a lower end ring (2) having uniform diameters. A plurality of working rib plates (3) are affixed in between the upper end ring (1) and the lower end ring (2). The working rib plates (3) are evenly distributed surrounding the circumference of the upper end ring (1) or the lower end ring (2). The width of the working rib plates (3) is between 30 and 130 mm. Further comprised are a plurality of stress-relieving grooves (4). On the basis of actual usage requirements, the stress-relieving grooves (4) are opened in working rib plates (3) of different widths, and in the places of connection between the working rib plates (3) and the upper and lower end rings (1, 2). When the working rib plates (3) experience extreme compressional deformation, said stress-relieving grooves (4) provide a main body elastic material with space for stress deformation, thereby preventing the organizational structure of a main body elastic material from being broken or partially damaged.

Description

A centralizer

Technical field

The invention belongs to the technical field of oil drilling and cementing equipment, and specifically relates to a centralizer.

Background technique

The centering degree of the casing in the wellbore is one of the decisive factors for the quality of oil and gas well cementing, and the centralizer placement is the basis for whether the casing is centered. The centralizer is used to centralize the casing and ensure the concentricity of the casing in the wellbore. The performance of different types of centralizers has different effects on the running of the casing and the final centering degree. The problem with current centralizers is that the working ribs are prone to permanent deformation after being subjected to a large load, resulting in elastic casing centralizers Insufficient restoring force results in insufficient casing centering in the wellbore during cementing, which reduces cementing quality. If the eccentricity is too large, it will cause serious consequences such as cementing failure and oil and gas strata.

Summary of the invention

technical problem:

The purpose of the present invention is to provide a centralizer, which solves the problem that the working ribs of the centralizer in the prior art are easily deformed permanently after being subjected to a heavy load, resulting in insufficient reset force of the centralizer and insufficient centering in the wellbore. .

Technical solutions:

The technical solution adopted by the present invention is a centralizer, which includes an upper end ring and a lower end ring with the same diameter; a number of working ribs are fixed between the upper end ring and the lower end ring; the working ribs surround the upper end ring or the lower end ring The circumference is evenly distributed; the width of the working ribs is between 30 and 130 mm; it also includes several stress relief grooves; the length of the stress relief groove is 20 to 100 mm; the width is 1 to 5 mm.

The features of the present invention are:

The stress relief groove is opened on the working rib.

The shape of the stress relief groove is a horizontal straight line, a longitudinal straight line or an arc shape.

The arc-shaped stress relief groove located at the lower part of the working rib is arranged in a herringbone shape.

The radius range of the arc-shaped stress relief groove is R20～80mm.

The distance between the stress relief groove and the edge of the working rib on the same side is 10-20mm.

A number of stress relief grooves are also provided at the connection between the working rib and the upper end ring and the lower end ring, and the arrangement of the stress relief grooves at the upper connection and the arrangement of the stress relief grooves at the lower connection are symmetrical to each other.

Benefits:

The centralizer of the present invention is provided with stress relief grooves on the working ribs of different widths and the joints between the ribs and the end ring according to actual use requirements; the position, shape, size and quantity of the stress relief grooves are adjusted according to specific working conditions. The stress relief groove provides stress and deformation space for the elastic material of the main body when the ribs are extremely compressed and deformed, thereby avoiding damage or partial damage to the structure of the elastic material of the main body; avoiding the attenuation of the reset force of the elastic centralizer after a large load , Maintain the design performance of the elastic centralizer.

Description of the drawings

Figure 1 is a schematic diagram of the structure of the centralizer a of the present invention;

Figure 2 is a schematic diagram of the structure of the centralizer b of the present invention;

Figure 3 is a schematic diagram of the structure of the centralizer c of the present invention;

Figure 4 is a schematic diagram of the structure of the centralizer d of the present invention;

Figure 5 is a schematic diagram of the structure of the centralizer e of the present invention;

Figure 6 is a schematic diagram of the structure of the centralizer f of the present invention;

Figure 7 is a schematic diagram of the structure of the centralizer g of the present invention;

Figure 8 is a schematic diagram of the structure of the centralizer h of the present invention;

Figure 9 is a schematic diagram of the structure of the centralizer i of the present invention;

Figure 10 is a schematic diagram of the structure of the centralizer j of the present invention.

In the figure, 1-upper end ring, 2-lower end ring, 3 working ribs, 4 stress relief grooves.

Detailed ways

The present invention will be described in detail below with reference to the drawings and specific embodiments.

Example 1

As shown in Figure 1, the centralizer of the present invention includes an upper end ring 1 and a lower end ring 2 with the same diameter; a number of working ribs 3 are fixed between the upper end ring 1 and the lower end ring 2; the working ribs 3 surround the upper end ring 1 Or the circumference of the lower end ring 2 is evenly distributed; the width of the working rib 3 is between 30 and 130 mm; and it also includes several stress relief grooves 4. The stress relief groove 4 is opened on the working rib 3. The shape of the stress relief groove 4 is a horizontal linear shape, a longitudinal linear shape or an arc shape. The arc-shaped stress relief groove 4 located at the lower part of the working rib 3 is arranged in a herringbone shape. The radius range of the arc-shaped stress relief groove 4 is R20～80mm. The distance between the stress relief groove 4 and the edge of the working rib 3 on the same side is 10-20mm. The length of the single stress relief groove 4 is 20-100mm; the width is 1-5mm.

Specifically, the stress relief grooves 4 are opened on the upper and lower parts of the working ribs 3, and the arrangement of the upper stress relief grooves 4 and the arrangement of the lower stress relief grooves 4 are symmetrical with each other; the shape of the stress relief groove 4 is a horizontal straight line; The stress relief grooves 4 located at the lower part of the working rib 3 are distributed in several rows, one for each row; the distance between the two adjacent rows of stress relief grooves 4 is the same, which is 10-40mm.

Example 2

As shown in Figure 2, it is roughly the same as Embodiment 1, except that: the shape of the stress relief groove 4 is a longitudinal straight line; the stress relief groove 4 located at the lower part of the working rib 3 has several rows, the first row is one, And it is located on the longitudinal symmetry axis of the working rib 3; below the second row, there are two in each row, and the two stress relief grooves 4 are symmetrically distributed, and the symmetry axis is collinear with the longitudinal symmetry axis of the working rib 3; two adjacent rows The longitudinal distance between the stress relief grooves 4 is consistent, ranging from 10 to 40 mm; below the second row, the lateral distance between the two stress relief grooves 4 in each row is 20 to 100 mm.

Example 3

As shown in Figure 3, it is roughly the same as Embodiment 1, with the only difference: Specifically, the stress relief grooves 4 located at the lower part of the working ribs 3 are distributed in several rows. The first row is a longitudinal linear stress relief groove 4, and Located on the longitudinal symmetry axis of the working rib 3; below the second row, there are two in each row, and the two stress relief grooves 4 are distributed in a herringbone shape; the longitudinal distance between the two adjacent rows of stress relief grooves 4 is at least 10mm, the maximum is 40mm; below the second row, the lateral distance between the two stress relief grooves 4 in each row, the minimum is 5mm, and the maximum is 30mm.

Example 4

As shown in Figure 4, it is roughly the same as Embodiment 1, with the only difference: the stress relief grooves 4 located on the upper part of the working ribs 3 are distributed in several rows, the first row is a horizontal straight stress relief groove 4; the second row is below , Each row has two, and the two stress relief grooves 4 are distributed in an inverted chevron shape; the horizontal distance between the end of the first row of stress relief grooves 4 and the second row of stress grooves 4 on the same side is 5-20mm ; The longitudinal distance between the first row and the second row is 10mm at least and 40mm at the maximum; below the second row, the longitudinal distance between two adjacent rows of stress relief grooves 4 is or satisfies the formula 10～40mm, each row The lateral distance between the two stress relief grooves 4 is 5 mm minimum and 30 mm maximum.

Example 5

As shown in Figure 5, it is roughly the same as Embodiment 4, except that: the middle of the working rib 3 is also provided with several rows of longitudinal linear stress relief grooves 4; the first row and the last row are one, and they are located on the working rib 3. The longitudinal symmetry axis of the other rows, each row has two, and the two stress relief grooves 4 are symmetrically distributed, and the symmetry axis is collinear with the longitudinal symmetry axis of the working rib 3; between two adjacent rows of stress relief grooves 4 The longitudinal distance is 10～40mm; the horizontal distance between the two stress relief grooves 4 in each row in even-numbered rows satisfies the formula: L ₁ = working rib width-2×(5～25); in odd-numbered rows, two in each row The lateral distance between the stress relief grooves 4 satisfies the formula: L ₂ = width of the working stiffener -2×(5-15).

Example 6

As shown in Figure 6, it is roughly the same as Embodiment 1, the only difference is: the working rib 3 and the upper end ring 1, the lower end ring 2 are also provided with a number of stress relief grooves 4, and the upper connection of the stress relief groove 4 The arrangement is symmetrical to the arrangement of the stress relief grooves 4 at the lower connection; the stress relief grooves 4 at the lower connection are arranged in a square shape; the stress relief grooves 4 arranged in a square shape are arranged in a horizontal direction Linear.

Example 7

As shown in Figure 7, it is roughly the same as Embodiment 2, except that the working rib 3 and the upper end ring 1 and the lower end ring 2 are also provided with several stress relief grooves 4, and the stress relief groove 4 at the upper connection The arrangement is symmetrical to the arrangement of the stress relief grooves 4 at the lower connection; the stress relief grooves 4 at the lower connection are two longitudinal linear stress relief grooves 4, and the lateral distance between the two stress relief grooves 4 is 20～ 100mm.

Example 8

As shown in Figure 8, it is roughly the same as Embodiment 3, except that the working rib 3 and the upper end ring 1 and the lower end ring 2 are also provided with a number of stress relief grooves 4, and the stress relief groove 4 at the upper connection The arrangement is symmetrical to the arrangement of the stress relief grooves 4 at the lower connection; the stress relief grooves 4 at the lower connection are arranged in a square shape; the stress relief grooves 4 arranged in a square shape are arranged in a round shape. arc. The radius range of the arc-shaped stress relief groove 4 is R20～80mm. For the stress relief grooves 4 arranged in a zigzag shape, the lateral distance between the two stress relief grooves 4 in even rows is 20-80 mm.

Example 9

As shown in Figure 9, it is roughly the same as Embodiment 4, except that: there is no horizontal linear stress relief groove 4; there are also several stress relief grooves 4 at the connection between the working rib 3 and the upper end ring 1 and the lower end ring 2. And the arrangement of the stress relief grooves 4 at the upper connection and the arrangement of the stress relief grooves 4 at the lower connection are symmetrical to each other; the stress relief grooves 4 at the lower connection are arranged in a magenta shape; the stress relief grooves 4 are arranged in a magenta shape, The shape of the single stress relief groove 4 is a circular arc shape. The radius of the arc-shaped stress relief groove 4 is R20～80mm. For the stress relief grooves 4 arranged in a zigzag shape, the lateral distance between the two stress relief grooves 4 in even rows is 20-80 mm.

Example 10

As shown in Figure 10, it is roughly the same as Embodiment 5, except that there is no horizontal linear stress relief groove 4; there are also several stress relief grooves 4 at the connection between the working rib 3 and the upper end ring 1 and the lower end ring 2. And the arrangement of the stress relief grooves 4 at the upper connection and the arrangement of the stress relief grooves 4 at the lower connection are symmetrical to each other; the stress relief grooves 4 at the lower connection are arranged in a magenta shape; the stress relief grooves 4 are arranged in a magenta shape, The shape of the single stress relief groove 4 is a circular arc shape. The radius range of the arc-shaped stress relief groove 4 is R20～80mm. For the stress relief grooves 4 arranged in a zigzag shape, the lateral distance between the two stress relief grooves 4 in even rows is 20-80 mm.

Test data comparison:

According to the comparison of the above-mentioned test data, it is found that the outer diameter of the ribs of the product with stress relief grooves is very small, and the flexibility resistance is obviously better than that of products without stress relief grooves.

Claims

A centralizer, characterized in that it comprises an upper end ring (1) and a lower end ring (2) with the same diameter; a number of working ribs (3) are fixedly connected between the upper end ring (1) and the lower end ring (2); The working ribs (3) are evenly distributed around the circumference of the upper end ring (1) or the lower end ring (2); the width of the working ribs (3) is between 30 and 130mm; it also includes several stress relief grooves (4); The length of the groove (4) is 20-100mm; the width is 1-5mm.
The centralizer according to claim 1, wherein the stress relief groove (4) is opened in the working rib (3).
The centralizer according to claim 2, characterized in that the shape of the stress relief groove (4) is a horizontal straight line, a longitudinal straight line or an arc shape.
The centralizer according to claim 3, characterized in that: the arc-shaped stress relief grooves (4) located at the lower part of the working ribs (3) are arranged in a herringbone shape.
The centralizer according to claim 4, characterized in that the radius of the arc-shaped stress relief groove (4) is R20～80mm.
The centralizer according to claim 5, characterized in that the distance between the stress relief groove (4) and the edge of the working rib (3) on the same side is 10-20 mm.
The centralizer according to claim 6, characterized in that: the connection between the working rib (3) and the upper end ring (1) and the lower end ring (2) is also provided with a number of stress relief grooves (4), and the upper part The arrangement of the stress relief grooves (4) at the connection and the arrangement of the stress relief grooves (4) at the lower connection are symmetrical to each other.